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Objective The purpose of this study was to determine the skin pressure needed to promote the macroscopic deformation of the asymptomatic patellar tendon and to verify if the pressure is associated with the individual’s characteristics. Methods A descriptive laboratory study was performed with a convenience sample of 18 young, voluntary, and asymptomatic individuals of both sexes. A progressively increasing pressure was applied on the skin over the patellar tendon, through an instrument designed to perform and control the pressure upon an ultrasound probe; data were recorded and analyzed by 2 blind investigators. All statistical analyses were conducted considering α = 0.05. Results The average pressure needed to promote a macroscopic deformation of the patellar tendon was 1.12 ± 0.37 kg/cm2. Female sex and age were inversely but not significantly associated with the pressure performed. Sports practice, weight, height, body mass index, muscle mass, and subcutaneous thickness were positively but not significantly associated with the pressure executed. Conclusion The average pressure needed to promote the macroscopic deformation of the patellar tendon was 1.12 ± 0.37 kg/cm2, which was not influenced by the characteristics of the participants.

Introduction: Nephron-sparing surgery (NSS) is of one of the most studied fields in urology due to the balancing between renal function preservation and oncological safety of the procedure. Aim of this short review is to report the state of the art of intra-operative ultrasound as an operative tool to improve localization of small renal masses partially or completely endophytic during robotassisted partial nephrectomy (RAPN). Material and methods: We performed a literature review by electronic database on Pubmed about the use of intra-operative US in RAPN to evaluate the usefulness and the feasibility of this procedure. Results: Several studies analyzed the use of different US probes during RAPN. Among them some focused on using contrastenhanced ultra sonography (CEUS) for improving the dynamic evaluation of microvascular structure allowing the reduction of ischemia time (IT). We reported that nowaday the use of intraoperative US during RAPN could be helpful to improve the preservation of renal tissue without compromising oncological safety. Moreover, during RAPN there is no need for assistant to hand the US probe increasing surgeon autonomy. Conclusions: The use of a robotic ultrasound probe during partial nephrectomy allows the surgeon to optimize tumor identification with maximal autonomy, and to benefit from the precision and articulation of the robotic instrument during this key step of the partial nephrectomy procedure. Moreover US could be useful to reduce ischemia time (IT). The advantages of nephron-sparing surgery over radical nephrectomy is well established with a pool of data providing strong evidence of oncological and survival equivalency. With the progressive growth of robot-assisted partial nephrectomy (RAPN) techniques, the use of several tools has been progressively developed to help the surgeon in the identification of masses and its vascular net. In this short review we tried to analyze the current use of intra-operative ultrasound as an operative tool to improve localization of small renal masses partially or completely endophytic during RAPN.

Intracardiac echocardiography (ICE) has become an effective alternative to trans-esophageal echocardiography (TEE) as a guidance during interventional procedures for structural heart diseases, allowing to proceed under conscious sedation. To guide percutaneous left atrial appendage (LAA) closure, the ICE probe is usually placed in the right atrium, in the pulmonary artery or in the left atrium (LA); however, the views from the right atrium or the pulmonary artery are often suboptimal, debarring a complete visualization of the LAA and the surrounding structures, whereas the LA location requires trans-septal puncture, may provoke LA wall mechanical stimulation and is often associated with unstable position of the ICE probe. In our case, after a second trans-septal puncture, the ICE probe was placed in the upper left pulmonary vein; this was safely performed and provided an optimal imaging of the LAA, comparable to that obtained by TEE, thus warranting an adequate guide during all procedural steps.

In this study, we propose a virtual learning environment for ultrasonography gestures based on an ultrasound (US) learning database. The learning database is comprised of US probe position and orie...

Background Improper infection prevention practice associated with ultrasound probe use has been linked to increased infection risk, outbreaks, and death. Although guidelines for reprocessing and use of probes exist, it is unclear how extensively these have been adopted in practice. Methods Infection preventionists from U.S. health care facilities were surveyed (N = 358). The anonymous survey had 31 multiple choice, sliding scale, and text response questions. The survey was developed and deployed and the data were stored in the REDCap system. Results A high degree of noncompliance with U.S. guidelines was identified. Surface probes used in invasive procedures were not high-level disinfected or sterilized 15% (intraoperative) to 78% (peripheral line placements) of the time. Of invasive procedures, 5%-47% did not use sterile gel (same procedures, respectively). Of the participants, 20% were aware of instances where an ultrasound probe was used but was not correctly reprocessed. Extensive breaches of infection control guidelines were reported. The rapid expansion in use of ultrasound has brought clinical benefit but may be exposing patients to preventable infection risk. Conclusions Infection preventionists are well placed to act as major drivers of change based on their expertise and experience in the management of infection risk across facilities and health systems. They, along with clinicians responsible for probe use and reprocessing, should review practices relating to ultrasound in their facilities. Where practice does not comply with guidelines, policy and training should be updated to ensure patient safety.

