help

[Ray.R]

Actually most (all?) sensors will work with LV.  It's a matter of acquiring the signal / transducing, etc.  🙂

Let's break it down to a few categories:  Goal, sensor, indicator.

Goal:  monitor heart beat

Does this mean you want to monitor the state of the heart (ie beating or stopped)?

Sensor:  sense heart beating (we'll cover that below)

Indicator:  No of heart beats per minute.

Sensor:  Let's consider a few things that are detectable with every heartbeat..  We also need to define accuracy.

1.  sound,  2. pulse (pressure wave), ECG (electrical impulse), optical (LED oxysensor..  may not be reliable to sense a "beat")

2.  mounting options:  this may vary based on the choice from #1.  Comfort may also be an issue.

OK .  This is a start.

So item 1 needs to be clarified as well as selecting a sensor option.  What is available to you as resources?

[akin]

Thanks everybody for ur help afta enuf research on my heart rate monitor project , the equipments am planning to use are amplifier + Active low  or band pass filter to filter out all the unnecessary noise.

Its Gonna be like Sensors to Amplifier+filter to Interface board 4 labview to labview display.I have not decided on the kind of sensors and for the amplifier i wanna use 411 instead of 741 bcos of its low base current.

 i just wanna know want to guys think about the iddea if am on the right track or not and if not can u put me on the right track pls.I wud be really greatful 

[Ray.R]

That's good.  Typically, you do need some sort of transducer (sensor) which converts the signal of interest to a electrical one.  Then some sort of interface ( based on the voltage level or some sort of circuitry) which can be read / interpreted by the test PC and read by Labview.

For instance, the use of DAQ boards, digital IO if the transducer converts it into digital pulse, or even the parallel port (poor man's digital IO..;)  )

There are many ways to implement this.

The first step is actually choosing the transducer / sensor.

JLV

[AdamB]

Hey,

My final year project at university was centered around monitoring a heart rate and I used a number of LED's and sensative photosensors.

PhotoPlethysMography. (If you look that word up you'll get a lot of information on the processes/sensors etc.)

Might be a good sensor to use?

AdamB

[akin]

Concerning the DAQ interface board  am suppose to build it or buy it bcos i ask my supervisor and he told me to search NI.com.Did dat and the ones i saw were very expensive like £500.Pls enlighten  me more

[Ray.R]

Hi akin,

I'm not sure I fully understand your question:  "Do I have 2 buy?"  It depends what are the requirements.  It is way cheaper to buy a DAQ board than to build one.  I don't know about the prices in the UK, but recently, NI came out with USB models that are economical.  Check with a local rep.

RayR

[akin]

hello guys i have done so many research and i have found out the type of components i need for the heart rate monitor.I found out that i am going to use either a phototransistor SFH309 or an infrared emitting diode SFH409.i dont kno were to get more information.Can u kindly tell me if u kno where i can get more information on this components .The amplifier is going 2 b designed with a band pass filter 2 filter out all unnecessary noise signal.thanks

[AdamB]

Try these links.

Farnell also did these kinds of components.  Are you looking at reflective or absorbtion?

http://www.maplin.co.uk/Module.aspx?ModuleNo=2260&TabID=1&C=SEO&U=StaticPages&doy=search&MenuName=SF...

http://www.maplin.co.uk/module.aspx?TabID=1&criteria=usb&ModuleNo=2259&doy=search&C=SEO&U=Strat15

If you are just looking at the heart rate then IR is the best way to go.. However if you also wanted to get out the oxygen saturation and breating rates then simply adding a red light (and the same sensor) and comparing their relative signal strenths will give you this information. (you would however need to pulse the lights one after the other.)

Does this help?

AdamB

[akin]

pls i wanna kno if i have 2 use an LED with a phototransistor for it be become an optical tranduscer becos i cant just figuer it out .and with dat i am building a differential amplifier with it plus bandpass filter.The main aim is jus 2 build am ECG to monitor the heart rate but dis is without the electrodes.All the research i ave been doin has sayin sometin about a preamp for the electrode but i dont get it.Concerning my case i dont think i need a preamp becase amm am doing is just to design a phototransistor plus LED wit 5V and connect it 2 ECG(differential amp plus filter)   with 15V supply.Is dat right or do i need a preamp?

[akin]

pls i wanna kno if i have 2 use an LED with a phototransistor for it be become an optical tranduscer becos i cant just figuer it out .and with dat i am building a differential amplifier with it plus bandpass filter.The main aim is jus 2 build am ECG to monitor the heart rate but dis is without the electrodes.All the research i ave been doin has sayin sometin about a preamp for the electrode but i dont get it.Concerning my case i dont think i need a preamp becase amm am doing is just to design a phototransistor plus LED wit 5V and connect it 2 ECG(differential amp plus filter)   with 15V supply.Is dat right or do i need a preamp?