The devices themselves consist of electrodes implanted into the retina, which can send signals to the nervous system which appear as spots of light to the user. A camera feed is used to capture images which are then translated into signals sent to the retinal electrodes. The results are low-resolution to say the least, and the vision supplied is crude, but it gives users that are blind a rudimentary sense that they never had before. It’s very much a visual equivalent to the cochlear implant technology.
The story is altogether too familiar; Second Sight Medical Products came out with a cutting-edge device, raised money and put it out into the world, only to go bankrupt down the road, leaving its users high and dry. Over 350 people have the implants fitted in one eye, while one Terry Byland is the sole person to have implants in both his left and right eyeballs. Performance of the device was mixed, with some users raving about the device while others questioned its utility.
Before the Medtronic Bravo Reflux Capsule was attached to his lower esophagus, [James] got a good look at a demo unit of the pencil-width gadget. Despite the medical technician telling him the device used a “Bluetooth-like” communications protocol to transmit his esophageal pH to a wearable receiver, the big 433 emblazoned on the hardware made him think it was worth taking a closer look at the documentation. Sure enough, its entry in the FCC database not only confirmed the radio transmitted a 433.92 MHz OOK-PWM encoded signal, but it even broke down the contents of each packet. If only it was always that easy, right?
Of course he still had to put this information into practice, so the next step was to craft a configuration file for the popular rtl_433 program which split each packet into its principle parts. This part of the write-up is particularly interesting for those who might be looking to pull data in from their own 433 MHz sensors, medical or otherwise
Unfortunately, there was still one piece of the puzzle missing. [James] knew which field was the pH value from the FCC database, but the 16-bit integer he was receiving didn’t make any sense. After some more research into the hardware, which uncovered another attempt at decoding the transmissions from the early days of the RTL-SDR project, he realized what he was actually seeing was the combination of two 8-bit pH measurements that are sent out simultaneously.
We were pleasantly surprised to see how much public information [James] was able to find about the Medtronic Bravo Reflux Capsule, but in a perfect world, this would be the norm. You deserve to know everything there is to know about a piece of electronics that’s going to be placed inside your body, but so far, the movement towards open hardware medical devices has struggled to gain much traction.
If you’ve ever taken a coast-to-coast car trip across the United States, the one thing that’s sure to impress you is the mind-bogglingly immense amount of corn that we grow here. If you take the northern route — I’ve done it seven times, so I know it by heart — you’ll see almost nothing but corn from Ohio to Montana. The size of the fields is simply staggering, and you’re left wondering, “Do we really eat all this corn?”
The simple answer is no, we don’t. We grow way more corn than we can eat or, once turned into alcohol, drink. We do feed a lot to animals, many of which subsequently end up as burgers or pork chops. But even after all that, and after accounting for exports, we still have a heck of a lot of corn to put to work. There are lots of industrial uses for this surplus corn, though, and chances are pretty good you’ve got an ear or two worth coiled up next to your 3D-printer, in the form of polylactic acid, or PLA.