Its my first message to the group!!
currently working on builiding Blood pressure monitor and currently
working on pressure sensning circuit.
I am using MPX2050GP pressure sensor to sense the blood pressure from
cuff wrapped around the arm. pressure sensor based on the pressure
applied to it gives an output in millil volts(around 8-10mVolts- based
on pressure). My task is to amplify that signal using AD622 amplifier.
I connected my milli volt output from pressure sensor and got it
directly into input of the amplifier. It sounds very simple but i am
facing few problems with it.
I set amplifier to amplify signal 100 times. When i check my output on
the scope it only shows some DC crap on the signal.I need a clean AC
signal whos AMPLITUDE would vary with change in pressure on the sensor.
Would appreciate ur suggestion and help. project is due in weeks time.
Please define the frequency band of interest.
I am also interested in the concept of how this mechanism will find
blood pressure from the signals measured.
The versions I am familiar with, use a combination of a slowly
changing cuff pressure (and a low pass filtered measurement of that
cuff pressure), and an acoustic pickup that listens for the opening
and closing of an artery that is being collapsed by the cuff pressure
and forced open by blood pressure (mimicking what a human would do
with a cuff and stethoscope).