Ryu Nakadate

Out-of-plane visual servoing method for tracking the carotid artery with a robot-assisted ultrasound diagnostic system

Up to now, there are different kinds of robot-assisted ultrasound diagnostic systems proposed in the last decade. However, the compensation of the ultrasound probe position according to the patient movement is still one of the most important and useful functions required for those systems. For this purpose, in this research, we aim at developing an automated diagnostic system for the measurement of the wave intensity which is usually measured at the common carotid artery. In particular, in this paper, we focus on proposing a robust visual servoing method for tracking out-of-plane motion for a robot-assisted medical ultrasound diagnostic system by using a conventional 2D probe. A robotic device which manipulates the ultrasound probe firstly scans a small area around the target position and records several B-mode images at a regular interval. In order to track the out-of-plane motion, an inter-frame block matching method has been proposed and implemented on the Waseda-Tokyo Womens Medical-Aloka Blood Flow Measurement System No. 2 Refined (WTA-2R). A set of experiments was proposed to verify the effectiveness of the proposed method. From the experimental results, we could confirm its robustness while doing the task with real human tissues.

Development of the two-wheeled inverted pendulum type mobile robot WV-2R for educational purposes

The rapidly increase of personal robotic platforms and their applications in Japan represents a great challenge for universities to introduce undergraduate students the basic knowledge required to develop intelligent automated mechanisms. For this purpose; in this paper, we are presenting our approach to introduce first year undergraduate students of the Department of Modern Mechanical Engineering the basics of robotics systems. In order to foster the creativity of undergraduate students of engineering fields, we focused in developing an education tool designed to introduce at different educational levels the principle of developing mechatronic systems. In particular, the development of an inverted pendulum mobile robot Waseda Wheeled Vehicle No. 2 (WV-2R) has been proposed. Different kinds of experiments were proposed to confirm the possibility of implementing controllers as well as changing physical properties of the system to observe differences on the response of the system. From the experimental results, we could confirm the effectiveness of the proposed systems to control the angle of pendulum respect to the body base as well as by changing the radius of the wheel.

Development of robot assisted measurement system for abdominal ultrasound diagnosis

In the medical literature, the ultrasound diagnosis is a quite well user-friendly method due to its non-invasiveness, portability and real-time imaging capabilities. Recently, some fatigue issues (including musculoskeletal injuries) with sonographers have been reported. Most of those issues are mainly due to the physical stress on the sonographers during their considerably long time task. During the diagnosis, the sonographers usually hold their wrist without touching the patients. Moreover, they are sometimes required to apply a force for the probe to push abdomen of the patients in order to obtain clearer ultrasound image. Therefore, our research aims in developing a probe supporting robot to reduce the fatigue of sonographers during the abdominal diagnosis. In this paper, we describe the design of the Waseda-Tokyo Womens Medical-Aloka System No. 2 (WTA-2) which is composed of an ultrasound diagnosis system, an actuated 3-DOFs robot arm with two different interchangeable end-effectors. One is for power assist of applied force, and the other is for supporting sonographers wrist. The design of the robot, a force sensing method using photo sensors and the control of the robot are detailed. A set of experiments were carried out in order to verify the effectiveness of the proposed system to support sonographers while performing the diagnosis.

Introduction of mechatronics to undergraduate students based on robotic platforms for education purposes

The rapidly increase of personal robotic platforms and their applications in Japan represents a great challenge for universities to introduce undergraduate students the basic knowledge required to develop intelligent automated mechanisms. For this purpose; in this paper, we are presenting our approach to introduce first year undergraduate students of the Department of Modern Mechanical Engineering the basics of robotics systems. In particular, the details of curricula of the Mechatronics Laboratory (1) and (2) are explained. In both lessons, the students receive lectures of the content of each proposed topic and then, a set of practical experiments are done. On the other hand, in order to foster the creativity of undergraduate students of engineering fields, we focused in developing an education tool designed to introduce at different educational levels the principle of developing mechatronic systems. In particular, the development of an inverted pendulum mobile robot Waseda Wheeled Vehicle No. 2R (WV-2R) has been proposed. Regarding the Mechatronics Laboratory, questionnaires were proposed to obtain information from the students about their impressions of the lessons. From the comments collected from the questionnaires, we observed the advantages of the proposed curricula to introduce them about robot technology. On the other hand, different kinds of experiments were proposed to confirm the possibility of implementing controllers as well as changing physical properties of the system to observe differences on the response of the system.

Gastric endoscopic submucosal dissection using novel 2.6-mm articulating devices: an ex vivo comparative and in vivo feasibility study.

