Mohs surgery is a staged procedure for microscopically excising basal cell carcinomas (BCCs) while preserving the surrounding normal skin. Serial excisions are performed with each excision being guided by examination of the frozen histology. Mohs surgery is a meticulous and time-consuming (15-45 minutes per excision) procedure requiring several (2-20) excisions and frozen histology prepared for each excision. Real-time confocal reflectance microscopy may make Mohs surgery more efficient by enabling rapid detection of BCCs directly in fresh, unprocessed excisions, and thereby possibly avoiding frozen histology. As previously reported, we are developing an acetowhitening-and-cross polarized method to detect BCCs with a confocal reflectance microscope. Acetowhitening compacts the chromatin within the nucleus, increasing nuclear backscatter, and brightening the nuclei in the confocal images of the tissue. Our experiments to optimize acetowhitening, using acetic acid concentrations from 1% to 30% and treatment times from 30 seconds to 5 minutes, show that a minimum concentration of 2% with minimum washing time of 2 minutes is required for enhancing nuclear morphology. Increased depolarization is observed within the compacted chromatin relative to the surrounding collagen, and imaging in brightfield or crossed polarization brightens or darkens the cellular cytoplasm and birefringent dermis; thus, we may potentially vary nuclear/cytoplasm and nuclear/dermis contrast. Images are collected, oriented, and tiled to create mosaics and sub-mosaics to view large excisions at variable 2X - 10X magnifications. To create and display mosaics, adequate pixelation relative to resolution must be maintained and precise mechanical fixturing is necessary to control tilt, sag, flattening and stability of the excised tissue specimen.

The effects of varying lens housing temperature on subsurface temperature profiling of a tissue-simulating phantom were studied using pulsed photothermal radiometry (PPTR). A temperature feedback system was used to control systematically the infrared (IR) detector lens housing temperature. Temperature feedback system maintained lens housing temperature at constant level for external temperature fluctuation. The radiometric signal intensity and temperature calibration was substantially affected by lens housing temperature change. Temperature values as a function of depth profiles reconstructed from pulsed photothermal radiometry measurements increased when lens housing temperatures were elevated during the radiometric temperature calibration run. These experiments demonstrate that lens housing temperature fluctuations affect the accuracy of radiometric subsurface temperature measurements using an infrared camera system.

Background and Objectives: Pulsed dye laser (PDL) irradiation is the standard clinical treatment for vascular lesions. However, PDL treatment of port wine stain birthmarks (PWS) is variable and unpredictable. Photodynamic therapy (PDT) using benzoporphyrin derivative monoacid ring A (BPD) and yellow light may induce substantial vascular effects and potentially offer a more effective treatment. In this study, we utilize a rodent dorsal skinfold model to evaluate the vascular effects of BPD-PDT at 576 nm as compared to PDL. Study Design/Materials and Methods: A dorsal skinfold window was created on the backs of female Sprague-Dawley rats, allowing epidermal and subdermal irradiation and subdermal imaging. One mg/kg BPD was administered intravenously via a jugular venous catheter. Study groups were: control (no BPD, no light), PDL (585 nm, τ_p 1.5 ms, 10 J/cm²), and PDT (BPD + continuous wave irradiation (CW) at 576nm, τ_p 16 min, 96 J/cm²). Vessels were imaged and assessed for damage using laser speckle imaging (LSI) before, immediately after, and 18 hours post-intervention. Results: Epidermal irradiation was accomplished without blistering, scabbing or ulceration. PDL and PDT resulted in similar reductions in vascular perfusion 18 hours post-intervention (34.6% and 33.4%, respectively). Conclusions: BPD-PDT can achieve safe and selective vascular effects and may offer an alternative therapeutic option for treatment of hypervascular skin lesions including PWS birthmarks.

In the cosmetics industry, skin color is very important because skin color gives a direct impression of the face. In particular, many people suffer from melanin pigmentation such as liver spots and freckles. However, it is very difficult to evaluate melanin pigmentation using conventional colorimetric values because these values contain information on various skin chromophores simultaneously. Therefore, it is necessary to extract information of the chromophore of individual skins independently as density information. The isolation of the melanin component image based on independent component analysis (ICA) from a single skin image was reported in 2003. However, this technique has not developed a quantification method for melanin pigmentation. This paper introduces a quantification method based on the ICA of a skin color image to isolate melanin pigmentation. The image acquisition system we used consists of commercially available equipment such as digital cameras and lighting sources with polarized light. The images taken were analyzed using ICA to extract the melanin component images, and Laplacian of Gaussian (LOG) filter was applied to extract the pigmented area. As a result, for skin images including those showing melanin pigmentation and acne, the method worked well. Finally, the total amount of extracted area had a strong correspondence to the subjective rating values for the appearance of pigmentation. Further analysis is needed to recognize the appearance of pigmentation concerning the size of the pigmented area and its spatial gradation.

We previously proposed a new method for monitoring adhesion of skin graft by measuring photoacoustic (PA) signal originated from the neovascularities. In this study, immunohistochemical staining (IHC) with CD31 antibody was performed for grafted skin tissue to observe neovascularity, and the results were compared with PA signals. We also used a laser Doppler imaging (LDI) to observe blood flow in the grafted skin, and sensitivity of PA measurement and that of LDI were compared. In rat autograft models, PA signals were measured for the grafted skin at postgrafting times of 0-48 h. At 6 h postgrafting, PA signal was observed in the skin depth region of 500-600 mm, while the results of IHC showed that angiogenesis occurred at the depth of about 600 mm. Depths at which PA signal and angiogenesis were observed decreased with postgrafting time. These indicate that the PA signal observed at 6 h postgrafting originated from the neovascularities in the skin graft. Results of LDI showed no blood-originated signal before 48 h postgrafting. These findings suggest that PA measurement is effective in monitoring the adhesion of skin graft in early stage after transplantation.

Noninvasive monitoring of a therapeutic intervention is desired to provide the clinician or scientist with insight into the efficacy of the intervention. Since blood flow is tightly coupled into the health status of biological tissue, several instruments have been developed to monitor blood flow and perfusion dynamics. One such instrument is laser speckle imaging (LSI). The goal of this study was to characterize the relationship between speckle flow index (SFI) and actual flow rate. To achieve this goal, we employed an in vitro flow model. With whole blood as the flow fluid, we found that the actual flow rate and SFI had a linear relationship (R = 0.99) over a physiologically relevant 0 to 5 mm/s range. From our data it appears that a predictive model from the literature underestimates considerably the actual dynamic range of LSI for flow imaging.

The use of autofluorescence technique in the characterization of the sequential tissue transformation process in 7,12-dimethylbenz(a)anthracene and 12-O-tetradecanoylphorbol-13-acetate (DMBA & TPA) induced two-stage mouse skin carcinogenesis model in conjunction with a suitable statistical method is being explored. The fluorescence excitation emission matrix (EEM) from experimental group (n=40; DMBA/TPA application), control group (n=6; acetone application) and the blank group (n=6; no application of DMBA/TPA or acetone) were measured every week using Fluoromax3 spectrofluorometer coupled with a waveguide fiber optic bundle (JY Horiba, NJ). The EEM was recorded for 19 excitation wavelengths from 280 to 460 nm at 10 nm intervals and the fluorescence emission was scanned from 300 to 750 nm. During the tissue transformation the epithelial tissues underwent biochemical and structural changes that are manifested in the tissue fluorescence. To correlate the tissue morphology with the observed fluorescence differences in the fluorescence emission, animals were sacrificed and the tissue biopsies were subjected to histopathological evaluation. The fluorescence emission corresponding to different fluorophores was extracted from the EEM, and the spectral data were used in multivariate statistical algorithm for the earliest diagnosis of the onset of tissue transformation. The intrinsic fluorescence from tryptophan, NADH and prophyrins showed distinct differences in the spectral signature during the tissue transformation, due to the altered metabolic activities of the cells. The statistical analysis of the spectral data corresponding to each excitation wavelength showed better classification accuracy at 280, 320, 350 and 405 nm excitations, corresponding to tryptophan, collagen, NADH and porphyrins with the classification accuracy of 74.3, 68.1, 64.6 and 74.7 % respectively. The variations in the spectral signature and the results of the statistical analysis suggest that porphyrins, tryptophan and NADH can be targeted as potential tumor markers in the early detection of the tissue transformation process.

Traditional biopsy requires the removal, fixation, and staining of tissues from the human body. Its procedure is invasive and painful. Therefore, a novel method of optical biopsy is desired which can perform in vivo examination and is noninvasive, highly penetrative, with no energy deposition and damage, without invasive pharmaceutical injection, and with three-dimensional (3D) imaging capability and sub-micron spatial resolution. Two-photon fluorescence microscopy (TPFM) is previously applied for biopsy of skin due to its high lateral resolution, low out-of-focus damage, and intrinsic 3D section capability. However, for future clinical applications without surgery, current 700-850 nm based laser scanning technology still presents several limitations including low penetration depth, in-focus cell damages, multi-photon phototoxicity due to high optical intensity in the 800 nm wavelength region, and toxicity if exogenous fluorescence markers were required. Here we demonstrate a novel noninvasive optical biopsy method called harmonics optical biopsy (HOB), which combines both second harmonic generation imaging and third harmonic generation imaging. Due to virtual transition nature of harmonic generations and based on light sources with an optical wavelength located around the biological penetration window (~1300nm), our HOB can serve as a truly non-invasive biopsy tool with sub-micron three-dimensional spatial resolution without any energy deposition and exogenous contrast agents. From preliminary experiment result, our HOB can reconstruct 3D cellular and subcellular images from skin surface through dermis. Besides, by utilizing backward propagating detection geometry, we will show that this technique is ideal for non-invasive clinical biopsy of human skin diseases and even useful for the early diagnosis of skin cancer symptom such as the angiogenesis.

Physical and chemical enhancement techniques have proven to be useful in promoting transdermal delivery of therapeutic agents. However, it has been difficult to follow the changes to the skin during these processes microscopically. In this work, we use multiphoton polarization (P) and generalized polarization (GP) imaging of the membrane probe Laurdan to monitor changes to the stratum corneum under conditions of chemically enhanced delivery by oleic acid. We show that the combination of P and GP Laurdan imaging helps to reveal both the physical and chemical changes to the stratum corneum under enhanced delivery. Our work can help to develop more efficient transdermal delivery strategies.

In recent years, non-linear imaging techniques such as multiphoton fluorescence and harmonic generation microscopy have been successfully applied to dermatological imaging. Confocal-like image quality, enhanced depth penetration, and non-linear spectral signatures are among the main advantages of this family of techniques. In this presentation, we will focus on the applications of multiphoton microscopy to skin specimens in different physiological states. Images of normal and diseased tissue specimens will be presented and spectrally characterized. Our work has potential applications in developing multiphoton microscopy into a clinically applicable diagnostic tool.

For quantitative prediction and evaluation of pulsed dye laser therapy of port wine stain (PWS) skin, the CIE L*a*b* color difference, ΔE*, has been utilized to characterize numerically the color differences between normal untreated and treated PWS skin. Three optical instruments (Minolta chromameter CR-200, a cross-polarized diffuse reflectance imaging system, and visual reflectance spectrometers) are compared to investigate their clinical feasibility for quantitative color assessment. Compared to the chromameter as a standard measurement instrument, other instruments also provide valuable measurements of skin color for the relative quantification of PWS treatment outcome. The fiber-optic visual reflectance spectrometer is preferable for continuous measurement of a small area of skin. The cross-polarized imaging system is useful as a simple non-contact measurement technique to provide spatially resolved color difference images.

