Medical Hacks

692 Articles

Digital Stethoscope Can Record, Playback, And Analyzer Heart Sounds

May 11, 2012 by 7 Comments

It’s somewhat amazing how these rather inexpensive electronics can augment the functionality of a common stethoscope. This digital stethoscope is using audio processing to add the features. A standard chest piece feeds a condenser microphone which is fed through a pretty standard OpAmp circuit which supplies the ADC of an ATmega644. After being digitized, the heart sound can be recorded in ten second increments to a 1 Mb flash memory chip. The data can also be fed to MATLAB via a USB cable in real-time. There it is displayed as a waveform and the heart rate is calculated on the fly. Check  out the video after the break for a great demo of the system.

The picture above shows a set of ear buds used as output. But this is a standard headphone jack, so the heart sounds can be played on speakers which we think would come in handy for teaching purposes. There’s also the option to hook it to a computer input which could be the audio used for a Skype session if a doctor is not close at hand. There is lots of potential here at a fairly low cost and we love that!

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Building A Prosthetic Leg From Scratch

May 5, 2012 by 18 Comments

[Radek] from Poland sent in a neat video of a bionic prosthetic leg he made for one of his patients. Even though [Radek] says it’s a ‘prototype of a prototype,’ we’d have to agree with him that it’s a very neat build that could provide inexpensive motorized prosthetic legs to amputees in the future.

[Radek] has been working on his project for about two years now, after building the motor and electronics by hand. The leg is powered by 1.5 kilogram battery pack – no details on the chemistry of the batteries, but [Radek] says it will last 12 hours on one charge. There are also small vibration sensors in the leg for a bit of feedback, and a few switches so the knee joint can be operated by the stump.

If you’re wondering where [Radek] got the proper tools and materials to make a carbon fiber prosthesis, he works for Carbon Prosthetics where builds simple prosthetic devices. His bionic leg creation looks really cool, and he says the final product will be much less expensive than the very high-end bionic prosthetic legs.

[Radek] was kind enough to share some more videos and a few pictures of his robotic prosthetic leg; you can check those out after the break.

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Tearing Down A Colonoscopy Pill Camera

April 20, 2012 by 60 Comments

Normally, colonoscopies are rather invasive affairs. Swallowing a small pill with a camera is much more amenable to a patient’s dignity and are seeing increasing usage in colon cancer screening. [Mike] acquired a pillcam from a relative who underwent the procedure and did a teardown to figure out how it works.

To get the video signal out of the body, the pillcam has two contacts that conduct the video signal through the body to stick-on contacts; It’s a more power efficient way of doing things versus a radio transmitter. After opening the plastic and metal capsule, [Mike] found three batteries and an impressively small circuit that contained an array of LEDs, a camera, and what might be a small MCU.

Taking a scope to the electronics in the pill, [Mike] found an impressively complex waveform that sends uncompressed image data to the receiver every few seconds. Although the camera was somewhat destroyed in the teardown, we’re pretty confident [Mike] could decode the image data if he had another… ‘sample.’

[Mike] says if you can ‘retrieve’ another one of these pill cameras, he’ll gladly accept any donations and look into the differences between different makes and models. Just make sure you sanitize it first. After the break you can see [Mike]’s teardown and the inevitable poop jokes in the comments. One last thing – if you’re over 50, doctors should be looking at your colon every 5 or 10 years. Get screened.

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Building An Artificial Heart With Ferrofluids

March 27, 2012 by 61 Comments

Here’s something we thought we’d never see on Hackaday. [Chris Suprock] is developing an artificial heart he calls Steel Heart. It’s an artificial heart powered by electromagnets and ferrofluids.

The idea behind [Chris]’ artificial heart is ingenious in its simplicity. An elastic membrane is stretched across a frame and a magnetic liquid (or ferrofluid, if you prefer) is poured across the membrane. An electromagnet is activated and the membrane stretches out, simulating the beating of a heart. Put a few of these together and you’ve got a compact, biologically inert pump that’s perfect for replacing an aging ticker.

[Chris]’ plan to use ferrofluids and electromagnets as an artificial heart give us pause to actually think about what he’s done here. Previously, artificial hearts used either pneumatics or motors to pump blood throughout the body. Pneumatic pumps required plastic tubes coming out of the body – not a satisfactory long-term solution. Motor-driven pumps can rupture red blood cells leading to hemolysis. Using ferrofluids and an elastic membrane allows for the best of both worlds – undamaged blood cells and transdermal induction charging.

Not only is [Chris] designing a freaking artificial heart, he also came up with a useful application of ferrofluids. We were nearly ready to write off magnetic particles suspended in a liquid as a cool science toy or artistic inspiration. You can check out [Chris]’ indiegogo video with a demo of the ferrofluid pump in action after the break.

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Automated Squinting Instead Of Glasses, Contacts, Or Lasik

February 22, 2012 by 41 Comments

[Lee] is nearsighted and has had it with contacts and glasses. When trying to figure out an alternative, he looked at the core of the problem. The eye is not shaped correctly and therefore cannot focus adequately. The solution is to change the shape of the lens. This is exactly what lasik (laser eye surgery) does, but instead of going under the incredibly bright knife [Lee] built some headgear that pulls on your face to reshape your eye.

The hardware is from an old portable CD player. The sled that moved the laser lens has been repurposed to pull a thread taped to the skin at the corner of his eye. He built a control system that lets him adjust the tension by moving his fingers. Basically when the skin is pulled tight it causes him to squint and possibly reshapes the cornea just a bit. We’re not sold on the idea, but we can’t poo-poo the experiment; who knows what discovery this could lead to? We’re just glad he didn’t use electrical impulses to hack his peepers.

You can find some test video embedded after the break.

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See In The Dark With This Bracelet Build

February 13, 2012 by 27 Comments

Even though she’s only in 8th grade, [Hannah Prutchi] is turning into a very respectable builder. She designed SharkVision, a wearable distance sensor that is meant to help the blind find objects they might bump into.

The SharkVision gets its name from shark’s ability to ‘see’ prey in their surroundings by sensing the local magnetic field. Instead of building her own Ampullae of Lorenzini, [Hannah] decided to take the easy route and use a few infrared sensors mounted to a bracelet. Whenever something is picked up by the proximity sensor, a voltage is applied to a pager motor telling the wearer they’re about to run into something.

[Hannah] and her classmates have successfully tested the SharkVision bracelet by walking around their classroom with eyes closed. They didn’t bump into anything, a fact [Hannah] attributes to neuroplasticity. We think it’s a neat build, but we’re wondering if this could be given to a population of blind people.