PurposeThe use of ultrasound imaging is not widespread in prostate cancer radiotherapy workflows, despite several advantages (eg, allowing real-time volumetric organ tracking). This can be partially attributed to the need for a trained operator during acquisition and interpretation of the images. We introduce and evaluate an algorithm that can propose a patient-specific transperineal ultrasound probe setup, based on a CT scan and anatomical structure delineations. The use of this setup during the simulation and treatment stage could improve usability of ultrasound imaging for relatively untrained operators (radiotherapists with less than 1yr experience with ultrasound).MethodsThe internal perineum boundaries of three prostate cancer patients were identified based on bone masks extracted from their CT scans. After projection of these boundaries to the skin and exclusion of specific areas, this resulted in a skin area accessible for transperineal ultrasound probe placement in clinical practice. Several possible probe setups on this area were proposed by the algorithm and the optimal setup was automatically selected. In the end, this optimal setup was evaluated based on a comparison with a corresponding transperineal ultrasound volume acquired by a radiation oncologist.ResultsThe algorithm-proposed setups allowed visualization of 100% of the clinically required anatomical structures, including the whole prostate and seminal vesicles, as well as the adjacent edges of the bladder and rectum. In addition, these setups allowed visualization of 94% of the anatomical structures, which were also visualized by the physician during the acquisition of an actual ultrasound volume.ConclusionProvided that the ultrasound probe setup proposed by the algorithm, is properly reproduced on the patient, it allows visualization of all clinically required structures for image guided radiotherapy purposes. Future work should validate these results on a patient population and optimize the workflow to enable a relatively untrained operator to perform the procedure.

Introduction: Though invasive intracranial devices are gold standard to calculate intracranial pressure (ICP); these are not without any complications. Non-invasive measurement of ICP by Ultrasonography could be a safe and portable technique.Objectives: The objective of the study was to measure and compare values of optic nerve sheath diameter of both eyes in healthy Nepalese adults.Methodology: A prospective cross-sectional study of healthy adult Nepalese volunteers was performed using a 7.5 MHz linear Ultrasound probe on the closed eyelids; optic nerve sheath diameter (ONSD) was measured 3 mm behind the globe in each eye.Results: Optic nerve sheath diameter (ONSD) of both eyes was measured in 100 healthy volunteers of age ranged from 15 to 75 years with a mean of 30.21 ± 14.05 years. There were 18 (18%) male and 82 (82%) female. ONSD for right eye ranged from 3.20 to 4.90 mm with mean of 4.10 ± 0.50 mm and left eye from 3.20 to 4.80 mm with mean of 4.22 ± 0.49 mm. P value for right and left eye ONSD (P = 0.06) and male and female (P = 0.12 and 0.85 for right and left ONSD respectively) were within normal limits. ONSD has no correlation with age (P = 0.27 and 0.27 for right and left ONSD respectively).Conclusion Mean of optic nerve sheath diameter (ONSD) is 4.10mm and 4.22 mm for right and left eye respectively. There is no statistical significant difference in mean of ONSD between right and left eye. BJHS 2018;3(1)5 : 357-360

Robotic ultrasound systems have turned into clinical use over the past few decades, increasing precision and quality of medical operations. In this paper, we propose a fully automatic scanning system for three-dimensional (3-D) ultrasound imaging. A depth camera was first used to obtain the depth data and color data of the tissue surface. Based on the depth image, the 3-D contour of the tissue was rendered and the scan path of ultrasound probe was automatically planned. Following the scan path, a 3-D translating device drove the probe to move on the tissue surface. Simultaneously, the B-scans and their positional information were recorded for subsequent volume reconstruction. In order to stop the scanning process when the pressure on the skin exceeded a preset threshold, two force sensors were attached to the front side of the probe for force measurement. In vitro and in vivo experiments were conducted for assessing the performance of the proposed system. Quantitative results show that the error of volume measurement was less than 1%, indicating that the system is capable of automatic ultrasound scanning and 3-D imaging. It is expected that the proposed system can be well used in clinical practices.

Background The aim of this retrospective analysis was to evaluate the clinical effectiveness of the supraclavicular ultrasound-guided cannulation of the brachiocephalic vein in preterm infants. Methods The ultrasound probe was placed in the supraclavicular region so as to obtain the optimum sonographic long-axis view of the brachiocephalic vein. By using a strict in-plane approach the brachiocephalic vein was cannulated by advancing a 22- or 24-gauge iv cannula from lateral to medial under the long axis of the ultrasound probe under real-time ultrasound guidance into the vein. Results One hundred and forty-two cannulations in infants weighing between 0.59 and 2.5 kg (median: 2.1; CI: 2.0 to 2.2) were included. Ultimate success rate was 94% (134 of 142). One cannulation attempt was required in 100 (70%) patients, two attempts in 21 (15%), and three attempts in 13 (9%). The smaller the weight of the infant the more attempts were needed. More attempts also were needed for the right brachiocephalic vein, which was primarily targeted in 75 (53%) neonates. One (1%) inadvertent arterial puncture was noted. Conclusions This supraclavicular, in-plane, real-time, ultrasound-guided cannulation of the brachiocephalic vein seems to be a convenient and effective method to insert central venous catheters in preterm infants.

