This PDF file contains the front matter associated with SPIE Proceedings Volume 11229 including the Title Page, Copyright information, Table of Contents, Introduction, and Conference Committee listing.

In this work, we evaluate the potential for Fluorescence Lifetime Imaging (FLIm) to complement a surgeon's visual, endoscopic, and pathologic assessment of the adequacy of intraoperative tumor resection in clinical cancer applications of the oral cavity and oropharynx. Using a custom-built FLIm instrument during both non-robotic and robotic assisted surgical procedures, we show that intrapatient contrast between healthy and tumor tissue can be achieved intraoperatively in vivo prior to cancer resection with statistical significance (p<0.001) in 9/9 patients using at least 1/6 FLIm parameters, and ex vivo for surgically excised specimens (p<0.001) for 8/9 patients. We employ a multi-parameter linear discriminant analysis approach to demonstrate superior pathology discrimination ability through leveraging a weighted combination of all FLIm metrics. We also highlight interpatient comparisons to evaluate how FLIm signatures vary across different patients and disparate tissue anatomies.

Real-time visualization of imaging data constitutes a critical part of surgical workflow. Augmented reality (AR) is a promising tool to assist in conventional surgical navigation systems. We have been developing an AR framework for clinical imaging and guidance using an optical see-through head-mounted display (OST-HMD) and fluorescence lifetime imaging (FLIm) instrumentation. This framework supports in vivo scanning of FLIm data and the real-time visualization of diagnostic information overlaid on the interrogated tissue area. With the high discriminative power of FLIm, our FLIm-AR concept has the potential for indicating tumor margins and assisting with tumor excision surgery.

Breast cancer is the most commonly diagnosed cancer among women. Positive margin status after breast-conserving surgery (BCS) is a predictor of higher rates of local recurrence. Intraoperative margin detection helps to complete tumor excision at the first operation. A margin tool that is capable of imaging all six margins of large lumpectomy specimens with both high resolution and fast speed (within 20 min) is yet to be developed. Deep UV light allows simultaneous excitation of multiple fluorophores and generating surface fluorescence images. We have developed a deep UV fluorescence scanning microscope (DUV-FSM) for slide-free, high-resolution and rapid examination of tumor specimens during BCS. The DUV-FSM uses a deep UV LED for oblique back illumination of freshly excised breast tissues stained with propidium iodide and Eosin Y and motorized XY stages for mosaic scanning. Fluorescence images are captured by a color CCD camera. Both invasive lobular carcinoma (ILC) and invasive ductal carcinoma (IDC) images showed excellent contrast from that of the normal cells in color, tissue texture, and cell density and shapes. This contrast have been consistently observed in all samples (n = 20) we have imaged so far. Statistical analysis showed a significant difference (p<0.0001) in nucleus-to-cytoplasm (NC) ratio between normal and invasive tissues. Thus, it may be utilized either visually by a trained individual or quantitatively by an algorithm to detect positive margins of lumpectomy specimens intraoperatively.

In thyroid surgeries, it is often difficult to visually distinguish parathyroid glands (PTGs) from their surrounding anatomical structures such as lymph nodes, fat, and thyroid tissues. There is a clear need to provide head and neck surgeons with intraoperative surgical guidance to safely distinguish PTGs and assess its viability to prevent the risk of hypocalcemia. This study aims to develop a portable hand-held imager that eliminates the need for complex set up for intraoperative imaging to increase the efficiency and performance for surgeons during thyroid surgeries. The performance of the device prototype was evaluated via in-vivo testing throughout preclinical studies.

Dermal filler injections are common skin cosmetic procedure, but intravascular injection of fillers can lead to various complications. Therefore, real-time imaging of vessels and fillers will be helpful to lower the complications. In this study, angiographic optical coherence tomography (A-OCT) was used for real-time visualization of vessels and fillers. This method was demonstrated in an in vivo mouse model by monitoring filler injection in the tail. The locations of main artery and fillers were identified by A-OCT imaging before and after injection. Our study suggests that the real-time angiographic OCT can serve as a useful tool for filler injection guide.

The purpose of this study was to develop an ultrahigh-speed, high-resolution, large imaging area optical coherence tomography (OCT) imaging system for improved evaluation of breast cancer surgical specimens. A 2-axis direct-drive servo motorized linear translation stage enables automatic acquisition and stitching of multiple OCT volumes, providing large-area imaging of tissue sizes up to 10cm x 10cm surface area x 2mm imaging depth. OCT images of breast specimens with this system will demonstrate normal breast parenchyma, cysts, radial scars, benign neoplasms such as fibroadenoma, atypical ductal/lobular hyperplasia, and carcinomas in situ and invasive.

