Walking Through MRIs With A Vive

June 24, 2018 by Dan Maloney 10 Comments

If you were to make a list of the most important technological achievements of the last 100 years, advanced medical imaging would probably have to rank right up near the top. The ability to see inside the body in exquisite detail is nearly miraculous, and in some cases life-saving.

Navigating through the virtual bodies generated by the torrents of data streaming out of something like a magnetic resonance imager (MRI) can be a challenge, though. This intuitive MRI slicer aims to change that and makes 3D walkthroughs of the human body trivially easy. [Shachar “Vice” Weis] doesn’t provide a great deal of detail about the system, but from what we can glean, the controller is based on a tablet and Vive tracker. The Vive is attached to the back of the tablet and detects its position in space. The plane of the tablet is then interpreted as the slicing plane for the 3D reconstruction of the structure undergoing study. The video below shows it exploring a human head scan; the update speed is incredible, with no visible lag. [Vice] says this is version 0.1, so we expect more to come from this. Obvious features would be the ability to zoom in and out with tablet gestures, and a way to spin the 3D model in space to look at the model from other angles.

Interested in how the machine that made those images works? We’ve covered the basics of MRI scanners before. And if you want to go further, you could always build your own.

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E-Dermis: Feeling At Your (Prosthetic) Fingertips

June 24, 2018 by Kristina Panos No comments

When we lose a limb, the brain is really none the wiser. It continues to send signals out, but since they no longer have a destination, the person is stuck with one-way communication and a phantom-limb feeling. The fact that the brain carries on has always been promising as far as prostheses are concerned, because it means the electrical signals could potentially be used to control new limbs and digits the natural way.

A diagram of the e-dermis via *Science Robotics*.

It’s also good news for adding a sense of touch to upper-limb prostheses. Researchers at Johns Hopkins university have spent the last year testing out their concept of an e-dermis—a multi-layer approach to expanding the utility of artificial limbs that can detect the curvature and sharpness of objects.

Like real skin, the e-dermis has an outer, epidermal layer and an inner, dermal layer. Both layers use conductive and piezoresistive textiles to transmit information about tangible objects back to the peripheral nerves in the limb. E-dermis does this non-invasively through the skin using transcutaneous electrical nerve stimulation, better known as TENS. Here’s a link to the full article published in Science Robotics.

First, the researchers made a neuromorphic model of all the nerves and receptors that relay signals to the nervous system. To test the e-dermis, they used 3-D printed objects designed to be grasped between thumb and forefinger, and monitored the subject’s brain activity via EEG.

For now, the e-dermis is confined to the fingertips. Ideally, it would cover the entire prosthesis and be able to detect temperature as well as curvature. Stay tuned, because it’s next on their list.

Speaking of tunes, here’s a prosthetic arm that uses a neural network to achieve individual finger control and allows its owner to play the piano again.

Thanks for the tip, [Qes].

MRI To 3D Print Gets Much Faster

June 15, 2018 by Al Williams 19 Comments

A surprising use of 3D printing has been in creating life-like models of human body parts using MRI or CT scans. Surgeons and other medical professionals can use models to plan procedures or assist in research. However, there has been a problem. The body is a messy complex thing and there is a lot of data that comes out of a typical scan. Historically, someone had to manually identify structures on each slice — a very time-consuming process — or set a threshold value and hope for the best. A recent paper by a number of researchers around the globe shows how dithering scans can vastly improve results while also allowing for much faster processing times.

As an example, a traditional workflow to create a 3D printed foot model from scan data took over 30 hours to complete including a great deal of manual intervention. The new method produced a great model in less than an hour.

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Internal Power Pills

June 12, 2018 by Brian McEvoy 20 Comments

Arguably the biggest hurdle to implanted electronics is in the battery. A modern mobile phone can run for a day or two without a charge, but that only needs to fit into a pocket and were its battery to enter a dangerous state it can be quickly removed from the pocket. Implantable electronics are not so easy to toss on the floor. If the danger of explosion or poison isn’t enough, batteries for implantables and ingestibles are just too big.

Researchers at MIT are working on a new technology which could move the power source outside of the body and use a wireless power transfer system to energize things inside the body. RFID implants are already tried and tested, but they also seem to be the precursor to this technology. The new implants receive multiple signals from an array of antennas, but it is not until a couple of the antennas peak simultaneously that the device can harvest enough power to activate. With a handful of antennas all supplying power, this happens regularly enough to power a device 0.1m below the skin while the antenna array is 1m from the patient. Multiple implants can use those radio waves at the same time.