We have developed an optical fingerprint sensor for personal identification. Conventional sensors detect contact between the convex parts of fingerprints and the input surface of the sensor, however, we have devised a novel sensor that utilizes the optical characteristics of the skin tissue under fingerprints. We obtained tomographic images from under fingerprints by optical coherence tomography (OCT), and discovered that the reflected and scattered light from the skin tissue under the concave parts of fingerprints was lower than the convex parts. In other words, the concave parts had a higher light transmittance than the convex parts. Moreover, even when there were wrinkles in a fingerprint, the same optical characteristics were present. Based on this, we made an experimental sensor that detected fingerprint patterns using light transmittance dispersion in the skin tissue. This sensor consists of light emitting diodes (LED) that irradiate red light from the side of a fingernail and an image formation system that forms an image onto an imaging device, by using the light that penetrated the finger. Using this sensor, we obtained fingerprint pattern images in which the concave parts were brighter than the convex parts. These results showed good agreement with the transmittance dispersion described above. Consequently, it has been demonstrated that a fingerprint sensor utilizing the optical can efficiently increase the recognition of fingerprint patterns of wrinkled or wet fingers, which conventional sensors have difficulty recognizing.

Cryogen spray cooling (CSC) provides thermal protection to the epidermis during dermatologic laser surgery (DLS) for removal of port wine stain (PWS) birthmarks. The objectives of this study are: to improve the thermal modeling of skin undergoing CSC-assisted DLS for PWS treatment; and, to address the effect of temporal and lateral variations in surface heat transfer during CSC on epidermal protection. The finite element method is used to solve the light and heat diffusion equations in a skin-cross section composed by epidermis, dermis and two blood vessels. Thermal conductivities of each biological structure are modeled as temperature dependent functions. The model accounts for the latent heat of fusion and vaporization, and temporal and spatial thermal variations---due to the inherent non-homogeneous nature of sprays---in surface cooling. Thermal damage due to laser irradiation is evaluated by an Arrhenius integral model. For a 60 ms cryogen spurt, temperature maps of epidermis show that at the end of the spurt there are significant temperature differences, which resulted in epidermal damage after a 5 J/cm² 0.45 ms laser pulse at 585 nm on light color skin type. A 60 ms delay between end of spurt and laser onset produced a relative more homogeneous temperature distribution at the epidermis, and, subsequently, a more effective CSC-DLS for which only the blood vessels were thermally damaged. Temporal and lateral variations in surface cooling must be taken into account to guarantee that enough epidermal protection is provided.

Multiphoton optical tomography provides the capability of non-invasive optical sectioning of skin with high spatial and intracellular resolution as well as high NIR (near infrared) light penetration into pigmented skin areas. The imaging system DermaInspect based on femtosecond laser pulses was used to perform multiphoton optical tomography in clinical studies. Patients with abnormal pigmented tissues were imaged in vivo. After the multiphoton imaging procedure, biopsies were taken, imaged again and further processed with standard histological methods. We report on preliminary results. The visualization of pigmented cell clusters based on non-linear luminescence using the novel multiphoton device was possible. These clusters could be clearly distinguished from non-pigmented cells. Cancerous tissues showed significant differences in the cell structure of the epidermal layers. The system DermaInspect might become a high resolution diagnostic tool for melanoma diagnostics.

High resolution optical tomography studies on topically applied probes and UVA exposed skin were performed with the novel imaging system DermaInspect. 3D images with submicron resolution based on the two-photon excitation of the probes and the autofluorescence of epidermal cells and structures with femtosecond laser pulses in the near infrared (NIR) spectral range between 750 nm and 850 nm were obtained. The distribution of natural endogenous fluorophores, mainly keratin and NAD(P)H, as well as of the exogenous probe molecules was detected in situ. The high resolution imaging system DermaInspect offers an unique chance of in situ, non-invasive drug screening in skin on a molecular level and to study the effect of UV exposure.

Oxygenation of the facial skin was evaluated in rosacea using a hyperspectral camera. A portable imaging system utilizing crossed-polarization optics for illumination and recording is described. Relative oxygen saturation was determined from rosacea features and compared with normal skin. Saturation maps and light absorption spectra showed a significant increase in the oxygen saturation of the blood in rosacea-affected skin.

Intense Pulsed Light (IPL) sources produce broad wavelength spectra and relatively long pulses. The spectral distribution and intensity profile of a pulse depend on, and thus can be controlled by, an electric current via a flash lamp. This adds new dimensions to IPL technology, providing considerable improvement in both safety and efficacy of IPL treatments by designing target-specific pulse shapes. Theoretical considerations and computer simulations have shown that the current-controlled pulses may be 20-30% more safe/effective than previously-used IPL pulses. Clinical results confirm the conclusions of these simulations.

A less invasive method of reliably detecting skin cancers is required. Raman spectroscopy is just one of several spectroscopic methods that look promising, but are not yet sufficiently reliable. More information is needed on how and why the Raman spectra of cancerous skin tissue is different from its normal counterpart. We have used confocal micro-Raman spectroscopy with a spatial resolution of about a micron to obtain spectra of unstained thin sections of human skin. We found that there were clear differences in the Raman spectra between cancerous and non-cancerous tissue both in cells and in the connective tissue. The DNA contribution to the spectra was generally stronger in malignant cells than normal ones. In regions of the dermis far away from the tumor one obtains the usual collagen spectra of normal skin, but adjacent to the tumor the spectra no longer appeared to be those of native collagen.

Carotenoids are an important part of the antioxidant system in human skin. Carotenoid molecules, provided by fruits and vegetables, are potent free radical quenchers that accumulate in the body. If not balanced by carotenoids and other antioxidants, free radicals may cause premature skin aging, oxidative cell damage, and even skin cancers. As carotenoids depletion may predispose a person to cancer or other disease, rapid and noninvasive measurement of carotenoid level in skin may be of preventive or diagnostic help. At the very least, such measurement can be used to obtain a biomarker for healthy levels of fruit and vegetable consumption. Recently we have developed noninvasive optical technique based on Raman spectroscopy. In this paper we describe compact optical detector for clinical applications that utilizes two-wavelength excitation. It selectively measures the two most prominent skin carotenoids found in the human skin, lycopene and carotenes. According to the medical literature, these two compounds may play different roles in the human body and be part of different tissue defense mechanisms. Dual-wavelength Raman measurements reveal significant differences in the carotenoid composition of different subjects.

True borders of certain skin cancers are hard to detect by the human eye. For this reason, techniques such as polarized light imaging have been used to enhance skin cancer contrast before Mohs surgery procedures. In standard polarized light imaging the effect of the rough surface is minimized using a matched boundary, such as a glass slide and gel. Moreover, the surface glare is eliminated using skewed illumination. In this paper, we study the effect of the surface roughness on the polarized light backscattered from the skin. We demonstrate that rough surface effects can be minimized using out-of-plane polarized illumination in conjunction with polarized viewing.

While cryogen spray cooling (CSC) can protect skin epidermis from non-specific thermal damage, spray droplets in-flight and the cryogen/frost layer that forms on the skin surface may pose a potential problem for laser light attenuation due to absorption and/or scattering. Employing a hand piece expressly designed for concurrent light and cryogen delivery on skin phantoms, we studied the effect of relative humidity on light transmittance during and after spray cooling. Cryogen spurts were aimed at a microscope glass slide and a deformable agar phantom preheated at 32°C. According to our results, relative humidity plays a very important role in the light transmission during CSC. Light absorption and/or scattering by the spray droplets in-flight and cryogen/frost layer formation at the surface induced light attenuation values of up to 45%. The higher the relative humidity is, the lower the light transmission.

We compared urinary calculus fragmentation with long pulsed Ho:YAG (λ= 2.12 μm) versus Er:YAG (λ = 2.94 μm) lasers. We measured the ablation width, depth, volume and efficiency as a function of pulse energy from calculus threshold energy to clinical energy typically used for Ho:YAG laser lithotripsy. Ablation effects were evaluated for three types of urinary calculi (calcium oxalate monohydrate, cystine, and uric acid), for single and multiple pulses applied at various optical energy levels. By means of comparing laser-induced crater topography and ablation volume for each stone type, the feasibility of Er:YAG laser lithotripsy was appraised. The Er:YAG laser pulse energy generated deeper and narrower crater shapes with relatively smooth contours whereas the Ho:YAG laser produced shallower and wider craters with irregular shapes. In terms of multiple pulses ablation, the Er:YAG produced larger ablation volume than Ho:YAG. The deeper crater induced by the Er:YAG was attributed to the higher absorption coefficient of stones at the 2.94 μm wavelength, and widening of crater by Ho:YAG was perhaps caused by lateral expansion of ablated material. Comparing the ablation efficiency, Er:YAG was superior to Ho:YAG for both single and five-pulses.

The objective of this study is to evaluate in an animal model differences in wound healing and scar formation in healthy urethra and bladder neck incised with the Erbium:YAG and Holmium:YAG lasers. In each of 18 domestic pigs, three 1-cm-long incisions were made, two at the bladder neck and one in the mid-urethra using either the Er:YAG laser (9 pigs) or the Ho:YAG laser (9 pigs). In each laser group, three animals were sacrificed on postoperative (POD) days 0, 6, and 14. Width of collateral damage, as evidenced by coagulation necrosis and granulation tissue at the wound base, and incision depth were evaluated during tissue analysis. Collateral damage with the Er:YAG laser at POD 0, 6 and 14 was 20 ± 5 mm, 900 ± 100 mm, and 430 ± 100 mm, respectively. Damage with the Ho:YAG laser was 660 ± 110 mm, 2280 ± 700 mm, and 1580 ± 250 mm, respectively. The granulation tissue was significantly less (p < 0.05) at all time points with the Er:YAG laser. Similarly, incision depths for the two laser groups at days 6 (1100 ± 200 mm vs 1500 ± 300 mm) and 14 (670 ± 140 mm vs 1240 ± 140 mm) were also significantly less (p < 0.05) for the Er:YAG laser group, indicating faster healing of the wound created. In this in vivo animal study, incisions in the urethra and bladder neck made with the Er:YAG laser healed faster and with less scar formation than incisions made with the Ho:YAG laser.

The Thulium fiber laser may have several advantages over current urology lasers, including smaller size, more efficient operation, improved spatial beam quality, more precise tissue incision, and operation in pulsed or continuous-wave modes. However, previous laser-tissue interaction studies utilizing the Thulium fiber laser have been limited to laser powers of less than 5 W. This study describes high-power Thulium fiber laser vaporization of the canine prostate, ex vivo. A continuous-wave, 110-watt Thulium fiber laser operating at a wavelength of 1.91 mm, delivered 88.5 ± 2.3 W of power through a 600-mm-core silica fiber for non-contact vaporization of canine prostates (n=6). The Thulium fiber laser vaporized prostate tissue at a rate of 0.83 ± 0.11 g/min. The thermal coagulation zone measured 500-2000 mm. The high-power Thulium fiber laser is capable of rapid vaporization and coagulation of the prostate, ex vivo. In vivo animal studies are currently in development for evaluation of the Thulium fiber laser for prostate vaporization and potential treatment of benign prostate hyperplasia.

