Jovanov E, Raskovic D, Hormigo R
Electrical and Computer Engineering Department, University of Alabama in Huntsville 301 Sparkman Drive, Huntsville, AL 35899, USA.
Biomed Sci Instrum. 2001;37:493-7.
One of the most frequently used methods to sense breathing pattern is to detect airflow using a nasal thermistor or a thermocouple sensor. Prolonged, minimally intrusive measurement of the breathing pattern is particularly important for polysomnography, sleeping disorders, stress monitoring, biofeedback techniques, and circadian rhythm analysis. Although most applications require only breathing pattern, some applications and diagnostic procedures require monitoring of the rhythm of change of dominant nostril. In this paper we present our design of a differential thermistor-based breathing sensor for prolonged monitoring during the normal activity. The system is designed using a low power microcontroller Texas Instruments MSP430F149 with an on-chip A/D converter for data acquisition and signal processing. We use wireless RF link to a PC for long-term data acquisition and storage. Precise measurement requires decreasing zero and sensitivity errors of the measurement. We discuss signal processing methods, calibration and parameters used to characterize breathing patterns necessary for circadian breathing rhythm evaluation.
检测呼吸模式最常用的方法之一是使用鼻热敏电阻或热电偶传感器来检测气流。对于多导睡眠图、睡眠障碍、压力监测、生物反馈技术和昼夜节律分析而言，长时间、侵入性最小的呼吸模式测量尤为重要。尽管大多数应用仅需要呼吸模式，但一些应用和诊断程序需要监测主导鼻孔变化的节奏。在本文中，我们展示了一种基于差分热敏电阻的呼吸传感器设计，用于在正常活动期间进行长时间监测。该系统采用低功耗微控制器德州仪器MSP430F149进行设计，其带有片上A/D转换器用于数据采集和信号处理。我们使用无线射频链路连接到PC进行长期数据采集和存储。精确测量需要降低测量的零点和灵敏度误差。我们讨论了用于昼夜呼吸节律评估的信号处理方法、校准以及表征呼吸模式所需的参数。