Although open liver resection using ultrasound (US) probe compression of the hepatic vessel has been reported, laparoscopic liver resection using the same method has not yet been reported. Magnetic resonance imaging of a 55-year-old man with hepatitis B-related liver cirrhosis revealed a 2.5 cm liver mass in segment VI. He underwent laparoscopic segmentectomy. After right liver mobilization, the subglissonean pedicle of segment VI was identified and it was compressed with laparoscopic US probe with confirmation using Doppler US. The liver parenchyma was transected with a Cavitron ultrasonic surgical aspirator and advanced bipolar system along the ischemic line. The patient was discharged 9 days after surgery without complications. Laparoscopic segmentectomy using laparoscopic US probe compression has advantages including preservation of the hepatic parenchyma and prevention of injury to the adjacent Glissonean pedicle.

In high and pathologic myopia eyes, staphyloma, an outpouching of the eyewall, is associated with risks of permanent vision loss. Automated detection of staphyloma in ultrasound B-modes could assist clinicians in quickly identifying patients at risk. In this study, an algorithm to detect the presence of staphyloma and locate the staphyloma apex was developed. A 10 MHz ultrasound probe was used to acquire 127 B-modes, from 82 eyes and 52 patients. Sixty-one of the B-modes included staphyloma, as determined by an experienced ophthalmologist who also marked the staphyloma apex in each image where present. In each B-mode, the vitreoretinal boundary was automatically detected by a thresholding method. The local radius of curvature (K) was computed, and the ability of the standard deviation of K to detect staphyloma was evaluated by receiver-operating characteristic analysis. The staphyloma apex was automatically detected as the point on the vitreoretinal boundary furthest from the center of the transducer. The area under the curve using standard deviation of K for staphyloma detection was 0.927. The average error in detected staphyloma apex location was 1.34 ± 1.36 mm. These results demonstrate the potential of automated staphyloma detection and localization from ultrasound, which could assist in quick diagnosis of staphyloma.

The long-axis in-plane approach is amenable to ultrasound-guided central venous catheterization. However, the long-axis in-plane approach is considered difficult to learn because the needle should remain visible in the ultrasound beam during the procedure. We developed a novel competency-based modular system to acquire the skills for the long-axis in-plane approach. The purpose of this study is to evaluate the efficacy of this system. The study was approved by the local ethics committee. Participants performed ultrasound guided venous catheterization (pre-test), attended a 2-hour hands-on session with the teaching system and were then evaluated again (posttest). The teaching system is a simulator device consisting of an ultrasound probe, a simulated vessel, a needle, and an endoscope connected to a computer to visualize the image inside the simulated vessel. The success rate, visualization of the needle tip, and puncture accuracy were measured before and after training. The puncture accuracy was determined by evaluating the distance of the needle tip and needle shaft from the center of a simulated vessel. Primary outcomes were the success rate and the puncture accuracy. The secondary outcome was needle tip visualization. McNemar test was used to analyze success rate and needle tip visualization. Tukey test was used to analyze puncture accuracy. A P value

PURPOSE Range errors constrain treatment planning by limiting choice of ion beam angles and requiring large margins. Ionoacoustic range verification requires recovering the location of an acoustic source from low frequency signals. A priori information is applied to stably overcome resolution limits of inverse acoustic source imaging in this simulation study. In particular, the accuracy and robustness of ionoacoustic range verification for lateral and oblique delivery of high-energy protons to the prostate is examined. METHODS Dose maps were computed using GEANT4 Monte Carlo simulations via the TOPAS user interface. Thermoacoustic pulses were propagated using k-Wave software, with initial pressures corresponding to instantaneous dose deposition and piecewise constant maps of tissue properties derived from the planning CT. A database of dose maps with corresponding thermoacoustic emissions and Bragg peak locations, referred to as "control points," were precomputed. Corresponding thermoacoustic emissions were also precomputed. Pulses were recorded at four coplanar locations corresponding to the outer surface of a virtual transrectal array. To model experimental beam delivery, k-Wave results were convolved in time with a Gaussian envelope to account for noninstantaneous proton delivery by a synchrocyclotron. Thermoacoustic pulses were bandlimited below 150 kHz, and amplitudes were directly proportional to charge delivered. To test robustness of our method, white noise was added. Range was estimated in a two-step process. The first step obtained a preliminary range estimate by one-way beamforming. The second step was taken using data corresponding to the "control point" nearest to the preliminary range estimate. For each receiver, the time of flight difference, ∆t, between the measured and control thermoacoustic signals were accurately estimated by applying the Fourier shift theorem. Receiver-Bragg peak distance was then estimated by adding vs ∆t to the known distance of the control point, where vs is soundspeed. A linear system of equations based upon all receiver locations and distances was solved to recover the Bragg peak location. All simulations were performed relative to the planning CT. Because ultrasound (US) images were not available, results were overlaid onto the planning CT. RESULTS Beamformed estimates from noise-free data tracked all beam locations within 1 cm. Final estimates for oblique and lateral beams were accurate to within 1.0 and 1.6 mm respectively. Average errors of final range estimates for oblique beams from data with SNR = 0 dB were no greater than 2.0 mm. CONCLUSIONS Ionoacoustic range verification may improve current practice. Ionoacoustic range estimates can be inherently co-registered to ultrasound images of underlying anatomy. To ensure estimates are robust in clinical practice, dose maps based upon the planning CT should be overlaid onto ultrasound volumes acquired at time of treatment and acoustic simulations re-computed to provide a database of control points and corresponding thermoacoustic emissions. Computation times for beamformed estimates are already fast enough for online range verification, but are not accurate enough for a measurement aperture limited to the surface of a transrectal ultrasound probe. Accelerated acoustic simulations will be required to enable online two-stage correction, but offline calculation is already suitable for adaptive planning.