Kidney transplantation is currently the most favorable treatment for patients with end stage renal disease (ESRD).1,2 Although transplantation from living donors (LD) promises higher survival rate, transplantation from deceased donors (DD) accounts for more than half of all kidney transplantation in the United States.5 Minimizing the ischemic damage on donor kidneys is essential for successful DD kidney transplantation because manifestations of the reperfusion injury after transplantation depend on the extent of ischemic insult.6 In this study, we investigate the correlation between the extent of ischemia and the renal microvasculature damage in an animal model of kidney ischemia and reperfusion injury using Optical Coherence Tomography Angiography (OCTA).

Optical coherence tomography (OCT) is being investigated as an intraoperative margin assessment tool for breast cancer. In this work, we developed a customized deep convolutional neural network (CNN) for classification of breast cancer in OCT images. Images were acquired with a custom ultrahigh-resolution OCT system and a standard resolution system. We classify healthy tissues such as stroma and adipose tissue, as well as diseased tissue including ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC). Future work involves increasing representation from different kinds of tumors such as mucinous carcinoma, papillary carcinoma, and phyllodes tumors.

Automatic tissue classification using optical coherence tomography (OCT) explores the possibility to control laser ablation in prevention for collateral damage of critical tissues. During ablation, tissue experience thermal dissipation which induces mechanical expansion and optical properties alteration. We reconstructed OCT images of bone, fat, and muscle tissues for pre and post ablation temperatures condition using Monte Carlo simulation. We trained a deep neural network to recognize tissue type based on reconstructed OCT images with pre-ablation temperature condition and tested it on post-ablation temprature condition. The reconstructed images show small changes in the tissue structure but do not significantly affect the performance of the classifier.

Near infrared diffuse optical tomography (DOT) is a significant potential means of detecting breast cancer. Compared with other system structures, the parallel-plate scanning mode has such advantages like adapting to different breast size, as well as increasing the transmission of light by compressing. Traditional parallel-plate DOT systems utilized the fibers for photon transmission and photomultiplier tube (PMT) or CCD for photon detection, which resulted in the high complexity and cost. In this study, we propose a fiber-free parallel-plate continuous-wave DOT system for breast cancer detection based on Silicon photomultiplier (SiPM) and multi-wavelength light emitting diode (LED). 50 three-wavelength (660 nm, 750nm and 840nm) LEDs are arranged in a printed circuit board (PCB) array as the source plate. Parallel to this plate, the other plate with 56 silicon photomultipliers (SiPM) arranged is designed as the detection plate. The control of the light source excitation and the detection of the SiPMs output are implemented by a module based on a data acquisition card. The structure of proposed system is very simple, and the acquisition time is no more than 5 minutes. The feasibility of the system was verified by polyoxymethylene and agar phantom experiments, which indicated that the parallel-plate system can accurately reconstruct optical parameters.

The ADEPT system is an angular domain optical projection tomography imaging system being developed to address the problem of undetected micrometastases in lymph node biopsy tissues. The relatively weak scattering nature of lymph nodes combined with a very low numerical aperture enables the approximation of straight-line projections that can be reconstructed into images simply with filtered back-projection (FBP). This was demonstrated in previous work where 0.2 mm diameter inclusions were detected in ~1 cm diameter lymph nodes; and while FBP was sufficient, the Radon transform is not a true representation of the imaging system. To investigate the degree of improvement that a more complex reconstruction algorithm could provide, a Monte Carlo based system matrix was generated and used to solve the inverse problem. Simulated phantoms were used to test this, and results revealed greater detection sensitivity at the periphery of samples. Such findings lend guidance in the ongoing design of the ADEPT system and so more robust evaluation of the reliability of the system matrix will be implemented in future work.

Imaging spectropolarimetry is an informative technique that can be useful as a tool to detect and analyze cancerous tissues. However, to fit clinical standards, imaging spectropolarimeters must be fast, drift-free, and without any recurrent calibration, which is not the case for most imaging spectropolarimeters based on nematic liquid crystal phase modulators. Here, we present an instrument based on a novel architecture of differential liquid crystal variable retarders cells. A complete spectropolarimeter was built using this architecture and is now part of a clinical study at the dermatology department of the Strasbourg University Hospital.