BACKGROUND AND STUDY AIMS The conventional procedure of endoscopic submucosal dissection (ESD) is technically demanding. This study investigated the efficiency of novel articulating devices (maximum diameter 2.6 mm), which can be used with commercially available, standard endoscopes. PATIENTS AND METHODS In an ex vivo comparative study, eight endoscopists were divided into novices and experienced operators, and performed ESD using new devices and the conventional setup. An in vivo animal experiment was performed by two experts. Procedure times for incision and dissection were recorded, and unit times for circumferential length and area of specimens were calculated. RESULTS All procedures were successfully completed with en bloc resection. In the ex vivo study, the unit procedure times for incision and dissection by novices were significantly shorter using the new system (P < 0.01 and P < 0.05), whereas there was no significant difference for experienced endoscopists. Perforation occurred during one procedure in which the new system was used. The in vivo experiments were successfully completed without adverse events. CONCLUSIONS ESD using novel articulating devices was feasible. These devices were able to reduce the procedure time for novices.

Development of robotic system for autonomous liver screening using ultrasound scanning device

Physicians use ultrasound scans to do diagnosis by making real-time images of internal organs, because such scans are safe, inexpensive, and non-invasive. However, aging society and limited numbers of physician make it difficult for patients in remote areas to be diagnosed. Besides, physicians technical skills affect the interpretation of the scans and thus the results of the examination. Thus, development of a robotic system for remote diagnosis is required to solve the problems. For this purpose, we proposed the development of a robotic system for automatic ultrasound imaging focusing on human liver. In this paper, we present several elements developed for the robotic system. First element is an algorithm for estimating the position of liver to guide the probe to scan initial position which is the epigastric region. Second element is ultrasound probe scanning protocol design to obtain whole image of the liver. Third element is force control algorithm to maintain the contact between the probe and human body even though the patient is breathing. Fourth element is an algorithm for detecting and correcting the probes position when improper ultrasound images occurred. These algorithms with an implementation program control the apparatus: a Mitsubishi Electrics MELFA RV-1 six axis manipulator and tested on human subjects. The results confirmed the effectiveness of the approach.

Next-generation robotic surgery--from the aspect of surgical robots developed by industry.

Abstract At present, much of the research conducted worldwide focuses on extending the ability of surgical robots. One approach is to extend robotic dexterity. For instance, accessibility and dexterity of the surgical instruments remains the largest issue for reduced port surgery such as single port surgery or natural orifice surgery. To solve this problem, a great deal of research is currently conducted in the field of robotics. Enhancing the surgeon’s perception is an approach that uses advanced sensor technology. The real-time data acquired through the robotic system combined with the data stored in the robot (such as the robot’s location) provide a major advantage. This paper aims at introducing state-of-the-art products and pre-market products in this technological advancement, namely the robotic challenge in extending dexterity and hopefully providing the path to robotic surgery in the near future.

Implementation of an automatic scanning and detection algorithm for the carotid artery by an assisted-robotic measurement system

In this paper, we present a robotic system which automatically searches and detects the longitudinal section of the carotid artery using a conventional medical ultrasound diagnostic system. In order to obtain a clear image of the carotid artery ready for medical diagnosis, the authors developed real-time image processing algorithms to detect the carotid artery and tissue layers of its walls in the B-mode ultrasound images. Sequential patterns of the ultrasound probe trajectory for scanning the surface of the neck and searching the carotid, were implemented and tested on the Waseda-Tokyo Womens Medical-Aloka Blood Flow Measurement Robot System No. 1 Refined II (WTA-1RII). An experiment with eleven volunteers was carried out and the results show that the system obtained clear images of the carotid artery in 91% of the trials.

Improving the strength of sutureless laser-assisted vessel repair using preloaded longitudinal compression on tissue edge

Little is known about the approximation of coapted edges in sutureless laser‐assisted vessel welding. Tissue shrinkage by laser irradiation may cause coapted edges to separate, reducing strength of welding. This may be avoided by preloaded longitudinal compression on the tissue edges to be welded. This study compared welding strength with and without preloaded compression in ex vivo animal experiments.

Development of the Ultrasound Probe Holding Robot WTA-1RII and an Automated Scanning Algorithm based on Ultrasound Image Feedback

In this paper, we present our research on the development of an automated medical ultrasound scanning system for the carotid artery using probe a supporting manipulator (parallel link mechanism). In particular, we detail the mechanism design of the manipulator and a real-time image processing algorithms to detect the carotid artery and tissue layer of its walls (in the B-mode of ultrasound image). Several sequential patterns of ultrasound probe trajectory were implemented in order to enable the manipulator to scan the surface of neck effectively. A set of experiments has been carried out to verify the effectiveness of the proposed system.