Leprosy is a bacterial disease that affects the skin, nerves, eyes, and mucosal surfaces of the upper respiratory tract. It is transmitted via droplets and causes skin lesions and loss of sensation in these regions. Also known as Hansen’s disease after the 19th century scientist who discovered its bacterial origin, leprosy has been around since ancient times, and those afflicted have been stigmatized and outcast for just as long. For years, people were sent to live the rest of their days in leper colonies to avoid infecting others.
Until Alice Ball came along, the only thing that could be done for leprosy — injecting oil from the seeds of an Eastern evergreen tree — didn’t really do all that much to help. Eastern medicine has been using oil from the chaulmoogra tree since the 1300s to treat various maladies, including leprosy.
The problem is that although it somewhat effective, chaulmoogra oil is difficult to get it into the body. Ingesting it makes most people vomit. The stuff is too sticky to be applied topically to the skin, and injecting it causes the oil to clump in abscesses that make the patients’ skin look like bubble wrap.
In 1866, the Hawaiian government passed a law to quarantine people living with leprosy on the tiny island of Moloka’i. Every so often, a ferry left for the island and delivered these people to their eventual death. Most patients don’t die of leprosy, but from secondary infection or disease. By 1915, there were 1,100 people living on Moloka’i from all over the United States, and they were running out of room. Something had to be done.
We’ll just go ahead and say it right up front: we love teardowns. Ripping into old gear and seeing how engineers solved problems — or didn’t — is endlessly fascinating, even for everyday devices like printers and radios. But where teardowns really get interesting is when the target is something so odd and so specialized that you wouldn’t normally expect to get a peek at the outside, let alone tramp through its guts.
[Mads Barnkob] happened upon one such item, a Fujifilm FCR XG-1 digital radiography scanner. The once expensive and still very heavy piece of medical equipment was sort of a “digital film system” that a practitioner could use to replace the old-fashioned silver-based films used in radiography, without going all-in on a completely new digital X-ray suite. It’s a complex piece of equipment, the engineering of which yields a lot of extremely interesting details.
The video below is the third part of [Mads]’ series, where he zeroes in on the object of his desire: the machine’s photomultiplier tube. The stuff that surrounds the tube, though, is the real star, at least to us; that bent acrylic light pipe alone is worth the price of admission. Previous videos focused on the laser scanner unit inside the machine, as well as the mechatronics needed to transport the imaging plates and scan them. The video below also shows experiments with the PM tube, which when coupled with a block of scintillating plastic worked as a great radiation detector.
For all the cool regenerative tricks the human body can do, it’s kind of weird that we only have one shot at tooth enamel with no way to get it back. That may be about to change, as researchers at the University of Washington have developed a lozenge that rebuilds this precious protective coating a few microns at a time and are taking it to the trial stage. Could it really work? It’s certainly something to chew on.
The lozenge uses a genetically-engineered peptide (a chain of amino acids) derived from a protein that’s involved in developing enamel in the first place, as well as with the formation of the root surface of teeth. Inside the lozenge, this peptide works alongside phosphorus and calcium ions, which are the building blocks of tooth enamel. It’s designed to bind to damaged enamel without harming the gums, tongue, or other soft tissues of the mouth.
The researchers have already verified the efficacy on teeth extracted from humans, pigs, and rats, so the trials will largely revolve around comparing it to other whitening methods and documenting their findings.
One added advantage is that the new enamel the lozenges produce is really white, because it’s brand new. These lozenges sound like an all-around great solution, especially compared with traditional whitening techniques that often make enamel weaker. The researchers are also developing an over-the-counter toothpaste and some kind of solution for hypersensitivity, which is right up our alley.
What are single-celled organisms good for, you may wonder? Science has found a wonderful new use for one of them — restoring partial sight to people with inherited forms of blindness. More specifically, they took a gene from algae that responds to light and moves toward it in order to replace dead or defective photo-receptor cells that lie between the human pupil and the optic nerve.