Safe and accurate placement of spinal screws remains a critical step during open and minimally invasive spinal fusion surgery. We investigated the application of diffuse reflectance spectroscopy (DRS) for real-time instrument guidance during a spinal screw placement procedure. A custom-built screw probe with integrated optical fibers was inserted into a vertebra under image guidance in an ex vivo human setting. We found that fat content derived from the spectra gradually changed as the probe approached the cortical bone boundary. The results indicate that DRS integrated into surgical instruments has the potential to improve the safety and accuracy of spinal screw placement procedures.

A shift toward increased patient-centeredness is taking place in healthcare, from clinical care to medical product innovation, evaluation, and reimbursement decision-making. The U.S. Food and Drug Administration (FDA) Center for Devices and Radiological Health (CDRH) has engaged the scientific and patient communities in developing rigorous scientific methods to integrate patient input into regulatory decision-making. This patient input comes in several forms, including patient-reported outcomes (PROs) and patient preference information (PPI). These studies have helped identify unmet needs, develop novel endpoints, improve clinical investigation design, and inform the benefit-risk assessment.

Bionic vision restoration systems incorporating an implantable device belong to the highest regulatory risk class in the USA and Europe (i.e Class III). As such, their release to the market or their use in clinical trials is subject to authorization by the competent authorities. These authorizations are based on thorough evaluation procedures which impose on the manufacturer the highest level of evidence of compliance with regulatory requirements. In order to obtain these authorizations in the shortest possible time, it is necessary to understand, in detail, the requirements specified in the regulations and their interpretation by the competent authorities. The means of demonstration of conformity and the criteria for acceptance must also be defined to ensure that they meet the expectations of the competent authorities. In the case of breakthrough innovation, these different aspects are even more difficult to determine as there is no predicate or state of the art on which the manufacturer and the competent authorities can rely. It is therefore necessary to deploy a regulatory strategy very early on incorporating as much input as possible from the competent authorities, in order to increase the probability of approval and thus streamline the regulatory pathway. We will present, as an example, the method we developed for the Prima Bionic Vision System and discuss the specificities of medical devices; including incremental development and short development cycles versus regulatory time and how to manage this particularity for breakthrough devices.

I will discuss the core optical technologies and the development cycles of three companies that I have co-founded over the last 10 years, namely Holomic/Cellmic, Lucendi and Pictor, which focus on mobile diagnostics, cytometry and pathology, respectively. These companies are at different stages of their lifespan, and faced different types of challenges that will be discussed in this talk.

My talk will describe the evolution of a technology to tackle a global health disparity, cervical cancer and the process from conceptualization of the technology to scaling it globally.

Laser osteotomy offers several advantages over conventional mechanical bone surgery such as precise and small cuts, functional cut geometry, accelerated healing, and less trauma. However, laser osteotomy system considered as a “dumb” system because it cannot provide information about the tissue being cut, thus damaging important tissue (e.g. nerve) cannot be avoided. Smart laser osteotomy should provide not only precise tissue cuts but also real-time feedback, control and guidance during surgery. Integrating smart laser osteotomy system in minimally invasive way will further push the boundaries of possible applications for the benefits of the patient. The presentation will give an overview about how the optical and optoacoustic technologies could be used as feedback for development of minimally invasive smart laser osteotomy.

Laser interstitial thermal therapy (LITT) has received increased interest in recent years, especially for treating neurological disorders such as gliomas and epilepsy. In LITT, monitoring tissue temperature is critical. For hyperthermia treatment of tumors, temperature must be controlled between 43 – 45°C to kill cancer cells through apoptosis. Heating tissue to higher temperatures between 50 – 80°C will quickly coagulate the tissue through necrosis. The success of LITT depends on accurate real-time temperature feedback. The advance of magnetic resonance imaging (MRI) thermometry has greatly enabled LITT for neurosurgery. However, the FDA has recently warned that MRI thermometry has a slow response time, which may lead to overtreatment. Here, we report our progress in developing a thermal sensing system based on blackbody radiation in the short-wave infrared range (SWIR, 1 μm – 2.5 μm) through a 2 m silica fiber to monitor temperatures as low as 40°C. In the SWIR range, water absorption and silica fiber attenuation are relatively low, making tissue temperature measurement feasible during LITT. We demonstrate the feasibility of using SWIR blackbody radiation for real-time temperature monitoring through bench-top studies and ex vivo tissue studies. This new thermal sensing technology could be seamlessly integrated with current MRI thermometry to improve response time. It could also be used standalone during LITT for applications when use of MRI thermometry is not feasible.

