Deep visual nerve tracking in ultrasound images.

Ultrasound-guided regional anesthesia (UGRA) becomes a standard procedure in surgical operations and pain management, offers the advantages of nerve localization, and provides region of interest anatomical structure visualization. Nerve tracking presents a crucial step for practicing UGRA and it is useful and important to develop a tool to facilitate this step. However, nerve tracking is a very challenging task that anesthetists can encounter due to the noise, artifacts, and nerve structure variability. Deep-learning has shown outstanding performances in computer vision task including tracking. Many deep-learning trackers have been proposed, where their performance depends on the application. While no deep-learning study exists for tracking the nerves in ultrasound images, this paper explores thirteen most recent deep-learning trackers for nerve tracking and presents a comparative study for the best deep-learning trackers on different types of nerves in ultrasound images. We evaluate the performance of the trackers in terms of accuracy, consistency, time complexity, and handling different nerve situations, such as disappearance and losing shape information. Through the experimentation, certain conclusions were noted on deep learning trackers performance. Overall, deep-learning trackers provide good performance and show a comparative performance for tracking different kinds of nerves in ultrasound images.

Adaptive median binary patterns for fully automatic nerves tracking in ultrasound images.

BACKGROUND AND OBJECTIVE: In the last decade, Ultrasound-Guided Regional Anesthesia (UGRA) gained importance in surgical procedures and pain management, due to its ability to perform target delivery of local anesthetics under direct sonographic visualization. However, practicing UGRA can be challenging, since it requires high skilled and experienced operator. Among the difficult task that the operator can face, is the tracking of the nerve structure in ultrasound images. Tracking task in US images is very challenging due to the noise and other artifacts. METHODS: In this paper, we introduce a new and robust tracking technique by using Adaptive Median Binary Pattern(AMBP) as texture feature for tracking algorithms (particle filter, mean-shift and Kanade-Lucas-Tomasi(KLT)). Moreover, we propose to incorporate Kalman filter as prediction and correction steps for the tracking algorithms, in order to enhance the accuracy, computational cost and handle target disappearance. RESULTS: The proposed method have been applied on real data and evaluated in different situations. The obtained results show that tracking with AMBP features outperforms other descriptors and achieved best performance with 95% accuracy. CONCLUSIONS: This paper presents the first fully automatic nerve tracking method in Ultrasound images. AMBP features outperforms other descriptors in all situations such as noisy and filtered images.

Cardiac ultrasonography over 4G wireless networks using a tele-operated robot.

This Letter proposes an end-to-end mobile tele-echography platform using a portable robot for remote cardiac ultrasonography. Performance evaluation investigates the capacity of long-term evolution (LTE) wireless networks to facilitate responsive robot tele-manipulation and real-time ultrasound video streaming that qualifies for clinical practice. Within this context, a thorough video coding standards comparison for cardiac ultrasound applications is performed, using a data set of ten ultrasound videos. Both objective and subjective (clinical) video quality assessment demonstrate that H.264/AVC and high efficiency video coding standards can achieve diagnostically-lossless video quality at bitrates well within the LTE supported data rates. Most importantly, reduced latencies experienced throughout the live tele-echography sessions allow the medical expert to remotely operate the robot in a responsive manner, using the wirelessly communicated cardiac ultrasound video to reach a diagnosis. Based on preliminary results documented in this Letter, the proposed robotised tele-echography platform can provide for reliable, remote diagnosis, achieving comparable quality of experience levels with in-hospital ultrasound examinations.

Medical telerobotic systems: current status and future trends.

Teleoperated medical robotic systems allow procedures such as surgeries, treatments, and diagnoses to be conducted across short or long distances while utilizing wired and/or wireless communication networks. This study presents a systematic review of the relevant literature between the years 2004 and 2015, focusing on medical teleoperated robotic systems which have witnessed tremendous growth over the examined period. A thorough insight of telerobotics systems discussing design concepts, enabling technologies (namely robotic manipulation, telecommunications, and vision systems), and potential applications in clinical practice is provided, while existing limitations and future trends are also highlighted. A representative paradigm of the short-distance case is the da Vinci Surgical System which is described in order to highlight relevant issues. The long-distance telerobotics concept is exemplified through a case study on diagnostic ultrasound scanning. Moreover, the present review provides a classification into short- and long-distance telerobotic systems, depending on the distance from which they are operated. Telerobotic systems are further categorized with respect to their application field. For the reviewed systems are also examined their engineering characteristics and the employed robotics technology. The current status of the field, its significance, the potential, as well as the challenges that lie ahead are thoroughly discussed.

Phase-based probabilistic active contour for nerve detection in ultrasound images for regional anesthesia.

