Investigation of in vivo Wireless Communication Chip

生物传感器是微全分析系统（μ-TAS）的关键器件，采用生物MEMS技术研制而成。本课题研究了一种利用人体无线通信的小型医疗设备。可实现胃内pH值、体内体温等交互传感。测量了人体在不同频率下的传输特性。传输方式有电磁波传输和电磁耦合传输两种。电磁耦合传输由于具有衰减特性，有利于电磁波的传输。我们开发了一种利用13.56MHz频率电磁耦合传输的活体无线通信芯片。采用感应电动势供电，可实现无电池通信。在这种大衰减环境下，我们提出了一种脉冲间隔调制。PIM不依赖于传输信号的大小。在此基础上，建立了对活体无线通信系统的研究。

Bio sensors have been developed using bio MEMS technology as a key device of μ-TAS (micro-Total Analytical System). This work investigates a small-size healthcare device which uses wireless communication through human body. It can realize interactive sensing of pH in stomach, internal body temperature, and so on. Transmission characteristics of human body are measured at several frequencies. There are two types of transmission : electromagnetic wave transmission and electromagnetic coupling transmission. The electromagnetic coupling transmission has advantageous to the electromagnetic wave transmission because of attenuation characteristics. We developed an in-vivo wireless communication chip using the electromagnetic coupling transmission at 13.56MHz. It can realize battery-less communication since power is supplied by induced electromotive force. We propose a pulse interval modulation to communicate under such the large attenuation environment. PIM does not depend on magnitude of transmitted signal. From these results, the survey for in-vivo wireless communication system has been established.