Useful signals from a heart monitor?

has anyone here used heart monitoring with their music? i’m a huge milford graves fan and his health issues have make me think about the heart as it relates to music again. i’ve got an overly basic idea that i’d love to take my heart beats and use them to trigger events on my modular while drumming live - interested to see how my internal rhythms interact with my external rhythms - if at all.

could a contact mic taped to my torso be sensitive enough? would the physical activity of drumming disrupt that? is it better to get equipment that is built for heart monitoring and try to convert the signal into something applicable? i’m starting from zero but figured there might be someone here who has done this or something like it before.

It sounds like the ADDAC heart sensing module https://www.addacsystem.com/en/products/modules/addac300-series/addac307 does exactly what you’re looking for if you’re looking for an out of the box (DIY only) solution.

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interesting… i’d love to build it but it appears out of stock, and perfect circuit seems to have it built.

might be a nice way to start, and at least see if i like what i’m able to get out of heart rate as a trigger… great find!

exactly, that’s what i was thinking - get a good signal in, then i could use it as a trigger or even a sound source. i guess my bigger question here is how to get a good signal in the first place.

the module posted above is great and i’m looking into it - but i’m worried the clip-on method of getting the signal would be tough to maintain while drumming. i was figuring i’d get or make something and athletic tape it to my torso for a clear signal and mobility’s sake.

i’ve used my heart rate to control the bpm of my sequencers. its actually pretty easy. you can use a simple pulse sensor which sends the pulses to a computer (with help from an arduino) which computes a bpm and sends that to connected instruments via midi clk.

here’s my instructions and a demo on how to use your heartbeat for triggering electronic instruments.

while it works pretty well, i’ve noticed that its hard to maintain a steady signal if you plan on jamming out hard (moving too much displaces the sensor). also, the signal doesn’t vary too much in a single session, unless you get really excited (or fall alseep). however, to get around this, i’ve been playing with pre-recording my heart rate data. that way i can use extreme environments (running / taking cold bath / taking hot bath) to modulate my heart rate in a more extreme way. i’m planning on then plugging in the pre-recorded heart-rate data to modulate instruments.

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Just theorizing here but there are different ways to transfer your heart’s beat:

  1. Acoustically. That’s what a stethoscope does. A stethoscope is a bit of a special construct that enables a health practitioner to hear nuances of the heart’s beat. That degree of nuance is not necessary for a musical application. You might get good sound results by placing a funnel on your chest and insert a good microphone on the other end of the funnel (similar to what a satellite dish does). Maybe try spanning a membrane (cling wrap in the US?) over the funnel’s end that touches your chest. That’s essentially what a stethoscope does

  2. Electrically. That’s what an ECG does. It measures the electrical current that your heart produces with each heart beat. it is a weak current that needs to be amplified.

  3. Vibrationally. A good contact mic might be able to pic up the vibration caused by your heart valves open and close. I would try around the upper edges left and right of your sternum as well as the lower left front of your chest over the ribs.

  4. Doppler ultrasound. Ever heard a baby’s heartbeat in its mom’s tummy?

  5. Photodetection. From Wikipedia: In its most common (transmissive) application mode, a sensor device is placed on a thin part of the patient’s body, usually a fingertip or earlobe, or in the case of an infant, across a foot. The device passes two wavelengths of light through the body part to a photodetector. The above linked ADDAC is in this category

  6. Functional MRI for those that have a MRI standing around at home? (just kidding)

Marius

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I’ve done it with a pulse sensor and the Koma Field Kit.

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This article seems relevant: https://www.nytimes.com/2020/08/05/nyregion/milford-graves-drummer.html?fbclid=IwAR3NBTL8xwqQ_WgWPa3jpAwGG1p021KK9_FijfCLj4yRtCCZJRTkCqk8iqY

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yep. this is what i read this morning that put me on this train of thought!

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As a cyclist and runner, I’ve got a couple of heart rate sensing chest straps hanging around the house. These transmit via bluetooth or a protocol called ANT+, which is a Garmin proprietary thing, but open.
My though would be to use one of these straps plus a microcontroller with bluetooth built in, or a Raspberry Pi, and DIY a small module that would output a gate or trigger every time it receives a heart beat packet over bluetooth.
Of course, the strap may send a “number of beats per time period” packet, so you’d have to reconstruct the pulse on the microcontroller / RaspPi.
It could be a lot of work!

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Having spent quite a lot of time connected to some of these last year (& I’ve even got an embedded ICD now that measures all this stuff from a wire in my heart AND sends it somewhere by wifi but I have no access to that (probably a good thing :wink: ). It was frustrating they didn’t have any way of sharing any more than pictures of data with me. (I did ask)

this would certainly be the most useful - strongest and likely most stable signal. It is just an electrical signal measured from one of your limbs to your chest. I wonder if you could actually rig something up with an Arduino type affair (it wouldn’t be medical grade but that’s not what we are aiming for)

This is the one that interested me the most - made lots of interesting sounds when they measured my heart. You can get home ultrasounds for pregnancy - has anyone tried these? (they are a bit expensive for take a punt)

I have no idea what they measured or got when I was in that thing. but kind of unwieldy :wink:

following with interest

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