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The Moscone Center
San Francisco, California, United States
28 January - 2 February 2017
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Translational Research Presentations

Tissue Optics, Laser-Tissue Interaction, and Tissue Engineering
(ordered by conference and paper number)


In vivo monitoring laser tissue interaction using high resolution Fourier-domain optical coherence tomography
Paper 10062-42

Author(s):  Hang Chan Jo, Dankook Univ. (Korea, Republic of), et al.
Conference 10062: Optical Interactions with Tissue and Cells XXVIII
Session PMon: Posters-Monday

In this study, we demonstrate laser tissue interaction images of various sample tissues using high resolution Fourier-domain optical coherence tomography (Fd-OCT). We use a Q-switch diode-pumped Nd:YVO4 nanosecond laser (532nm and 1064nm wavelengths) with a 4W maximum output at a 20 kHz repetition rate to ablate ex vivo and in vivo samples including chicken breast and mouse ear tissues. The Fd-OCT system acquires time-series B-scan images at the same location during the tissue ablation experiments with 532nm and 1064nm laser irradiation. These experiments can demonstrate non-invasive quantification of the laser tissue ablation efficiency as well as qualitative assessment of blood coagulation


Investigation of the efficacy of ultrafast laser in large bowel excision
Paper 10062-6

Author(s):  Syam Mohan P. C. Mohanan, Heriot-Watt Univ. (United Kingdom), et al.
Conference 10062: Optical Interactions with Tissue and Cells XXVIII
Session 2: Short Pulsed Laser Effects

The soft tissue resection by ultrafast laser pulses has attracted significant research attention over the last two decades because of the capability to produce a crater with a precisely defined size, shape, depth and with minimal thermal damage when compared to conventional surgical techniques. We used a picosecond laser operating at 1030 and 515 nm to investigate the regimes that are optimal for tissue resection and coagulation in a healthy pig colon tissue. We demonstrate that ultrafast laser excision has the capability to control the collateral thermal damage and depth of ablation with higher precision than conventional surgical techniques.


Algorithmic processing of dual intrinsic signals in affixed transmission speckle analysis (ATSA)
Paper 10063-10

Author(s):  Michael T. Ghijsen, Univ. of California, Irvine (United States), et al.
Conference 10063: Dynamics and Fluctuations in Biomedical Photonics XIV
Session 2: Clinical Imaging

Affixed Transmission Speckle Analysis (ATSA) is a method recently developed to measure blood flow that is based on laser speckle imaging miniaturized into a clip-on form factor the size of a pulse-oximeter. Measuring at a rate of 250 Hz, ATSA is capable of obtaining the cardiac waveform in blood flow data, referred to as the Speckle-Plethysmogram (SPG). In this work we present novel algorithms for extracting harmonic content from the SPG waveform relevant to human physiology. Finally, we apply these methods to a case study of several patients with known arterial disease.


Intrinsic fluorescence of protein in turbid media using empirical relation based on Monte Carlo lookup table
Paper 10063-23

Author(s):  Ganesan Singaravelu, Anna Univ., Chennai (India), et al.
Conference 10063: Dynamics and Fluctuations in Biomedical Photonics XIV
Session 7: Functional Imaging

Fluorescence of Protein has been widely used in diagnostic oncology for characterizing cellular metabolism. However, the intensity of fluorescence emission is affected due to the absorbers and scatterers in tissue, which may lead to error in estimating exact protein content in tissue. Extraction of intrinsic fluorescence from measured fluorescence has been achieved by different methods. Among them, Monte Carlo based method yields the highest accuracy for extracting intrinsic fluorescence. In this work, we have attempted to generate a lookup table for Monte Carlo simulation of fluorescence emission by protein. Furthermore, we fitted the generated lookup table using an empirical relation. The empirical relation between measured and intrinsic fluorescence is validated using tissue phantom experiments. The proposed relation can be used for estimating intrinsic fluorescence of protein for real-time diagnostic applications and thereby improving the clinical interpretation of fluorescence spectroscopic data.


