Medical Hacks

658 Articles

RFID Stethoscope Wheezes And Murmurs For Medical Training

February 16, 2017 by 10 Comments

You’d think that with as many sick people as there are in the world, it wouldn’t be too difficult for a doctor in training to get practice. It’s easy to get experience treating common complaints like colds and the flu, but it might take the young doctor a while to run across a dissecting abdominal aortic aneurysm, and that won’t be the time for on the job training.

Enter the SP, or standardized patient – people trained to deliver information to medical students to simulate a particular case. There’s a problem with SPs, though. While it’s easy enough to coach someone to deliver an oral history reflecting a medical condition, the student eventually needs to examine the SP, which will reveal none of the signs and symptoms associated with the simulated case. To remedy this, [Chris Sanders] and [J Scott Christianson] from the University of Missouri developed an open-source RFID stethoscope to simulate patient findings.

This is one of those “why didn’t I think of that?” ideas. A cheap stethoscope is fitted with an Arduino, and RFID reader, and a small audio board. RFID tags are placed at diagnostic points over an SP’s chest and abdomen. When the stethoscope is placed over a tag, a specific sound file is fetched from an SD card and played over earbuds. The student doesn’t have to ask, “What am I hearing?” anymore – the actual sound of bruits or borborygmi are heard.

We can easily see expanding this system – RFID tags that trigger a faux ultrasound machine to display diagnostic images, or tiny OLED screens displaying tagged images into an otoscope. A good place to start expanding this idea might be this digital stethoscope recorder and analyzer.

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Paper Toy Can Save Lives

January 22, 2017 by 68 Comments

Although there is a lot of discussion about health care problems in big countries like the United States, we often don’t realize that this is a “first world” problem. In many places, obtaining health care of any kind can be a major problem. In places where water and electricity are scarce, a lot of modern medical technology is virtually unobtainable. A team from Standford recently developed a cheap, easily made centrifuge using little more than paper, scrap material like wood or PVC pipe, and string.

A centrifuge is a device that spins samples to separate them and–to be effective–they need to spin pretty fast. Go to any medical lab in a developed country and you’ll find at least one. It will be large, heavy, expensive, and it will require electricity. Some have tried using hand-operated centrifuges using mechanisms like an egg beater or a salad spinner, but these don’t really move fast enough to work well. At the least, it takes a very long time to get results with a slow centrifuge.

[M. Saad Bhamla] and his colleagues at Stanford started brainstorming on this problem. They thought about toys that rotate, including a yo-yo. Turns out, those don’t spin all that fast, either. Then they considered a whirligig. We had forgotten what those are, but it is the real name for a toy that has a spinning disk and (usually) a string. When you pull on the string, the disk spins and the more you pull, the faster the disk spins. These actually have an ancient origin appearing in medieval tapestries and almost 2,500 years ago in China.

[Bhamla] found that how the toy worked was poorly understood (from a scientific standpoint)  and took pictures of one in operation with a high-speed camera. The team was able to create the “paperfuge”, a human-powered centrifuge that would spin at 125,000 RPM, enough to separate plasma from blood in under two minutes and isolate malaria parasites in 15. Some versions of the device could cost as little as twenty cents and don’t require anything more exotic than paper and string. You can see a video about the paperfuge, below.

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[Marla]’s New Arm

January 19, 2017 by 32 Comments

It is especially rare to see coverage in the mainstream media that involves a hackspace, so it was a pleasant surprise yesterday when the local TV news where this is being written covered a story that not only highlighted a hackspace’s work, but did so in a very positive light.

[Marla Trigwell] is a young girl from Newbury, UK, who was born without a left hand. She had been provided with prosthetics, but they aren’t cheap, and as a growing child she quickly left them behind. Her parents researched the problem as modern parents do, and found out about recent advances in 3D-printed prosthetics lowering the bar to access for those like [Marla] born without a limb. Last month [Marla] received her new 3D-printed arm, and she did so courtesy of the work of [Andrew Lindsay] at Newbury and District Hackspace.

The arm itself is a Team Unlimbited arm version 2.0 Alfie edition, which can be found on Thingiverse with full sizing instructions for adjusting to the recipient in Customizer. As the video below the break shows, [Marla] appears very pleased with it, and is soon mastering its ability to grip objects.

This story is a fantastic demonstration of the ability of a hackspace to be a force for good, a true community organisation. We applaud [Andrew], NADHack, and all involved with it for their work, and hope that 3D printed arms will keep [Marla] with a constant supply of comfortable and affordable prosthetics as she grows up.

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Recording Functioning Muscles To Rehab Spinal Cord Injury Patients

January 10, 2017 by 3 Comments

[Diego Marino] and his colleagues at the Politecnico di Torino (Polytechnic University of Turin, Italy) designed a prototype that allows for patients with motor deficits, such as spinal cord injury (SCI), to do rehabilitation via Functional Electrical Stimulation. They devised a system that records and interprets muscle signals from the physiotherapist and then stimulates specific muscles, in the patient, via an electro-stimulator.