When light enters the eye, it triggers photo-receptor cells that in turn send signals to nerve cells called ganglions. These add information about motion and send the complete picture to the brain via the optic nerve. The researchers basically hacked the ganglion cells and turned them into photo-receptors. First they used a virus to get light-sensing molecules called chrimson into one of the retinas of the lone volunteer they’d managed to train before the pandemic. He’d been wearing the goggles out on walks and told them he could see the stripes of the crosswalk.
They were able to get him into the lab in summer 2020, where he donned a pair of goggles that register light changes and send amber light into the eye whenever that happens. He also wore a cap full of electrodes so the researchers could see what parts of his brain lit up when the goggles do their thing. With the goggles on and ready to fire, the man was able to distinguish whether a black cup was in front of him, and was even able to count multiple cups correctly most of the time. Although this is not a full restoration of vision, it’s an excellent development in that direction, and we’re excited to see where it goes.
We know you love a good biohack as much as we do, so we thought you would like [Tony’s] brainwave-controlled RC truck. Instead of building his own electroencephalogram (EEG), he thought he would use NeuroSky’s MindWave. EEGs are pretty complex, multi-frequency waves that require some fairly sophisticated circuitry and even more sophisticated signal processing to interpret. So, [Tony] thought it would be nice to off-load a bit of that heavy-lifting, and luckily for him, the MindWave headset is fairly hacker-friendly.
To control the car, he utilized the existing remote control instead of making his own. Like most people, [Tony] thought about hooking up the Arduino pins to the buttons on the remote control, thereby bypassing the physical buttons, but he noticed the buttons were a bit smaller than he was comfortable soldering to and he didn’t want to risk damaging the circuit board. [Tony’s] RC truck has a pistol grip transmitter, which inspired a slightly different approach. He mounted the servo onto the controller’s wheel mechanism, allowing him to control the direction of the truck by rotating the wheel using the servo. He then fashioned another servo onto the transmitter such that the servo could depress the throttle when it rotates. We thought that was a pretty nifty workaround.
Computers haven’t done much for the quality of our already poor handwriting. However, a man paralyzed by an accident can now feed input into a computer by simply thinking about handwriting, thanks to work by Stanford University researchers. Compared to more cumbersome systems based on eye motion or breath, the handwriting technique enables entry at up to 90 characters a minute.
Currently, the feat requires a lab’s worth of equipment, but it could be made practical for everyday use with some additional work and — hopefully — less invasive sensors. In particular, the sensor used two microelectrode arrays in the precentral gyrus portion of the brain. When the subject thinks about writing, recognizable patterns appear in the collected data. The rest is just math and classification using a neural network.
If you want to try your hand at processing this kind of data and don’t have a set of electrodes to implant, you can download nearly eleven hours of data already recorded. The code is out there, too. What we’d really like to see is some easier way to grab the data to start with. That could be a real game-changer.
Over the years, we’ve seen plenty of projects that use ultrasonic or time-of-flight sensors as object detection methods for the visually impaired. Ultrasonic sensors detect objects like sonar — they send sound pulses and measure the time it takes for the signal to bounce off the object and come back. Time-of-flight sensors do essentially the same thing, but with infrared light. In either case, the notifications often come as haptic feedback on the wrist or head or whatever limb the ultrasonic module is attached to. We often wonder why there aren’t commercially-made shoes that do this, but it turns out there are, and they’re about to get even better.
Today, Tec-Innovation makes shoes with ultrasonic sensors on the toes that can detect objects up to four meters away. The wearer is notified of obstacles through haptic feedback in the shoes as well as an audible phone notification via Bluetooth. The company teamed up with the Graz University of Technology in Austria to give the shoes robot vision that provides even better detail.
Ultrasonic is a great help, but it can’t detect the topography of the obstacle and tell a pothole from a rock from a wall. But if you have a camera on both feet, you can use the data to determine obstacle types and notify the user accordingly. These new models will still have the ultrasonic sensors to do the initial object detection, and use the cameras for analysis.
Whenever they do come out, the sensors will all be connected through the app, which paves the way for crowdsourced obstacle maps of various cities. The shoes will also be quite expensive. Can you do the same thing for less? Consider the gauntlet thrown!