Unobtrusive monitoring of heart rate using a cost-effective speckle-based SI-POF remote sensor
Paper 10063-5

Author(s):  Carmen Vázquez García, Univ. Carlos III de Madrid (Spain), et al.
Conference 10063: Dynamics and Fluctuations in Biomedical Photonics XIV
Session 1: Speckle Technologies

Optical sensing features include small size, light weight, geometrical flexibility, chemical inertness, electric and thermal insulation, and immunity to electromagnetic interference. Additionally, Plastic Optical Fibers (POFs) may overcome biocompatibility concerns as well as provide multiple applications in sensing systems at a very low or competitive cost compared to the well-established conventional technologies. In this work a novel speckle-based sensing technique for cost-effective heart-rate monitoring is proposed. The proposed technique detects periodical changes in the spatial distribution of energy on the speckle pattern in the output of a Step-Index-POF lead. The scheme operates in reflective configuration thus performing a centralized interrogation unit scheme. The prototype has been tested on 5 patients lying on a bed in different positions without direct contact with the sensor cable.


Characteristics of blood components: markers of diseases as assessed by optical techniques
Paper 10063-7

Author(s):  Alexander V. Priezzhev, M.V. Lomonosov Moscow SU (Russian Federation), et al.
Conference 10063: Dynamics and Fluctuations in Biomedical Photonics XIV
Session 2: Clinical Imaging

This paper focuses at the characteristics of blood that can be measured in-vitro and/or in-vivo by laser-optic techniques, and which alterations can be considered as an indication of disease. The techniques to be discussed are: laser diffractometry of erythrocytes, laser scattering aggregometry of erythrocytes, digital optical capillaroscopy and measurement of the microcirculation parameters, erythrocytes trapping and manipulation with laser tweezers, fluorescence spectroscopy of blood plasma, etc. The obtained results allow us to conclude that the overviewed laser-optic techniques comprise a powerful tool for efficiently identifying and assessing a set of clinically informative bio-optical markers of diseases.


Multi-exposure speckle imaging of cerebral blood flow: a pilot clinical study
Paper 10063-8

Author(s):  Lisa M. Richards, The Univ. of Texas at Austin (United States), et al.
Conference 10063: Dynamics and Fluctuations in Biomedical Photonics XIV
Session 2: Clinical Imaging

Monitoring cerebral blood flow (CBF) during neurosurgery is essential for detecting ischemia in a timely manner for a wide range of procedures. In this clinical study (n = 7), multi-exposure speckle imaging (MESI) was evaluated intraoperatively during brain tumor resection procedures. The results demonstrate that shorter exposure times (≤1 ms) provide the highest dynamic range and sensitivity for sampling flow rates in human neurovasculature, and that MESI-estimated flows were highly conserved in vascular bifurcations. Results from this study demonstrate the importance of exposure time selection for LSCI, and that intraoperative MESI can be performed with high quantitative accuracy.


Possibility of transrectal photoacoustic imaging-guided biopsy for detection of prostate cancer
Paper 10064-100

Author(s):  Miya Ishihara, National Defense Medical College (Japan), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session PSun: Posters-Sunday

The purpose of this study is to demonstrate clinical feasibility of the transrectral photoacoustic (PA) image. Obtained prostate biopsy cores were stained with anti-CD34 antibodies as a marker of endothelium of the blood vessel in order to find a pattern of map of small vessel network, which allows for imaging-based identification of prostate cancer. We demonstrated TRUS-merged-with-PA imaging guided targeted biopsy combined with standard biopsy for capturing the clinically significant tumors. This study describes initial results with TRUS-merged-with-PA imaging guided targeted biopsy.


First patient results of photoacoustic computed tomography imaging of inflamed finger joints in rheumatoid arthritis
Paper 10064-11

Author(s):  Srirang Manohar, Univ. Twente (Netherlands), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 2: Clinical Applications

We study the feasibility of using photoacoustics in a tomography geometry to image vascular structures in inflamed and healthy finger joints in the context of rheumatoid arthritis. A laboratory system is developed based on a curved ultrasound detector array capable of rotation around the finger. We present results of imaging index finger joints of 3 healthy volunteers and 3 patients with inflamed fingers at 800 nm. We observe indications of restless regions around the inflamed joint where the thickness and tortuosity of the vasculature is increased. We consider these first results to be promising and worthy of further investigation.


