These days we are a little spoiled. There are many sensors you can grab, hook up to your favorite microcontroller, load up some simple library code, and you are in business. When [Raivis] got a MAX30100 pulse oximeter breakout board, he thought it would go like that. It didn’t. He found it takes a lot of processing to get useful results out of the device. Lucky for us he wrote it all down with Arduino code to match.
A pulse oximeter measures both your pulse and the oxygen saturation in your blood. You’ve probably had one of these on your finger or earlobe at the doctor’s office or a hospital. Traditionally, they consist of a red LED and an IR LED. A detector measures how much of each light makes it through and the ratio of those two quantities relates to the amount of oxygen in your blood. We can’t imagine how [Karl Matthes] came up with using red and green light back in 1935, and how [Takuo Aoyagi] (who, along with [Michio Kishi]) figured out the IR and red light part.
The MAX30100 manages to alternate the two LEDs, regulate their brightness, filter line noise out of the readings, and some other tasks. It stores the data in a buffer. The trick is: how do you interpret that buffer? Continue reading “Pulse Oximeter is a Lot of Work”
[Diego Marino] and his colleagues at the Politecnico di Torino (Polytechnic University of Turin, Italy) designed a prototype that allows for patients with motor deficits, such as spinal cord injury (SCI), to do rehabilitation via Functional Electrical Stimulation. They devised a system that records and interprets muscle signals from the physiotherapist and then stimulates specific muscles, in the patient, via an electro-stimulator.
The acquisition system is based on a BITalino board that records the Surface Electromyography (sEMG) signal from the muscles of the physiotherapist, while they perform a specific exercise designed for the patient’s rehabilitation plan. The BITalino uses Bluetooth to send the data to a PC where the data is properly crunched in Matlab in order to recognize and to isolate the muscular activity patterns.
After that, the signals are ‘replayed’ on the patient using a relay-board connected to a Globus Genesy 600 electro-stimulator. This relay board hack is mostly because the Globus Genesy is not programmable so this was a fast way for them to implement the stimulator. In their video we can see the muscle activation being replayed immediately after the ‘physiotherapist’ performs the movement. It’s clearly a prototype but it does show promising results.
Continue reading “Recording Functioning Muscles to Rehab Spinal Cord Injury Patients”
Citizen science isn’t limited to the nerd community. When medical professionals get a crazy idea, their options include filling out endless paperwork for human consent forms and grant applications, or hacking something together themselves. When [David Wartinger] noticed that far too many of his patients passed kidney stones while on vacation, riding rollercoasters, he had to test it out.
Without the benefit of his own kidney stones, he did the next best thing: 3D printed a model kidney, collected some urine, and tossed a few stones that he’d collected from patients into the trap. Then he and a colleague rode Big Thunder Mountain Railroad sixty times, holding the model in a backpack at kidney height.
Continue reading “Riding Rollercoasters with 3D Printed Kidneys, Passing Stones”
Slit lamps are prohibitively expensive in the third world areas of India where they are most needed. An invention that’s been around for over a hundred years, the slit lamp is a simple-in-concept way to see and diagnose a large array of ocular issues.
Since they are relatively old by technological standards, the principles behind them have become more and more understood as time has gone on. While a nice lab version with a corneal microscope is certainly better, innovations in manufacturing have brought the theoretical minimum cost of the device way down, or at least that’s what [Kewal Chand Swami] hopes.
His design aims for portability and cost reduction. It must be able to travel to remote locations and it must be significantly cheaper than the lab versions. It uses off-the-shelf lenses in a 3D printed housing with a simple LED torch, the kind you can buy for a dollar at the check-out stand.
The assembly slides onto the user’s head and is held there with straps. The doctor can adjust where the slit the lamp shines and also look through a microscope to diagnose the issue. Hopefully devices like this will see similar community support to the prosthetic projects we’ve covered.
There’s a lot of implantable medical technology that is effectively a black box. Insulin pumps monitor blood sugar and deliver insulin, but you can’t exactly plug in a USB cable and download the data. Pacemakers and cardiac defibrillators are the same way. For these patients, data is usually transmitted to a base station, then sent over the Internet to help doctors make decisions. The patient never gets to see this data, but with a little work and a software defined radio, a team on Hackaday.io is cracking the code to listen in on these implanted medical devices.
The team behind ICeeData was assembled at a Health Tech Hackathon held in Latvia last April. One of the team members has an implanted defibrillator keeping her ticker in shape, and brought along her implant’s base station. The implant communicates via 402-405MHz radio, a region of the spectrum that is easily accessible by a cheap RTL-SDR TV Tuner dongle.
Right now the plan is to intercept the communications between the implant and the base station, decode the packets, decipher the protocol, and understand what the data means. It’s a classic reverse engineering task that would be the same for any radio protocol, only with this ones, the transmissions are coming from inside a human.
What do you print with your 3D printer? Key chains? More printer parts (our favorite)? Enclosures for PC boards? At Johns Hopkins, they want to print bones. Not Halloween skeletons, either. Actual bones for use in bodies.
According to Johns Hopkins, over 200,000 people a year need head or face bone replacements due to birth defects, trauma, or surgery. Traditionally, surgeons cut part of your leg bone that doesn’t bear much weight out and shape it to meet the patient’s need. However, this has a few problems. The cut in the leg isn’t pleasant. In addition, it is difficult to create subtle curved shapes for a face out of a relatively straight leg bone.
This is an obvious application for 3D printing if you could find a suitable material to produce faux bones. The FDA allows polycaprolactate (PCL) plastic for other clinical uses and it is attractive because it has a relatively low melting point. That’s important because mixing in biological additives is difficult to do at high temperatures.
Continue reading “3D Printing Bone”
From watching a heart valve in operation to meeting your baby before she’s born, ultrasound is one of the most valuable and least invasive imaging tools of modern medicine. You pay for the value, of course, with ultrasound machines that cost upwards of $100k, and this can put them out of reach in many developing countries. Sounds like a problem for hackers to solve, and to help that happen, this 2016 Hackaday prize entry aims to create a development kit to enable low-cost medical ultrasounds.
Developed as an off-shoot from the open-source echOpen project, [kelu124]’s Murgen project aims to enable hackers to create an ultrasound stethoscope in the $500 price range. A look at the test bench reveals that not much specialized equipment is needed. Other than the Murgen development board itself, everything on the test bench is standard issue stuff. Even the test target, an ultrasound image of which leads off this article, is pretty common stuff – a condom filled with tapioca and agar. The Murgen board itself is a cape for a BeagleBone Black, and full schematics and code are available.
We’ll be paying close attention to what comes out of the ultrasound dev kit. Perhaps something as cool as this augmented reality ultrasound scope?