DSP-based electroencephalogram digital filtering method and device

Abstract

The invention discloses a DSP-based electroencephalogram digital filtering method and an electroencephalogram acquisition device. For requirement on the accuracy of signals when electroencephalogram signals are acquired, firstly, a differential amplifier circuit is utilized to amplify the electroencephalogram signals, a 16-bit AD with high accuracy is adopted so that the accuracy of the electroencephalogram signals is 0.5 uV, and on such a basis, a DSP performs signal processing. The DSP adopts a fixed-point signal processor of 5,000 series developed by the TI Company to perform the signal processing comprising band-pass filtering and wave trapping by adopting a Chebyshev best consistent approximation FIR filtering method to obtain the electroencephalogram signals of high quality. The method has the advantages of clear concept, the high accuracy and high speed. The invention provides a filtering algorithm with the high accuracy, which can be applied to the design of an electroencephalogram front-end amplifier and lay the foundation for the further analysis of the electroencephalogram signals.

Description

technical field [0001] The invention relates to a DSP-based digital filtering method and device, which are mainly applied to the collection of EEG signals at the front end of an EEG-based anesthesia monitor to provide necessary data for clinical analysis. Therefore, the method belongs to the field of biomedical engineering. Background technique [0002] Even in the United States, the birthplace of modern anesthesiology, until the 1960s, the death rate of anesthesia was still high at a few per thousand, and it was only in the 1970s that it dropped to a few per 10,000. Statistics from the late 1980s show that the death rate from anesthesia in some medical centers in the United States has reached 1 / 200,000 to 1 / 500,000. Sophisticated technical equipment is an important material basis for anesthesia safety. These equipment mainly include anesthesia machines (including precise volatilization devices, ventilators and carbon dioxide absorbers), ECG monitoring, arterial blood gas de...

AI Technical Summary

Problems solved by technology

[0004] Although the acquisition technology of EEG signals has been continuously improved for decades, due to the particularity of EEG signals and environmental factors, high-precision EEG amplifiers are still a challenging technology and subject.

First of all, the amplitude of the EEG signal is very small, generally ±200uV, but the output impedance of the EEG signal source is very high; the interference of the working environment is another important factor. In the operating room environment, power frequency interference is common. However, electrosurgical interference and EMG interference are obstacles to the extraction of EEG signals; thirdly, as a device for clinical application, it must be considered that the acquisition will not affect the safety of the test patient.

Images