- 著者
-
萩 浩司
牧川 方昭
飯泉 仁美
- 出版者
- 一般社団法人 日本生体医工学会
- 雑誌
- 医用電子と生体工学 (ISSN:00213292)
- 巻号頁・発行日
- vol.33, no.4, pp.334-342, 1995 (Released:2011-10-14)
- 参考文献数
- 19
In this study we have developed a transcutaneous digital communication technique by using Pulse-Code-Modulated (PCM) infrared rays. The communication protocol examined here is serial, asynchronous and half duplex. The electric power should be considered for a computer system implanted inside the body, because it is driven by batteries and the power is insufficient. Its size should also be miniaturized as small as possible. Therefore the following methods were adopted here; the weak infrared rays emitted inside the body were received by a high sensitive avalanche photodiode; the infrared rays of high brightness was used to send data into inside of the body; and the digital data were converted into an optical signal after the pulse-code-modulation (PCM). This modulation yields some advantages; 1) absorbing the response delay of the photosensor, 2) intensifying infrared rays luminescence outside body and 3) saving the electric power on the luminescence inside body. Some communication experiments were done by using pork with the skin; the communication speed was 9600 baud from inside to outside and 1200 baud in the opposite direction, 15 infrared LEDs were set for outside of the body, 4 for inside, three nickel hydride batteries of 1200mAh were used for an electric power inside the body. As a result, a stable bi-directional digital communication was realized through the skin and the pork of about 9cm and it could continue to operate for about 19 hours.