If you have this thing beeping with the heart-rate, you may get a bio-feedback kind of response with the user panicking and running the rate up higher.

Quite right, never thought of Bio-feedback effect :-)

Morse code report consists of dih-dah sound only and consists of time and pulse rate numbers at 750Hz monotone; for example, .---- ----- ----- ..... ----- -.... ...--, which stands for 1005 061 meaning 10:05am 061 Beat-per-minute, a bare minimum

human interface.

BTW, a new iPhone application is to monitor your heart rate via the built-in microphone (through either the onboard mic on the iPhone or through the mic/headset combo). This gives me a hint that a standard Infrared heartrate monitor clip is not a must, rather an tiny condensor-michrophone, which requires a dc voltage fed, could be used. Again, audible report (Morse code!) requirement implies a speaker or earphone being used as the output device. Such earphone could be used as a dynamic michrophone as well when the cicuit switches its use, perhaps. I'm coming up with a hardware design with PIC computers and a earlobe fixed earphone. Again, this device is used while jogging outdoors.

I was going to suggest using a Pic18 and I would suggest a finger sensor used by most hospitals much more comfortable than ear lobe. You would do better yet since I used to design Cardiac Pacemakers and have worked with patients that you design a voice synthesiser announcement of BPM which is more useful than beat by beat. Knowing your heart rate during exercise is very useful. You could in addition use a strobe light instead of a beep. This will not distract you so much.

Suggestion: I would suggest a finger sensor used by most hospitals much more comfortable than ear lobe.

I don't know of a commercially successful sports heart rate monitor using an oximeter probe, probably because joggers would find them uncomfortable to use. Those available are based on a chest belt recording ECG or wrist strap with a pressure transducer over the radial artery.

A suggestion:

- a Morse code requires a complex processing and interpretation at brain level

- variable frequency sound offers a much easier understanding especially for a communication which has to be more qualitative than quantitative

I also think that the sound will lead to less biofeedback.

Back comments are welcome.

Hi mktoni,

I use a Polar heart rate monitor and download the results into my PC after every excercise session.

I only keep the results, not the scond by second beeps . I would need a better more expensive Polar system than the one that I have and I believe that the second by second stuff is what the coach needs, not the individual but hey, i am no expert.

At this point the coach will be looking at power ouput from power measurement devices - on bikes anyway, and trying to correlate herat rate, poewer output, speed, what the other fellows are doing etc.

During this years Tour de France teh commentators had access to this stuff and were feeding this out to the public , "Joe is putting ouit 400 watts on this climb with his HR nearing 180 and a few seconds later, he was heading towards 200 and time to ease back a trifle."

i started using this system many years ago when I had a minor stroke and I was diagnosed with excercise! That has been a fairly consant part of my life ever since although I am nowhere near as fit as I ought to be!! But I keep the Polar monitor going.

the only problem that I have found is that I cannot use it for swimmimng as during the turn, you take a deep breath and it tends to slip down and stop recording! Otherwise it works well for running, cycling, gym excercise and so on.

There are other manufacturers of these systems but Polar have the edge for me as they have been around a long while.

Some have moved to a wrist strap but I am not sure how accurate they are? But they might overcome the swim problem above.

Good Luck, let us know what you decide to do and how it works out. We all need feedback in this life.

Sleepy

thank you all for your suggestions and insights. I will use PIC CPU for not only to program Morse code audible reporting, but also for 'trend' analysis of heart beats. Let me explain. My training coach tells me to keep the heart beat at my 'age level' number plus/minus some depending on your fitness, and maintain for minimum of 15 minutes to benefit from the aerobic effect during each 1 hour run session. Actual problem I encounter in my cardiovascular excercise session is to know exactly whether I'm maintaining the excercise strength level, i.e., the heart beat. My heart rate monitor shows the number but its LCD display is always 15 seconds delayed. I guess it's because some calculation time is involved. If that calculation is used to see if the actual heartbeat is accelerating or slowing down, it will help me to maintain the excercise strength. For heartbeat indication somebody suggested, instead of Morse code beep, some special sound burst to signal the pace change (up side or down side). Also If I am going to topple my max. heart rate number. it will sound a warning to me to slow down to avoid risk. de JN1HRG Fujisawa Solder Smoke Club

I'm thinking of a 3 in a box design; the heart rate monitor, a radio frequency telemetry transmitter derived from an AM/FM radio, and an MP3 player as a base assembly which usually has 3 Volt LiION rechargeable battery and USB connector for charging. This 3-in-1 design will be a nice breadboard. Eventually the heart rate monitor will become an independent unit packed very tiny like the hearing aids. Because of 3 in 1 design in a hip pouch, I will use body attachment of an pair of electrodes like cardiogram sensors instead of IR sensor clip. I can't wait till the weekend free time to begin scoping (I have an oscillocope from 70's ) for the best attchment point(s). Foot, legs, arms and fingers are out of question.

I'll start software simulation using sound card on my laptop PC for the sound burst / Morse code readout.

de JN1HRG Fujisawa Solder Smoke Club