Photoacoustic tomography of intraocular tumors: Investigation on laser safety
Paper 10064-113

Author(s):  Guan Xu, Univ. of Michigan Medical School (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session PSun: Posters-Sunday

Intraocular tumors are life-threatening conditions. Current clinical diagnostic modalities are unable to assess the molecular components inside the tumors, which is an important factor in differential diagnosis. In our previous study, we have differentiated uveal melanoma and retinoblastoma in enucleated human eye globes with photoacoustic imaging with illumination through sclera to avoid the cornea. This study investigates the safety limit to optical density for photoacoustic imaging of intraocular tumors through sclera with rabbit eyes. Retinal electroretinogram will be performed to evaluate the retinal toxicity after the exposures to illumination. The rabbit eyes will be harvested and examined with histopathology.


Computationally efficient error estimate for optimal choice of regularization in photoacoustic tomography
Paper 10064-129

Author(s):  Manish Bhatt, Indian Institute of Science (India), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session PSun: Posters-Sunday

The model based image reconstruction techniques for photoacoustic tomography require an explicit regularization. An error estimate minimization based approach is developed for the determination of optimal regularization parameter for photoacoustic imaging. The regularization is used within Lanczos bidiagonalization framework, which provides the advantage of dimensionality reduction for a large system of equations. The proposed method is computationally faster than the state of the art techniques and provides similar performance in terms of quantitative accuracy in reconstructed images. This error estimate can also be utilized in determining suitable regularization parameter for other popular techniques such as Tikhonov and exponential filtering methods.


Simultaneous measurements of total hemoglobin concentration and blood oxygenation with laser diode-based optoacoustic system
Paper 10064-24

Author(s):  Rinat O. Esenaliev, The Univ. of Texas Medical Branch (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 4: Functional Imaging

Noninvasive techniques for total hemoglobin concentration (THb) and blood oxygenation (SO2) monitoring often fail to provide accurate measurements. We built a compact, multi-wavelength, nanosecond, fiber-coupled laser diode-based optoacoustic system for noninvasive, accurate monitoring of blood THb and SO2 in blood vessels such as the radial artery. We tested the system in human subjects with different THb. Moreover, we compared performance of the system with that of commercially available systems for measurements of these parameters. The optoacoustic system provided rapid, simultaneous measurement of THb and SO2 with high accuracy. At conditions simulating circulatory shock the optoacoustic system provided more stable monitoring.


Cerebral blood oxygenation measurements in neonates with optoacoustic technique
Paper 10064-25

Author(s):  Rinat O. Esenaliev, The Univ. of Texas Medical Branch (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 4: Functional Imaging

Cerebral hypoxia in neonates results in death and severe complications such as cerebral palsy. We proposed to use optoacoustics for this application by probing the superior sagittal sinus (SSS), a large central cerebral vein. We developed and built a multi-wavelength, OPO- and laser diode-based optoacoustic systems for measurement of SSS blood oxygenation through open anterior and posterior fontanelles as well as through the skull in the occipital area. We tested the systems in neonatal SSS phantoms and in neonates. The systems were capable of detecting SSS signals with high signal-to-noise ratio and provided real-time, continuous oxygenation monitoring with high precision.


Real-time intravascular photoacoustic/ultrasound imaging of lipid-laden plaque at 20-frames per second
Paper 10064-28

Author(s):  Jie Hui, Purdue Univ. (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 5: Multimodality Imaging and Contrast Agents


Real-time photoacoustic flow cytography and photothermolysis of single circulating melanoma cells in vivo
Paper 10064-50

Author(s):  Yun He, Washington Univ. in St. Louis (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 8: Preclinical Imaging

Dissemination of circulating tumor cells (CTCs) is the major route of melanoma metastasis, which causes most melanoma-related mortalities. Detection and destruction of melanoma CTCs can impede metastasis and improve prognosis. Exploiting the intrinsic optical absorption contrast of CTCs, we developed dual-wavelength photoacoustic flow cytography coupled with laser therapy tuned for CTC targeting. Single CTCs in mice are successfully imaged with a high contrast. Further, the photoacoustic signal from a CTC immediately hardware-triggers a lethal laser irradiation to lyse it in a thermally confined manner. This technology can be easily translated to clinics, facilitating metastasis treatment of by purging CTCs from vasculature.


