Noune Sarvazyan

Prostate mechanical imaging: a new method for prostate assessment.

OBJECTIVES To evaluate the ability of prostate mechanical imaging (PMI) technology to provide an objective and reproducible image and to assess the prostate nodularity. METHODS We evaluated the PMI device developed by Artann Laboratories in a pilot clinical study. For the 168 patients (ages 44 to 94) who presented to an urologist for prostate evaluation, PMI-produced images and assessment of prostate size, shape, consistency/hardness, mobility, and nodularity were compared with digital rectal examination (DRE) findings. The PMI and DRE results were further tested for correlation against a transrectal ultrasound of the prostate (TRUS) guided biopsy for a subgroup of 21 patients with an elevated prostate-specific antigen level. RESULTS In 84% of the cases, the PMI device was able to reconstruct three-dimensional (3D) and 2D cross-sectional images of the prostate. The PMI System and DRE pretests were able to determine malignant nodules in 10 and 6 patients, respectively, of the 13 patients with biopsy-confirmed malignant inclusions. The PMI System findings were consistent with all 8 biopsy negative cases, whereas the DRE had 1 abnormal reading for this group. The correlation between PMI and DRE detection of palpable nodularity was 81%, as indicated by the area under the receiver operating characteristic curve. Estimates of the prostate size provided by PMI and DRE were statistically significantly correlated. CONCLUSIONS The PMI has the potential to enable a physician to obtain, examine, and store a 3D image of the prostate based on mechanical and geometrical characteristics of the gland and its internal structures.

Characterization of forces applied by endoscopists during colonoscopy by using a wireless colonoscopy force monitor

BACKGROUND To perform a colonoscopy, the endoscopist maneuvers the colonoscope through a series of loops by applying force to the insertion tube. Colonoscopy insertion techniques are operator dependent but have never been comprehensively quantified. OBJECTIVE To determine whether the Colonoscopy Force Monitor (CFM), a device that continually measures force applied to the insertion tube, can identify different force application patterns among experienced endoscopists. DESIGN Observational study of 6 experienced endoscopists performing routine diagnostic and therapeutic colonoscopy in 30 patients. SETTING Outpatient ambulatory endoscopy center. PATIENTS Adult male and female patients between 30 and 75 years of age undergoing routine colonoscopy. INTERVENTIONS CFM monitoring of force applied to the colonoscope insertion tube during colonoscopy. MAIN OUTCOME MEASUREMENTS Maximum and mean linear and torque force, time derivative of force, combined linear and torque vector force, and total manipulation time. RESULTS The CFM demonstrates differences among endoscopists for maximum and average push/pull and mean torque forces, time derivatives of force, combined push/torque force vector, and total manipulation time. Endoscopists could be grouped by force application patterns. LIMITATIONS Only experienced endoscopists using conscious sedation in the patients were studied. Sample size was 30 patients. CONCLUSIONS This study demonstrates that CFM allows continuous force monitoring, characterization, and display of similarities and differences in endoscopic technique. CFM has the potential to facilitate training by enabling trainees to assess, compare, and quantify their techniques and progress.

Multi-frequency axial transmission bone ultrasonometer.

The last decade has seen a surge in the development of axial transmission QUS (Quantitative UltraSound) technologies for the assessment of long bones using various modes of acoustic waves. The condition of cortical bones and the development of osteoporosis are determined by numerous mechanical, micro-structural, and geometrical or macro-structural bone properties like hardness, porosity and cortical thickness. Such complex manifestations of osteoporosis require the evaluation of multiple parameters with different sensitivities to the various properties of bone that are affected by the disease. This objective may be achieved by using a multi-frequency ultrasonic examination The ratio of the acoustic wavelength to the cortical thickness can be changed by varying the frequency of the ultrasonic pulse propagating through the long bone that results in the change in composition of the induced wave comprised of a set of numerous modes of guided, longitudinal, and surface acoustic waves. The multi-frequency axial transmission QUS method developed at Artann Laboratories (Trenton, NJ) is implemented in the Bone Ultrasonic Scanner (BUSS). In the current version of the BUSS, a train of ultrasonic pulses with 60, 100, 400, 800, and 1200 kHz frequencies is used. The developed technology was tested on a variety of bone phantoms simulating normal, osteopenic, and osteoporotic bones. The results of this study confirm the feasibility of the multi-frequency approach for the assessment of the processes leading to osteoporosis.