In open surgery, observing organ blood circulation and distinguishing artery and vein are important to improve precision of surgery. However, there are some difficulties in this judgement and distinction because there are only slight color differences in the color of ischemic or healthy organs. Peripheral vessels between artery and vein also have subtle difference in their color. The difference in absorption coefficients between oxygenated and deoxygenated hemoglobin mainly affects these characteristics. Therefore, if the illuminant spectrum can be optimized based on the optical properties, there is a possibility to enhance the difference between the two types of vessels and blood-oxygenation levels. To achieve these purposes, we conducted a spectroscopic design of a surgical illuminant combining 14 kinds of commercially available light-emitting diode (LED) spectra by maximizing color differences between blood samples. Spectral reflectance of the blood samples whose oxygen saturation (SO₂) measured in advance were employed for computer simulation. In this study, we prototyped a spectrally tunable light source which contains the same LED sets used in the simulation of the surgical illuminant. A conventional illuminant and the designed illuminant spectrum were spectrally adjusted by the spectrally tunable light source to evaluate the effectiveness of the optimal illuminant. Two kinds of cattle blood samples that have different SO₂ were enclosed in glass cells and covered with cattle artery for subjective evaluation. Research participants were instructed to compare the color of samples and to sort these blood samples in a SO₂ order under the two illuminant conditions. The percentage of correct answers under the designed illuminant was superior to that under the conventional illuminant. This results showed the effectiveness of the designed illuminant.

Human communication is to a large extend based on the use and variation of the voice. The correct use of the vocal system is learned from childhood on by auditory feedback. Hearing-impaired people do not receive this acoustic feedback and alternative methods are used if language is to be learned in addition to other forms of communication. Resonance frequencies play a decisive role in the formation of vowels. Hearing-impaired people may not be able to hear the vowel dependent resonances; however, they might be able to feel the corresponding vibrational structure within their vocal tract. In order to elucidate this process further, we performed vibrometric measurements of 3D printed model with uniform wall thickness which was acoustically excited with via a broadband loudspeaker. The resonance frequencies in the range of 100 - 5000Hz were clearly visible and the locations of the strongest vibrations could be determined. Furthermore, vibrometric data showed specific regions, were hearing-impaired people may feel some vibrations if the vowels are supported by the vocal tract structure. Vibrometric data, such as velocity amplitudes at selected regions and frequencies could be measured.

Optical Coherence Tomography (OCT) has been proven to be a precise monitoring tool for laserosteotomy which can provide three-dimensional, high resolution and real-time images of a target sample. However, the main technical drawback of utilizing OCT as a monitoring system for laser ablation is the limited imaging range. In this paper, we reported a prototype where we integrated a long-range swept-source OCT system (3.3cm imaging range in the air) with an Er:YAG laser for ablation. We demonstrated that the integrated system can monitor the ablation of bone by Er:YAG with varying pulse energy levels and durations.

During neurovascular surgery the vascular function can be checked intraoperatively and qualitatively by observing the blood dynamics inside the vessel via Indocyanine Green (ICG) Fluorescence Angiography. This state-of-theart method provides the surgeon with valuable semi-quantitative information but needs to be improved towards a quantitative assessment of vascular volume flow. The precise measurement of volume flow rely on the assumption that both the inner geometry of the blood vessel and the blood flow velocity can be precisely obtained from Fluorescence Angiography. The correct reconstruction of the inner diameter of the vessel is essential in order to minimize the propagated error in the flow calculation. Although ICG binds specifically on blood plasma proteins the fluorescence light radiates also from outside the inner vessel volume due to multiple scattering in the vessel wall, causing a fading edge intensity contrast. A spatial gradient based segmentation method is proposed to reliably estimate the inner diameter of cerebral vessels from intraoperative Fluorescence Angiography images. As result the minimum of the second deviation of the intensity values perpendicular to the vessels edge was identified as the best feature to assess the inner diameter of artificial vessel phantoms. This method has been applied to cerebrovascular vessel images and the results, since no ground truth is available, comply with literature values.