Intraoperative navigated ultrasonography has reached clinical acceptance, while published data for the accuracy of some systems are missing. We technically quantified and optimised the accuracy of the integration of an external ultrasonography system into a BrainLab navigation system. A high-end ultrasonography system (Elegra; Siemens, Erlangen, Germany) was linked to a navigation system (Vector Vision; BrainLab, Munich, Germany). In vitro accuracy and precision was calculated from differences between a real world target (high-precision crosshair phantom) and the ultrasonography image of this target in the navigation coordinate system. The influence of the intrinsic component of the calibration phantom (for ultrasonography probe registration), type of target definition (manual versus automatic) and orientation of the ultrasound probe in relation to the navigation tracking device on accuracy and precision were analysed in different settings (100 measurements for each setting) resembling clinically relevant scenarios in the neurosurgical operating theatre. Line-of-sight angles of 45°, 62° and 90° for the optical tracking of the navigated ultrasonography probe and a distance of 1.8 m revealed best accuracy and precision. Technical accuracy of the integration of ultrasonography into a standard navigation system is high [Euclidean error: median, 0.79 mm; mean, 0.89 ± 0.42 mm for 62° angle; median range: 1.16–1.46 mm; mean range (±SD): 1.22 ± 0.32 mm to 1.46 ± 0.55 mm for grouped analysis of all angles tested]. Software-based automatic target definition improved precision significantly (p

The aim of this study was to perform a blinded trial, comparing the results of a visual inspection of the in-air reverberation pattern with the results of an electronic probe tester in detecting ultrasound probe faults. Sixty-two probes were tested. A total of 28 faults were found, 3 only by in-air reverberation assessment and 2 only by the electronic probe tester. The electronic probe tester provided additional information regarding the location of the fault in 74% of the cases in which both methods detected a fault. It is possible to detect the majority of probe faults by visual inspection and in-air reverberation assessment. The latter provides an excellent first-line test, easily performed on a daily basis by equipment users. An electronic probe tester is required if detailed evaluation of faults is necessary.

Objectives The aim of the present study was to assess the educational plan of first-year students of medicine by analyzing their scores in ultrasound body scanning. Methods Since 2009, the San Paolo Medical School (Milan, Italy) has vertically integrated the study of anatomy with ultrasound-assisted virtual body dissection. Three modules were supplied: musculoskeletal system, heart and abdomen pelvis. 653 first-year students were trained. The students alternated as mutual model and operator. A skillfulness score was assigned to each student. The scores were consequently listed. Nonparametric exact multiple contrast tests were employed to determine relative group effects. Results Statistical analysis showed that: no gender-related differences were found (0:49; p=0.769); peer learners performed less well than peer tutors (0.677; p=0); between modules, scores in the musculoskeletal system (pMS=0.726) tend to be higher (p Conclusion The students considered this didactic course an engaging and exciting approach. Acceptance of peer teaching was extraordinarily high. Autonomous exercitation allowed the students to improve self-criticism and enhance their own skills. The level of expertise obtained by peer tutors and by peer learners can be considered satisfactory. The main objective of training future physicians on personal stethoechoscope with the necessary competence seems to have been successfully started.

Prostate cancer is the second deadliest form of cancer, even though it is less invasive and easily curable in early stages, due to the lack of an efficient and accurate diagnosis strategy. To date, the standard diagnosis procedure involves a blind biopsy with a high rate of false negative results. In order to overcome these limitations, the paper proposes the development of a novel parallel robotic structure for transperineal prostate biopsy that enables an accurate diagnosis through ultrasound-guided targeted tissue sampling. The robotic system consists of two parallel modules, each with 5 degrees of freedom (DOFs): one module guiding the transrectal ultrasound probe (TRUS) and the other guiding the biopsy gun. The two modules are designed to work together in order to help the physician with the tissue sampling of the prostate. The singular configurations of both robotic modules are analyzed and solutions for avoiding them are provided. The experimental model of the robotic structure is described along with the initial test results, which evaluate the robot accuracy for several medically relevant sets of coordinates.

This article proposes a framework to design and implement e- Health interventions in a comprehensive manner. We draw on complexity science to study the interplay of the ecosystem, the behavior and interactions among its agents. We provide a platform to estimate the Quality of Experience (QoE) to assess the relationship between technology and human factors involved in e-Health projects. Our aim is to estimate QoE in e-Health ecosystems from the perspective of complexity by adopting a methodology that uses fuzzy logic to study the behavior of the ecosystem’s agents. We apply the proposed framework to a remote diagnosis case by means of an ultrasound probe through a satellite link. Despite the ambiguities for determining QoE, the experiment demonstrates the applicability of the framework and allows to stressing the importance of human factors in the implementation of e-Health projects. En este artículo se propone un marco de referencia para diseñar e implementar intervenciones de e-Salud de una manera integral. Recurrimos a la ciencia de la complejidad para estudiar la interacción de los agentes del ecosistema. Para ello, proporcionamos una plataforma para estimar la Calidad de Experiencia (o QoE, por sus siglas en inglés) para evaluar la relación entre la tecnología y los factores humanos que intervienen en los proyectos de e-Salud. Nuestro objetivo es estimar la QoE en los ecosistemas de e-Salud desde la perspectiva de la complejidad mediante la adopción de una metodología que utiliza la lógica difusa para estudiar el comportamiento de los agentes del ecosistema. Aplicamos el marco propuesto a un caso de diagnóstico remoto por medio de una sonda de ultrasonido a través de un enlace por satélite. A pesar de las ambigüedades involucradas en la determinación de calidad de la experiencia, el experimento demuestra la aplicabilidad del marco de referencia propuesto y permite subrayar la importancia de los factores humanos en la implementación de proyectos de e-Salud.

