A man with dark skin in a red shirt and khaki shorts sits in a chair. His left leg has a prosthetic below the knee. The upper half of the prosthethic is an off white plastic socket with flecks of different off white plastic throughout hinting at the recycled nature of the plastic. The lower half is a metal tube attached to an artificial foot in black sandals.

Precious Plastic Prosthetics

Plastic waste is a major problem, but what if you could turn the world’s trash into treasure? [Yayasan Kaki Kita Sukasada (YKKS)] in Indonesia is doing this by using recycled plastic to make prosthetic legs.

Polypropylene source material is shredded and formed into a sheet which is molded into the required shape for the socket. A layer of cloth and foam is used to cushion the interface between the patient and the socket itself. Using waste plastic to make parts for the prosthetics lowers the price for patients as well as helps to keep this material out of the landfill.

What makes this project really exciting is that [YKKS] employs disabled people who develop the prosthetics and also trains patients on how to maintain and repair their prosthetics with easily sourced tools and materials. With some medical device companies abandoning their devices, this is certainly a welcome difference.

We’ve previously covered the Precious Plastic machines used to make the plastic sheets and the organization’s developments at small scale injection molding.

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Top left of image shows a picture of a purplish-grey sea cucumber. Above the cucumber is the word "bio-inspiration." Arrows come from the cucumber to anthropomorphized cartoons of it saying "rigid" at the top with a cartoon sea cucumber standing straight up with spikes and the arrow captioned "soft" pointing down showing a crawling sea cucumber that looks more like a slug. To the right of the cucumber images is a set of three images stacked top to bottom. The top image is of a silver sphere with a zoomed-in atomic diagram with aligned magnetic poles next to it saying "solid state." The middle image shows arrows going up and down next to a snowflake and an artistic rendering of magnetic fields labeled "transition." The bottom image of this section shows a reddish sphere next to a zoomed-in atomic diagram where the magnetic poles are not aligned labeled "liquid state."

Phase Change Materials For Flexible And Strong Robots

Shape shifters have long been the stuff of speculative fiction, but researchers in China have developed a magnetoactive phase transitional matter (MPTM) that makes Odo slipping through an air vent that much more believable.

Soft robots can squeeze into small spaces or change shape as needed, but many of these systems aren’t as strong as their more mechanically rigid siblings. Inspired by the sea cucumber’s ability to manipulate its rigidity, this new MPTM can be inductively heated to a molten state to change shape as well as encapsulate or release materials. The neodymium-iron-boron (NdFeB) microparticles suspended in gallium will then return to solid form once cooled.

An image of a LEGO minifig behind bars. It moves toward the bars, melts, and is reconstituted on the other side after solidifying in a mold.

Applications in drug delivery, foreign object removal, and smart soldering (video after the break) probably have more real world impact than the LEGO minifig T1000 impersonation, despite how cool that looks. While a pick-and-place can do better soldering work on a factory line, there might be repair situations where a magnetically-controlled solder system could come in handy.

We’ve seen earlier work with liquid robots using gallium and bio-electronic hybrids also portending the squishy future of robotics.

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A Low Budget DIY Vibrotactile Stimulator For Experimental CRS

Modern techniques of Coordinated Reset Stimulation (CRS), which is usually administered with invasive deep brain stimulation, can have a miraculous effect on those suffering from Parkinson’s disease. However, the CRS technique can also apparently be administered via so-called vibrotactile CRS (vCRS) which essentially means vibrating certain nerve endings corresponding to brain regions that have a large cortical representation.

An example is vibrating the tips of the fingers using special gloves. This is a medical technique and as such is governed by the FDA. With ongoing trials, patients all around the world will simply have to wait. [HackyDev] has been working with a group of people on developing an open source vCRS glove.

This neuromodulation technique seems so promising, that this upfront effort by hackers around the world is simply a joy to see. Patents be dammed; we can work around them. Interested parties can follow the (very long, tricky-to-follow) thread here.

The hardware [HackyDev] put together uses a nodeMCU as the controller, driving eight motor coils via MOSFETS. The finger-mounted actuators are constructed by ripping the electromagnet out of a relay and mounting it in a 3D printed frame, with a magnet suspended on a spring. This part is mounted on each finger. The nodeMCU presents a simple web form that enables the configuration of the pulse parameters.

A permanent magnet is housed in the spring’s top section

The way the gloves appear to work is due to the way the body perceives sensory input, with a massive bias towards the hands and mouth region, referred to as the cortical homunculus. Each finger has an individual haptic element, which is actuated in a specific sequence with a carefully formed pulse at approx. 250 Hz.

This appears to activate similar in-brain effects as traditional (and invasive) DBS therapy by effectively de-synchronizing certain over-synchronized brain pathways and alleviating the overactive ß-wave activity in the brain. And this calms the tremors as well as many other PD symptoms. It’s all very exciting stuff, and we’ll be following this story closely.