Label free aggressive prostate cancer identification with ultraviolet photoacoustic spectral analysis
Paper 10064-52

Author(s):  Guan Xu, Univ. of Michigan Medical School (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 10: Novel Methods and Systems

Prostate biopsy is the standard procedure for evaluating the aggressiveness of prostate cancer (PCa). The microarchitecture of the biopsied tissues visualized by histology process is assigned a Gleason score as a quantification of the cancer aggressiveness. Photoacoustic spectral analysis (PASA) has shown the capability of quantifying the Gleason scores of the H&E stained human prostate tissues. In this study, we attempt to assess the Gleason scores without staining using PASA at 266 nm. A correlation of 0.86 was observed between the signal intensities and the cell concentrations. A correlation of 0.89 was found between the Gleason scores and PASA slopes.


In-vitro and in-vivo high-resolution fluorescence imaging in centimeter-thick tissue via ultrasound-switchable fluorescence
Paper 10064-57

Author(s):  Baohong Yuan, The Univ. of Texas at Arlington (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 10: Novel Methods and Systems

We developed a high-resolution fluorescence imaging technology, ultrasound-switchable fluorescence (USF), for cancer imaging. It achieves high-resolution fluorescence imaging in centimeter deep tissue. Different types of USF contrast agents are synthesized and characterized. Several USF imaging systems are developed. High-resolution USF imaging in centimeter-thick tissue phantoms and in-vitro tissue samples are successfully achieved. Simultaneously imaging multiple targets via multi-colored USF signals is achieved. Ex-vivo USF imaging of mouse organs and in-vivo USF imaging of mouse tumors have been studied and demonstrated. The effects of biological environments on USF contrast agents are also investigated. Challenging and future directions are summarized and discussed.


Photoacoustic physio-chemical analysis for prostate cancer diagnosis
Paper 10064-81

Author(s):  Guan Xu, Univ. of Michigan Medical School (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 13: Molecular Imaging

Photoacoustic physio-chemical analysis (PAPCA) is a recently developed technology capable of simultaneously quantifying the content of molecular components and the corresponding microarchitectures in biological tissue. In this study, we implemented PAPCA to the diagnosis of prostate cancers (PCa). Statistically significant differences in molecular components, including lipid, collagen and hemoglobin were observed between the normal and cancerous regions in ex vivo human prostates. The diagnostic information in the PCPCA can be further enriched by F3 PAA-PEG nanoparticles capable of visualizing the microarchitecture in PCa, which was validated in a transgenic mouse model in vivo.


Photoacoustic imaging of intestinal strictures: microscopic and macroscopic assessment in vivo
Paper 10064-83

Author(s):  Guan Xu, Univ. of Michigan Medical School (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 13: Molecular Imaging

The pathology of Crohn’s disease (CD) is characterized by inflammatory and fibrotic intestinal strictures. Inflammatory strictures are medically treated. Fibrotic strictures have to be removed surgically. The accurate characterization of the strictures is critical for the management of CD. Currently the comprehensive assessment of a stricture is difficult, as the standard diagnostic procedure, endoscopic biopsy, is superficial and with limited locations as well as depth. This study investigates the capability of multispectral photoacoustic (PA) imaging in characterizing the intestinal strictures in rats in vivo. Endoscopic and transcutaneous approaches were both tested. The findings in PA images were confirmed by histology results.


Optoacoustic mapping of cerebral blood oxygenation in humans
Paper 10064-9

Author(s):  Rinat O. Esenaliev, The Univ. of Texas Medical Branch (United States), et al.
Conference 10064: Photons Plus Ultrasound: Imaging and Sensing 2017
Session 2: Clinical Applications

Noninvasive mapping, monitoring, and imaging of cerebral blood is important for management of patients with traumatic brain injury, stroke, and other neurological conditions. We proposed to use optoacoustics for this application, built optoacoustic systems for cerebral blood oxygenation mapping, and tested them in adults and neonates. The systems provide transcranial optoacoustic measurements in the NIR spectral range (680-950 nm). Novel, ultra-sensitive optoacoustic probes were built for detection of optoacoustic signals from large cerebral blood vessels and cerebral tissues. Measurement of the optoacoustic signals at different locations allowed for mapping of cerebral blood oxygenation beneath the skull.


