Method and system for acquiring biosignals during delivery of anesthesia or sedation in the presence of HF interference

摘要

The present invention, herein is a method and apparatus that significantly limits the effect of high frequency (“HF”) interferences on acquired electro-physiological signals, such as the EEG and EMG. Preferably, this method comprises of two separate electronic circuitries and steps or electronics for processing the signals. One circuit is used to block the transmission of HF interferences to the instrumentation amplifiers. It is comprised of a front-end active filter, a low frequency electromagnetic interference (“EMI”) shield, and an isolation barrier interface which isolates the patient from earth ground. The second circuit is used to measure the difference in potential between the two isolated sides of the isolation barrier. This so-called “cross-barrier” voltage is directly representative of the interference level that the instrumentation amplifier is subjected to. This circuit is used to confirm that the acquired signals are not corrupted by the interference.

主权项

1. A method of acquiring biopotential signals from a subject during surgery in the presence of high frequency (HF) electrical interference resulting from an electrosurgical unit comprising the steps of:
attaching at least 2 electrodes to the subject, performing surgery on the subject utilizing an electrosurgical unit, acquiring and filtering biopotential signals from the subject using circuitry while performing surgery on the subject utilizing the electrosurgical unit, with said circuitry comprising:
at least one active input filter for rejection of HF electrical interference caused by the electrosurgical unit, andan isolation barrier where data is transmitted via magnetic coupling; transmitting the biopotential signals to a processor, and obtaining a quantitative measure of a level of HF interference, wherein said processor uses said measure of HF electrical interference to modify at least one behavior of the at least one input filter.