SIGNAL CONDITIONING & DATA ACQUISITION SYSTEM FOR SLEEP DEPRIVATION STUDIES

信号调理

• 批准号: 3789404
• 负责人: C P MUDD
• 金额: --
• 依托单位: NATIONAL CENTER FOR RESEARCH RESOURCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3789404
• 关键词: bioengineering /biomedical engineering; body temperature; computer program /software; computer system design /evaluation; electroencephalography; electromyography; laboratory rat; sleep deprivation; thermometry

An AT-type microcomputer with a resident 16-channel, 12-bit A/D board is used to measure and store signals from freely moving rats in a sleep-deprivation study. The computer acquires brain temperature signals from small, glass-encapsulated thermistors. The calibration values for each thermistor are stored in a separate calibration file and loaded into the program when it is started. A thermistor bridge circuit accommodates a tolerance of q20% in the nominal thermistor resistance, and covers a range of 25~ to 45~C with 0.01~C resolution and 0.04~C accuracy. The system also acquires a "core" or peritoneal temperature, using small RF transmitters that change frequency with temperature. The transmitter system is capable of 0.02~C resolution with 0.07~C accuracy. Custom software controls the sample acquisition rate, filtering linearization, calibration, and storage of the temperature signals. In addition to the temperature signals, the computer also acquires 2 EEG signals and an EMG. The custom software uses a weighted combination of these signals to determine the animal's sleep state, which can then be correlated with the temperatures. The system also has a provision to acquire the heart rate, but that feature has not yet been implemented. The A/D card runs in a "background" mode for 30-second intervals, with the data transferred directly to a specified memory location. This mode of operation frees the CPU for processing the previous interval's data and allows uninterrupted, or continuous, data acquisition. To reduce calibration errors in the transmitter temperature system, a computer-controlled water bath calibrator was developed that performs an automatic 3-point calibration of the transmitters to within 0.04~C. The use of this calibrator improved the transmitters' accuracy from 0.22~C to 0.07~C.

本文介绍一种AT型微型计算机，它具有16通道12位A/D转换板， 用于测量和存储来自自由移动的大鼠的信号， 睡眠剥夺研究。 电脑采集大脑温度信号 小的玻璃封装的热敏电阻。 的校准值 每个热敏电阻存储在单独的校准文件中， 程序启动时。 一种热敏电阻电桥电路， 标称热敏电阻的公差为q20%，并涵盖 测量范围为25~ 45 ℃，分辨率为0.01 ℃，精度为0.04 ℃。 的 系统还使用小型射频（RF） 频率随温度变化的发射器。 发射机 系统分辨率为0.02~C，精度为0.07~C。 自定义 软件控制采样采集速率，滤波线性化， 温度信号的校准和存储。 除了有 除了温度信号外，计算机还采集了2个EEG信号和1个EMG信号。 定制软件使用这些信号的加权组合， 确定动物的睡眠状态，然后可以将其与 温度 该系统还具有获取心率的装置， 但该特征尚未实现。 A/D卡运行在 30秒间隔的“后台”模式，数据传输 直接存储到指定的内存位置。 这种操作模式释放了 CPU用于处理前一个间隔的数据并允许 不间断或连续的数据采集。 减少校准 变送器温度系统出现误差，由计算机控制出水 浴校准器的开发，执行自动3点 将变送器校准到0.04 ℃以内。 使用这种 校准器将变送器的精度从0.22 ℃提高到0.07 ℃。