For more on the backstory check out the 2017 paper by Peter A. Tass, as well as this later one, and this one. We’ve seen some recent success with diagnosing or at least detecting PD, by smell as well as via audio, so the future might look a little brighter for quite a number of people.

A four-fingered partial hand prosthesis in fuschia with black fingerpads is attached to a man's left hand (palm and thumb are original). He holds the left hand + prosthetic with his right hand and an aluminum hand prosthetic sits on the table to the left of his hands.

Designing A Simpler Prosthetic Finger

Prosthetic limb design is an area where desktop manufacturing has made huge strides, but there’s always room for improvement. For example, take a look at [Ian Davis] and his attempts to design a simpler prosthetic finger.

[Davis] favors his aluminum partial hand prosthetic for its strength, but because it was scratch built for his particular situation, it isn’t easy to recreate for someone else. To this end, he has started working on a simpler design that might be applicable in the future for people who want to build their own prosthetics. With less than ten major components per finger including the replaceable TPU fingerpads, this is a major step toward that end.

According to [Davis], one of the more exciting parts of the build is that while this hand has a more limited feature set, he was able to get it closer to the size of his natural hand. Because of the durability problems he’s experienced for day-to-day use of plastic prosthetics, he is having the next iteration 3D printed in stainless steel for further testing.

If you want to see some more interesting prosthetic designs, checkout the Kid Who Designed His Own Prosthetic Arm or this Skull Lamp Prosthetic Eye.

Blood Pressure Monitoring, Courtesy Of Cameras And AI

At the basic level, methods of blood pressure monitoring have slowly changed in the last few decades. While most types of sphygmomanometer still rely on a Velcro cuff placed around the arm, the methodology used in measurement varies. Analog mercury and aneroid types still abound, while digital blood pressure monitors using electrical sensors have become mainstream these days.

Researchers have now developed a new non-invasive method of measurement that does away with the arm cuff entirely. The method relies entirely on video capture with a camera and processing via AI.

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The display of a medical ultrasound scanner showing "HackedScan II"

Medical Ultrasound Scanner Gives Up Its Secrets, Runs DOOM

Medical equipment often makes for interesting teardown videos: the strict requirements imposed by certification bodies mean you’ll find good quality components and a high standard of design and manufacturing. But when [Buy It Fix It] bought an ultrasound scanner on eBay, he wasn’t interested in tearing it down: his plan was to use it to find out if his sheep are in lamb, so he went on to repair it and modify it for its new purpose.

The device in question is a Mediwatch Bardscan II, which is meant to be used for scanning people’s bladders. The mainboard has a completely different model number however, which suggests that the basic design is used for several types of ultrasound scanners. The system is powered by an AMD Geode processor that runs Windows XP Embedded stored on a CompactFlash card, so examining the internal software is easy: the scanner interface even runs on a regular Windows PC.

Several files on the internal drive point at hidden features, with filenames like kidney.dib and liver.dib indicating that the instrument can scan more than just bladders. The drive also holds several versions of the scanning app, as well as a .ini file in which lots of features can be enabled or disabled. By running the executable through x32dbg, [Buy It Fix It] was even able to recover the password to enable the “Advanced Settings” menu — it’s “u10” in case you were wondering.

With a bit of file editing, [Buy It Fix It] managed to turn the rather basic system into a way more flexible ultrasound scanner. For example, he can now adjust the scan depth, replay previous scans and make notes on top of any captured images. It can even run DOOM, as he demonstrates at the end of the video — though we can imagine his sheep might not enjoy the sight of their owner approaching them with a box full of flame-throwing demons.

Medical ultrasound scanners, which have been around for quite a while, may appear to be complex machines, but it is possible to make a simple version with easily available components.

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A scan (x-ray?) of a human skull. Electrodes trace around the skull and are attached to the brain. These implants are for reducing Parkinson's tremors.

What Happens When Implants Become Abandonware?

You’ve probably had a company not support one of your devices as long as you’d like, whether it was a smart speaker or a phone, but what happens if you have a medical implant that is no longer supported? [Liam Drew] did a deep dive on what the failure of several neurotechnology startups means for the patients using their devices.

Recent advances in electronics and neurology have led to new treatments for neurological problems with implantable devices like the Autonomic Technologies (ATI) implant for managing cluster headaches. Now that the company has gone out of business, users are left on their own trying to hack the device to increase its lifespan or turning back to pharmaceuticals that don’t do the job as well as tapping directly into the nervous system. Since removing defunct implants is expensive (up to $40k!) and includes the usual list of risks for surgery, many patients have opted to keep their nonfunctional implants. Continue reading “What Happens When Implants Become Abandonware?”