The acquisition system is based on a BITalino board that records the Surface Electromyography (sEMG) signal from the muscles of the physiotherapist, while they perform a specific exercise designed for the patient’s rehabilitation plan. The BITalino uses Bluetooth to send the data to a PC where the data is properly crunched in Matlab in order to recognize and to isolate the muscular activity patterns.

After that, the signals are ‘replayed’ on the patient using a relay-board connected to a Globus Genesy 600 electro-stimulator. This relay board hack is mostly because the Globus Genesy is not programmable so this was a fast way for them to implement the stimulator. In their video we can see the muscle activation being replayed immediately after the ‘physiotherapist’ performs the movement. It’s clearly a prototype but it does show promising results.

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Cornell Students Have Your Back

January 8, 2017 by 21 Comments

Back problems are some of the most common injuries among office workers and other jobs of a white-collar nature. These are injuries that develop over a long period of time and are often caused by poor posture or bad ergonomics. Some of the electrical engineering students at Cornell recognized this problem and used their senior design project to address this issue. [Rohit Jha], [Amanda Pustis], and [Erissa Irani] designed and built a posture correcting device that alerts the wearer whenever their spine isn’t in the ideal position.

The device fits into a tight-fitting shirt. The sensor itself is a flex sensor from Sparkfun which can detect deflections. This data is then read by a PIC32 microcontroller. Feedback for the wearer is done by a vibration motor and a TFT display with a push button. Of course, they didn’t just wire everything up and call it a day; there was a lot of biology research that went into this. The students worked to determine the most ideal posture for a typical person, the best place to put the sensor, and the best type of feedback to send out for a comfortable user experience.

We’re always excited to see the senior design projects from university students. They often push the boundaries of conventional thinking, and that’s exactly the skill that next generation of engineers will need. Be sure to check out the video of the project below, and if you want to see more of this semester’s other projects, we have you covered there too.  Continue reading “Cornell Students Have Your Back” →

The Cyborg Artist – Tattoo Machine Arm Prosthesis

January 4, 2017 by 13 Comments

[JC Sheitan Tenet] lost his right arm when he was 10 years old. As most of us, he was right-handed, so the challenges he had to face by not having an arm become even harder.

Have you ever tried to perform mundane tasks with your non-dominant hand? If you’re right-handed, have you ever tried to feed yourself with your left? Or if you’re left-handed, how well can you write with your right? For some people, using both hands comes naturally, but if you’re anything like me, your non-dominant hand is just about useless.

The thing is, he wanted to be a tattoo artist. And he wasn’t giving up. Even facing the added difficulty of not finding a tattoo artist that wanted to take him as an apprentice, he did not gave up. So he became a tattoo artist, using only his left arm. That is, until some months ago, when he met [Jean-Louis Gonzal], a bio-mechanical artist with an engineer background, at a tattoo convention. After seeing [Gonzal] work, he just asked if it was possible to modify a prosthesis and attach a tattoo machine to it.

The Cyborg Artist is born. The tattoo machine in the prosthesis can move 360 degrees for a wide range of movements. [JC Sheitan Tenet] uses it to help with colours, shadows and abstract forms in general. It’s a bad-ass steam punk prosthesis and it’s not just for show, he actually works with it (although not exclusively) . This, it seems, is only the beginning, since the first version of prototype worked so well, the second version is already being planned by [JC] and [Gonzal]. We can’t wait to see what they’ll come up with, maybe a mix between current version and a tattoo robotic arm or a brain controlled needle?

Check it out in the video:

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Old fashioned polygraph

Retro-Style DIY Polygraph: Believe It Or Not

January 3, 2017 by 10 Comments

A polygraph is commonly known as a lie detector but it’s really just a machine with a number of sensors that measure things like heart rate, breathing rate, galvanic skin response and blood pressure while you’re being asked questions. Sessions can be three hours long and the results are examined by a trained polygraph examiner who decides if a measured reaction is due to deception or something else entirely. Modern polygraphs feed data into a computer which analyses the data in real-time.

Cornell University students [Joyce Cao] and [Daria Efimov] decided to try their hand at a more old fashioned polygraph that measures heart and breathing rates and charts the resulting traces on a moving strip of paper as well as a color TFT display. They had planned on measuring perspiration too but didn’t have time. To measure heart rate, electrodes were attached to the test subject’s wrists. To measure breathing they connected a stretch sensor in the form of a conductive rubber cord around three inches long to a shoelace and wrapped this around the test subject’s abdomen.

While the output doesn’t go into a computer for mathematical analysis, it does go to a PIC32 for processing and for controlling the servos for drawing the traces on the paper as well as displaying on the TFT. The circuit between the breathing sensor and the PIC32 is fairly simple, but the output of the heart rate electrodes needed amplification. For that they came up with a circuit based off another project that had a differential amplifier and two op-amps for filtering.

Since parts of the circuit are attached to the body they made some effort to prevent any chance of electrocution. They used 12 volts, did not connect the test subject to power supply chassis ground, and tested the heart rate electrodes with a function generator first. They also included DC isolation circuitry in the form of some resistors and capacitors between the heart rate electrodes and the amplifier circuit. You can see these circuits, as well as a demonstration in the video below. The heart rate output looks a little erratic, no surprise given that the body produces a lot of noise, but the breathing trace looks very clear.

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