This study investigates deep laser coagulation of tissue in combination with contact cooling of the tissue surface for potential use in noninvasive urology procedures. A laser probe was designed, built, and tested for combination Nd:YAG laser irradiation and sapphire contact cooling of liver and skin tissue samples, ex vivo. Gross and histologic examination was used to quantify thermal lesion dimensions. Liver lesions measured 5.5 ± 0.3 mm in diameter, while preserving the tissue surface to a depth of 2.1 ± 0.2 mm (n = 5). Skin lesions measured 4.3 ± 0.9 mm in diameter, while preserving the skin surface to a depth of 1.1 ± 0.2 mm (n = 6). There were no statistical differences in lesion diameter and layer of preserved tissue between contact (sapphire) cooling and prior non-contact (cryogen spray) cooling results for a given tissue type (p > 0.05). Noninvasive laser procedures targeting tissue structures for thermal coagulation within a few millimeters of the tissue surface are feasible and may expand the use of combined laser/cooling techniques for applications in urology. In vivo animal studies are currently in development to optimize the laser and cooling parameters for potential clinical applications.

Photoselective vaporization of the prostate (PVP) is evolving as an alternative outpatient surgical treatment to transurethral resection of the prostate (TURP) in the management of patients with symptomatic benign prostatic hypertrophy/enlargement (BPH/BPE). The purported benefits of PVP include rapid vaporization of the prostate with an instant creation of TURP-like anatomic defect, an excellent hemostasis, shorter (<24 hours) duration of catheterization, short (< 24 hours) hospital stay, and quick return to work. We retrospectively reviewed the video clips of our cases to determine whether or not the anatomic appearance of the post-PVP prostatic cavity per se could predict clinical outcome. Forty-three, non-consecutive patients, diagnosed with symptomatic BPH have been treated with PVP using the 80W KTP laser and followed for at least 18 months (range 18-24). A majority (N=32) of the patients was enrolled under an Institutional Review Board approved multi-center protocol at the Hunter McGuire Veterans Administration Medical Center, Richmond, Virginia. We reviewed the urodynamic parameters: AUA-SI, QOL, Qmax and PVR at 3, 6, 12, 18 and 24 months postoperatively. We plan to present video documentations of the various anatomic appearances of the TURP-like prostatic cavity at the conclusion of the PVP treatment along with summaries of the short and long term clinical outcomes.

This work determines on an in vitro porcine urothelium model the threshold values of different parameters such as photosensitizer concentration, irradiation parameters and production of reactive oxygen species in order to control the damage on normal urothelium and spare about 50% of normal mucosa. For a three hours HAL incubation time, these threshold values were with blue light (0.75J/cm at 75 mW/cm2 or 0.15J/cm2 at 30 mW/cm2) and with white light (0.55J/cm2, at 30 mW/cm2). This means that for identical fluence rates, the threshold value for white light irradiation may be 3 times higher than for blue light irradiation.

The anti-inflammatory, anti-microbial, antiviral, and antidepressant activities of the Greek herb, Hypericum Perforatum L, HP L, have been attributed to the total extract or single constituents. We investigated the use of the extract,specifically of the polar methanolic fraction (PMF) of Epirus’HPL in photodynamic therapy (PDT) alone and in combination with recombinant Interferon-a2b (IFN) and gemcitabine (GCB) in the treatment of human bladder cancer cells. The PMF was extracted from the dry herb with methanol, followed by liquid-liquid extraction with petroleum ether. T-24 bladder cancer cells were plated (105 cells/well) and placed in the incubator (370 C, 5%CO) for 24 hours prior to addition of drugs. PMF 60ug/ml was added and incubation continued. After 24 hours, the cells were subjected to laser light (630nm) treatment with 0, 1, 4 and 8 Joules. After reincubation for 24 hours, IFN, (50,000 IU) or GCB, (2ug/ml) was added to the PDT-treated cells. After this incubation cell survival was assessed by the MTT assay. PMF-PDT alone-induced percent cell kill of 0%, 8%, 44% and 80% versus 31%, 64 and 86 % for PMF-PDT and IFN, versus 63%, 80% and 88% for MPF-PDT plus GCB at 1, 2, 4 and 8 Joules respectively. IFN and GCB induced 20% and 53% cell kill respectively. Our data suggest that MPF may be an effective agent for in vitro photodynamic therapy. PMF-PDT combined with Intron A, or gemcitabine achieved improved kill of cultured bladder cancer cells. Confirmation of these results in preclinical studies may lead to clinical trials.

Prostate cancer is the most common cancer in American men excluding skin cancer, and approximately 230,000 cases of prostate cancer will be diagnosed in the U.S. in 2004. In the non-surgical treatment of localized prostate cancer, fiberoptically delivered interstitial laser thermal therapy may be ideal for treating discrete tumors with minimal invasiveness. Real-time magnetic resonance imaging can be used to compute temperature changes based on the proton resonance frequency (PRF) shift, and two-dimensional maps of temperature rise and chronic thermal damage can be constructed in order to control laser therapy. In this work, we describe an MRI-compatible percutaneous grid template and localization and planning software for precise placement of minimally invasive laser catheters to effect a target ablation zone. We evaluated the accuracy of the catheter placement, and we present our preliminary experience with percutaneous MRI-guided feedback controlled laser ablation in a canine prostate model. Histological analysis is used to assess the effectiveness and accuracy of treatment visualization.

Connection of small vessels is usually done by suturing which is very cumbersome. Laser tissue soldering can circumvent that obstacle if a handy procedure can be defined. Our principle approach consists of a bioresorbable hollow stent with an expected degradation time of 3 weeks in combination with laser soldering. The stent is to be fed into the vessel to stabilize both ends and should allow percolation immediately after joining. The stents are made of Poly(D,L-lactid-co-glycolid) and solder is prepared from bovine serum albumin (BSA) doped with Indocyanine green (ICG) as chromophore to increase the absorption of laser light. After insertion, solder is applied onto the outer surface of the vessel and coagulated by laser radiation. The wavelength of 810 nm of a diode laser fits favorably to absorption properties of tissue and solder such that heating up of tissue is limited to prevent from necrosis and wound healing complications. In our study the preparation of stents, the consistency and doping of solder, a beam delivery instrument and the irradiation conditions are worked out. In-vitro tests are carried out on sperm ducts of Sprague-Dowlae (SD) rats. Different irradiation conditions are investigated and a micro-optical system consisting of a lens and a reflecting prism to ensure simultaneous irradiation of front and back side of the vessels tested. Under these conditions, the short-term rupture strength of laser anastomosis revealed as high as those achieved by suturing.

In order to attain complete seal of catheter sheath hole just after catheter intervention, we applied laser welding technique. We employed combination of diode laser (wavelength: 810nm) irradiation and indocyanine green stain to enhance heat generation on the stained surface. We studied laser sealing of catheter sheath hole on an ex vivo vascular model using porcine carotid artery. We successfully demonstrated the sheath hole closure in this welding in the model with 1.8W, 8s diode laser irradiation. In this case, we estimated 78 °C of the maximum temperature at welding surface by thermal conduction calculation. Collagen fiber melting was found in welding region. To know vascular wall at the fiber tip to perform laser welding in blind procedure, we constructed fiber-optic backscattering light measurement system. We used green He-Ne laser light (543nm) to distinguish hemoglobin concentration in the tissue. We obtained tissue discrimination at fiber tip in blind procedure. We think our particular laser welding in combination with novel tissue discrimination technique at the fiber tip may attain the catheter sheath hole closure with sufficient mechanical strength in blind procedure.

Resection of a segment of the trachea is a procedure applied for the removal of cervical tumors invading the trachea, or for the treatment of severe tracheal stenosis. The current method of anastomosis is based on multiple sutures. The main drawbacks of this method are: 1) A long procedure time, 2) An air leakage, and 3) An inflammatory response to the sutures. In this study we evaluated the feasibility and effectiveness of the use of temperature controlled CO₂ laser soldering of incisions in pig tracheas in vitro. A transverse incision was made in a separated pig trachea. A flexible albumin band was prepared and was laser soldered with albumin solder to the outer surface of the trachea, covering the incision. The soldered trachea ends were sealed and the burst pressure was measured. In a series of in vitro experiments, the mean burst pressure was found to be 230 mm Hg. These preliminary results demonstrated that laser soldering using a flexible albumin band may be a useful method for sealing an incision in the trachea.

In this study, 72 different combinations of laser welding parameters were compared for their effectiveness in welding ocular tissue. The laser employed in the welding system was a near infrared (NIR) erbium fiber laser with a wavelength of 1.455 μm . The laser system used a motorized translational stage and shutter to control the laser exposure of the tissue being welded. The emission wavelength of the laser in the NIR range corresponds to one of the lesser absorption bands of water. Parameters of the laser welding system that could be changed to allow a more effective distribution of the laser energy and therefore management of thermal energy included: the number and kinds of intricate offset patterns of light on or around the incision, the number of lines per pattern, the power level, the speed of the laser beam movement over the tissues, the spot size, dwell time and the focus plane of the light beam in the tissue. Histopathology was used as an endpoint indication of the effects that the various sets of welding parameters had on the welded tissues. Standard Hematoxylin and Eosin stain and Sirius Red F3B (Direct Red 80) in combination with polarization microscopy were used to stain and visualize the welded ocular tissue. Paradoxically, the best cornea welds quantified using histopathology occurred with fluence of 4,500 mJ/cm² or less while the corneal welds exhibiting the strongest tensile strengths, but most tissue damage had a delivered fluence above 7,000 mJ/cm². The best histological representatives of welded corneas had an average delivered fluence of 2,687 mJ/cm² and an irradiance of 14 W/cm². Using the properly determined parameters, the NIR erbium fiber welding system provided full thickness welds without the requirement of extrinsic dyes, chromophores, or solders. The NIR laser system with the appropriately developed parameters can be used effectively to weld ocular tissues.

Laser skin welding (LSW) is being pursued for scarless wound healing. We present a new LSW approach using a contact glass slide over the sample and rapid scanning of the laser beam around the area to be welded. This led to dramatic improvement in welding efficacy. A 400 mW beam at 1455 nm with a focused spot diameter of 80 μm in air was scanned at a rate of 5mm/second over a 5mm line of incision in 5 mm x 20 mm human skin samples. Histological analysis of the welded samples using hematoxyline and eosin under unpolarized light showed full-thickness full-length weld, and that with picrosirius red F3BA stain under polarized light revealed that there was no appreciable damage. Measured tensile strength of 2.1 kg/cm² is markedly greater than our previous LSW results of 1.05 ± 0.19 kg/cm², which is greater than the typical values of 0.4 kg/cm² obtained using sutures.

Gold nanoshells are a new class of nanoparticles with tunable optical absorption that can be placed in the near infrared. Gold nanoshells consist of a spherical silica core surrounded by a thin gold shell. The ratio of the sizes of the core diameter to the shell thickness as well as the total size of the nanoshell determines the optical absorption properties. Previous experiments have shown that these nanoparticles are stable at >325°C for durations typical of laser tissue welding. We have investigated the use of gold nanoshells as exogenous NIR absorbers to facilitate ex vivo laser tissue soldering. For ex vivo testing, gold nanoshells with peak absorption at approximately 820 nm were suspended in an albumin solder formulation and applied to muscle strips, followed by irradiation of the tissue at 821 nm. Mechanical testing of nanoshell-solder welds in muscle revealed successful fusion of tissues with tensile strengths of the weld site equal to the native tissue. The use of thermally stable nanoshells as an exogenous absorber allows the usage of light sources that are minimally absorbed by tissue components, thereby minimizing damage to surrounding tissue and producing welds sufficient for wound closure.