Ultrasound guided regional anesthesia (UGRA) is steadily growing in popularity, owing to advances in ultrasound imaging technology and the advantages that this technique presents for safety and efficiency. The aim of this work is to assist anaesthetists during the UGRA procedure by automatically detecting the nerve blocks in the ultrasound images. The main disadvantage of ultrasound images is the poor quality of the images, which are also affected by the speckle noise. Moreover, the nerve structure is not salient amid the other tissues, which makes its detection a challenging problem. In this paper we propose a new method to tackle the problem of nerve zone detection in ultrasound images. The method consists in a combination of three approaches: probabilistic, edge phase information and active contours. The gradient vector flow (GVF) is adopted as an edge-based active contour. The phase analysis of the monogenic signal is used to provide reliable edges for the GVF. Then, a learned probabilistic model reduces the false positives and increases the likelihood energy term of the target region. It yields a new external force field that attracts the active contour toward the desired region of interest. The proposed scheme has been applied to sciatic nerve regions. The qualitative and quantitative evaluations show a high accuracy and a significant improvement in performance.

Towards a new tool for the evaluation of the quality of ultrasound compressed images.

This paper presents a new tool for the evaluation of ultrasound image compression. The goal is to measure the image quality as easily as with a statistical criterion, and with the same reliability as the one provided by the medical assessment. An initial experiment is proposed to medical experts and represents our reference value for the comparison of evaluation criteria. Twenty-one statistical criteria are selected from the literature. A cumulative absolute similarity measure is defined as a distance between the criterion to evaluate and the reference value. A first fusion method based on a linear combination of criteria is proposed to improve the results obtained by each of them separately. The second proposed approach combines different statistical criteria and uses the medical assessment in a training phase with a support vector machine. Some experimental results are given and show the benefit of fusion.

Clinical trials and evaluation of a mobile, robotic tele-ultrasound system.

We have developed a robotic tele-ultrasound system (OTELO) that allows an expert to examine a distant patient by ultrasound. At the expert station, a sonographer controls a virtual probe. Movements are reproduced at the patient station, which may be several kilometres away, on a real probe held by a lightweight robot, which is positioned on the patient by a paramedic. Two medical teams tested the tele-ultrasound system at two different hospitals on a total of 52 patients. Except for some difficulties caused by particular conditions, the diagnosis obtained with the remote scanning system agreed in at least 80% of the cases with the diagnosis made by conventional scanning. The results demonstrate the feasibility and efficiency of the device.

A tele-operated mobile ultrasound scanner using a light-weight robot.

This paper presents a new tele-operated robotic chain for real-time ultrasound image acquisition and medical diagnosis. This system has been developed in the frame of the Mobile Tele-Echography Using an Ultralight Robot European Project. A light-weight six degrees-of-freedom serial robot, with a remote center of motion, has been specially designed for this application. It holds and moves a real probe on a distant patient according to the expert gesture and permits an image acquisition using a standard ultrasound device. The combination of mechanical structure choice for the robot and dedicated control law, particularly nearby the singular configuration allows a good path following and a robotized gesture accuracy. The choice of compression techniques for image transmission enables a compromise between flow and quality. These combined approaches, for robotics and image processing, enable the medical specialist to better control the remote ultrasound probe holder system and to receive stable and good quality ultrasound images to make a diagnosis via any type of communication link from terrestrial to satellite. Clinical tests have been performed since April 2003. They used both satellite or Integrated Services Digital Network lines with a theoretical bandwidth of 384 Kb/s. They showed the tele-echography system helped to identify 66% of lesions and 83% of symptomatic pathologies.

Echographic examination in isolated sites controlled from an expert center using a 2-D echograph guided by a teleoperated robotic arm.

The objective of the present project was to design and validate a method for teleoperating (from an expert site) an echographic examination in an isolated site. A dedicated robotic arm holding a real ultrasound (US) probe is remotely controlled from the expert site with a fictive probe, and reproduces on the real probe all the movements of the expert hand. The isolated places, defined as areas with reduced medical facilities, could be secondary hospitals 20 to 50 km from the university hospital, or dispensaries in Africa or Amazonia, or a moving structure like a rescue vehicle or the International Space Station (ISS). These sites are linked to the expert one by ISDN (numeric) telephone or satellite lines. At the expert center, the US medical expert moves a fictive probe, connected to a computer (no. 1) that sends the coordinate changes of this probe via an ISDN or satellite line to a second computer (no. 2), located at the isolated site, that applies them to the robotic arm holding the real echographic probe. The system was tested on 20 patients. In all cases, the expert was able to perform the main views (longitudinal, transverse) of the liver, gallbladder, kidneys, aorta, pancreas, bladder, prostate and uterus as during direct examination on the patient. The heart and spleen were not visualized in 2 and 4 of the 20 cases, respectively. The mean duration of the robotized echography (27 +/- 7 min for three to four organs) was approximately 50% longer than direct echography of the patient.

The TERESA project: from space research to ground tele-echography.

Ultrasound examinations represent one of the major diagnostic modalities of future healthcare. They are currently used to support medical space research but require a high skilled operator for both probe positioning on the patient's skin and image interpretation. TERESA is a tele-echography project that proposes a solution to bring astronauts and remotely located patients on ground quality ultrasound examinations despite the lack of a specialist at the location of the wanted medical act.