Needle guides may allow the practitioner to align the needle with the probe when ultrasound-guided nerve block is performed. The author's goal was to design and fabricate an inexpensive ($1.90), disposable, needle guide that could articulate over a range from 85 degrees to 0 degrees with a three-dimension printer. Three-dimensional representations of an L50, L25, and C 60 ultrasound probe (Sono Site, Bothell, WA) were created using a laser scanner. Computer-aided design software (Solid Works, Waltham, MA) was used to design a needle bracket and needle guide to attach to these probes. A three-dimensional printer was used to fabricate the needle bracket and guide with acrylonitrile polybutadiene polystyrene. An echogenic needle was held in plane with the needle guide. The author performed a supraclavicular block in a morbidly obese patient. The needle was easily visualized. Similar guides that are commercially available cost as much as $400. A knowledge of computer-aided design is necessary for this work.

The effects of ultrasound pretreatments on mass transfer kinetics, microstructure, carotenoid and vitamin C contents of sweet potato were investigated. Sweet potato samples were treated in distilled water with ultrasound (DWU), osmotic dehydration without ultrasound (OD) and ultrasound-assisted osmotic dehydration (UOD). Samples were subjected to ultrasound probe of 2 cm diameter, frequency of 28 kHz at 300 W maximum power at different pretreatment times of 20, 30, 45 and 60 min. The Azuara model used in this study fitted the experimental data well with high coefficient of correlation ranging from 0.92 to 0.98, low values of chi-square ( 70%) in sweet potato samples treated in DWU and UOD.

To the Editor We thank Drs Qin and Xie for their interest in our paper, and we agree with their comments that the maxillary artery is an important landmark when performing the ultrasound-guided maxillary nerve block.[1–3][1] However, a high-frequency, small fingerprint ultrasound probe offers

The medical context of this thesis is transoral robotic surgery for base of tongue cancer and robot-assisted laparoscopic surgery for low-rectal cancer. One of the main challenges for surgeons to perform these two surgical procedures is to identify the tumor resection margins accurately, because tumors are often concealed in base of tongues or rectal walls and there is lack of efficient intraoperative guidance systems. However, ultrasonography is widely used to image soft-tissue tumors, which motivates our proposition of an augmented reality framework based on intraoperative ultrasonography images for tumor resection guidance. The framework, proposed, with clinical partners, consists to adapt to the surgical workflow of robot-assisted surgery for treating base of tongue cancer and low-rectal cancer. For this purpose, we developed a fast and accurate 3D ultrasound probe calibration method to track the probe and facilitate its intraoperative use. Moreover, we evaluated the performance of the proposed framework augmenting an intraoperative endoscopic camera with ultrasound information, which shows less than 1mm error. Furthermore, we designed experimental protocols using a silicone rectum phantom and an ex-vivo lamb tongue, that simulate the integration of the implemented framework into the current surgical workflow. The experimental results show that, according to the augmented endoscopic views provided by the proposed framework, a surgeon is able to accurately identify the resection margins of the simulated tumors in these phantoms., Cette thèse porte sur le développement d’une solution de réalité augmentée dans le cadre de la chirurgie robotisée et plus particulièrement pour la chirurgie transorale des tumeurs de la base de langue et la chirurgie laparoscopique des cancers du bas-rectum. Une des problématiques pour les chirurgiens est de repérer sur la vue endoscopique les limites de la tumeur et les marges de résections. Celles-ci sont en effet non visibles directement. L’échographie peropératoire est largement utilisée pour repérer les tumeurs lors des interventions. Nous proposons donc une solution de réalité augmentée dans laquelle l’information extraite de l’échographie est reprojetée sur la vision binoculaire de la station de chirurgie robotisée afin de guider le chirurgien dans la résection de la tumeur. Plusieurs verrous de cette chaîne de traitement ont été repérés et étudiés. Nous avons ainsi proposé une nouvelle méthode pour la calibration de sondes d’échographie. Nous avons démontré que cette méthode était plus facile à mettre en œuvre, plus rapide et plus précise que les méthodes proposées dans la littérature. Cette sonde calibrée, associée à des outils de localisation et de calibration de la sonde endoscopique nous a permis de proposer une solution de réalité augmentée qui permettait de reprojeter l’information acquise sur l’image sur la vue endoscopique avec des erreurs inférieures à 1 mm. Nous avons alors établi la preuve de concept de l’application de cette chaîne de réalité augmentée dans deux expérimentations, l’une sur un fantôme physique en silicone du rectum et l’autre sur une langue de mouton en ex-vivo. Les résultats expérimentaux ont montré que l’information augmentée avait permis au chirurgien de percevoir avec précision les marges de résections des tumeurs simulées et d’accomplir le geste opératoire à l’aide de cette perception.