Conventional methods for dura repair are normally based on sutures or stitches. These methods have several disadvantages: (1) The dura is often brittle, and the standard procedures are difficult and time consuming. (2) The seal is leaky. (3) The introduction of a foreign body (e.g. sutures) may cause an inflammatory response. In order to overcome these difficulties we used a temperature controlled fiber optic based CO2 laser soldering system. In a set of in vitro experiments we generated a hole of diameter 10 mm in the dura of a pig corpse, covered the hole with a segment of fascia, and soldered the fascia to the edges of the hole, using 47% bovine albumin as a solder. The soldering was carried out spot by spot, and each spot was heated to 65° C for 3-6 seconds. The soldered dura was removed and the burst pressure of the soldered patch was measured. The average value for microscopic muscular side soldering was 194 mm Hg. This is much higher than the maximal physiological pressure of the CSF fluid in the brain, which is 15 mm Hg. In a set of in vivo experiments, fascia patches were soldered on holes in five farm pigs. The long term results of these experiments were very promising. In conclusion, we have developed an advanced technique for dural reconstruction, which will find important clinical applications.

To test laser-assisted high flow bypass in cerebral revascularization procedures, we set up an experimental model on rabbits which included harvesting a jugular vein graft and its implantation on the common carotid artery through a double end-to-side anastomosis. The study was carried out on 25 New Zealand rabbits by performing on each animal the proximal anastomosis using conventional suturing, while the distal one was obtained by means of low-power diode laser welding in association with the topical application of Indocyanine Green (ICG) solution to enhance local absorption of the laser light. After the procedure, the animals were subjected to a follow-up from 2 to 9 days. Bypass patency was evaluated by means of Doppler study. The vascular segments were excised and evaluated by histological and immunohistochemical examinations. Utilization of the diode laser was associated with a substantial shortening of the operative time, as well as with a more active endothelial regeneration process at the anastomotic site.

Bilayered tube structures consist of epithelial cell-seeded collagen lattice and muscle layer have been fabricated for esophageal tissue engineering. Good adhesion between layers in order to facilitate cell infiltration and neovascularization in the collagen lattice is required. Previous efforts include using other bioglues such as fibrin glue and silicone tube as the physical support. However, the former is subjected to chances of transmitting blood-born infectious disease and is time consuming while the latter requires a second surgical procedure. The current project aimed to bond the cell-seeded collagen lattice to muscle layer using photochemical bonding, which has previously been demonstrated a rapid and non-thermal procedure in bonding collagenous tissues. Rat esophageal epithelial cells were seeded on collagen lattice and together with the latissimus dorsi muscle layer, were exposed to a photosensitizer rose Bengal at the bonding surface. An argon laser was used to irradiate the approximated layers. Bonding strength was measured during the peeling test of the collagen layer from the muscle layer. Post-bonding cell viability was assessed using a modified NADH-diaphorase microassay. A pilot in vivo study was conducted by directly bonding the cell-seeded collagen layer onto the muscle flap in rats and the structures were characterized histologically. Photochemical bonding was found to significantly increase the adherence at the bonding interface without compromising the cell viability. This indicates the feasibility of using the technique to fabricate multi-layered structures in the presence of living cells. The pilot animal study demonstrated integration of the collagen lattice with the muscle layer at the bonding interface although the subsequent surgical manipulation disturbed the integration at some region. This means that an additional procedure removing the tube could be avoided if the approximation and thus the bonding are optimized. Cell infiltration and neovascularization were also evident demonstrating that direct bonding of engineered tissue structures in particular those with low processability such as collagen lattice to the host tissue is feasible.

Monte Carlo simulations were performed to delineate the role of local fluence rates and absorption in histologic success and tensile strength analysis of laser welding of ocular corneal tissue using an erbium fiber laser system operating at 1455nm wavelength. Porcine cornea was used for in vitro welding, while varying power, scan time, and irradiance. Immediate histologic analysis was performed, as well as tensile strength studies. Simulations were performed using MCML code, with a total of 10⁹ photons started. CONV code was used to convolve the output from MCML for a flat photon beam of 80-800 μ focal spot size and power specified by the experiment. The absorption coefficient, μa, was assumed to reflect that of water, 28.6 cm^-1. The scattering coefficient, μs, and anisotropy factor, g, were both neglected due to the poor scattering capabilities of water in the wavelength of the laser beam. Fluence rates were determined and were within 0.3%-4% of surface dose calculations for a beam diameter of 80 μ. Interactive Data Language (IDL) was used to sum the dose for one convolved beam to an experiment with multiple scans across the porcine cornea. Achieving optimal usage of the laser system requires maximal use of the variables (power, scan patterns, scan time, irradiance) available to use, and the correlation between Monte Carlo-aided dosimetry and the histopathological and tensile strength studies was performed. Optimal parameters for use in this 1455 nm laser system can be studied, and will allow users the ability to predict histology scores of welding success and tissue injury based on absorption values. These results can refine our experience with laser tissue welding of porcine cornea and aid in determining optimal delivered dose for successful tissue apposition and minimal adverse thermal heating.

Stereotactic radiosurgery (SRS) combines the principles of sterotaxy, or 3_D target localization, with multiple cross-fired beams from a high-energy radiation source to precisely irradiate an abnormal (oftentimes cancerous) lesion within a patient's body. This technique allows maximally aggressive dosing of the target, while normal surrounding tissue receives lower, non-injurious doses of radiation. The ideal objective is the destruction of the targeted area without damaging any normal tissue. Stereotactic radiosurgery differs from conventional radiotherapy in several ways. The efficacy of radiotherapy depends primarily on the greater sensitivity of tumor cells to radiation relative to normal brain tissue. In standard radiotherapy, the spatial accuracy of the treatment is a secondary concern as normal tissues are protected by administering the radiation dose over multiple sessions (fractions) daily for a period of several weeks. Radiosurgery requires much greater targeting accuracy. Stereotactic radiosurgery protects normal tissues by both selectively targeting only the abnormal lesion, and using cross-firing techniques to minimize the exposure of the adjacent normal tissue.

Confocal endomicroscopy is a novel, noninvasive microscopic technique that enables surface and subsurface imaging of living tissues or cells in vivo. This study was to explore the possibility of utilizing a novel rigid confocal endomicroscope (RCE) system for detecting morphological changes in living normal and neoplastic human and murine tongue tissue in combination with different photosensitizers, i.e. hypericin and 5-aminolevulinic acid (ALA) induced endogenous protoporphyrin IX (PPIX) fluorescence. Subjects were topically or systemically applied photosensitizer to the oral mucosa, and then fluorescence confocal endomicroscopy was performed on the tongue using the RCE system with the laser excitation wavelength at 488 nm. The preliminary results showed that confocal fluorescence images of the tongue can be acquired in real-time with well-defined micro-morphological structures, and changes of tissue structures associated with cancer transformation can also be identified. This study suggests that photosensitizer-mediated confocal endomicroscopy have a significant potential for rapid, non-invasive detection of early oral cancers in vivo.

Endoscopic polarization-sensitive optical coherence tomography (PS-OCT) was used to obtain cross-sectional images of laryngeal tissues in human subjects, in vivo. Imaging in tissue to a depth of 1.2 mm and with axial resolution below 10 micrometers enabled the epithelial layer to be readily identified in OCT intensity images, with the underlying superficial lamina propria characterized by an increased backscatter signal, and increased birefringence in polarization-sensitive images.

The CO₂ laser is the most widely used laser in laryngology, offering very precise cutting, predictable depth of penetration, and minimal collateral damage due to the efficient absorption of CO₂ laser by water. Surgical applications of CO₂ laser in microlaryngoscopy include removal of benign lesions and early-stage laryngeal cancer. A Transoral Laser Microsurgery (TLM) approach is routinely employed for treatment of laryngeal cancer; however, the role of TLM in advanced malignant lesions remains controversial. The main limiting factor of TLM is the restrictive exposure of the endoscopes combined with the limited cutting ability offered by the existing micromanipulator, enabling cutting only along the straight line-of-sight axis. A flexible fiber delivery system offering a very high quality output beam can offer tangential cutting and can therefore significantly enhance the existing surgical capabilities. Moreover, a flexible fiber for CO₂ laser delivery can be used for treatment of benign conditions through flexible endoscopy in an office setting using local anesthesia. OmniGuide Communications Inc. (OGCI) has fabricated a photonic bandgap fiber capable of flexibly guiding CO₂ laser energy. Results of laryngeal in-vivo and in-vitro animal studies will be presented. We will discuss the system setup, fiber performance and clinical outcomes. In addition we will present the results of the first human treatment and highlight additional otolaryngology conditions, which will likely benefit from the new technology herein presented.

Introduction: Chronic sinusitis with nasal polyps is one of the commonest diseases of the upper airways, with a recurrence rate of about 15%. Minimally-invasive endoscopic laser procedures have been established to reduce the need for conventional revision surgery whenever medical follow-up fails. However, laser surgery requires special considerations for surgical, safety and economic aspects. This study evaluates the feasibility of coblation versus laser resection for recurrent nasal polyps. Material and methods: 6 nasal polyps were harvested each from the ostiomeatal complex of patients undergoing microscopic endonasal surgery for chronic sinusitis. 3 were dissected using a Neodymium:YAG laser system (Dornier MediLas 5060N) set at 10, 20 and 30w in cw mode with a 600μm bare fiber in contact mode with negative feedback power control, while further 3 polyps were dissected using a Coblation system (ArthroCare® Coblator® I) with a 30° angled and a 0° straight probe with 2.4 mm outer diameter. The specimens were examined histologically for carbonization and coagulation as well as unaltered tissue. Results: Laser resection resulted in a carbonization zone of 30μm in depth plus a coagulation zone of about 100μm, depending on the water content and type of tissue. While the carbonization zone was smaller with coblation, coagulation zones were comparable, leaving ample amount of unaltered tissue available for further diagnosis. Conclusion: Both resection techniques are generally feasible to be used in day case surgery for recurrent polyps. While the coblation system required no special safety requirements, accessibility of the sinuses was limited by the rigidity of applicators that are available.

Optical coherence tomography (OCT) is a new non-invasive method to investigate biological tissue with a penetration depth of up to three millimeters. In this study OCT was used on the porcine larynx. The vocal folds were assigned to defined areas and examined by OCT followed by traditional histo-morphological analysis. We were able to validate this new method by showing that both the OCT-tomographs and the histological assays showed a clear demarcation of epithelium mucosae from the deeper layers. The current standard procedure to ensure the diagnosis, if tissue is malignant, is still an invasive one. Our results show that OCT allows the collection of crucial information about the quality of morphological changes on a vocal fold without the necessity of being invasive. Thus, we propose that optical coherence tomography should be introduced as a new and easy method for the detection of morphological changes of the vocal fold complementary to other established methods.

Though sinusitis is a significant health problem, it remains a challenging diagnosis for many physicians mainly because of its vague, non-specific symptomology. As such, physicians must often rely on x-rays and CT, which are not only costly but also expose the patient to ionizing radiation. As an alternative to these methods of diagnosis, our laboratory constructed a near infrared (NIR) transillumination system to image the paranasal maxillary sinuses. In contrast to the more conventional form of transillumination, which uses visible light, NIR transillumination uses light with a longer wavelength which is less attenuated by soft tissues, allowing increased signal intensity and tissue penetration. Our NIR transillumination system is low-cost, consisting of a light source containing two series of light emitting diodes, which give off light at wavelengths of 810 nm and 850 nm, and a charge coupled device (CCD) camera sensitive to NIR light. The light source is simply placed in the patient’s mouth and the resultant image created by the transmittance of NIR light is captured with the CCD camera via notebook PC. Using this NIR transillumination system, we imaged the paranasal maxillary sinuses of both healthy patients (n=5) and patients with sinus disease (n=12) and compared the resultant findings with conventional CT scans. We found that air and fluid/tissue-filled spaces can be reasonably distinguished by their differing NIR opacities. Based on these findings, we believe NIR transillumination of the paranasal sinuses may provide a simple, safe, and cost effective modality in the diagnosis and management of sinus disease.

