SIGNAL CONDITIONING & DATA ACQUISITION SYSTEM FOR SLEEP DEPRIVATION STUDIES

信号调理

• 批准号: 3852937
• 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/3852937
• 关键词: biomedical equipment development; body temperature; 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 small (0.5 mm dia. x 3 mm long), fast (20 msec), glass-encapsulated thermistors. The calibration values for each thermistor are stored in a separate calibration file and are loaded into the program when the program is started. A thermistor bridge circuit accommodates a tolerance of +/-20% in the nominal thermistor resistance, and covers a range of 25 degrees to 45 degrees C with 0.01 degrees C resolution. Custom software controls the sample acquisition rate, filtering linearization, calibration, and storage of the signals. 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. After the first cycle, the memory location is switched and another cycle is started. The program then downloads the 16-channel data from the previous memory location and determines the resistance of each thermistor from the voltage readings. From this resistance and the calibration values, the temperature of each thermistor is calculated. The "background" operation also allows updating or changing the calibration values (new thermistor) or relocating the thermistor (channel change) without interrupting the data acquisition.

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小（0.5 mm直径）x 3 mm长）， 快速（20毫秒）玻璃封装热敏电阻。 校准值 存储在单独的校准文件中， 在程序启动时载入程序。 热敏电阻电桥 电路可容纳标称热敏电阻+/-20%的公差 电阻，并覆盖25度至45摄氏度的范围，0.01 C分辨率。 定制软件控制样品采集 速率、滤波线性化、校准和信号存储。 A/D卡以“后台”模式运行30秒， 数据直接传送到指定的存储器位置。 此模式 的操作释放CPU以处理前一个间隔的数据 并允许不间断或连续的数据采集。 后 在第一个周期中，存储器位置被切换，并且另一个周期 开始了 然后，程序从 前一个存储器位置，并确定每个热敏电阻的电阻 从电压读数来看 从这个电阻和校准 值，计算每个热敏电阻的温度。 的 “后台”操作还允许更新或更改校准 值（新热敏电阻）或重新定位热敏电阻（通道更改） 而不中断数据采集。