【Summer Seminar BMIE】Week_1 Report

Our Project is Non contact sign monitoring mattress with multi-sensor fusion.
The sensors mainly contain three parts, Piezoelectric Film, Microwave Detector and Electronic Fabric. In the first week, the sensor that we dealed with is fiezoelectric film.
First, let’s see what is fiezoelectric film. Here is the introduction.

The fiezoelectric film  that we use is PVDF(polyvinylidene fluoride)  fiezoelectric film. Compared with the traditional film, its measurement accuracy is much higher than before and also the impedance is much lower.

 

In the first week, we mainly designed the drive circuit (also is known as charge amplification circuit). The circuit structure is shown as followed.

 
The operational amplifier that we chose is AD8601 (made by Texa Instruments (Ti ) ). The resistance we chose is different from the figure. Because our fiezoelectric film is different, the  resistance that we finally chose is 1M. Here is our charge amplification circuit.

 

The ECG signal is shown as followed.

 

From the wave shape we can see that ECG signal is not very obvious and interfere is serious, especially the power-line interference (50Hz). So next we will design a trap circuit to eliminate interference. Thank you.
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