Post by thread:More Heart Monitors

Recent discussion here and on several newsgroups has discussed the type of heart rate monitor that uses a light directed through a finger or earlobe. But the majority of current commercial exercise heart rate monitors use a strap that goes across the users chest. You dampen the two pads on the strap and it picks up your heart rate, transmitting it to a display. Anyone have some thoughts on how to build one of these? Rock T _________________________________________________________ DO YOU YAHOO!? Get your free @yahoo.com address at http://mail.yahoo.com

> But the majority of current commercial exercise heart >rate monitors use a strap that goes across the users chest. You >dampen the two pads on the strap and it picks up your heart rate, >transmitting it to a display. Anyone have some thoughts on how to >build one of these? I have one of these. What I find amazing is that the electronics has been running on one 3V watch battery for about 5 years or so, which also includes RF transmission from the monitoring strap to a watch. Amazing. I assume it must be simple single pulse RF with each heart beat. What is interesting about the IR type is that they can measure both oxygenated and non-oxygenated blood levels (using different IR wavelengths) and I've also even heard of some researchers doing studies with the shape of the pulse curve which can tell information about heart valves and blockages, etc. Very interesting. C. Webb At 07:10 AM 3/30/98 -0800, you wrote: {Quote hidden}>Recent discussion here and on several newsgroups has discussed the >type of heart rate monitor that uses a light directed through a finger >or earlobe. > But the majority of current commercial exercise heart >rate monitors use a strap that goes across the users chest. You >dampen the two pads on the strap and it picks up your heart rate, >transmitting it to a display. Anyone have some thoughts on how to >build one of these? > >Rock T > > > > >_________________________________________________________ >DO YOU YAHOO!? >Get your free @yahoo.com address at http://mail.yahoo.com > >

The interesting part of this is the fact that you can get an ECG with an instrumentation amp. Just detect peaks to calculate HR. I have the schematics at home, e-mail private if you want to see. +--------------------------+-----------------------+ | | ABL Canada inc. | | Jacques Audette | 8550 Cote-de-Liesse | | Hardware design | St-Laurent, Qc | | Video Codecs | H4T 1H2 | | | Tel: (514)344-5432 | | spam_OUTjacques.audetteTakeThisOuTabl.ca | Fax: (514)344-5439 | +--------------------------+-----------------------+ {Quote hidden}> ---------- > From: Rock Thompson[SMTP:.....rock_tKILLspam@spam@YAHOO.COM] > Reply To: pic microcontroller discussion list > Sent: Monday, March 30, 1998 10:10 AM > To: PICLISTKILLspamMITVMA.MIT.EDU > Subject: More Heart Monitors > > Recent discussion here and on several newsgroups has discussed the > type of heart rate monitor that uses a light directed through a finger > or earlobe. But the majority of current commercial exercise heart > rate monitors use a strap that goes across the users chest. You > dampen the two pads on the strap and it picks up your heart rate, > transmitting it to a display. Anyone have some thoughts on how to > build one of these? > > Rock T > > > > > _________________________________________________________ > DO YOU YAHOO!? > Get your free @yahoo.com address at http://mail.yahoo.com >

> From: Craig Webb <.....lucidKILLspam.....MAGNET.CA> > > What is interesting about the IR type is that they can measure both > oxygenated and non-oxygenated blood levels (using different IR wavelengths) No, not different IR wavelength. Pulseoximetrs use 2 LEDs - one RED and one IR. > and I've also even heard of some researchers doing studies with the shape of > the pulse curve which can tell information about heart valves and blockages, > etc. Very interesting. Yes, but it is an expecive device. You need 20-bit ADC to measure REDmax, REDmin, IRmax, IRmin value and then calculate SO2, but I never see the formula to calculate it..... Alex Torres, Kharkov, Ukraine (exUSSR) EraseMEaltorspam_OUTTakeThisOuTchat.ru 2:461/28@FidoNet www.geocities.com/SiliconValley/Lab/6311

In a not too old issue of Electronic Design, there was a very interesting design of a pulse meter, that used the LED-SENSOR pair principle, and had a brief but good explanation of the theory behind it. One of the nice things about this design was that it had an analog output, and a digital one. If anyone is interested I can dig the mag, and let you know the exact issue and page. Calvin {Original Message removed}

> From: Calvin <tgospam_OUTCHIH1.TELMEX.NET.MX> > > In a not too old issue of Electronic Design, there was a very interesting > design of a pulse meter, that used the LED-SENSOR pair principle, and had a > brief but good explanation of the theory behind it. One of the nice things > about this design was that it had an analog output, and a digital one. > > If anyone is interested I can dig the mag, and let you know the exact issue > and page. I'm interesting. Alex Torres, Kharkov, Ukraine (exUSSR) @spam@altorKILLspamchat.ru 2:461/28 FidoNet www.geocities.com/SiliconValley/Lab/6311