hello
I am a engineering student working on his final project and i need some help choosing a pressure sensor.
i need a piezo pressure sensor that can detect a pulse (heart beat) from a blood pressure cuff.
i just want to detect the presence of a pulse - so the actual values of the pressure/heart beat are not so impotent. I have this pulse sensor, but im trying to detect the pulse by sound (pressure changes inside the cuff)
I am working with Arduino uno.
Any suggestions for me?
Why do you think you need a piezo pressure sensor?
What other types of pressure sensors have you considered and rejected?
jremington:
Why do you think you need a piezo pressure sensor?
What other types of pressure sensors have you considered and rejected?
at every digital blood pressure device you have a piezoelectric element that detects the Korotkoff sounds.
i didnt rejected any other type of sensor yet. if you know about a non piezo pressure sensor that i can use - i will be more then happy to know about it
I've disassembled a few of the simple blood pressure and pulse monitors intended for home use, and they all used a pressure-sensitive capacitor as a key component of the pressure sensing circuit.
The capacitor in turn controls the frequency of a free-running RC-type oscillator. The frequency decreases as the pressure increases, and that is easy to convert to digital information.
i also disassembled a few blood pressure monitors and some of them had a piezoelectric sensor like this one
but others have a pressure sensor similar to the one used in this project or something like this one
i have no luck detecting a pulse using the first sensor (the piezo disc one).
can you provide me with a link to the component you are talking about? (the pressure-sensitive capacitor)
can you provide me with a link to the component you are talking about?
The ones I've seen were custom built onto the circuit board. That was a few years ago and perhaps they are no longer common. This article describes a complete circuit based on a commercially available MEMS pressure sensor.
And you think this sensor (the MPXV5050GP) can detect the presence of a pulse?
The MPXV5050GP detects pressure between 0 and 375mmHg; blood pressure is around 90mmHg. The only way the sensor could be more perfect if it was the MPX5050GP model (6 pin SIP which is easier to wire up).
Beware that the MPS20N0040D-D needs an external amplifier circuit to go with it (HX711 is typically used). By contrast the MPXV5050GP has an internal amplifier and outputs 0-5V so it can be read directly with analogRead().
Chagrin:
The MPXV5050GP detects pressure between 0 and 375mmHg; blood pressure is around 90mmHg. The only way the sensor could be more perfect if it was the MPX5050GP model (6 pin SIP which is easier to wire up).Beware that the MPS20N0040D-D needs an external amplifier circuit to go with it (HX711 is typically used). By contrast the MPXV5050GP has an internal amplifier and outputs 0-5V so it can be read directly with analogRead().
thank you for your help!
that is exactly what i needed!
the difference between the MPXV5050GP and the MPX5050GP is only with the pins configuration?
also just to be sure - i can detect a pulse using this sensor right?
???