A flexible fiber optic endoscope system for investigations in medical cavities using specially designed probe distal and proximal ends so as to facilitate speckle correlation analysis and simultaneous cavity imaging is presented in this paper. The design of the endoscope probe and associated detection system facilitating the analysis of deformation components and their derivatives in cavity surfaces is discussed. The distal end of the probe consists of a single fiber optic port for illumination and an imaging lens-image fiber unit for imaging the reflected speckle pattern from the cavity surface. An optical component selection unit is designed and used at the probe proximal end, for switching between deformation and derivative configurations. Theoretical analysis regarding speckle fringe formation on curved surfaces, for out-of-plane and shear configurations are discussed. Preliminary experimental investigations using the developed probe on inner surfaces of curved phantom tissue specimens are carried out for the abnormal growth detection and the results are analyzed. The obtained experimental results are compared with the developed theory. This probe system and its associated concepts may later lead into the improvements of currently used surgical assisted endoscopic techniques for early cancer diagnosis.

A challenging and frequent problem in premature neonates is vascular access because of their very small blood vessels. The use of small tourniquets and direct light has been the traditional technique, but its limitations are most apparent in the extremely small child. In the last three years we have been using Light Emitting Diodes (Red light) to transiluminate the vascular structures in arms and legs in these small patients, this has improved significantly the visualization and access of the vascular structures in our smallest patients. Light Emitting Diodes (LED) are small and inexpensive devices that emit powerful "Cold light" capable to transiluminate a portion of an infant's extremity without burning the area of contact. The individual working on the IV access virtually sees through the tissues to place a catheter at the precise location of the extremity. According to an extensive search of the available literature, this LED application for vascular access in small newborns has not been described. In our physician's and neonatal nurse's hands, it is a simple and very efficient procedure for vascular access in the smallest patients. This paper presents an overview of vascular access technique using LED in the premature infant.

Optical Coherence Tomography (OCT) is a new high spatial resolution, real-time optical imaging modality, known from prior pilot studies for its high sensitivity to invasive cancer. We reported our results in an OCT feasibility study for accurate determination of the proximal border for esophageal carcinoma and the distal border for rectal carcinoma. The OCT study enrolled 19 patients with rectal adenocarcinoma and 24 patients with distal esophageal carcinoma (14 squamous cell carcinomas, 10 adenocarcinomas). During pre-surgery planning endoscopy we performed in vivo OCT imaging of the tumor border at four dial clock axes (12, 3, 6 and 9 o’clock). The OCT border then was marked by an electrocoagulator, or by a methylene blue tattoo. A cold biopsy (from the esophagus) was performed at visual and OCT borders and compared with visual and OCT readings. 27 post-surgery excised specimens were analyzed. OCT borders matched the histopathology in 94% cases in the rectum and 83.3% in the esophagus. In the cases of a mismatch between the OCT and histology borders, a deep tumor invasion occurred in the muscle layer (esophagus, rectum). Because of its high sensitivity to mucosal cancer, OCT can be used for pre-surgery planning and surgery guidance of the proximal border for esophageal carcinoma and the distal border for rectal carcinoma. However, deep invasion in the rectum or esophageal wall has to be controlled by alternative diagnostic modalities.

Laparoscopic radical prostatectomy (LRP) is a relatively new technique for treating organ-confined prostate cancer. Recent progress of laparoscopic/endoscopic techniques allow to perform these complex oncological procedure. Since the first description of LRP in the early 1990s the technique has undergone significant technical modifications. Two operation routes were mainly used: the transperitoneal LRP and the extraperitoneal endoscopic radical prostatectomy (EERPE). Here we review the surgical techniques of both operation routes, and highlight results, outcome and complications. The transperitoneal LRP and the EERPE can be used successfully and reproducibly, giving results comparable with those from the open retropubic procedure. Despite many advantages, transperitoneal LRP is associated with potential intraperitoneal complications. The technical improvements of the EERPE completely obviates these complications. The available data are encouraging and promising, but long-term oncological results will define the definitive role of these new techniques. We truly believe that minimally invasive surgery in treating localized prostate cancer has a bright future and that these techniques will continue to be developed.

This paper presents a non-invasive, non-contact measurement of pulse waveforms by applying optical triangulation technology on skin surface vibration. The arterial pulsation information can be obtained with this measurement system. An algorithm to evaluate the pulsing activities from center of laser spot intensity on a certain wrist point has been conducted by fast Fourier Transform (FFT). The amplitude and frequency of skin vibration can be known by this measurement system. The advantages of this optical triangulation method are non-contact, low cost, remote sensing, and it can be combined with image processing system.

According to Taber's Cyclopedic Medical Dictionary "cellulite" is defined as: "a non-technical term for subcutaneous deposits of fat, especially in the buttocks, legs, and thighs." These deposits result in puckered, dimply skin and they are a cause for major aesthetic concerns in affected patients. The etiology of this condition is still unclear. Female predilection is witnessed in clinical practice as it is reported in the literature. It remains a subject for further studies whether it is a structural problem of connective tissue or as suggested probably related to hormonal causes. Magnetic resonance imaging may provide some answers to these questions. Not knowing what is causing this nuisance makes it almost impossible to treat. No wonder that there is little scientific validation to support any of the many treatments that are advertised on the Internet or in women's magazines. This review focuses on mechanical and microinvasive interventions that claim to alleviate "cellulite": lipoplasty, liposcultpure, liposuction, subcision, and laser. Among the parameters analyzed are the proposed modes of action of these techniques as well as adverse events and complications that may occur. Of special interest will be the evidence that backs these procedures. Extracting reliable data is hampered by methodical problems with the design of most of the published trials. In essence, at this time there is no "cure" for cellulite. Safe treatment recommendations are related to healthy life style choices that include toning exercises, dietary changes, and weight loss.

The publication is presenting the Einstein Matrix Treatment Method and initial results for blood borne diseases on example of hepatitis, HIV and arthritis. The initial research was conducted at Einstein Clinical Laboratories S.A. on limited funds. The treatment and method is strongly recommended for specific viruses bacteria in blood borne diseases but also for treatment of none specific viruses and bacteria in emergency treatments as SARS or ANTHRAX to safe life of the human. In the past years the Individual's Safety is in jeopardy by natural viral infections as well as by engineering cultured viruses and bacteria. Viruses mutate and become more resistant to current known medical treatment, in many cases partially efficient. This event required new testing method to investigate the possibility of treatments and to create new vaccine for non-specific viral and bacteria or viruses infections that causes death to thousands adults and children. The authors present in this paper the possibility of treatment of the non-specific viral, bacterial infections of the blood in human body. This treatment has safe procedure and no known side effect up to this time for patients that were treated at Einstein Clinical Laboratories SA.

It is a challenging task to accurately describe complicated biological tissues and bioluminescent sources in bioluminescent imaging simulation. Several graphic editing tools have been developed to efficiently model each part of the bioluminescent simulation environment and to interactively correct or improve the initial models of anatomical structures or bioluminescent sources. There are two major types of graphic editing tools: non-interactive tools and interactive tools. Geometric building blocks (i.e. regular geometric graphics and superquadrics) are applied as non-interactive tools. To a certain extent, complicated anatomical structures and bioluminescent sources can be approximately modeled by combining a sufficient large number of geometric building blocks with Boolean operators. However, those models are too simple to describe the local features and fine changes in 2D/3D irregular contours. Therefore, interactive graphic editing tools have been developed to facilitate the local modifications of any initial surface model. With initial models composed of geometric building blocks, interactive spline mode is applied to conveniently perform dragging and compressing operations on 2D/3D local surface of biological tissues and bioluminescent sources inside the region/volume of interest. Several applications of the interactive graphic editing tools will be presented in this article.

Many methods for detecting and measuring vulnerable atherosclerotic plaques have been proposed. These include reflection spectroscopy, thermography, ultrasound, computed tomography (CT) and magnetic resonance imaging (MRI). This paper presents an analysis and a comparison of two of these methods, near-infrared reflection spectroscopy (NIRS) and thermography. Most of the published literature evaluate methods statistically. A more analytic approach will make it easier to compare the different methods and determine if the measured signal will be strong enough in a real measurement situation. This is the approach taken in this article. Eight samples of human aorta were examined by NIRS and subsequently prepared for histology. A total of 28 measurement points were selected. A measure of the lipid content based on reflection spectra is proposed. Comparisons of this lipid measure with histology show that the lipid content in the plaques yields relatively small changes in the value of this lipid-index. Reflectance spectra from models based on the diffusion approximation for total reflectance were simulated. Temperature measurements were performed on three Watanabe heritable hyperlipidemic (WHHL) rabbits and one New Zealand white (NZW) rabbit with a thermistor-type intravascular temperature sensor. The measurements gave no significant signals which correlated with the subsequent histology. A simple analytic model was developed which indicates that a temperature increase of more than 0.01-0.04 °C at the surface of a vessel wall, due to inflammation in a plaque, is unlikely. Such a small temperature difference will probably be obscured by normal variation in the vessel wall temperature.

High intensity focused ultrasound (HIFU) is a promising method for ablation therapy in the heart. Little is understood about early lesion development with HIFU because the lesions cannot be imaged reliably with sufficient resolution, and no other real time monitoring techniques are available to date. We investigated Optical coherence tomography (OCT) for monitoring early lesion formation. We created a series of lesions in fresh canine cardiac tissue using 5W (frequency=4.23Mhz, F#=1.2) of acoustic power with 10sec., 7sec., and 5sec. exposures. The lesions were then imaged using an OCT imaging system with an axial resolution of 12μm and a lateral resolution of 15μm. The maximum width of the lesions were measured using custom software. In separate experiments, lesion formation was investigated under varying acoustic power levels ranging from 5W to 20W at 0.1sec. and 0.2 sec. exposures. The average maximum widths of the lesions were 1.06mm for 10sec. lesions, .65mm for 7sec. lesions, and .59mm for 5sec. lesions. We observed both subsurface lesions and superficial blister-like formations, which may be a precursor of cavitation inception or tissue vaporization. The subsurface lesion forms over time as expected from thermal energy deposition. The surface blister forms prior to the subsurface lesion at high power, and after subsurface lesion formation at lower powers. OCT provides a method for monitoring HIFU lesion formation at high resolution, and can potentially be used to optimize HIFU dose for clinical applications.

We have been proposed novel short-term (<10s) heating balloon using the combination of light-heat conversion mechanism and heated contrast medium irrigation in the balloon to improve dilatation characteristics of balloon angioplasty. Our new balloon angioplasty had suppressed intimal hyperplasia in rabbit model. We designed following experiments to understand the mechanism of suppression of intimal hyperplasia in our new thermal balloon angioplasty. We also aimed to obtain the suitable heating condition in our angioplasty to suppress intimal hyperplasia. We studied influence of the short-term heating on smooth muscle cells (SMCs) lethality in vitro. We investigated number of SMCs reduction in media in order to prevent intimal hyperplasia. We applied to our heating balloon dilatation to chronic rabbit model using normal iliac artery to study relation between heating condition and hyperplasia suppression. We estimated temperature history of the rabbit vascular wall by thermal conduction calculation. We related the estimated temperature history to the hyperplasia suppression effect in the chronic rabbit model. Finally, we obtained the relation between number of SMCs decreases and intimal hyperplasia suppression. We obtained that the short-term heating with 10s laser irradiation corresponding to estimated temperature of 50°C in the media and prevented intimal hyperplasia in the rabbit chronic model. In this case, we estimated about 30 percents of SMCs cellular lethality in media.

