Heart Rate designer lamp

Marcello · 2009-11-20 13:48

I just whish to show you a nice project.

The small PCB samples the persons heart rate and transmits it via radio to the designer lamp.
The designer lamp flashes with your heart and plays a sound according to your heart beat.

Here some photos:

Leon · 2009-11-20 14:13

Are you using a microphone as the HR sensor?

Leon

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Amateur radio callsign: G1HSM

heater · 2009-11-20 15:07

Maecello, that is one weird but very stylish lamp. It would meake an excellent design for a vacuum tube audio amplifier. In fact combining the heart rate monitor lamp with a tube amp might be a match made in heaven.

Wow, did I just find the long lost perfect project that combines vacuum tubes and Propllers?

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For me, the past is not over yet.

Post Edited (heater) : 11/20/2009 3:13:01 PM GMT

ElectricAye · 2009-11-20 16:38

Leon said...
Are you using a microphone as the HR sensor?

Leon

I bet what Leon really wants to know is this: is your heart rate sensor properly isolated from the person?

heater · 2009-11-20 16:46

Well the first post says it uses a wireless link from the heart end to the lamp end. So unless the heart end is run off the mains or contains some taser circuitry it sounds pretty safe whatever means of detection is used.

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For me, the past is not over yet.

Leon · 2009-11-20 17:47

I was partly thinking about safety, although it looks like he's got a mic pre-amp on the board. I just wanted it confirmed. He might be using one of those finger or ear lobe sensors, of course.

Leon

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Amateur radio callsign: G1HSM

Post Edited (Leon) : 11/20/2009 5:53:00 PM GMT

ElectricAye · 2009-11-20 17:50

heater said...
Well the first post says it uses a wireless link from the heart end to the lamp end. So unless the heart end is run off the mains or contains some taser circuitry it sounds pretty safe whatever means of detection is used.

Maybe I'm wrong about this, but I think you can still stop a beating heart with a 9 volt battery and some badly designed circuits. And certainly if the Prop is running off a wall power supply, or something else that the Prop is connected to is powered by the line, you can get zapped if things are not isolated properly.

heater · 2009-11-20 19:11

Perhaps if you opened up you chest and applied the battery directly to the heart that might do it. Otherwise I think not.

I'm busy looking for a 9v battery to jam onto my chest to prove the point. If you don't hear from me again you have learned an important result.

You should not fear the volts or even the amps but how much energy delivered over what time.
I believe defibrillator output is calibrated in joules for this reason.

Shocks from Van Der Graff generators at many 10's of thousands of volts are unlikely to kill you.

There are those who maintain that 42.4 Volts is the minimum lethal voltage.www.ednasia.com/article-7565-hazardousvoltageprimer-Asia.html
Claiming 3 digits of accuracy here is obviously absurd so lets say 40 to be safe.

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For me, the past is not over yet.

Harley · 2009-11-20 20:18

Marcello,

I am looking for the simplest isolated heart pulse sensor myself. Possibly an IR LED and photo transistor would suffice. But I've not delved into this sensor area enough yet. Could you provide info/schematic of the 'front end'? Thanks.

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Harley Shanko

SciNemo · 2009-11-20 20:21

I thought the amps killed you. I doubt 40 or even 1 million volts would do much of anything to a person if the amperage was low enough.

And very nice project. I'm also curious about the method of heart rate detection. I worked on a project that used an IR LED to shine light through a person's earlobe, easily detecting the pulse because less lights gets through when more blood is present, and that happens every time the heart beats (but you have to account for the delay if you want the actual heart beat, as the pulse actually travels quite slowly to the earlobe or finger).

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Not the fish.
sites.google.com/site/bitwinproject/

Post Edited (SciNemo) : 11/20/2009 8:26:34 PM GMT

ElectricAye · 2009-11-20 22:10

Hmmmm... all this speculation about whether or not an improperly wired heart monitor might kill you.... I guess I'm wrong about that.

But does anyone else find it strange that we haven't heard from Marcello for a while?

Marcello, if you can still hear us, stop staring at the ceiling and blink your eyes.... Marcello? ...... Marcello, are you okay?

Marcello!

Speak to me, Marcello!

MasterC · 2009-11-20 22:34

SciNemo said...
I thought the amps killed you. I doubt 40 or even 1 million volts would do much of anything to a person if the amperage was low enough.

