3D Printing Delivers “Glass” Eyes In Record Time

December 10, 2021 by Al Williams 13 Comments

Obviously, losing an eye would be bad for your vision. But if you think about it, it is also a detriment to your appearance. You might not need a prosthetic eye, and you can certainly rock an eye patch, but a lot of people with this problem get an artificial or “glass” eye. These glass eyes are hand-painted disks that fit into the eye socket. However, a British man now has a new kind of eye prosthesis that is 3D printed, a technology that can potentially cut waiting time for patients in half.

The existing process is lengthy because it requires taking a mold of the eye socket and manually matching the remaining eye with the new artificial eye. With the 3D printed technology, scans of the eye socket and the other eye make this process much simpler.

Moorfields Eye Hospital, the source of the eye, says that a conventional eye takes about six weeks, but the new ones take no more than three weeks. The patient only needs to spend about a half-hour doing the scans before the wait starts. We presume it can be made for less cost, as well.

Medicine is embracing 3D printing and we’ve seen a 3D ear. We are waiting for our personal exoskeleton. Some of the medical 3D printing we’ve seen is for the birds.

E4 Empatica device for measuring location, temperature, skin conductance, sleep, etc. on arm

Wearable Sensor For Detecting Substance Use Disorder

December 9, 2021 by Orlando Hoilett 14 Comments

Oftentimes, the feature set for our typical fitness-focused wearables feels a bit empty. Push notifications on your wrist? OK, fine. Counting your steps? Sure, why not. But how useful are those capabilities anyway? Well, what if wearables could be used for a more dignified purpose like helping people in recovery from substance use disorder (SUD)? That’s what the researchers at the University of Massachusetts Medical School aimed to find out.

In their paper, they used a wrist-worn wearable to measure locomotion, heart rate, skin temperature, and electrodermal activity of 38 SUD patients during their everyday lives. They wanted to detect periods of stress and craving, as these parameters are possible triggers of substance use. Furthermore, they had patients self-report times during the day when they felt stressed or had cravings, and used those reports to calibrate their model.

They tried a number of classification models such as decision trees, discriminant analysis, logistic regression, and others, but found the most success using support vector machines though they failed to discuss why they thought that was the case. In the end, they found that they could detect stress vs. non-stress with an accuracy of 81.3% and craving vs. no-craving with an accuracy of 82.1%. Not amazing accuracy, but given the dire need for medical advancements for SUD, it’s something to keep an eye on. Interestingly enough, they found that locomotion data alone had an accuracy of approximately 75% when it came to indicating stress and cravings.

Much ado has been made about the insufficient accuracy of wearable devices for medical diagnoses, particularly of those that measure activity and heart rate. Maybe their model would perform better, being trained on real-time measurements of cortisol, a more accurate physiological measure of stress.

Finally, what really stood out to us about this study was how willing patients were to use a wearable in their treatment strategy. It’s sad that society oftentimes has a very negative perception of SUD patients, leading to fewer treatment options for patients. But hopefully, with technological advancements such as this, we’re one step closer to a more equitable future of healthcare.

The Challenges Of Finding A Substitute For Human Blood

December 9, 2021 by Maya Posch 19 Comments

Throughout history, the human body has been the subject of endless scrutiny and wonder. Many puzzled over the function of all these organs and fluids found inside. This included the purpose of blood, which saw itself alternately disregarded as being merely for ‘cooling the body’, to being responsible for regulating the body’s humors, leading to the practice of bloodletting and other questionable remedies. As medical science progressed, however, we came to quite a different perspective.

Simply put, our circulatory system and the blood inside it, is what allows us large, multi-celled organisms to exist. It carries oxygen and nutrients to cells, while enabling the removal of waste products as well as an easy path for the cells that make up our immune system. Our blood and the tissues involved with it are crucial to a healthy existence. This is something which becomes painfully clear when we talk about injuries and surgeries that involve severe blood loss.

While the practice of blood transfusions from donated blood has made a tremendous difference here, it’s not always easy to keep every single type of blood stocked, especially not in remote hospitals, in an ambulance, or in the midst of a war zone. Here the use of artificial blood — free from complicated storage requirements and the need to balance blood types — could be revolutionary and save countless lives, including those whose religion forbids the transfusion of human blood.

Although a lot of progress has been made in this field, with a limited number of practical products, it’s nevertheless proving to be a challenge to hit upon a replacement that ticks all of the boxes needed to make it generic and safe.

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Respiratory rate measuring device attached to volunteer's abdomen along with automated antidote injection system

Researchers Use Wearable To Detect And Reverse Opioid Overdoses In Real-Time

December 4, 2021 by Orlando Hoilett 32 Comments

Opioid overdose-related deaths have unfortunately been increasing over the last few decades, with the COVID-19 pandemic exacerbating this public health crisis even further. As a result, many scientists, healthcare professionals, and government officials have been working tirelessly to end this deadly epidemic. Researchers at the University of Washington are one such group and have recently unveiled a wearable to both detect opioid overdose and deliver an antidote, in real-time, restoring normal bodily function.

As the researchers describe in their paper, opioid overdose causes respiratory rate depression which will lead to hypoxia (insufficient oxygen in the blood) and ultimately death. Fortunately, opioid overdose can be readily reversed using naloxone, a compound that binds to receptors in the brain, outcompeting the opiates themselves, and restoring normal breathing. Unfortunately, if someone is overdosing, they are unable to self-administer the antidote and with many opioid overdoses occurring when the victim is alone (51.8%), it is necessary to develop an automated system to deliver the antidote when an overdose is detected.

