To provide shock-wave exposure with high accuracy and widen the application area of shock-wave therapy, a miniaturized shock-wave device for endoscopic surgery was developed. The shock-wave device applies an electrohydraulic mechanism for generating shock waves in light of device miniaturization and suitability for standard clinical practice. The outer diameter of the shock-wave generator is 11 mm, so it can be inserted in the body through a trocar used in endoscopic surgery or a natural orifice in the case of natural-orifice translumenal endoscopic surgery (NOTES). The distance between the shock-wave focal point and the front of the device is 10 mm. The focused shock wave was observed at the focal point by visualization with the schlieren imaging technique. The pressure at the focal point was measured, and the measurement revealed that the device can produce a peak pressure of 2.32±0.81 MPa at 2-kV discharge voltage, 3.69±1.06 MPa at 3 kV, 5.67±2.44 MPa at 4 kV, and 7.27±2.33 MPa at 5 kV.

Keywords

Underwater Shock Waves, Minimally Invasive Surgery, Forceps-Compatible Shock-Wave Device, Endoscopic Surgery, Electrohydraulic Shock-Wave Generator

Paper information

Keiichi NAKAGAWA, Akira TSUKAMOTO, Tatsuhiko ARAFUNE, Hongen LIAO, Etsuko KOBAYASHI, Takashi USHIDA and Ichiro SAKUMA, “A Miniaturized Shock-Wave Device for Mounting on Forceps”, Journal of Biomechanical Science and Engineering, Vol. 8, No. 1 (2013), pp. 17-26. doi:10.1299/jbse.8.17

Finger Braille is one of the communication media of deafblind people. In one-handed Finger Braille, a sender dots the left part of the Braille code on the distal interphalangeal (DIP) joints of the index, middle and ring fingers of a receiver, and subsequently dots the right part of the Braille code on the proximal interphalangeal (PIP) joints of the same fingers. Because there is a small number of non-disabled people who are skilled in Finger Braille, deafblind people communicate in this medium only through an interpreter. In this study, we developed a Finger Braille recognition system using small piezoelectric accelerometers worn by the receiver. We first conducted a measurement experiment to derive algorithms for the recognition of the dotted fingers and positions. The results showed that the accuracy of the recognition of dotted fingers was 92.9%, and the recognition system was independent of the dotted strength, dotted position and receiver. The accuracy of the recognition of dotted positions was 81.9%, and the recognition system could recognize dotted positions if the receiver's hand formed a natural longitudinal arch on the desk. Next, an evaluation experiment was carried out. The results showed that the accuracy of the recognition of dotted fingers by dotting was 89.7%, and the accuracy of recognition of dotted positions by dotting was 92.3%. Therefore, the recognition system could recognize sentences accurately when the interpreter dotted clearly.

Keywords

Finger Braille, Deafblind, Recognition System, Communication Aid, Accelerometer, Shock Acceleration, Recognition of Dotted Fingers, Recognition of Dotted Positions

Paper information

Yasuhiro MATSUDA, Ichiro SAKUMA, Yasuhiko JIMBO, Etsuko KOBAYASHI, Tatsuhiko ARAFUNE and Tsuneshi ISOMURA, “Development of Finger Braille Recognition System”, Journal of Biomechanical Science and Engineering, Vol. 5, No. 1 (2010), pp.54-65 . doi:10.1299/jbse.5.54