We proposed new method of blood removal using Ho:YAG laser(λ=2.1μm)-induced water-vapor bubble to prevent distal tissue ischemia during angioscopic imaging. We successfully demonstrated capability of this blood removal method using blood-filled pocine coronary artery ex vivo. We used laser irradiation conditions of 200mJ in pulse energy and 2Hz in repetition rate. Ho:YAG laser for blood removal and flash lamp lighting for endoscopic illumination were irradiated in the porcine coronary artery through individual fiber optics. Timing of the flash lamp lightning of 2μs in duration was arranged to illuminate the maximum blood removal space, i.e. the laser induced water-vapor bubble. We successfully obtained intra-lumen view via a thin angioscope using the laser blood removal without using saline injection. We studied to determine the optimum laser-induced bubble formation which indicated the minimum invasion against the blood vessel. The time resolved photography in vitro, transient pressure measurement in vitro, and acute historogical study on irradiated vessel wall in vivo were employed for this determination.

Imaging of human autopsy samples was performed from the luminal side with a high (3.5 μm axial and 7 μm lateral) resolution OCT system (around 800 nm) or a regular (15-20 μm axial and 20 μm lateral resolution) OCT system (around 1300 nm). For each sample, dimensions were measured by histomorphometry and OCT and the optical attenuation was measured. Quantitative analysis showed a strong and significant correlation between OCT and histology cap thickness measurements for both OCT systems. For both systems, the measured attenuation coefficients of diffuse intimal thickening and lipid-rich regions differed significantly from media and calcifications. Both the high and regular resolution OCT systems can precisely image the atherosclerotic plaques. Quantitative analysis of the OCT signals allowed in situ determination of the intrinsic optical attenuation coefficient of atherosclerotic tissue components within regions of interest, which can further help to discriminate the plaque and arterial wall components.

We present an integrated methodology for human brain mapping by simultaneous BOLD fMRI and NIR imaging. This methodology consists of three innovative components: the construction of MRI-compatible optical probes that can be affixed to any part of the human head inside a standard MRI head-coil with minimal MR image distortion, the accurate determination of optode positions on the head from MR images, and the application of a perturbation approach and Monte Carlo method to compute the integral kernel of the Born solution to the diffusion equation for baseline optical properties. This integrated approach has been used to demonstrate promising capabilities for studying functional hemodynamic activation in human visual cortex by simultaneous fMRI and NIR tomography.

Recent advances in diffuse optical imaging and spectroscopy (DOIS) allow the noninvasive measurement of local changes in cerebral oxygenation and hemodynamics. Available DOIS devices fall into three categories: time domain (TD), frequency domain (FD) and continuous wave (CW). The TD and FD devices have potential for high spatial resolution, high temporal resolution and high accuracy measurement, but the instrument cost and the hardware size prevent their wide clinical application. Furthermore, the presence of the low scattering cerebrospinal fluid layer (CSF) and its thickness variation during motion challenges quantitative, continuous monitoring of the cortex layer oxygenation and blood content. MRI has been used to provide a priori knowledge of the head anatomy that helps the NIR image reconstruction. However, the technology is expensive and lacks portability. This paper proposes a method that combines the accuracy of a TD/FD system and the portability of a CW device. With the optical baseline measured by a TD or FD device and the layer thickness characterized by an ultrasound transducer, a conventional CW system may be able to quantify the cortex layer optical absorption with high accuracy. In this paper, the feasibility of using ultrasound guided CW spectroscopy to monitor brain activities was studied on a multi layer head model using Monte Carlo simulation and order of magnitude analysis. A forward algorithm based on diffuse approximation and 2D Fourier Transform was used to optimize the source detector separation. Both analytical and neuron network approaches were developed for inverse calculation of the cortex layer absorption in real time. An ultrasound transducer was used to monitor the thickness of different layers surrounding the cerebral cortex. The concept of ultrasound guided CW spectroscopy was demonstrated by numerical simulation on a 2 layer head model and the use of the ultrasound transducer for layer thickness characterization was verified by animal and bench top results.

Acquiring functional near infrared spectroscopy (fNIRS) and functional magnetic resonance-imaging (fMRI) data are usually done asynchronously. In order to correlate these two different modalities’ data, measurements must be performed at the same time. In this study, we have designed a new MR compatible continuous wave intensity based fNIRS device to overcome this problem. For MR compatible fNIRS, we used two LEDs with wavelengths at 660 and 870 nm. There are four photodiodes for light detection. LEDs operated in a sequential multiplexing mode with adjustable "on" time for each LED. Emitted and diffused light was transferred to and from the tissue through 10 m long single mode plastic optical fibers (INDUSTRIAL FIBER OPTICS, INC.). By using fibers, we overcome MR compatibility problems that can be caused by semi-conductors on probe. This MR compatible fNIRS design can provide synchronous measurements with low cost.

This study was done to use near infrared (NIR) spectroscopy to bring out differences in the anatomical substructures in the rat spinal cord and further to differentiate scattering between demyelinated and normal sciatic nerves in rat models, thereby exploring a new methodology to localize MS (multiple Sclerosis) lesions in vivo for animal studies. The experimental setup consisted of a tungsten light source, CCD array spectrometer, and bifurcated optical fibers for light delivery and detection of back scattered light from tissue. The measurement system was calibrated with reflectance standard. The spinal cord of 14 rats was exposed by laminectomy, and the measurements were taken on 8 points at intervals of 1 mm on the right and left lumbar-sacral regions and the central blood vessel. For measurements on the sciatic nerve, the spinal nerves of 84 rats were ligated according to the Chung Model. Measurements were taken on five points on both the ligated and the control nerve side after 1, 4, 7 and 14 days. The reduced scattering coefficient, μ_s', was found to be higher in the lumbar-sacral regions (34.17 ± 2.05 cm^-1) than that near the central blood vessel (19.9 ± 3.8 cm^-1). Statistically, there was significant difference in scattering between the control side and the ligated side on postoperative days 4, 7, and 14. This study shows a promising diagnostic value in the future for monitoring of demyelinated CNS (central nervous system) diseases, like Multiple Sclerosis.

Deep Brain Stimulation (DBS) is FDA-approved for the treatment of Parkinson's disease and essential tremor. Currently, placement of DBS leads is guided through a combination of anatomical targeting and intraoperative microelectrode recordings. The physiological mapping process requires several hours, and each pass of the microelectrode into the brain increases the risk of hemorrhage. Optical Coherence Domain Reflectometry (OCDR) in combination with current methodologies could reduce surgical time and increase accuracy and safety by providing data on structures some distance ahead of the probe. For this preliminary study, we scanned a rat brain in vitro using polarization-insensitive Optical Coherence Tomography (OCT). For accurate measurement of intensity and attenuation, polarization effects arising from tissue birefringence are removed by polarization diversity detection. A fresh rat brain was sectioned along the coronal plane and immersed in a 5 mm cuvette with saline solution. OCT images from a 1294 nm light source showed depth profiles up to 2 mm. Light intensity and attenuation rate distinguished various tissue structures such as hippocampus, cortex, external capsule, internal capsule, and optic tract. Attenuation coefficient is determined by linear fitting of the single scattering regime in averaged A-scans where Beer’s law is applicable. Histology showed very good correlation with OCT images. From the preliminary study using OCT, we conclude that OCDR is a promising approach for guiding DBS probe placement.

The effects of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy (PDT) and gamma radiation, and PDT and hyperthermia (HT) are investigated in human glioma spheroids. In the case of ionizing radiation and PDT, the degree of interaction between the two modalities depends in a complex manner on a number of factors, including light fluence, fluence rate and radiation dose. It is shown that, under certain conditions, PDT and gamma radiation interact synergistically to produce enhanced cell kill. The degree of interaction appears to be independent of both sequence and time intervals investigated. TUNEL assays show that low fluence-rate ALA-PDT is a very efficient inducer of apoptosis, whereas neither high-fluence rate PDT nor ionizing radiation results in significant apoptosis in this system. Synergistic interactions between HT and PDT are observed when the two modalities are given concurrently. The degree of synergism increases with increasing temperature and light fluence. It is shown that apoptosis is the primary mode of cell death following combined HT and low-fluence rate ALA-PDT.

An in vivo shell-less chick chorioallantoic membrane (CAM) brain tumor model has been developed to investigate the effects of photodynamic therapy (PDT) and anti-antiogenic treatments. Multicellular human glioma spheroids were placed on the CAM at day 7 of embryonic development. Angiogenesis was observed four days post implantation. Significant damage to the CAM vasculature was observed immediately following 5-aminolevulinic acid (ALA) mediated PDT.

Introduction: Failure of treatment for high grade gliomas is usually due to local recurrence at the site of surgical resec-tion indicating that a more aggressive form of local therapy could be of benefit. Photodynamic therapy (PDT) is a local form of treatment involving the administration of a tumor-localizing photosensitizing drug that is activated by light of a specific wavelength The results of in vitro experiments indicated that PDT, given at low fluence rates was substantially more effective at inhibiting glioma spheroid growth than short term high fluence rate regimes. This prompted the initia-tion of in vivo studies of low fluence rate 5-aminolevulinic acid (ALA) PDT in a rat glioma model. Methods:BT4C cell line tumors were established in the brains of inbred BD- IX rats. Eighteen days following tumor induction the animals were injected with 125 mg/kg ALA ip. and four hours later light treatment at various fluences and fluence rates were given after the introduction of an optical fiber. Tumor histology and animal survival were examined. Results: In vitro experiments verified that the cell line was sensitive to ALA PDT. Microfluorometry of frozen tissue sections showed that PpIX is produced with a greater than 20:1 tumor to normal tissue selectivity ratio four hours after ALA injection. Histological examination demonstrated neutrophil infiltration and tumor central necrosis in low fluence rate treated tumors. Conclusions: Low fluence rate long term ALA mediated PDT had a more pronounced effect on tumor histology than single shot short duration treatments at similar total fluence levels.

We assumed that edema causes a decrease in the scattering coefficient of brain tissue and hence a decrease in the intensity of diffuse reflectance from the brain. On the basis of this assumption, we attempted to transcranially detect a formation of brain edema by measuring diffuse light reflectance. In rats, edema was induced by making a cold injury in the brain. The skull was irradiated with 633-nm and 532-nm laser light delivered through an optical fiber, and the diffuse light reflectance from the brain was collected with another optical fiber. We observed that reflectance intensities were significantly decreased around the cold injury both at 633 nm and 532 nm, suggesting that scattering coefficient of brain tissue was reduced due to a formation of edema in this area. In the injury, reflectance intensity was increased at 532 nm, indicating that cerebral blood volume was decreased in this region.