The medical context of this thesis is transoral robotic surgery for base of tongue cancer and robot-assisted laparoscopic surgery for low-rectal cancer. One of the main challenges for surgeons to perform these two surgical procedures is to identify the tumor resection margins accurately, because tumors are often concealed in base of tongues or rectal walls and there is lack of efficient intraoperative guidance systems. However, ultrasonography is widely used to image soft-tissue tumors, which motivates our proposition of an augmented reality framework based on intraoperative ultrasonography images for tumor resection guidance. The framework, proposed, with clinical partners, consists to adapt to the surgical workflow of robot-assisted surgery for treating base of tongue cancer and low-rectal cancer. For this purpose, we developed a fast and accurate 3D ultrasound probe calibration method to track the probe and facilitate its intraoperative use. Moreover, we evaluated the performance of the proposed framework augmenting an intraoperative endoscopic camera with ultrasound information, which shows less than 1mm error. Furthermore, we designed experimental protocols using a silicone rectum phantom and an ex-vivo lamb tongue, that simulate the integration of the implemented framework into the current surgical workflow. The experimental results show that, according to the augmented endoscopic views provided by the proposed framework, a surgeon is able to accurately identify the resection margins of the simulated tumors in these phantoms.; Cette thèse porte sur le développement d’une solution de réalité augmentée dans le cadre de la chirurgie robotisée et plus particulièrement pour la chirurgie transorale des tumeurs de la base de langue et la chirurgie laparoscopique des cancers du bas-rectum. Une des problématiques pour les chirurgiens est de repérer sur la vue endoscopique les limites de la tumeur et les marges de résections. Celles-ci sont en effet non visibles directement. L’échographie peropératoire est largement utilisée pour repérer les tumeurs lors des interventions. Nous proposons donc une solution de réalité augmentée dans laquelle l’information extraite de l’échographie est reprojetée sur la vision binoculaire de la station de chirurgie robotisée afin de guider le chirurgien dans la résection de la tumeur. Plusieurs verrous de cette chaîne de traitement ont été repérés et étudiés. Nous avons ainsi proposé une nouvelle méthode pour la calibration de sondes d’échographie. Nous avons démontré que cette méthode était plus facile à mettre en œuvre, plus rapide et plus précise que les méthodes proposées dans la littérature. Cette sonde calibrée, associée à des outils de localisation et de calibration de la sonde endoscopique nous a permis de proposer une solution de réalité augmentée qui permettait de reprojeter l’information acquise sur l’image sur la vue endoscopique avec des erreurs inférieures à 1 mm. Nous avons alors établi la preuve de concept de l’application de cette chaîne de réalité augmentée dans deux expérimentations, l’une sur un fantôme physique en silicone du rectum et l’autre sur une langue de mouton en ex-vivo. Les résultats expérimentaux ont montré que l’information augmentée avait permis au chirurgien de percevoir avec précision les marges de résections des tumeurs simulées et d’accomplir le geste opératoire à l’aide de cette perception.

Point-of-care ultrasound (POCUS) is expanding with an increasing role in clinical decision-making and as an adjunct for clinical procedures. As transducers come into contact with more patients, sonologists must keep in mind the potential for a transducer to transmit pathogens between patients. Cleaning and disinfection of medical equipment is a necessary step to prevent the spread of infectious disease. Infections and deaths related to healthcare-associated infections burden the US healthcare system by $28 to $33 billion annually. In spite of this, there are no universally adhered-to guidelines for the disinfection of ultrasound probes. Across institutions, transducer decontamination practices vary widely. A recent trend has shown increasing stringency by hospitals and medical centers in enforcing strict decontamination practices, sometimes more than recommended. In this chapter, we will discuss probe contamination risks, disinfection recommendations, and several options for covering the ultrasound probe.

Ultrasound has been trialed in biometric recognition systems for many years, and at present different types of ultrasound fingerprint readers are being produced and integrated in portable devices. An important merit of the ultrasound is its ability to image the internal structure of the hand, which can guarantee improved recognition rates and resistance to spoofing attacks. In addition, ambient noise like changes of illumination, humidity, or temperature, as well as oil or ink stains on the skin do not affect the ultrasound image. In this work, a palmprint recognition system based on ultrasound images is proposed and experimentally validated. The system uses a gel pad to obtain acoustic coupling between the ultrasound probe and the user&rsquo, s hand. The collected volumetric image is processed to extract 2D palmprints at various under-skin depths. Features are extracted from one of these 2D palmprints using a line-based procedure. Recognition performances of the proposed system were evaluated by performing both verification and identification experiments on a home-made database containing 281 samples collected from 32 different volunteers. An equal error rate of 0.38% and an identification rate of 100% were achieved. These results are very satisfactory, even if obtained with a relatively small database. A discussion on the causes of bad acquisitions is also presented, and a possible solution to further optimize the acquisition system is suggested.

