Electronic Stethoscope and Analyzer for under $5.00

Hello All - This posting looks at designing "Low-Cost Electronic Stethoscopes – Heart/Lung Sound Analyzers."

First off, here's something I made for under $5.00. Essentially, I modified a pre-natal heartbeat monitor with a standard stethoscope head, then fed the results into an open-source heart/lung analysis software program.

Below are instructions and see photo album at http://picasaweb.google.com/tgideas/20090716#

1. Find a prenatal heart monitor. I bought mine at a charity shop for $3.00.

2. I found it works better to have an external standard stethoscope head attached to the monitor. Use a plumbing gasket and flexible tubing. Glue the gasket into the monitor head. Push the tubing into the gasket. Connect the other end of the tubing to a standard stethoscope head. I suppose you could use a small funnel if you can't find a stethoscope head.

3. On my monitor, I force the LISTEN button permanently down with a soda bottle cap and duct-tape. I then only use the ON/OFF volume control to turn the monitor on/off and adjust volume.

4. Connect the output of the monitor to the input of a laptop.

5. Download for free - Thinklabs Phonocardiography Open-Source Software

6. You're done! I plan to take a printout of my heartbeat and lung sounds with me on my next physical exam, along with normal heart and lung sound printouts too.

7. Long term, I plan to send these sounds and analysis to my doctor (telemedicine).

If you don't like what I did – here's a few others...plus some other links you might find useful.
http://nielsolson.us/Haversian/2007/12/stethophone.php

http://www.ymec.com/hp/signal2/heart1.htm

http://www.electronics-lab.com/projects/science/019/index.html

http://www.videojug.com/film/how-to-make-a-high-tech-spy-stethoscope

http://www.youtube.com/watch?v=iqjxOapIKbE

http://www.openheartsurgery.com/heart_sounds.html

If you still don't see what you're looking for, check out these patents. Please remember that newer patents are probably not expired, and therefore active. Patents that have expired due to age (generally more than 20 years old from the filing date) are free to use by anyone. Please note that just because something is patented or written, it might not work all that well or might not be safe in today's standards. Use your own judgment, or seek help, to stay safe and out of trouble.
Electronic sound amplifier stethoscope with visual heart beat and blood flow ...US Pat. 4783813 - Filed Dec 24, 1986

Universal stethoscope amplifier with graphic equalization and teaching and ...US Pat. 5832093 - Filed Jan 4, 1996

Compact hybrid stethoscopeUS Pat. 4528690 - Filed Mar 12, 1984

ACOUSTIC AND ELECTRONIC STETHOSCOPEUS Pat. 3247324 - Filed Jun 26, 1964

AMPLIFIED STETHOSCOPEUS Pat. 2419471 - Filed Oct 28, 1944

Noise-reducing stethoscopeUS Pat. 5492129 - Filed Dec 3, 1993

In addition, here's some Idea Seeds for new and improved versions.
* Computer assisted heart/lung sound analysis with preliminary diagnosis. See http://www.ncbi.nlm.nih.gov/pubmed/17701776 and http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=548236

* Garment showing best places to place the stethoscope head for untrained people. Also, this could be shown in a training video.

* Indicator on stethoscope head showing best place for heart and lung sounds for the untrained user.

That's about all for now. As background, the site "Design for the Other 90%" said to "GET INVOLVED", so I did. I plan to continue posting these LOW-COST DESIGN TOPICS on my Blog for a while yet. Let me know if you have a topic you would like covered. I'm open to suggestions on improving my blog format, too. Please e-mail me directly.. I hope you find this helpful. I'm sure you can do much better though! Good Luck!For more of my LOW COST DESIGN TOPICS - Click on the tag below "design for the other 90%".See disclaimers on TG Ideas LLC publications and website - http://my.athenet.net/~ideas/, Thanks!