Introduction: Photodynamic therapy (PDT) for Barrett’s esophagus, advanced esophageal cancer, and both early and late inoperable lung carcinoma is now FDA-approved using the first generation photosensitizer PhotofrinTM (Axcan Pharma, Birmingham, AL). Photofrin-mediated PDT of glioma is now in Phase III clinical trials. A variety of second generation photosensitizers have been developed to provide improved: (1) specificity for the target tissue, (2) tumoricidal capability, and (3) rapid clearance the vascular compartment, skin, and eyes. The phthalocyanine Pc 4 is a second generation photosensitizer that is in early phase I clinical trials for skin cancer. We have undertaken a preclinical study that seeks to determine if Pc 4-mediated PDT can be of benefit for the intra-operative localization and treatment of glioma. Methods: Using a stereotactic frame, 250,000 U87 cells were injected via Hamilton syringe through a craniotomy, and the dura, 1-2 mm below the cortical surface of nude (athymic) rat brains (N=91). The craniotomy was filled with a piece of surgical PVC and the scalp closed. After two weeks of tumor growth, the animals received 0.5 mg/kg Pc 4 via tail vein injection. One day later the scalp was re-incised, and the PVC removed. The tumor was then illuminated with either 5 or 30 Joule/cm2 of 672-nm light from a diode laser at 50 mW/cm2. The animals were sacrificed one day later and the brain was cold-perfused with formaldehyde. Two thirds of the explanted brains are now being histologically surveyed for necrosis after staining with hematoxylin and eosin and for apoptosis via immunohistochemistry (i.e., TUNEL assay). The other third were analyzed by HPLC-mass spectrometry for the presence of drug in tumor, normal brain, and plasma at sacrifice. Initial histological results show PDT-induced apoptosis and necrosis confined to the growing (live) portion of the tumor. Preliminary analysis shows an average selectivity of Pc 4 uptake in the bulk tumor to be 3.8 times greater than in normal brain tissue. Discussion: The observed specificity and tumoricidal activity of Pc 4 warrants further preclinical studies to determine the preferred Pc 4 drug and light dose for future glioma patient clinical trials.

We use near-infrared spectroscopy to investigate hemodynamic changes in humans during a breath holding exercise and their influence on the BOLD fMRI signal. We have quantitatively compared the BOLD fMRI signals with the hemoglobin concentration changes using correlation analysis of NIRS and fMRI data.

Oral application of 20 mg/kg bw of 5-aminolevulinic acid results in a highly specific accumulation of fluorescent and phototoxic Protoporphyrin IX in malignant glioma tissue. Surgical removal with fluorescence guidance is studied in a phase III clinical trial, adjuvant Photodynamic Therapy (PDT) to the surgical cavity is in phase II and for interstitial PDT of recurrent gliomas, a phase I/II study has started. Fluorescence guided resections have been shown to be safe and effective in augmenting neurosurgical removal of malignant gliomas in 52 consecutive patients. Intra-operative fluorescence spectroscopy showed statistically significant higher sensitizer accumulation in vital brain tumor versus the infiltration zone and in the infiltration zone versus adjacent normal brain, which contained very little PPIX. This is promisingly exploited for PDT - both to the surgical cavity by surface irradiation and for stereotactically guided interstitial irradiation.

Preterm infants have a high incidence of post hemorrhagic or post infectious hydrocephalus often associated with ventricular or arachnoic cysts which carry a high risk of entrapment of cerebrospinal fluid (CSF). In these cases fenestration and opening of windows within the separating membranes are neurosurgical options. Although Nd:YAG- and diode-lasers have already been used in neuroendoscopic procedures, neurosurgeons avoid the use of high energy lasers in proximity to vital structures because of potential side effects. We have used a recently developed diode pumped solid state (DPSS) laser emitting light at a wavelength of 2.0 μm (Revolix TM LISA laser products, Katlenburg, Germany), which can be delivered through silica fibres towards endoscopic targets. From July 2002 until June 2004 fourteen endoscopic procedures in 12 consecutive patients (age 3 months to 12 years old) were performed. Most children suffered from complex post hemorrhagic and post infectious hydrocephalus, in whom ventriculoperitoneal shunt devices failed to restore a CSF equilibrium due to entrapment of CSF pathways by the cysts. We used two different endoscopes, a 6 mm Neuroendoscope (Braun Aesculap, Melsungen, Germany) and a 4 mm miniature Neuroscope (Storz, Tuttlingen, Germany). The endoscopes were connected to a standard camera and TV monitor, the laser energy was introduced through a 365 μm core diameter bare ended silica fibre (PercuFib, LISA laser products, Katlenburg, Germany) through the endoscope’s working channel. The continuous wave laser was operated at power levels from 5 to 15 Watt in continuous and chopped mode. The frequency of the laser in chopped mode was varied between 5 and 20 Hz. All patients tolerated the procedure well. No immediate or long term side effects were noted. In 3 patients with cystic compression of the 4th ventricle, insertion of a shunt device could be avoided. The authors conclude that the use of the new RevolixTM laser enables safe and effective procedures in neuroendoscopy.

The integration of near-infrared (NIR) and functional MRI (fMRI) studies is potentially a powerful method to investigate the physiological mechanism of human cerebral activity. However, current NIR methodologies do not provide adequate accuracy of localization and are not fully integrated with MRI in the sense of mutual enhancement of the two imaging modalities. Results are presented to address these issues by developing an MRI-compatible optical probe and using diffuse optical tomography for optical image reconstruction. We have developed a complete methodology that seamlessly integrates NIR tomography with fMRI data acquisition. In this paper, we apply this methodology to determine both hemodynamic and early neuronal responses in the visual cortex in humans. Early results indicate that the changes in deoxyhemoglobin concentration from optical data are co-localized with fMRI BOLD signal changes, but changes in oxyhemoglobin concentration (not measurable using fMRI) show small spatial differences.

Previous research has examined the relationships between physiological parameters and frequency oscillations in hemodynamic activity of brain. The current study used functional near infrared spectroscopy (fNIRS) to examine the relationship between oscillatory hemodynamics and performance measures during a standard cognitive task. fNIR data (n=7) were collected from 16 optodes distributed over dorsolateral prefrontal and inferior frontal cortex during a standard visual "oddball" task while behavioral reaction times to each stimulus were recorded. A frequency analysis of the fNIRS data revealed that the ratio of the power at 0-30 mHz to the power at 30-150 mHz was correlated with the number of mistakes a subject made as, well as their reaction times. Relatively greater low-frequency oscillations were associated with more mistakes and increased behavioral reaction times.

The method of the local functional injury of somatic frog's nerve using high coherent UV-A radiation of N₂ laser (λ=337nm, P~10 mW), coherent mercury-vapor lamp radiation (λ=365; 312 nm P_Σ~2 mW/cm²) and low-coherence UV-A sun radiation (400-315 nm, PΣ~10 mW) was realized. The level of injury was assessed from the decrease of compound action potential of the nerve stimulated extracellularly by electrical pulses of millisecond duration. Study of dynamic response of the bundle of axons revealed the decrease of the number of action potential which can be generated (less than 10⁵). This decrease may be attributed to destruction of action transport and/or voltage-activated ion channels of axon membrane. The dose dependence of the level of nerve injury was studied using varied both intensity and duration of high and low-coherent UV-A irradiation.

We measure the concentration of oxy-, deoxy- and total hemoglobin by using the frequency-domain, near-infrared spectroscopy(NIRS) scanner. It is a non-invasive instrument that can provide real-time measurements of the changes in concentration. It can provide a diagnostic tool for the study of the brain in infants and children. However, it is difficult to apply it to the baby's head because of the contact of the probe on the soft baby's head. Therefore, we suggest the NIRS scanning system that can track the baby' head movement and detect NIRS parameters on the same position of the head. This system has three key components. The vision system performs the pattern matching for tracking the head by using the normalized cross correlation method with the target as a cross-line on the head during the diagnostic experiment. We can use the change of the position of the baby's head to re-target the light by the scanning system that uses four laser sources, a wavelength selector, and an x-y scanner. The detector system analyzes the resulting signal from the head using the diffusion model. Therefore, NIRS scanning system can provide a diagnostic tool to measure the changes of the NIRS parameters for the study of the baby's brain.

Ovarian cancer is not a common cancer-approximately 25,000 new cases in 2004-but it is the fifth leading cause of death from cancer in women (over 16,000 in 2004). Little is known about the precursors and early stages of ovarian cancer partially due to the lack of human samples at the early stages. A cohesive model that incorporates ovarian cancer induction into a menopausal rodent would be well suited for comprehensive studies of ovarian cancer. Non-destructive imaging would allow carcinogenesis to be followed. Optical Coherence Tomography (OCT), Optical Coherence Microscopy (OCM) and Light-Induced Fluorescence (LIF) are minimally invasive optical modalities that allow both structural and biochemical changes to be noted. Rat ovaries were exposed to 4-vinylcyclohexene diepoxide (VCD) for 20 days in order to destroy the primordial follicles. Plain sutures and sutures coated with 7,12-dimethylbenz(a)anthracene (DMBA) were implanted in the right ovary, in order to produce epithelial based ovarian cancers (a plain suture was inserted in the control). Rats were sacrificed at 4 weeks and ovaries were harvested and imaged with a combined OCT/LIF system and with the OCM. Histology was preformed on the harvested ovaries and any pathology determined. Two of the ovaries were visually abnormal; the OCT/LIF imaging confirmed these abnormalities. The normal ovary OCM and OCT images show the organized structure of the ovary, the follicles, bursa and corpus lutea are visible. The OCM images show the disorganized structure of one of the abnormal ovaries. Overall this pilot study demonstrated the feasibility of both the animal model and optical imaging.

Transendoscopic laser treatment for upper airway disorders has been performed in the horse for over twenty years. Endoscopic laser transmission utilizing flexible fiber optics is limited to certain discreet wavelengths. Initially, the laser of choice was the Nd: YAG laser (1064nm), but in the early 1990's, diode lasers (810nm, 980nm) were introduced to veterinary medicine and are currently used in private practice and universities. Precise application of laser irradiation is dependent on the user knowing the laser's output as well as the amount of energy that is delivered to tissue. Knowledge of dosimetry is important to the veterinarian for keeping accurate medical records by being able to describe very specific treatment regimes. The applied energy is best described as power density or energy density. Calculation of this energy is dependent upon the users ability to determine the laser's spot size when irradiating tissue in a non-contact mode. The charts derived from this study provide the veterinarian the ability to estimate spot size for a number of commonly used lasers with the fiber positioned at various distances from the target.

Transendoscopic laser surgery has been performed in large animals since 1984. It is used to treat many upper respiratory disorders, as well as urogenital diseases. Initially, the Nd:YAG laser was the laser of choice until the early 1990's, when smaller, more compact diode lasers entered the veterinary field. In the mid 1980's, several attempts were made to transmit CO₂ laser energy transendoscopically. True success was not obtained until 2004 when the OmniGuide CO₂ Laser Hollow Light Guide (fiber) was fabricated. Although there is attenuation of energy, this very flexible fiber allows the CO₂ laser to be used transendoscopically for incision and ablation of tissue. Both healing and recuperation time are reduced, compared to other wavelengths transmitted through solid quartz fiber. The OmniGuide fiber can be coupled to the output ports of CO₂ lasers commonly used in veterinary medicine. Transendoscopic application of the CO₂ laser is advantageous in that there is no endoscopic white-out, no volume heating of tissue, and it provides accurate means of performing upper respiratory surgery in the standing large animal.

