Development of a pulse pressure and atherosclerosis monitoring system based on radial artery implant cuff

• Main Authors: Meng-Kin Chao, 周健銘
• Other Authors: Shyh-Liang Lou
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/05003806889528133512

碩士 === 中原大學 === 生物醫學工程研究所 === 99 === The central arteries become ageing and stiff with increase of age. It is important to early diagnose these deleterious effects because they increase cardiovascular risks such as morbidity of hypotension and atherosclerosis resulted in angina pectoris or myocardial infarction. The ultimate goal of this study is to develop a batteryless implantable cardiovascular monitoring system to provide a solution of long term cardiovascular status monitoring. The implanted system (IS) was equipped with a cuff sensor directly detecting arterial pressure signals and was powered by an external relay system (ERS) based on radio frequency (RF) technology. The detected signals were transferred to a personal computer via a blue-tooth device implemented in the ERS. An index representing the stiffness of artery vessels, known as augmentation index (AIx), was then calculated from the detected signals. The wireless communications between the completed ERS and IS can tolerate a vertical displacement of 7 mm, and maximum horizontal displacement of 24 mm, which data transfer rate is 54 packets per second with power consumption of 1.9 W. The prototype of cuff pressure sensor has been produced; it is a biocompatible cylindrical cuff sac with a length of 14 mm and diameter of 8 mm. An in vivo study was performed in this course by sensing femoral arterial pressure of New Zealand white rabbits. The result show that the developed system is able to perform pressure measurements for seven days, but the distortion of the detected signals appeared at the fourth day. The cause is likely due to the loose of the pressure sensor from the femoral arteries. In conclusion, this course completed an implantable pressure sensing system and its functionality has been confirmed with the in vivo studies. There is a potential that the system can be applied for monitoring cardiovascular diseases.