This paper presents the integration steps towards a prototype forward-looking intra-vascular ultrasound probe. An ASIC (Application Specific Integrated Circuit) is laser cut to create a 1.6mm circular shaped die that can be integrated at the tip of a small catheter. The ASIC is designed such that it can be used to transmit and receive on 64 piezo-electric transducers while using a single cable for the supply, communication, transmit signals and amplified receive signals. Piezo elements are directly integrated on top of the ASIC to create a miniature probe.Electrical tests show that the circuitry still operates correctly after laser cutting. The functionality of a prototype has been successfully demonstrated in a 3D imaging experiment.

Real-time probe motion information may enhance the information gathered by ultrasound probes and permit the use of artificial intelligence or computer vision to reduce dependence upon a sonographers’ knowledge and skill in the performance of ultrasound studies. Multiple types of tracking sensors and their combinations are integrated with ultrasound machines to provide real-time six degree of freedom (6-DOF) probe motion information. The accuracy and the precision of the tracking data are significant to the quality of obtained frames for all image dimensions. In this study, we proposed a system that integrates the camera-based tracking with an ultrasound device for obstetric ultrasound imaging. The tracking resolutions for position and orientation were evaluated to be less than 1 mm and 1°, respectively. Imaging tests with a fetus phantom was further conducted to verify the feasibility of camera-based probe tracking in obstetric ultrasound. The scanning frames were found to be repeatable with the aid of real-time probe motion.

Unmanned Aerial Vehicles (UAVs) are receiving increasing attention for use in Non-Destructive Testing due to their ability to access areas where manual inspection is not practical. Contact-based UAV ultrasonic inspections grant the opportunity to remotely monitor the structural health of an industrial asset with enhanced internal integrity information. Ultrasonic inspection is a Non-Destructive Testing (NDT) method conventionally used in corrosion mapping. Surface contacting ultrasonic transducers provide enhanced structural integrity information. However, due to near-surface aerodynamic effects, angular sensitivity of the ultrasound probe and alignment error during autonomous inspections, ultrasonic thickness measurements with low Signal-to-Noise Ratio (SNR) are common. Coded excitation consists of a series of binary bits, whereby the polarity of the voltage is varied following a set excitation sequence to produce desirable signal properties. Here, coded excitation is utilised to increase SNR and thereby reduce measurement uncertainty originating from non-ideal transducer alignment with asset surfaces during inspections. This paper evaluates the performance of two binary code sequences (8-bit Golay, 13-bit Barker) for use in autonomous airborne inspections.

Magnetomotive ultrasound (MMUS) is an emerging technique to image in vivo magnetic nanoparticle (MNP) distribution, which is challenging to conventional B-mode ultrasound, and has shown its potential in extravascular ultrasound molecular imaging, monitoring of magnetic nano-drug delivery, and sentinel lymph node identification. To date, MMUS is mainly implemented in forward mode where the imaging object must lie in between an ultrasound probe and an electromagnet, and the imaging frame rate is low, both of which hinder its clinical translation. To facilitate clinical translation of MMUS, here we move toward the development of a real time backward-mode pulsed magnetomotive ultrasound system based on an ultrasound research engine, Prodigy (S-Sharp Corp., Taiwan), featuring an MMUS probe integrating a linear array and an electromagnet. The MMUS probe facilitates the backward-mode MMUS, improving the portability of MMUS. All the processing exploits the fast Prodigy-to-MATLAB interface, PSRT, automatically streaming beamformed ultrafast baseband data to MATLAB for post-processing and image display. Overall, we demonstrate that the imaging frame rate of our MMUS system can achieve 3.4 Hz with free hand scanning, which is about nine time faster than those of the previously reported systems. We believe that such handheld and toward real-time capability would push MMUS toward clinical usage.

Some newborn babies require particular cares and are therefore placed in neonatal incubators. Intracranial ultrasound examinations are regularly performed in order to monitor the development of their brain. Due to the repetitivity and uncomfortability associated with this clinical task, the design of a robotic system capable of performing this task is proposed. The manipulation of an ultrasound probe inside a neonatal incubator is studied using a motion capture system. The kinematic specifications associated with this clinical task are established. A mechanical architecture based on two combined pantographic linkages is proposed. One pantographic mechanism performs the linear positioning of the end effector around a center of rotation. The orientation of the ultrasound probe around another center of rotation is mainly provided by a second pantographic linkage. The forward and inverse kinematic models are calculated to study the linear and angular positioning of the mechanism. The trajectories measured during the motion capture experiments are then tested on the mechanism to validate its suitability with the intracranial echography on newborns inside incubators.

The ilioinguinal and iliohypogastric nerves are branches of the lumbar plexus and are consistently located between the transversus abdominis and internal oblique muscle when the ultrasound probe is placed lateral to the anterior superior iliac spine. This chapter discusses the anatomy, sonoanatomy, patient selection, and injection technique of ultrasound-guided injection.