Fluorescent imaging and artificial neural networks in the classification of vascular immune reaction
Paper 10065-17

Author(s):  Vyacheslav Kalchenko, Weizmann Institute of Science (Israel), et al.
Conference 10065: Biophotonics and Immune Responses XII
Session 4: Novel Detection Techniques

We developed a simple approach dedicated for characterization of immune responses during preclinical studies. The main principle of the proposed methodology is based on the use of fluorescence imaging of vascular permeability in response to topical administration of immunologically active agents (IAA). In previous studies we proposed a quantitative analysis based on methods derived from astronomical observations, in particular by using a space-time Fourier filtering analysis followed by a polynomial orthogonal modes decomposition. Herein we demonstrate the usability of a new methodology for quantification, classification and automatic analysis of immune responses to IAA. The proposed methodology is a combination of supervised and unsupervised techniques based on Artificial Neural Networks (ANNs) as one of deep learning method. We also summarize advantages and disadvantages of the use of various types of ANNs and deep learning during optical imaging of immune responses.


Near infrared photoimmunotherapy rapidly elicits specific host immunity against cancer cells
Paper 10065-6

Author(s):  Hisataka Kobayashi, National Cancer Institute (United States), et al.
Conference 10065: Biophotonics and Immune Responses XII
Session 2: Photoimmunotherapy and Immune Responses

Near infrared photoimmunotherapy (NIR-PIT) is a new type of molecularly-targeted cancer photo-therapy, which employs a NIR silica-phthalocyanine, IR700, conjugated to a monoclonal antibody targeting cell-surface molecules. Morphological and biochemical analysis demonstrated that cancer cell-targeting NIR-PIT purely induced necrotic/ immunogenic cell death (ICD) that promoted maturation of immature dendritic cells adjacent to dying cancer cells. Alternatively, NIR-PIT can target negative regulatory immune cells such as Treg only in the tumor bed and induce cancer cell-specific CD8+-T and NK cell responses. Cancer cell-targeting and immuno-suppressor cell-targeting NIR-PITs effectively induce innate and acquired immunity specifically against cancer cells growing in patients, respectively.


Immunotherapy for advanced solid tumors
Paper 10065-8

Author(s):  Mark F. Naylor, Baylor Scott & White Health (United States), et al.
Conference 10065: Biophotonics and Immune Responses XII
Session 2: Photoimmunotherapy and Immune Responses

Immunologic therapy (immunotherapy) has been demonstrated to be the best way to treat advanced melanoma, the prototypical chemotherapy-resistant solid tumor. What remains to be established is the efficacy and benefit of immunotherapy for other tumors that are at least partly responsive to chemotherapy. We are currently undertaking a study of InCVAX for the treatment of advanced breast cancer patients in Peru, and hope to show that this immunologic treatment can reduce tumor burden, extend survival, and do so in a cost-effective way that has less impact on quality of life compared with traditional chemotherapy for advanced breast cancer.


A visible Chinese human-combined Monte Carlo simulation study on low-level light therapy of stroke
Paper 10066-11

Author(s):  Ting Li, Univ. of Electronic Science and Technology of China (China), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 3: Low-Level Energy Treatment

Optimum LLLT treatment has a dominant influence on therapy of stroke. While more than thousands clinical trials have been halted, only a few trials on animals have been reported. We addressed this issue by simulating near-infrared light propagation within accurate visible Chinese human head by Monte Carlo modeling. The visible human head embody region of atherosclerotic plaques in the head. Through comparing the light propagation of different light illumination, we can get a precise, optimized and straightforward treatment. Here, we developed a LLLT helmet with 3D display of light fluence rate distribution for treating stroke to verify optimum LLLT treatment.


Simple coil-powering techniques for generating 10KA/m alternating magnetic field at multiple frequencies using 0.5KW RF power for magnetic nanoparticle hyperthermia
Paper 10066-12

Author(s):  Daqing Piao, Oklahoma State Univ. (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 4: Nanoparticle Medicine

Alternating magnetic field (AMF) configurable at a range of frequencies is a critical need for optimization of magnetic nanoparticle based hyperthermia, for their application in targeted drug delivery. However, generating AMF of 10KA/m strength at multiple frequencies using less than 1KW RF power remains a challenge. We have developed a relatively low cost and modular AMF device with 0.5KW RF amplifier that generates up to 10KA/m field strength at multiple-frequencies. A simple method allowing continuous adjustment of the RF-input-tap for optimally powering the coil-capacitor resonance network has been instrumental to producing 10KA/m AMF at multiple frequencies with 0.5KW RF power.