Modeling and In Vitro Experimental Validation for Kinetics of the Colonoscope in Colonoscopy

Colonoscopy is the most sensitive and specific means for detection of colon cancers and polyps. To make colonoscopy more effective several problems must be overcome including: pain associated with the procedure, the risk of perforation, and incomplete intubation colonoscopy. Technically, these problems are the result of loop formation during colonoscopy. Although, several solutions such as modifying the stiffness of the colonoscope, using an overtube and developing image-guided instruments have been introduced to resolve the looping problem, the results of these systems are not completely satisfactory. A new paradigm to overcome loop formation is proposed that is doctor-assistive colonoscopy. In this approach, the endoscopists performance is enhanced by providing using a kinetic model that provides information such as the shape of the scope, direction of the colon and forces exerted within certain sections. It is expected that with the help of this model, the endoscopist would be able to adjust the manipulation to avoid loop formation. In the present studies, the kinetic model is developed and validated using an ex vivo colonoscopy test-bed with a comprehensive kinematic and kinetic data collection. The model utilizes an established colon model based on animal tissue with position tracking sensors, contact force sensors for the intraluminal portion of the scope and a Colonoscopy Force Monitor for the external insertion tube.

Objective Differences in Colonoscopy Technique Between Trainee and Expert Endoscopists Using the Colonoscopy Force Monitor

BackgroundLearning to perform colonoscopy safely and effectively is central to gastroenterology fellowship programs. The application of force to the colonoscope is an important part of colonoscopy technique.AimsWe compared force application during colonoscopy between novice and expert endoscopists using a novel device to determine differences in colonoscopy technique.MethodsThis is an observational cohort study designed to compare force application during colonoscopy between novice and experienced trainees, made up of gastroenterology fellows from two training programs, and expert endoscopists from both academic and private practice settings.ResultsForce recordings were obtained for 257 colonoscopies by 37 endoscopists, 21 of whom were trainees. Experts used higher average forward forces during insertion compared to all trainees and significantly less clockwise torque compared to novice trainees.ConclusionsWe present significant, objective differences in colonoscopy technique between novice trainees, experienced trainees, and expert endoscopists. These findings suggest that the colonoscopy force monitor is an objective tool for measuring proficiency in colonoscopy. Furthermore, the device may be used as a teaching tool in training and continued medical education programs.

Quantitative Assessment and Interpretation of Vaginal Conditions

Introduction Few means exist to provide quantitative and reproducible assessment of vaginal conditions from biomechanical and functional standpoints. Aim To develop a new approach for quantitative biomechanical characterization of the vagina. Methods Vaginal tactile imaging (VTI) allows biomechanical assessment of soft tissue and function along the entire length of the anterior, posterior, and lateral vaginal walls. This can be done at rest, with applied vaginal deformation, and with pelvic muscle contraction. Results Data were analyzed for 42 subjects with normal pelvic floor support from an observational case-controlled clinical study. The average age was 52 years (range = 26–90 years). We introduced 8 VTI parameters to characterize vaginal conditions: (i) maximum resistance force to insertion (newtons), (ii) insertion work (millijoules), (iii) maximum stress-to-strain ratio (elasticity; kilopascals per millimeter), (iv) maximum pressure at rest (kilopascals), (v) anterior-posterior force at rest (newtons), (vi) left-right force at rest (newtons), (vii) maximum pressure at muscle contraction (kilopascals), and (viii) muscle contraction force (newtons). We observed low to moderate correlation of these parameters with subject age and no correlation with subject weight. 6 of 8 parameters demonstrated a P value less than .05 for 2 subject subsamples divided by age (≤52 vs >52 years), which means 6 VTI parameters change with age. Conclusions VTI allows biomechanical and functional characterization of the vaginal conditions that can be used for (i) understanding “normal” vaginal conditions, (ii) quantification of the deviation from normality, (iii) personalized treatment (radiofrequency, laser, or plastic surgery), and (iv) assessment of the applied treatment outcome. Egorov V, Murphy M, Lucente V, et al. Quantitative Assessment and Interpretation of Vaginal Conditions. Sex Med 2018;6:39–48.