Apparatus for acquiring biosignals in the presence of HF interference

Inventors

SALIGA, THOMAS V • Bibian, Stéphane • Zikov, Tatjana

Assignees

Neurowave Systems Inc

Abstract

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.

Core Innovation

The invention relates to an apparatus for acquiring signals from a subject in the presence of high frequency (HF) interference. The apparatus includes at least 2 electrodes adapted for attaching to the subject, where each electrode acquires a signal when attached to the subject, and amplification circuitry for HF rejection connected to the at least 2 electrodes. The HF rejection circuitry comprises at least one active input filter for HF electrical interference rejection and an isolation barrier where power is transmitted via an optimized transformer.

The circuitry measures the quantitative level of HF interference across the isolation barrier and transmits both the acquired signals and the measured HF interference level to a processor. This enables the processor to receive a measurement of the HF interference level together with the biosignals for the acquisition process.

The described system architecture includes an isolation barrier configured with power transmitted via an optimized transformer and associated isolation barrier implementation elements. The invention further includes measurement of cross-barrier voltage and transmission of the measured HF interference level with the acquired signals to support confirmation of interference levels and subsequent signal handling behavior.

Claims Coverage

The document provides one independent apparatus claim. The inventive coverage is driven by two core requirements: HF rejection amplification circuitry with an active input filter and an isolation barrier with power transmitted via an optimized transformer, and measuring and transmitting a quantitative HF interference level across the isolation barrier to a processor alongside the acquired signals.

Overall, the claims cover an apparatus that acquires subject signals via at least 2 electrodes while HF rejection circuitry includes an active input filter and an isolation barrier powered by an optimized transformer, and measures and transmits a quantitative HF interference level across the isolation barrier to a processor together with the acquired signals.

Stated Advantages

Documented Applications