Intraoperative imaging of brain tumors using spectral signatures of tissue, based on injected fluorescent dye such as 5-ALA, has enabled surgeons to target residual malignant tissue near the boundaries of the tumor cavity where extent of resection is most difficult. This paper presents a novel approach to intraoperative tumor boundary detection based on a moving excitation laser crossing a tumor boundary while measuring spectral signatures generated. In prior work, we have characterized the intrinsic spectral signatures of glioblastoma and healthy brain tissue from in vivo mouse models within the 400 to 700 nm range given a 405 nm excitation source at a single spot, without the use of injected dye. In this work, we present a theoretical model of expected spectral signature observations for a moving excitation laser across a tumor boundary based on discretized contribution of known spectral signatures (i.e. GBM, healthy) within the region of the laser spot on the surface of a tissue. This approach allows for improved intraoperative boundary detection despite having a laser spot size larger than the desired resolution of detection.

Confocal laser endomicroscopy (CLE) has found an increasing number of applications in clinical and pre-clinical studies, for it allows intraoperative in-situ tissue morphology at cellular resolution. CLE is considered as one of the most promising systems for in-vivo pathological diagnostics. Miniaturized imaging probes are designed for intraoperative applications. Due to less sophisticated optical design, CLE systems are more prone to image aberrations and distortions. While diagnostics with CLE takes reference from the corresponding histological images, the determination of the resolution and aberrations of the CLE systems becomes essential. Thereby on-site quality check of system performance is required. Additionally, these compact systems enable a field of view of less than half square millimeter without zooming function, which makes it difficult to correlate human vision to the microscopic scenes. Therefore, it is necessary to have defined microstructures working as a test target for CLE systems. We have extended the 2D bar pattern in 1951 USAF test chart to 3D structures for both lateral and axial resolution assessment, since axial resolution represents the optical sectioning ability of CLE systems and is one of the key parameters to be assessed. The test target was produced by direct laser writing. Yellow-green fluorescence emission can be excited at 488 nm. It can also be used for other fluorescence microscopic imaging modalities in the corresponding wavelength range.

Hyperspectral imaging techniques measure spatial and spectral information, which enables discrimination between healthy tissue and lesions. Hyperspectral imaging applications in endoscopy for clinical diagnostic applications are still limited due to image distortion challenges that arise when working with a flexible endoscope, for example in the gastrointestinal tract. Here, we developed a hyperspectral endoscopy (HySE) system by exploiting a line-scanning spectrograph to measure spectral information at high spectral resolution and combining it with a CMOS camera that records wide-field images for hyperspectral image reconstruction. Moreover, we developed an image normalisation method using near-infrared light to obtain accurate hyperspectral signals by correcting uneven illumination conditions during clinical endoscopy. Our next step is to apply HySE to patients to identify abnormal features in the gastrointestinal tract in vivo.

Identification of positive margins during breast cancer conserving surgery is crucial for successful tumor resection. To address this clinical need, we developed a microscope that combines fluorescent microscopy, optical coherence tomography (OCT), and reflectance confocal microscopy (RCM) to identify the presence of positive tumor margins in surgical specimens. A cancer-targeting fluorescent agent is used to highlight potentially positive margins and guide combined RCM/OCT imaging. Combined RCM/OCT is used to accurately determine the extent of the positive margins, aided by custom image-processing techniques. This instrument has the potential to provide tumor margin guidance in the surgical suite, reducing reliance on lengthy histopathological inquiry and reducing the need for repeated surgery.

Diabetic polyneuropathy (DPN) is a diabetic complication impacting 200,000 people in the United States where gold-standard clinical diagnosis require invasive and costly skin biopsies. Here we combine Spatial Frequency Domain Imaging (SFDI) and Laser Speckle Contrast Imaging (LSCI) to explore hemodynamic states in normal and diabetic skin for DPN detection. SFDI is a non-invasive diffuse optical technique sensitive to oxy- and deoxyhemoglobin composition through the multi-spectral separation of optical properties. In addition to SFDI, multi-exposure LSCI has the advantage of quantifying changes in tissue perfusion based on interference patterns detected from Doppler-shifted photons. In this work, we have developed a multi-layer Monte-Carlo based model to address both SFD and LSC inverse problems utilizing depth-modulating spatial projections coupled with a coherent source sensitive to flow dynamics.

