Implantable Pressure Measurement System

研究了一种植入式压力测量系统。研究结果如下：1.研制了一种新型植入式压力传感器的电馈线结构。这种结构是绝对压力传感器不可缺少的。它能够在输出读取器部分实现气密密封，并使包装变得容易。开发了无残余应力的PYREX玻璃-硅阳极键合和可用于刻蚀窄通孔的电化学放电钻孔。2.制作了一种采用新型馈通结构的压阻式压力传感器。传感器的尺寸为1.8 mm×1.8 mm，厚度为580微米。膜片尺寸为0.8 mm×0.8 mm，参考腔深度为3um，当膜片厚度为9um时，灵敏度为13uV/mmHg/vs。3.研制了一种用于导管的电容式相对压力传感器。大小为0.7×3.5×0.4 mm。归一化压力灵敏度为3.45×10~(-4)/毫米汞柱，温度系数为0.17毫米汞柱/厘米。尺寸为2.2 mm×1.7 mm，厚度为500微米。CMOS型电容-频率转换电路集成在同一硅片上。该电路的输出通过位于硅膜片对面的玻璃孔来获取。通过监测电力线上的电源电流来检测输出频率，因此传感器只需要两根引线。热零点漂移小于0.1%F.S./C，灵敏度为-31.3赫兹/毫米汞柱(0.048%F.S./毫米汞)。功耗为86.5uW。该传感器具有稳定性好、功耗欺骗小、输出信号检测简单等优点，适合于植入式遥测系统。

An implantable pressure measurement system was studied. The results of the research are as follows; 1. A new electrical feedthrough structure for an implantable pressure sensors has been developed. This structure is indispensable for the absolute pressure sensor. It enables air-tight seal at the output read part and makes the packaging easy. The Pyrex glass-to-silicon anodic bonding, free from residual stress, and electrochemical discharge drilling which is useful to engrave narrow through-hole were developed. 2. A piezoresistive pressure sensor, using the new feedthrough structure was fabricated. The size of the sensor is 1.8mmxl.8mm and 580um in thickness. The diaphragm size is 0.8mmxO.8mm, and the depth of reference cavity is 3um.The sensitivity was 13uV/mmHg/Vs when the diaphragm thickness was 9um. 3. A capacitive relative pressure sensor for a catheter was fabricated. The size was 0.7x3.5xO.4mm. The normalized pressure sensitivity was 3.45xlO-4/mmHg and the temperature coefficient was 0.17mmHg/ C. 4. An integrated silicon capacitive pressure sensor has been fabricated. The size is 2.2mmxl.7mm and 500um in thickness. The CMOS capacitance to frequency converter circuit is integrated on the same silicon chip. output of the circuit is taken through glass holes which are at the opposite side of the silicon diaphragm. Output frequency is detected by monitoring the supply current in the power line, so that only two lead wires are necessary for the sensor. The thermal zero shift is less than 0.1%F.S./ C. The sensitivity is -31.3Hz/mmHg (0.048%F.S./mmHg). The power dissipation is 86.5uW. The sensor is suitable for implantable telemetry system because of its good stability, low power deception, and simple output signal detection.Design and fabrication principle of implantable pressure sensing system was established.