Title :
High frequency interference effects in amplifiers for biopotential recordings
Author :
van der Horst, M.J. ; Van Rijn, A. C Metting ; Peper, A. ; Grimbergen, C.A.
Author_Institution :
Dept. of Med. Phys., Amsterdam Univ. Acad. Med. Center, Netherlands
fDate :
29 Oct-1 Nov 1998
Abstract :
Due to the increasing use of cellular phones, computers and other digital electronics, high frequency interference becomes more and more a problem when measuring biopotentials. The high frequency fields induce voltages in the electrode wires and in the patient. These HF-voltages may cause distortion in the input stage of the amplifier. Low-pass filters at the input reduce the common mode rejection ratio and, due to the relative high valued resistors needed, the noise behaviour is deteriorated. In this paper a study is made of the mechanism of the interference and of the HF-susceptibility of various active devices
Keywords :
bioelectric potentials; biomedical electronics; differential amplifiers; operational amplifiers; radiofrequency interference; DC shift; HF interference effects; JFET; Taylor expansion; biopotential recording amplifiers; bipolar transistors; common mode rejection ratio; differential stage; electrode wires; harmonic distortion; induced voltages; interference mechanism; low-pass filters; noise behaviour; op amp; Cellular phones; Distortion measurement; Electrodes; Frequency measurement; Interference; Low pass filters; Noise reduction; Resistors; Voltage; Wires;
Conference_Titel :
Engineering in Medicine and Biology Society, 1998. Proceedings of the 20th Annual International Conference of the IEEE
Conference_Location :
Hong Kong
Print_ISBN :
0-7803-5164-9
DOI :
10.1109/IEMBS.1998.746206