Gynecologic surgery accounts for 75% of all intraoperative injuries to the ureters, which often occur due to the close proximity of the ureter to the uterine artery. We propose dual-wavelength photoacoustic imaging in order to distinguish the ureter from the uterine artery, identify the position of the surgical tool in proximity to these critical structures, and assist with guidance of hysterectomy procedures. Experiments were preformed in a pilot human cadaver study and a dual-wavelength approach was introduced to visualize the uterine artery and a ureter filled with urine and methylene blue. The ureter location was identified with low contrast at a wavelength of 750 nm and higher contrast at a wavelength of 690 nm, resulting in a 5.8 dB contrast difference in photoacoustic signals from the ureter at these two different wavelengths. The uterine artery was identified at laser wavelengths of both 690 nm and 750 nm, with similarly high contrasts of 17.4 dB and 16.0 dB, respectively. By using a dual-wavelength display, both the ureter and the uterine artery were identified and their position was estimated in the photoacoustic image. The proximity of a surgical tool tip to the ureter was additionally estimated based on the information provided in the dual-wavelength photoacoustic display and mapped to an auditory signal. This auditory information can be provided as either an alternative or an addition to photoacoustic images that inform surgeons of the risk of injury. Results highlight the promise of dual-wavelength photoacoustic imaging to achieve our ultimate goal of avoiding accidental ureteral injuries during hysterectomies and possibly other similar gynecologic surgeries and procedures.

Many cardiac interventional procedures (e.g., radiofrequency ablation) require fluoroscopy to navigate catheters in veins toward the heart. However, this image guidance method lacks depth information and increases the risks of radiation exposure for both patients and operators. To overcome these challenges, we developed a robotic visual servoing system that maintains visualization of segmented photoacoustic signals from a cardiac catheter tip. This system was tested in two in vivo cardiac catheterization procedures with ground truth position information provided by fluoroscopy and electromagnetic tracking. The 1D root mean square localization errors within the vein ranged 1.63 − 2.28 mm for the first experiment and 0.25 − 1.18 mm for the second experiment. The 3D root mean square localization error for the second experiment ranged 1.24 − 1.54 mm. The mean contrast of photoacoustic signals from the catheter tip ranged 29.8 − 48.8 dB when the catheter tip was visualized in the heart. Results indicate that robotic-photoacoustic imaging has promising potential as an alternative to fluoroscopic guidance. This alternative is advantageous because it provides depth information for cardiac interventions and enables enhanced visualization of the catheter tips within the beating heart.

Surgical resection is the primary treatment for malignant brain tumors. This procedure has a dilemma—aggressive surgical resection tends to extend patient survival; however, it also increases the risk of neurological deficiencies. Current medical imaging methods are not sensitive and their interpretation largely depend on surgeon’s impression. High-speed cellular imaging method by using clinically applicable moxifloxacin was demonstrated for fast and sensitive tumor-detection. The detailed cytoarchitecture of brain tumor mouse model and malignant human brain tumors was revealed. This study showed the potential and feasibility of moxifloxacin-based confocal microscopy as a surgery-guiding method for tumor removal.

Models of L4 and L5 vertebrae, sacrum and iliac bones were constructed on the basis of a computer tomogram. The sacrum model was constructed with three types of fractures: outward from the facet joint passing through the facet joint and inward relative to the facet joint. In addition, two main splinters of the sacrum were modeled, as well as screws passing through the iliac bones and elements of transpedicular fixation. Two variants of typical loads were considered: compression load and bending moment, compression load and rotation moment. In the case where screws passing through the iliac bones were combined with transpedicular screws, the maximum displacement in the models (for all three types of fracture) significantly decreased. This allows us to conclude that the variant of fixation with the help of a transpedicular structure makes the model more stable, that is, increases the rigidity of the structure, preventing the fixed elements of the vertebral-pelvic complex from shifting relative to each other. Equivalent stresses in the screws passing through the iliac bones were also reduced when installing the transpedicular structure. In this case, the stresses in the bone tissues did not differ significantly with different types of implants and loading options. Thus, if we evaluate the field of equivalent stresses in the models, a more rational from the point of view of biomechanics is the option of installing a transpedicular system in addition to screws passing through the iliac bones. This will reduce the risk of damage to both the structure and bone tissue.

