Medical technology has developed wide-ranging technologies to help the ill and disabled. Electronic pills, implants, or smart prosthetics – all of them are nothing other than wearables.
Electronic devices worn on and around the body already offer lots of opportunities in medicine – but devices implanted inside the body are an even more exciting prospect. They not only enable data from internal organs to be recorded and analysed, but can also communicate directly with the nervous system.
The electronic pill
A relatively new category of such wearables is ingestibles: devices that people can swallow like a pill. The first such products are already on the market, and many more are in development. One example is the ingestible sensor from Proteus Digital Health. It checks that medication is being taken correctly, thanks to a sensor the size of a grain of sand embedded in the medical pill itself. As soon as the medication has been swallowed and reaches the stomach, the sensor reacts to the stomach acid and sends a signal to a smart patch worn by the patient. The patch is in turn connected to a smartphone, and via that to the Cloud. The linked app enables the patient or doctor to check that the medication has been administered in the right dosage and at the right time.
The deaf can hear
Other wearables have been implanted into the body for years, including cochlear implants, which were developed 30 years ago. They enable deaf people to hear again – provided their cochlear nerve is still intact. The devices convert sound into electrical pulses which stimulate the cochlear nerve in the inner ear. They consist of two elements: the implant with the electrode for the cochlea, which is implanted surgically behind the earphones into the cranial bone, and the voice processor with the transmitter coil, which is worn on the ear like a hearing aid. Depending on the type of hearing loss, there are also solutions which convert the signals transmitted by the audio processor into mechanical vibrations and relay them directly to the middle-ear structures. One such solution is the Vibrant Soundbridge implant from MED-EL.
Wearable technology also offers solutions for blind people. The Argus II system, for example, is a state-of-the-art neurostimulation unit which provides people with severe to high-level degeneration of the outer retina with some visual capability. It bypasses the non-functioning photoreceptors, stimulating the remaining functional retina cells. The Argus II retinal prosthesis captures visual images of the surrounding environment by way of a miniature video camera integrated into a pair of glasses. The images are converted into a series of small electrical pulses and relayed wirelessly to the electrodes implanted on the retina. The pulses stimulate the remaining retina cells, generating patterns of light that are registered by the brain. By learning to interpret those patterns, patients are able to regain some of their functional sight. Argus II has already been implanted into more than 100 patients worldwide.
Medical wearables do not always have to be small and invisible, however. State-of-the-art prosthetics, which replace hands, arms or legs, also count as wearables. With active electronics, they incorporate functions which enable very natural movement. Like the Genium prosthetic leg from Ottobock, for example: it aids natural movement in every detail – without the wearer having to consciously control it. That is made possible by state-of-the-art computer, sensor and control technology. Thanks to that technology, the Genium responds intelligently to a wide variety of everyday situations, enabling the wearer to walk much more naturally than was previously possible with prosthetics. Built-in measurement sensors continuously monitor the current walking phase, taking into account factors including speed, acceleration, and also the positioning of the prosthesis. The bend of the knee joint or the pendulum motion of the lower leg is controlled accordingly. All this happens in real time. The Genium is intuitive, allowing the user to walk naturally and unselfconsciously.
(picture credits: OttoBock)