Magneto-thermo-acoustic differential-frequency imaging of magnetic nanoparticle with magnetic spatial localization: A theoretical prediction
Paper 10066-13

Author(s):  Daqing Piao, Oklahoma State Univ. (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 4: Nanoparticle Medicine

The magneto-thermo-acoustic effect associated with alternating magnetic field (AMF) mediation of magnetic nanoparticle that we predicted in 2013 has been observed by several independent studies including the discovery of acoustic-wave-generation at the second-harmonic-frequency of the AMF. We further propose that applying two AMFs with different frequencies produces acoustic-wave at the summation and difference of the two frequencies. The ratio of the acoustic-intensity at the summation- or difference-frequency over that at each second-harmonics is uniquely related to the two AMF field parameters. The results indicate a potential strategy for magnetic spatial localization during continuous-wave magneto-thermal-acoustic detection using full-field spatially-unresolved acoustic detection.


Vapor ablation in the human prostate: Evolution of tissue changes over the first 90 days
Paper 10066-18

Author(s):  Joshua L. Shrout, West Virginia Univ. Health Sciences Ctr. (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 5: Energy-Based Thermal Treatment

A variety of therapies are available for the treatment of benign and neoplastic diseases in the human prostate. Targeted vapor ablation of the diseased prostatic tissues is emerging as a clinical option for these patients. Utilizing the delayed human prostatectomy model, this study will present the evolution of the vapor ablation related tissue changes in the human prostate over the first 90 days.


A novel thermal accelerant for augmentation of microwave energy during image-guided tumor ablation
Paper 10066-2

Author(s):  William Park, Brown Univ. (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 1: Keynote Session

Here, we have demonstrated that a novel thermal accelerant (TA) can mitigate the tumor recurrence issue of the image-guided thermal ablation. TA can resonate with microwave (MW) energy, transition from a liquid (at room temperature) to a gel (36 oC), and be visible under ultrasound or CT. With these unique properties, TA can be accurately deposited using ultrasound or CT as image-guidance and stationed in the target area. Application of the MW energy extends the ablation zone to a size unattainable with antenna alone. The aspects of TA are demonstrated in various in vitro, ex vivo and porcine in vivo experiments.


Considerations for ex vivo thermal tissue modeling exemplified using the fresh porcine longissimus muscle model for endometrial ablation
Paper 10066-20

Author(s):  James E. Coad, West Virginia Univ. Health Sciences Ctr. (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 5: Energy-Based Thermal Treatment

A large number of minimally invasive medical devices are currently under development around the world. As these devices are developed, extensive research and developmental testing is preformed using both computational, artificial constructs and most importantly ex vivo and in vivo tissue testing. A number of considerations are important to ensure that the ex vivo results are optimized to emulate the devices future use in the clinical setting. These include the proper selection of animal species, tissue type, tissue viability, tissue experimental conditions, viability stain selection and interpretation. These issues will be illustrated using the fresh extirpated porcine longissimus muscle model for endometrial ablation.


A hand-held high energy delivery laser scalpel system for laser microsurgery
Paper 10066-28

Author(s):  Kaushik Subramanian, The Univ. of Texas at Austin (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 7: Energy-Based Surgical Tools

We present the development of a fully hand-held, 5 mm, piezo-actuated, ultrafast laser scalpel for microsurgery with a capability to deliver energies in excess of 5 μJ per pulse. The design incorporates kagome fiber based laser delivery, piezoelectric scanning for beam steering and a plug and play modular objective design with calcium fluoride lenses. Compared to our previous use of ZnS lenses, the new optical design and CaF2 lenses offer improved nonlinear performance, and hence allow higher peak powers to be transmitted through the system.