The researchers begin by describing their process for measuring respiration, of which there are several options. You could use photoplethysmography in much of the same way we measure heart rate. Or you could measure the changing impedance of the chest cavity during breathing or even use an intraoral sensor that measures airflow in the mouth. Instead, the researchers opt to measure respiration by attaching accelerometers to the patient’s abdomen and measuring the movement of the abdominal cavity during breathing. They admit their technique becomes problematic when the patient is not stationary, but argue that in the case of a drug overdose, the patient is likely to be immobilized and the device would be able to measure respiration with ease. They tested their device across dozens of healthy, human volunteers, and even some opiate users themselves, and showed their technique had good agreement with a reference respiratory belt placed around the volunteers’ chests.

The cool part about this paper is that they demonstrated a “closed-loop” feedback system in which their device measured respiration, detected cessation in breathing (indicating an overdose), and delivered the antidote. To deliver naloxone, they leveraged an existing, commercially-available drug delivery system that requires a user to manually activate the device by pressing a button. They hacked the device a bit such that the trigger could be actuated using a servo motor properly positioned to depress the button when an opioid overdose is detected. They simulated an overdose by asking the healthy, human volunteers to hold their breath for a period greater than 15 seconds. They were able to successfully deliver the antidote to 100% of their volunteer group, indicating the device could potentially work in real-world settings.

Now, the form factor of the device undoubtedly needs to improve in order to deploy this device into the field, but we imagine those are improvements are underway and patients have shown willingness to wear such devices already. Also, there’s still a bit of a question of whether or not accelerometer-based breathing detection is optimal since some drug overdoses cause seizures. Nevertheless, this is an important step in combating the alarming rise in opioid overdose-related deaths and we hope to see many more advances in patient monitoring technologies in this field.

Exploring The Healing Power Of Cold Plasma

November 12, 2021 by Tom Nardi 22 Comments

It probably won’t come as much surprise to find that a blast of hot plasma can be used to sterilize a surface. Unfortunately, said surface is likely going to look a bit worse for wear afterwards, which limits the usefulness of this particular technique. But as it turns out, it’s possible to generate a so-called “cold” plasma that offers the same cleansing properties in a much friendlier form.

While it might sound like science fiction, prolific experimenter [Jay Bowles] was able to create a reliable source of nonthermal plasma for his latest Plasma Channel video with surprisingly little in the way of equipment. Assuming you’ve already got a device capable of pumping out high-voltage, all you really need to recreate this phenomenon is a tank of helium and some tubing.

Cold plasma stopped bacterial growth in the circled area.

[Jay] takes viewers through a few of the different approaches he tried before finally settling on the winning combination of a glass pipette with a copper wire run down the center. When connected to a party store helium tank and the compact Slayer Exciter coil he built last year, the setup produced a focused jet of plasma that was cool enough to touch.

It’s beautiful to look at, but is a pretty light show all you get for your helium? To see if his device was capable of sterilizing surfaces, he inoculated a set of growth plates with bacteria collected from his hands and exposed them to the cold plasma stream. Compared to the untreated control group the reduction in bacterial growth certainly looks compelling, although the narrow jet does have a very localized effect.

If you’re just looking to keep your hands clean, some soap and warm water are probably a safer bet. But this technology does appear to have some fascinating medical applications, and as [Jay] points out, the European Space Agency has been researching the concept for some time now. Who knows? In the not so distant future, you may see a similar looking gadget at your doctor’s office. It certainly wouldn’t be the first time space-tested tech came down to us Earthlings.

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Brain Implant Offers Artificial Vision To The Blind

November 4, 2021 by Al Williams 12 Comments

Nothing makes you appreciate your vision more than getting a little older and realizing that it used to be better and that it will probably get worse. But imagine how much more difficult it would be if you were totally blind. That was what happened to [Berna Gomez] when, at 42, she developed a medical condition that destroyed her optic nerves leaving her blind in a matter of days and ending her career as a science teacher. But thanks to science [Gomez] can now see, at least to some extent. She volunteered after 16 years to have a penny-sized device with 96 electrodes implanted in her visual cortex. The research is in the Journal of Clinical Investigation and while it is a crude first step, it shows lots of promise and uses some very novel techniques to overcome certain limitations.

The 96 electrodes were in a 10×10 grid with the four corner electrodes missing. The resolution, of course, is lacking, but the project turned to a glasses-mounted camera to acquire images and process them, reducing them to signals for the electrodes that may not directly map to the image.

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Tech In Plain Sight: Glucose Meters

October 20, 2021 by Al Williams 27 Comments

If you or someone you know is diabetic, it is a good bet that a glucose meter is a regular fixture in your life. They are cheap and plentiful, but they are actually reasonably high tech — well, at least parts of them are.

The meters themselves don’t seem like much, but that’s misleading. A battery, a few parts, a display, and enough of a controller to do things like remember readings appears to cover it all. You wouldn’t be surprised, of course, that you can get the whole affair “on a chip.” But it turns out, the real magic is in the test strip and getting a good reading from a strip requires more metrology than you would think. A common meter requires a precise current measurement down to 10nA. The reading has to be adjusted for temperature, too. The device is surprisingly complex for something that looks like a near-disposable piece of consumer gear.

Of course, there are announcements all the time about new technology that won’t require a needle stick. So far, none of those have really caught on for one reason or another, but that, of course, could change. GlucoWatch G2, for example, was a watch that could read blood glucose, but — apparently — was unable to cope with perspiration.

Even the meters that continuously monitor still work in more or less the same way as the cheap meters. As Hackaday’s Dan Maloney detailed a few years back, continuous glucose monitors leave a tiny sensor under your skin and measure fluid in your body, not necessarily blood. But the way the sensor works is usually the same.

For the purposes of this article, I’m only going to talk about the traditional meter: you insert a test strip, prick your finger, and let the test strip soak up a little bit of blood.

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