Fryer T B, Sandler H, Freund S W, McCutcheon E P, Carlson E L
J Appl Physiol. 1975 Aug;39(2):318-26. doi: 10.1152/jappl.1975.39.2.318.
The design of telemetry systems for chronic implantation within the body have progressed from simple single-channel devices to complex multichannel systems over the last 15 yr. Although chronic measurements of temperature, ECG, and pressure have been reported with good results, measurements such as dimension and blood flow have been difficult because of heavy power requirements. The design to be described is a multiplex system that will measure up to eight individual parameters simultaneously, including blood flow. Flow is measured using an electromagnetic transducer, and by special design, the normal high power requirements of the electromagnetic technique have been reduced to a few hundred milliwatts. The system is powered by two NiCad, rechargeable batteries which are periodically recharged through the intact skin by induction at 250 kHz to an implanted pickup coil. The presently constructed units have been configured to measure ECG, two pressures, temperature and ascending aortic flow.
在过去15年里，用于体内长期植入的遥测系统设计已从简单的单通道设备发展到复杂的多通道系统。虽然已有关于长期温度、心电图和压力测量的报道，且结果良好，但诸如尺寸和血流等测量因功率需求过大而困难重重。本文所描述的设计是一种多路复用系统，它能同时测量多达八个单独参数，包括血流。血流通过电磁换能器进行测量，并且通过特殊设计，电磁技术通常所需的高功率已降至几百毫瓦。该系统由两节镍镉可充电电池供电，这两节电池通过250kHz的感应，经完整皮肤定期向植入的拾波线圈充电。目前构建的装置已配置为测量心电图、两种压力、温度和升主动脉血流。