This has become something of a pet peeve of mine for some reason. People go around saying, "It's not the volts, it's the amps that kill you!" This simply demonstrates a lack of knowledge of how electricity works. Voltage and current are proportional to each other, related by the resistance (V = IR). In other words, for a given amount of resistance, a higher voltage results in a higher current. There is no way to apply 1 million volts to a person's un-isolated body without also seeing a high enough current to do some damage.

As heater said, the duration of exposure is also a factor.

Sorry, this is certainly not the topic of the thread.

heater · 2009-11-20 22:55

I think the confusion comes because people may have seen something like a Van Der Graff generator and been told that it generates hundred of thousands of volts. Then they find you can draw a spark from it your finger without the slightest chance of injury or death. "Ah it must be the amps that does it then". It's an experiment we all did in school. No idea if that sort of thing still goes on in schools.

Missing the point that as soon as that spark jumps there is no more hundreds of thousands of volts.

So what is it really that kills you? Ultimately you need some amount of energy delivered fast enough. But if we start talking in Joules everyone is lost. Seems they don't teach basic physics in school any more.

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For me, the past is not over yet.

pmrobert · 2009-11-20 23:47

The amount of energy required to cause a lethal arrhythmia (death!) is extremely variable and depends on multiple factors. These include, but are not limited to:

Amount of energy delivered to the heart muscle (myocardium) - energy delivered from surface electrodes is greatly affected by skin and transthoracic resistance, among other things;
Timing of said impulse(s) in the intrinsic cardiac cycle;
Preexisting disease of any kind;
Electrolyte levels in both plasma and heart cells;
Existing medications/drugs in system;
Genetic variability;

It is even possible for a blow to the chest to initiate a lethal rhythm; See en.wikipedia.org/wiki/Commotio_cordis
I usually don't use Wikipedia for a cite but this article is pretty good.

Bottom line is that I fully support Leon's cautions.

mikediv · 2009-11-21 00:42

Marcello Top rate project very nicely done. You should consider doing this project in the completed projects section with code ans schematics its a very interesting and impressive design

mctrivia · 2009-11-21 03:30

Current is what kills. Static electricity is often in the 1-10kv range and with a good vandigraph generator can get it much higher.

On dry skin anything under 30v can not produce enough current across the heart to kill you. However a 9v on your toung can kill you under extreme circumstances

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24 bit LCD Breakout Board coming soon. $21.99 has backlight driver and touch sensitive decoder.

Marcello · 2009-11-21 08:54

Hi to all !

i live in Germany (but i am italian) so i slept while you were posting.

Now i've got only a few minutes to answere to so many questions.

- i read the pulse with an IR sensor on a finger, so there is no electrical contact between user and circuit.
· The circuit is running with a 9V battery. Great effort has been invested into power management.
·· In standby a battery would last for 3-5 years.
·· A tilt sensor wakes up the propeller when the "remote control" is shaken / picked up

- i communicate·with the lamp via 433 RF link.

- actually the project was made for an italian artist. I did a lot of projects with him.
· the lamp design is made by the artist + a wood specialist in ancient musical instruments.

I promise to go deeper in details later ...

Have a nice weekend !

Post Edited (Marcello) : 11/21/2009 9:10:00 AM GMT

Searider · 2009-11-21 14:06

I wonder what it would take to interface to the Heart rate pickups that are common with exercise equipment. I have one that straps around my chest and I get a read-out on the treadmill pannel. It does not have an on-off switch so it must have a very low power profile.

Marcello, the idea of a tilt sensor to detect when power is needed is a great idea !· Very cool project and thanks for sharing.

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Searider

David B · 2009-11-21 16:46

Nice project, Marcello!

I was also wondering how the heartrate was picked up, as I've also wanted to do something along those lines.

The battery in my Polar heartrate chest-strap sensor wore out, and I didn't want to bother sending it in to be replaced, so I ripped mine open and changed the battery myself. It works again, but I haven't closed it up yet. (I have another that still works)

Here's a photo. You can see a ferrite rod antenna unit that sends the signal. I put a scope on a pickup a few years ago and looked at the signal, but have forgotten just what it looks like, but it is quite a low frequency.

Sparkfun sells sensors that are supposed to receive these signals.

Harley · 2009-11-21 19:42

Marcello,

One more question, how much gain is required between the IR detector output and the Prop? This answer can save one much experimentation and time and expense purchasing the 'right' parts.

Would be nice to have a DigiKey right next door.

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Harley Shanko

Heart Rate designer lamp

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