The purpose of this study was to evaluate the outcome of horses treated for cutaneous masses with the carbon dioxide (CO₂) laser. The records of 65 horses were examined. Surgery was performed under general anesthesia or standing under sedation and local anesthesia. Excision was performed freehand using a focused beam with power settings ranging from 10 to 32 Watts in a continuous mode. Following en bloc removal of masses the subcutaneous tissue and wound margins were photovaporized using a defocused beam. Follow-up information was obtained via telephone interview with owners or referring veterinarians Cutaneous masses were divided into three groups: sarcoid (29), neoplasia including squamous cell carcinoma (15), melanoma (6), schwanoma (2), fibroma (1), and fibrosarcoma (1), and non-neoplastic masses (11). Mass reoccurrence developed in 8 of 29 (28%) sarcoids and 4 of 14 (29%) squamous cell carcinoma. No reoccurrence was reported for horses diagnosed with melanoma, schwanoma, fibrosarcoma, fibroma, or any of the non-neoplastic masses. Sixty of 63 owners (95%) reported that they were satisfied with the outcome of the procedure. This study demonstrates that the CO₂ laser is an effective means of treating cutaneous masses in horses.

Photodynamic therapy (PDT) involves the light activation of a drug within a tumor causing selective tumor cell death. Unfortunately, some photosensitizing drugs have been associated with adverse reactions in veterinary patients. Zinc phthalocyanine tetrasulfonate (ZnPcS₄) is a promising second-generation photosensitizer for use in veterinary medicine, however, it cannot be applied clinically until safety and efficacy data are available. ZnPcS₄ was given to Swiss Webster mice to assess acute toxicity. Doses >100 mg/kg were associated with acute toxicity and mortality, and doses >100 mg/kg resulted in renal tubular nephrosis, suggesting that the minimum toxic dose is approximately 100 mg/kg. Based on these data, a Phase I clinical trial of ZnPcS4-based PDT in tumor-bearing dogs is underway, with ZnPcS₄ doses up to 2 mg/kg producing no apparent toxicity. Tumor response has been observed after ZnPcS₄-based PDT using doses as low as 0.25 mg/kg, suggesting that conventional phase I clinical trials may not be appropriate for PDT protocols.

Nearly 80% of patients with newly diagnosed bladder cancer present with superficial bladder tumors (confined to the bladder lining such as transitional cell carcinoma [90%], squamous cell carcinoma [6-8%], and adenocarcinoma[2%]) in stages Ta, Tis, or T1. Segmental cystectomy is one surgical treatment for patients who have a low-grade invasive tumor. Transposition of small intestine is a viable surgical treatment option. Success of the transplantation is also dependent upon removal of the entire SI mucosal layer. A Clark Spitfire Ti:Sapphire laser operating at 775 nm and 1 kHz repetition rate, was used to investigate the damage induced to fresh cadaveric porcine small intestinal mucosal epithelium. The laser was held constant at a focal spot diameter of 100 μm using a 200 mm focal point lens, with a power output maximum of 257 mW. A high resolution motorized X-Y-Z stage translated the SI tissue through the beam at 500 μm/sec with a line spacing of 50 μm. This produced a 50% overlap in the laser etching for each pass over a 1 cm x 1.5 cm grid. To determine if the mucosal lining of the SI was adequately removed, the targeted area was covered with 1% fluorescein solution for 30 seconds and then rinsed with phosphate buffered saline. Fluorescein staining was examined under UV illumination, to determine the initial degree of mucosal removal. Tissues were fixed and processed for light and scanning electron microscopy by standard protocols. Brightfield light microscopy of hematoxylin and eosin stained 4 μm thick cross sections, scanning electron microscopy were examined to determine the degree of mucosal tissue removal. Clear delineation of the submucosal layer by fluorescein staining was also observed. The Ti:Sapphire laser demonstrated precise, efficient removal of the mucosal epithelium with minimal submucosal damage.

The past several years has seen a severe shortage of pathogen-free Indian origin rhesus macaques due to the increased requirement for this model in retroviral research. With greater than 30 years of research data accumulated using the Rhesus macaque as the model for laser eye injury there exists a need to bridge to a more readily available nonhuman primate model. Much of the data previously collected from the Rhesus monkey (Macaca mulatta) provided the basis for the American National Standards Institute (ANSI) standards for laser safety. Currently a Tri-service effort is underway to utilize the Cynomolgus monkey (Macaca fasicularis) as a replacement for the Rhesus macaque. Preliminary functional and morphological baseline data collected from multifocal electroretinography (mfERG), optical coherence tomography (OCT) and retinal cell counts were compared from a small group of monkeys and tissues to determine if significant differences existed between the species. Initial functional findings rom mfERG yielded only one difference for the n2 amplitude value which was greater in the Cynomolgus monkey. No significant differences were seen in retinal and foveal thickness, as determined by OCT scans and no significant differences were seen in ganglion cell and inner nuclear cell nuclei counts. A highly significant difference was seen in the numbers of photoreceptor nuclei with greater numbers in the Rhesus macaque. This indicates more studies should be performed to determine the impact that a model change would have on the laser bioeffects community and their ability to continue to provide minimal visible lesion data for laser safety standards. The continued goal of this project will be to provide that necessary baseline information for a seamless transition to a more readily available animal model.

The goal of this study is to determine if a high energy laser pulse can cause internal injury that cannot be grossly visualized. High power lasers are currently in development such as the Medical Free Electron Laser (MFEL), the Anti-Ballistic Laser (ABL) and the Tactical High Energy Laser (THEL) and the potential exists for human exposure. Little is known about the effects of these high output lasers on internal organs when a thoracic exposure occurs. This study utilized a 3.8 micron single 8 microsecond pulse laser for all exposures. Yucatan miniature pigs were exposed to a single pulse over the sternum. In addition, some animals were also exposed in the axillary region. Creatine phosphokinase (CPK) and troponin levels were measured prior to and post exposure to assess cardiac muscle damage. Gross and histologic changes were determined for the porcine skin, lung tissue, and cardiac muscle. This study explores if a greater than class 4 laser classification is warranted based on the potential for thoracic injury.

As a consequence of the enormous expansion of laser use in medicine, industry and research, specific safety standards must be developed that appropriately address eye protection. The purpose of this study is to establish injury thresholds to the cornea for 3.8 micron 8 microsecond laser light pulses and to investigate a possible replacement model to live animal testing. Previous studies of pulsed energy absorption at 3.8 microns were performed using rhesus monkey cornea and were at pulse durations two orders of magnitude different than the 8 microsecond pulses used in this study. Ex-vivo pig eyes were exposed at varying energies and evaluated to establish the statistical threshold for corneal damage. Histology was used to determine the extent of damage to the cornea. It is expected that the results will be used to assist in the establishment of safety standards for laser use and offer an alternative to future animal use in establishment of safety standards.

Background and purpose: The purpose of this study is to determine the impact of melanin on skin response to single 3.8 micron, eight microsecond laser pulses and the difference in lesion formation thresholds for input into laser safety standards. Williams et al., performed a study examining laser tissue interaction from 3.8-micron lasers in lightly pigmented Yorkshire pigs (Sus scrofa domestica). However, studies performed by Eggleston et al comparing pigmented and lightly pigmented skin with human skin found that the Yucatan mini-pig is a superior model for laser skin exposures. Methods: Five Yucatan mini-pigs under general anesthesia were exposed to 3.8 micron laser pulses ranging from 0.8 J/cm² to 93 J/cm². Gross examinations were done acutely and 24 hours after laser exposure. Skin biopsies were then collected at various times post exposure, and histologic examinations were conducted. Results: The 24 hour ED₅₀ was determined to be 4.5 J/cm² with fiducial limits of 6.2 and 2.2 J/cm². As deposited energy was increased, the lesion presentation ranged from whitening of the epidermis (4 J/cm²) to whitening with inflammatory centers (14 J/cm²), and at the highest energy levels inflammatory areas were replaced with an epidermal ulcerated central area (>21 J/cm²). Conclusion: Preliminary findings suggest pigmentation or melanin may play a minor role in the mechanism of laser-tissue damage. The ED₅₀ of Yorkshire pigs was 2.6 J/cm². The ED₅₀ of the Yucatan mini-pig was found to be 3.6 J/cm², and although it was higher, it is still within the 95% fiducial limits.

There can be no question that specific systemic physiological results occur, when red light (660nm) is applied to the skin, it is now more a question of detailed mechanisms. Before gathering statistically signifcant clinical trial data, it is important to first enumerate the type of results observed in practice. Case histories are presented highlighting the use of photonic therapy in veterinary medicine. Over 900 surgical procedures have been performed and documented, utilizing the principles of photonic therapy, and while hemostasis, pain relief, and nausea relief, were the primary goals, the peri-operative death rate, the post-operative seroma, and post-operative infection were reduced to almost zero, and there was a noticeable increase in the healing rate. Scientifically applied photonic therapy, rather than supplanting conventional veterinary medicine, compliments and increases the veterinarian's set of skills. This paper proposes a hypothesis of how 660 nm light applied to specific points on the skin, produces various physiological changes in animals. By using animals, there can be no placebo, hypnotic or psychosomatic confounding effects.

We report on clinical experiences with photodynamic therapy in patients with recurrent, multifocal superficial transitional cell carcinoma of the urinary bladder. PDT is performed by intravesically applied 5-aminolevulinic acid and a Xe arc lamp as a light source delivering more than 5 Watt white light for activation of 5-ALA induced Protoporphyrin IX. For whole bladder wall irradiation a special irrigation catheter system has been developed. Based on that technology we determined whether this treatment modality was effective in destroying urothelial carcinoma and preventing recurrent disease. The study should help defining the optimal target group of patients and is considered as basis for a long term and multicenter clinical trial. The initial clinical results indicate that white light photodynamic therapy with 5-ALA is an effective organ-preserving procedure for treating multifocal superficial transitional cell carcinoma of the bladder, even in patients with refractory urothelial carcinoma and is effective in selectively destroying flat neoplastic lesions like carcinoma in situ. None of the patients showed phototoxic skin reactions or loss of bladder capacity.

We used 5.0 MHz ultrasonic pulses to monitor stress relaxation in Nd:YAG (λ = 1.32 μm) laser irradiated porcine nasal septal cartilage. Cartilage is irradiated in both uniaxial compression and curved deformation. A thin beam load cell and IR thermocouple measure strain (Vpp) and temperature (°C), respectively. We show that the propagation speed of the ultrasonic pulse is indicative of permanent stress relaxation in porcine nasal septal cartilage.

Background: Tracheal cartilage deformities due to trauma, prolonged endotracheal intubation or infection are difficult to correct. Current treatment options such as dilation, laser ablation, stent placement, and segmental resection are only temporary or carry significant risks. The objectives of this project were to design and test a laser activated endotracheal stent system that can actively modify the geometry of tracheal cartilage, leading to permanent retention of a new and desirable tracheal geometry. Methods: Ex vivo rabbit tracheal cartilage (simulating human neonate trachea) were irradiated with an Er: Glass laser, (λ= 1.54um, 0.5W-2.5W, 1 sec to 5 sec). Shape change and gross thermal injury were assessed visually to determine the best laser power parameters for reshaping. A rigid endoscopic telescope and hollow bronchoscope were used to record endoscopic images. The stent was constructed from nitinol wire, shaped into a zigzag configuration. An ex vivo testing apparatus was also constructed. Results: The best laser power parameter to produce shape change was 1 W for 6-7 seconds. At this setting, there was significant shape change with only minimal thermal injury to the tracheal mucosa, as assessed by visual inspection. The bronchoscopy system functioned adequately during testing in the ex vivo testing apparatus. Conclusion: We have successfully designed instrumentation and created the capability to endoscopically reshape tracheal cartilage in an ex vivo rabbit model. The results obtained in ex vivo tracheal cartilage indicated that reshaping using Er: Glass laser can be accomplished.