Biomechanical modeling is used for preoperative planning of surgical treatment and allows you to choose the most rational option from the mechanical point of view. At the same time, the basic data for building models of the biological objects under study are the data of computed tomography (CT) and magnetic resonance imaging (MRI). To optimize and partially automate the process of constructing models of biological objects in Delphi, a software was developed that allows determining the outlines of areas corresponding to the object under examination on CT and MRI slices, to build a flat closed curve corresponding to the contour of a specific vessel lumen, to save data about the constructed curve to a file whose format corresponds to the format storage of curves in the software package Solid Works. The method of recursive two-dimensional frontal growth allows cutting off (due to the choice of the starting point) all “extra” shear vessels, which along with the section of interest can fall on the processed section. If the boundary of the object is determined, the algorithm does not imply further checks of the remaining pixels to reduce the number of operations and optimize the use of computer resources. In this case, the sensitivity of the method (the numerical value for the similarity criterion of pixels) can be changed manually by the user. Within the framework of the study, the frontal growth method is programmatically implemented. The created application allows you to create three-dimensional solid-state models of sections of the vascular bed on the basis of data from medical diagnostic equipment in a semi-automatic mode. This approach can significantly reduce the execution time of numerical modeling of hemodynamics of blood vessels.

MicroRNAs in exosomes (exosomal microRNAs) are attracting attention as cancer biomarkers for early diagnosis and prognosis due to their stability of body fluids. Since strong association exists between breast cancer and exosomal miRNA expression levels, it is important to develop effective methods that can monitor exosomal miRNA expression both over a wide range of concentrations and in ultralow amounts. Here, surface-enhanced-Raman scattering (SERS) based detection platform was developed for the quantitative analysis of exosomal miRNAs. The ultrasensitive detection of exosomal miRNA with single-nucleotide specificity was obtained by enhanced SERS signals from uniform plasmonic head-flocked gold nanopillar substrate, which generated multiple hotspots and enabled hybridization between short oligonucleotides, i.e., miRNAs and LNA probes. The proposed SERS sensor showed ultra-low detection limit without any amplification process, multiplex sensing capabilities, a wide dynamic range (1 aM to 100 nM) and sound miRNA recovery in serum. In addition, this sensor allowed to reliably observe exosomal miRNA expression patterns in breast cancer cell lines and is possible to discriminate breast cancer subtypes based on the difference in these expression patterns. Our results suggest that this sensor can be used for a universal cancer diagnosis cancer diagnosis and further biomedical applications through the quantitative measurement of exosomal miRNAs in body fluids.

Using of Decision Support System (DSS) in medicine affects the improvement of health care quality by means of increasing accuracy and specificity of diagnostics, customization of medical care, decreasing sequelae and terms of patients’ rehabilitation. DSS are using for proving of treatment efficacy and safety and let reduce personnel labour efforts. In this regard developing of DSS requires studying the needs of orthopedic surgeons as key users of such systems. Aim of this study performed at the base of 2 university medical centers in Saratov and Nizhny Novgorod which fulfill about 10% of surgeries in Russia concerning spine-and-pelvic complex pathology) deals with discovering the needs of orthopedic surgeons about desired DSS functionality by means of using the specially designed questionnaire. Results of the study determine following DSS functionality: use of geometric planning and biomechanical modeling before the surgery; surgery fate prognosis at the base of clinical and X-ray success criteria; ability to design the individual implants; integration of DSS with PACS and often using medical informational systems.

Planning of surgical reconstructive treatment of diseases and injuries of the vertebral-pelvic complex is a very responsible and complex challenge. For the successful outcome of surgery, doctors can use a prognosis based on a biomechanical simulation as support. It is very important for such simulation to know the physical properties, such as the estimation of Young's modulus value of bony tissues. The estimations of Young's modulus are possible only in vivo according to computed tomography (CT) since all calculations must be completed before the surgery. So the methods of determining proposed the value of Young's modulus (E) by Hounsfield units (HU) are proposed. Hounsfield units characterize the intensity of the gray color of bones on the tomogram. Within this article, in order to estimate the values of Young's modulus using the CT data, we performed a series of measurements in two ways on the same bony tissue samples. For the same bone tissue samples, measurements of Hounsfield units by a computer tomography data were first performed, and then during the experiment on the test machine, the values of maximum stresses and strains were determined, stressstrain graphs were constructed, and the values of Young's modulus were calculated. According to the results of two series of experiments, a comparative analysis was carried out. Note that changes caused by a disease or injury lead to an increase in bone heterogeneity, which is numerically expressed on the results of CT scan by an increase in the variation of Hounsfield units. The increase of HU variation in turn, affects the results of averaging, and consequently, the result of the study as a whole.