The influence of medium conductivity on cells exposed to nsPEF
Paper 10066-30

Author(s):  Erick K. Moen, The Univ. of Southern California (United States), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 8: Pulsed Electric Fields and Cell/Tissue Effects

A recently developed nonlinear optical technique based on Second Harmonic Generation (SHG) imaging is employed to identify the effect solution conductivity has on nsPEF-induced nanoporation. Because the method instantaneously and directly reports on membrane structure, we are able to separate electrophoretic and diffusion-related artifacts from our results. We demonstrate that cells exposed in lower conductivity solution experience increased nanoporation as compared to higher conductivity extracellular solutions. This supports the hypothesis that the membrane charges more quickly when the cytoplasm is comparatively more conductive than the extracellular solution. It also indicates that the electric field dominates conductive effects during membrane nanoporation.


Photocatalytic antibacterial effect of ZnO nanoparticles into coaxial electrospun PCL fibers to prevent infections from skin injuries
Paper 10066-7

Author(s):  Gina Prado-Prone, Univ. Nacional Autónoma de México (Mexico), et al.
Conference 10066: Energy-based Treatment of Tissue and Assessment IX
Session 2: Plasma Medicine and Reactive Species

Antibacterial studies of inorganic nps have become important due to the increased bacterial resistance against antibiotics. ZnOnps have shown antibacterial activity (AA) against several bacterial strains, this property is attributed by its ability to produce Reactive Oxygen Species (ROS) by photocatalysis. ROS can penetrate the cell membrane resulting in cell death. The application of inorganic nps in medical treatment is limited due to possible long-term side effects by nps release. To prevent this, ZnOnps were embedded into core-shell (PCL-ZnOnps/PCL) electrospun PCL fibers, increases its superficial contact area. We evaluated the AA against E. coli under UVA and sunlight pre-illumination conditions.


Dual-scanning optical coherence elastography for rapid imaging of two tissue volumes
Paper 10067-3

Author(s):  Qi Fang, Harry Perkins Institute of Medical Research (Australia), et al.
Conference 10067: Optical Elastography and Tissue Biomechanics IV
Session 1: Novel Methods and Devices

To increase image acquisition speed in applications of optical coherence elastography (OCE), we implemented a dual-scanning OCE system which scans opposite sides of a tissue and captures 3D elastograms of these regions simultaneously. This system comprises two interferometers interfaced to a common spectrometer. We performed OCT and OCE measurements on tissue-mimicking phantoms containing rigid inclusions and freshly excised samples of murine liver carcinoma. The findings indicate that our technique holds promise for in vivo and intraoperative applications.


Elastic resonator interference stress microscopy (ERISM): A new tool for the long-term measurements of cellular forces
Paper 10067-35

Author(s):  Malte C. Gather, Univ. of St. Andrews (United Kingdom), et al.
Conference 10067: Optical Elastography and Tissue Biomechanics IV
Session 10: Cellular Biomechanics and Applications: Joint Session with Conferences 10067 and 10074

We present a novel approach to measure the force exerted by live cells. The method is based on analyzing cell-induced local changes in the resonance wavelengths of an elastic optical micro-cavity. As a wide-field imaging modality, the technique measures each point of the image simultaneously and thus allows recording cell forces at high frame rates over many days. In contrast to many existing techniques, it requires no zero-force images, which eliminates the need to detach cells after force mapping and thus allows measurements of multiple cells on one substrate and further manipulation of cells, e.g. by immunostaining.


In situ dynamic mechanical analysis of heterogeneous soft tissue using a 1mm probe
Paper 10067-9

Author(s):  Steven V. Beekmans, Vrije Univ. Amsterdam (Netherlands), et al.
Conference 10067: Optical Elastography and Tissue Biomechanics IV
Session 4: Tissue Mechanical Contrast

There is a strong need for the local quantification of tissue mechanics at time scales relevant to biological processes. The available techniques for quantifying mechanical properties are either limited in spatial orientation (large tip size) or are unable to give depth resolved mechanical information (low penetration depth). Here, we present a nano-indentation device, actuated at the tip of a minimally invasive needle (diameter = 1 mm), that is engineered to quantify viscoelastic properties of soft, hydrated tissues. The potential of our device is demonstrated by a series of in situ measurements on biological tissue.


Important Dates

Author Notification
26 September 2016

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Journal of Biomedical Optics

Journal of Biomedical OpticsPublishes peer-reviewed papers that utilize modern optical technology for improved health care and biomedical research.