학술논문
광전용적맥파(PPG) 측정을 이용한 혈압 측정용 센서 인터페이스 회로 설계에 관한 연구 / A study on the design of sensor interface circuit for blood pressure measurement using photoplethysmogram
Document Type
Text
Source
Subject
Language
Korean
Abstract
본 논문에서는 광전용 적맥파를 이용하여 혈압 측정용 CMOS 인터페이스 회로를 제안하고 설계하였다. 이 회로는 PPG 센서에서 발생한 광전용적맥파를 이용하여 혈압을 측정하는 회로로서 센서의 전류신호를 전압으로 바꾼 아날로그 회로와 이를 디지털 신호를 변환시킨 디지털 회로로 구성하였다.기존방식에 비해 슈미트-트리거 회로와 구형파 발진기 회로에 OTA를 적용하여 동작속도를 높였고, 변환 선형오차를 줄였다. 또한, 전체 회로를 CMOS로 설계하여 저소비전력을 구현하였고, 기존 방식과 비교하여, 간단한 회로 구성과 높은 분해능, 저 전력의 특징을 가지도록 설계하였다.PTT을 분석하여 수축 압과 PTT에 과계 공식을 유도해 냈다. 수축 압 계산 하였다. PPG을 이용하여 혈과 변수를 찾았다. 인체 혈관 변수 와 PTT을 이용하여 이완 압을 추산하였다.
In this paper, Sensor Interface circuit for measuring PPG is proposed and designed by using current-control Schmitt trigger. This circuit detects the blood pressure using PPG which occurs blood pressure sensor and composed of analog parts. Current signal of sensor is converted into voltage in analog parts and then converted into digital signal in digital parts. Comparing to the conventional method, operation speed is increased and linear error is diminished by applying OTA to schmitt trigger circuit and oscillator. Also, proposed and designed circuit has some features of low power consumption , simple structure and high resolution comparing with previous method.It is expected that this circuit is also applicable to the other interface circuit for ECG sensor, pressure sensor and so on. Also, it is applicable to the low electric power system by low tension design.The theory of calculating systolic pressure by analyzing the pulse transit time, the method of calculating the calculating systolic by deriving the equation of pulse transit time and systolic pressure and calibrating parameters of the equation by experiment, are provided. The method to calculating systolic pressure by using Photoplethysmograph pulse wave is analyzed in this paper. Cardiovascular parameters are obtained in calculation experiment and diastolic pressure is figured out continuously by using systolic pressure and cardiovascular parameters.
In this paper, Sensor Interface circuit for measuring PPG is proposed and designed by using current-control Schmitt trigger. This circuit detects the blood pressure using PPG which occurs blood pressure sensor and composed of analog parts. Current signal of sensor is converted into voltage in analog parts and then converted into digital signal in digital parts. Comparing to the conventional method, operation speed is increased and linear error is diminished by applying OTA to schmitt trigger circuit and oscillator. Also, proposed and designed circuit has some features of low power consumption , simple structure and high resolution comparing with previous method.It is expected that this circuit is also applicable to the other interface circuit for ECG sensor, pressure sensor and so on. Also, it is applicable to the low electric power system by low tension design.The theory of calculating systolic pressure by analyzing the pulse transit time, the method of calculating the calculating systolic by deriving the equation of pulse transit time and systolic pressure and calibrating parameters of the equation by experiment, are provided. The method to calculating systolic pressure by using Photoplethysmograph pulse wave is analyzed in this paper. Cardiovascular parameters are obtained in calculation experiment and diastolic pressure is figured out continuously by using systolic pressure and cardiovascular parameters.