Development of a four-channel cardiovascular signals collector based on STM32 with digital-controlled gain

To get better methods on diagnosis of cardiovascular diseases and health assessment by comparison analysis of four kinds of cardiovascular signals, which are blood pressure signal (BPS), plus wave signal (PWS), electrocardiosignal (ECS) and cardiac sound signal (CSS), a four-channel signals collector is introduced in this article. This collector is composed of microcomputer STM32F103RB with integrated 12-bit analog to digital converters (ADCs) and some integrated chips (IC) such as PGA113, a programmable gain amplifier with internal calibration channels for system-level calibration. Therefore, the data of four kinds of cardiovascular signals can be both collected by this signal collector with a high precision and output to a computer by universal serial bus (USB) interface, which can also offers power for this instrument. In addition, the gain of input signal can be changed by computer software through USB interface under microchip commands. Thus it has many merits, such as the small volume, low cost, high performance and precision, digital-controlled gain and so on. Consequently, it is convenient to acquire the data of four kinds of cardiovascular signals by it, and a waveform of one sample is shown.