Venipuncture is a medical practice which is ordinarily performed in hospital. However, it is a difficult procedure as the occurrence of many failure of the puncture and sometimes medical accidents such as nerve damage and blood vessel damage are reported. This is caused by the difficulty of visually identification of the blood vessel. Although the depth information of the blood vessel is also important, the existing system in clinical practice can visualize vessels only by two dimensional images. In our previous work, we proposed a method that adds angle filtering to a refocus-based system using light field imaging to estimate the three-dimensional position of blood vessels. Angular filtering can reduce blurring of blood vessel image obtained using infrared light due to the strong scattering properties of biological tissue. By applying the refocusing technique to an image with reduced blur, it is possible to obtain enhanced cross-sectional information of a blood vessel using near-infrared light at each depth. However, in the previous study, only phantom model results were reported, and it was not possible to study practicality. In this paper, we report the results of applying and verifying the effectiveness of the proposed method to human hand.

Modeling of biological objects on the basis of computer and magnetic resonance imaging is a common practice today. DICOM source files (CT with contrast agent, heart without pathologies) were obtained at the Saratov cardiology center and correspond to diastole of cardiac cycle. The created geometric model consists of the internal volume of blood, ventricles, atria, heart valves and tendon chords. The resulting model can be studied using various computer systems, in particular, the finite element method.

The creation of systems for automatic processing of computed tomography (CT) results is associated with the task of recognizing individual areas in the image and building their contours. The paper proposes a method for constructing an external non-self-intersecting contour of a simply-connected two-dimensional region on a cross section of a computer tomogram, and also considers the main problems arising during its implementation.

All program code of the System is divided into three component types: Module, Package, Client. The System is developed on the microservice architecture principles, components are developed using the MVC design pattern. The System data handlers are DICOM with medical images and databases which accumulate and store the source information. The user software interfaces provided by so-called clients. Each software "client" is an application of three possible types: Desktop, Mobile, Web. Each package of software implies the possibility to reuse in all System components. This method of code organization makes it easy to maintain, complement, implement and scale the results.

Surgical methods form the basis of modern approach to forefoot deformities correction. Scientific and practical interest in this topic is based on the patients’ growing need for specialized care, which is required by 64% of women and 25% of men. In most cases, there is bilateral deformation of both feet. Some scientists are strongly against simultaneous surgery on both feet. It is obvious that the solution regarding acceptability of the load in the early postoperative period requires quantitative individual assessment. This assessment can be performed using biomechanics. This paper presents the technique for assessing the bone-screw system when performing corrective osteotomies of the first metatarsal bone based on biomechanical methods. This technique allows to perform comparative analysis of various osteotomy methods for a particular patient. In this study we examined Chevron and Scarf osteotomy with displacement of bone fragments by 1/3 and 2/3 with different fixation variants. To solve this problem, personalized geometric models of the first metatarsal bone were built on the basis of computed tomography data using 3D Slicer and SolidWorks systems. The implant models were built as well. Finite element analysis was carried out using Ansys Workbench software. The focus of the study was to analyse stresses that occur on the plantar surface of the first metatarsal bone head during walking. Assessment of the maximum allowable shift of bone fragments for normalization of the forefoot deformities was carried out. The developed technique allows to choose osteotomy variant and justify the possibility of simultaneous surgery on both feet for a particular patient.

The method of 2D segmentation of vertebrae based on computer tomography data (DICOM files) in sagittal projection using artificial neural network Mask-RCNNN is considered in this study. The effectiveness of network recognition was compared with manual segmentation performed by a professional physician. The comparison of accuracy between the neural network and manual segmentation was evaluated using the Sørens coefficient. The result of automatic 2D segmentation has been tested by professional physicians. The application of the method makes it possible to significantly speed up the process of modeling bone structures of the spine in 2D mode to solve the problems of biomechanics.

The study developed criteria for the success of surgical reconstructive treatment of patients with diseases and injuries of the spine and hip joints. Based on the analysis of scientific literature, success criteria were divided into three groups: clinical, geometric and biomechanical. The clinical criteria for the success of surgical treatment include international scales assessing the patient's condition before and after surgery. The geometrical criteria for success include the parameters of the frontal and sagittal balances of the elements of the vertebral-pelvic complex. Biomechanical criteria for the success of surgical treatment allow one to analyze the results of biomechanical modeling in order to substantiate the choice of the most rational option of surgical treatment for a particular patient. The biomechanical criteria for the success of surgical reconstructive treatment include: assessment of displacement values (displacements) of adjacent elements of the pelvic-pelvic complex, estimation of range of motion, evaluation of the values of effective (equivalent) stresses.