The limitations of these devices will become apparent, but they could be used for releasing drugs at prescribed times, sensing body chemistry, or giving signals to the body. At this point, just being able to get the devices to turn on so far under flesh is pretty amazing.

Recently, we asked what you thought of the future of implanted technology and the comment section of that article is a treasure trove of opinions. Maybe this changes your mind or solidifies your opinion.

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Ask Hackaday: What Is The Future Of Implanted Electronics?

June 7, 2018 by Brian Benchoff 139 Comments

Biohacking is the new frontier. In just a few years, millions of people will have implanted RFID chips under the skin between their thumb and index finger. Already, thousands of people in Sweden have chipped themselves to make their daily lives easier. With a tiny electronic implant, Swedish rail passengers can pay their train ticket, and it goes without saying how convenient opening an RFID lock is without having to pull out your wallet.

That said, embedding RFID chips under the skin has been around for decades; my thirteen-year-old cat has had a chip since he was a kitten. Despite being around for a very, very long time, modern-day cyborgs are rare. The fact that only thousands of people are using chips on a train is a newsworthy event. There simply aren’t many people who would find the convenience of opening locks with a wave of a hand worth the effort of getting chipped.

Why hasn’t the most popular example of biohacking caught on? Why aren’t more people getting chipped? Is it because no one wants to be branded with the Mark of the Beast? Are the reasons for a dearth of biohacking more subtle? That’s what we’re here to find out, so we’re asking you: what is the future of implanted electronics?

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Muscle Your Way Into Music

May 28, 2018 by Al Williams 6 Comments

Inspired by an old Old Spice commercial, [Juliodb96] decided he too wanted to make music by flexing his muscles. An Arduino and a MyoWare sensor did the trick. However, he also tells you how to make your own sensors, if you are so inclined. You can see the instrument in action in the video below.

If you use the ready-made MyoWare sensors, this is a pretty easy project. You just respond to sensor input by playing some notes. If you decide to roll your own, you’ll have some circuit building ahead of you.

In particular, the signal conditioning for the sensors involves filtering to eliminate signals not in the 20 Hz to 300 Hz passband, several amplifiers, a rectifier, and a clipper. This requires 3 IC packages and a handful of discrete components.

Unlike the original commercial (see the second video, below), there are no moving parts for actuating actual instruments. However, that wouldn’t be hard to add with some servo motors, air pumps, and the like. This may seem frivolous, but we had to wonder if it could be used to allow musical expression for people who could not otherwise play an instrument.

This isn’t the first time we’ve seen the MyoWare in action. We’ve even talked about signal processing that is useful for this kind of application.

People With Dementia Can DRESS Smarter

May 19, 2018 by Brian McEvoy 9 Comments

People with dementia have trouble with some of the things we take for granted, including dressing themselves. It can be a remarkably difficult task involving skills like balance, pattern recognition inside of other patterns, ordering, gross motor skill, and dexterity to name a few. Just because something is common, doesn’t mean it is easy. The good folks at NYU Rory Meyers College of Nursing, Arizona State University, and MGH Institute of Health Professions talked with a caregiver focus group to find a way for patients to regain their privacy and replace frustration with independence.

Although this is in the context of medical assistance, this represents one of the ways we can offload cognition or judgment to computers. The system works by detecting movement when someone approaches the dresser with five drawers. Vocal directions and green lights on the top drawer light up when it is time to open the drawer and don the clothing inside. Once the system detects the article is being worn appropriately, the next drawer’s light comes one. A camera seeks a matrix code on each piece of clothing, and if it times out, a caregiver is notified. There is no need for an internet connection, nor should one be given.

Currently, the system has a good track record with identifying the clothing, but it is not proficient at detecting when it is worn correctly, which could lead to frustrating false alarms. Matrix codes seemed like a logical choice since they could adhere to any article of clothing and get washed repeatedly but there has to be a more reliable way. Perhaps IR reflective threads could be sewn into clothing with varying stitch lengths, so the inside and outside patterns are inverted to detect when clothing is inside-out. Perhaps a combination of IR reflective and absorbing material could make large codes without being visible to the human eye. How would you make a machine-washable, machine-readable visual code?

Helping people with dementia is not easy but we are not afraid to start, like this music player. If matrix codes and barcodes get you moving, check out this hacked scrap-store barcode scanner.

Thank you, [Qes] for the tip.