Background and aims Ultrasound-guided peripheral nerve block (USGPNB) is a safe and reliable procedure. However, it is not easy for the novice to perform an appropriate procedure from the start. The aim of this study was to evaluate whether laser-guided ultrasound probe facilitated the performance of USGPNB for the novice practitioners compared with standard ultrasound probe. Methods 32 medical students and residents who have never performed USGPNB were enrolled in this study. The participants were randomly allocated into two groups: GroupL using laser-guided probe and GroupS using standard probe. Each participant performed USGPNB with each probe of the group on porcine phantom a total of six times, three times with linear probe for the simulated nerve embedded in the shallow layer and three times with convex probe for the nerve in the deep layer. A blinded researcher measured the time required for each procedure. Finally, the participants answered a 5-point impression scale of the difficulty for USGPNB. We evaluated the differences in the time required for the procedure and in the impression scale of the difficulty. The date was statistically analyzed with Mann-Whitney U test. Results The time required for the procedure (min, median[IQR]) was significantly shorter in GroupL than GroupS in using linear probe (GroupL: 65[37.5–96.5], GroupS: 92.5[55.5–162.25], P=0.013) and convex probe (GroupL: 54.5[34.5–88.5], GroupS: 93.5[61.25–143], P=0.003). There was no difference between two groups about the impression scale of the difficulty for USGPNB. Conclusions Our study demonstrated that laser-guided ultrasound probe might facilitate the performance of USGPNB from the start of their training for the novice.

This study presents a design process for the ergonomic design of a hockey stick ultrasound probe, based on clinical applications needs, competitors benchmarking and analysis of feedback about a commercially available probe. The design is performed in two phases: (1) design of the product and initial evaluation of subjective satisfaction of expert users; (2) the subsequent review of the project and the selection of the preferred probe grip design. This approach involves several successive stages allowing for progressively better results in terms of acceptability and comfort of the new product.

Because of the limitation of visual field and lack of tactile sense in traditional laparoscopic surgery, this study designs and implements an ultrasound image fusion technology with depth information of ultrasound images, which fuses ultrasound images in stereoscopic laparoscopic video. Firstly, the position of the ultrasound probe in stereoscopic video is determined by image features such as morphological information and image contour information. Then, the scanning plane of the ultrasound probe is solved according to the coordinate information representing the position of the ultrasound probe. Finally, the ultrasound image scanned by the probe is superimposed on the plane to achieve the effect of augmented reality. The accuracy of the proposed algorithm in ultrasound image fusion is verified by the experiment without probe. In addition, to further verify the effectiveness of the ultrasound image fusion technology in this paper, the experiment of ultrasound image fusion is designed when the ultrasound probe is horizontal and inclined. The experimental results show that the proposed algorithm can automatically identify the position of the probe and accurately fuse the ultrasound image into stereoscopic video.

A device and technique to acquire and construct 3D ultrasound volumes of the skin of the hand and arm were developed. The Repeated Skin Thickness Measurement (RSTM) Device moves a high frequency ultrasound probe linearly in 3 axes in a water tank and images a submerged arm. These images are combined into an ultrasound volume, the skin layer segmented, and the thickness extracted. One particular application is measuring progression of scleroderma, a skin thickening disease. The current ultrasound-based scleroderma diagnostic processes assess skin thickness based on a single ultrasound image taken by a clinician holding the ultrasound probe, resulting in low measurement repeatability. The imagery that results from the instrumentation and analysis presented here can be used to create quantitative maps of skin thickness, to monitor the progression of skin-thickening diseases, and to observe the structures of tendons, ligaments, and the other soft tissue of the hand.

An instrumented ultrasound probe system is designed to estimate the distribution of pressure applied across the probe face during image acquisition. The pressure distribution is used to investigate the effects of varying, and non-uniform, pressure distributions on shear wave elastography measurements in phantoms and ex vivo samples. Pressure distribution has a notable effect on shear wave elastography of ex vivo samples. The gradient in applied pressure across the probe face is mirrored in the gradient of elasticity measurements across the ultrasound elastogram image.

IntroductionThere is a need for a military tourniquet to control catastrophic haemorrhage in a chemical, biological, radiological or nuclear (CBRN) threat environment. No published data exist as to the efficacy of tourniquets while wearing British military CBRN individual protective equipment (IPE).Methods12 volunteers from the counter CBRN instructors’ course allowed testing on 24 legs. A Combat Application Tourniquet (C-A-T) was applied to all volunteers at the level of the midthigh. 12 legs were tested while wearing CBRN IPE (both operator and simulated casualty), and the control group of 12 legs was tested while wearing conventional combat dress state (both operator and simulated casualty). The order of leg laterality and dress state were sequenced according to a prerandomised system. Efficacy was measured via use of an ultrasound probe at the popliteal artery. Tourniquets were considered effective if arterial flow was completely occluded on ultrasound imaging. Data were collected on time to successful application, failure of tourniquets and pain scores as rated by the visual analogue scale (1–10).ResultsThere were no failures of tourniquet application in the CBRN group, and two failures (17%) in the control group. Failures were pain threshold exceeded (n=1) and tourniquet internal strap failure (n=1). The mean application time for the CBRN group was 28.5 s (SD 11.7) and 23.7 s (SD 9.8) for the conventional combat group. There was no statistically significant difference (p=0.27). The median CBRN pain score was 2.0 (IQR 2.0–3.5). The median control pain score was 4.0 (IQR 3–6). This was a statistically significant difference (p=0.002).ConclusionC-A-Ts applied to simulated casualties in CBRN IPE at the midthigh are at least as efficacious as those applied to the midthigh in a conventional combat dress state. The pain experienced was less in CBRN IPE than when in a conventional combat dress state.