Smart Sensors: The Internet of Medical Things

Telemedicine is making a comeback as people become more health-conscious and reliably accurate technology falls in price and size to allow wearable devices to become more functional. Just as in wartime, the battle against Covid-19 has also accelerated the development of products that will create a healthier environment. The Internet of Medical Things is upon us with a vengeance.

A couple of decades ago, it seemed like everybody was talking about telemedicine – but then disillusionment set in. Today, thanks to powerful data networks, AI support, and lots of new, smarter sensors, the field is booming and giving rise to the term the Internet of Medical Things (IoMT). This new form of medicinal practice is safe, confidential, ubiquitous, and inexpensive, and it ranges from fitness to digital health and all the way to tele-rehab. Telemedicine looks back on a long history. When Guglielmo Marconi’s invention became popular in the early 1920s, radio was used to give emergency advice to doctors on ships.

It wasn’t until the Vietnam War began in 1955, when qualified frontline medical facilities were rare, that the US military thought to combine radio, television, and data networks to deliver specialist advice for injured troops who needed instant attention out in the swamps and jungles of Southeast Asia. In the 1980s, telemedicine really took off as civilian research institutions became involved and numerous prototypes were developed.

A third of all patients don’t need to visit the doctor for further treatment.

Very soon, sparsely populated regions such as Alaska or northern Norway wanted to benefit from the new technology, but implementing such systems was difficult. Costs were prohibitive, data networks were slow and transmission protocols still had to be standardized. Every sensor was an expense and had to be built from scratch; specialized semiconductors were nowhere to be seen. Information about new applications flowed slowly to the public and general practitioners, so demand was low.

The turnaround came as late as the 2010s, when cheap fitness-tracking smart watches entered the market in droves. In 2017, around 36 million wristwatch devices were sold and this number is expected to surpass 50 million sales in 2022. Even more importantly, thanks to the rapid development of new types of sensors, the industry has been able to add features for things like blood glucose measurement and even electrocar-diography (ECG) tracers to smart watches. Today, hundreds of new kinds of intelligent “wearables” are pushing into the market, from smart diapers to intelligent sticking plasters. Caring for aging populations in the industrialized countries is also adding to the demand for devices.

Wearable technology is said to be an emerging trend that integrates electronics with daily activities and fits into our changing lifestyles. Market researcher Mordor Intelligence has estimated the 2019 wearables market at 216 million units and says it expects this to reach 614 million by 2025. Wearables can be worn on many parts of the body and the market divisions are based on product type, such as fitness tracker, smart watch, camera, head-mounted dis-play, smart clothing, and ear-worn, body-worn, exoskeleton, and medical devices. Some companies, like Palmsens from the Netherlands, offer modular systems that allow new suppliers to build their own products. All they need is the sensor for the vital function to be monitored.

The market growth shows that customer acceptance, a suitable product range, plus a suitable market environment are the keys to success. Prices are falling thanks to high volumes and growth is accelerated be-cause customers not only advertise the new product in their personal lives but are also willing to explain to others how to use it. IoT-supported health care today covers all aspects of fitness, prevention, therapy support, and assistance for sick, disabled, and elderly people. The dividing line between mass-market wellness helpers and genuine medical equipment is now blurring. This is not without problems because almost everywhere in the world the requirements for precision in real medical devices are much higher than for mere gadgets like fitness trackers. Doctors sometimes criticize the gadgets for not being calibrated adequately, but correct use is equally important because only then can the measured values be meaningful.

The trend toward devices seems to be irreversible. Some large hospitals have now recognized the new billion-dollar market and offer the analysis of medical data as a service. A webcam is used to talk to a doc-tor’s assistant, who is assisted by an AI-supported database. First experiences show that this is sufficient in a third of the cases and patients don’t need to visit the doctor for further treatment. Middleware provided by the Canadian start-up Dialogue and the Swiss telemedicine group Medgate, for example, means that telemedicine is no longer the privilege of wealthy private patients. In more and more countries, health insurance companies are reimbursing the costs of telemedicine and tele rehabilitation. Those who only need a prescription can use the video consultation service on the Kry platform, provided by the Swedish company of the same name. Chip manufacturers have also recognized the trend and are working hard to develop new, highly integrated components for the next generation of tele medicine. The latest chips can record several vital parameters but have a footprint of only a few millimeters and consume extremely little power.
There are many exciting sensor developments that are building the new Internet of Medical Things.

Fraunhofer IPA

Deep Breath

A thorax monitoring system from the Fraunhofer Institute for Production Technology and Automation (IPA) is so sensitive it has been used to measure the respiratory volume of a mouse without touching it. It has actually been devised for use with premature babies that need respiratory help from a ventilator. It’s extremely difficult to determine the tiny volume of air necessary to keep them alive and conventional sensors are too large and an infant’s extremely sensitive skin cannot tolerate these attachments. The institute, based in Mannheim, Germany, has developed a contact-free sensor based on radio technology. A premature baby is placed with its chest between two antennas, one of which transmits in the UHF range while the other receives the signals which are affected by the baby’s respiration. The measurements taken are then used to electronically calculate the breathing rate and volume. The IPA scientists use the fact that lung tissue contains a lot of water, which has a high dielectric constant that significantly changes and mpedes radio waves. When the child breathes in, the air, which has a dielectric constant close to 1, reduces the overall dielectric value, which also lessens the inhibition of the transmit-ted signal. The difference in signal strength between inhalation and exhalation is used to calculate how hard the attached ventilator works and sets a rhythm that matches the baby’s natural breathing rate rather than just forcing air in and out of the lungs.

Visit ipa.fraunhofer.de for more information.

MedWand Solutions

Magic Wand

US start-up MedWand Solutions has developed a telemedicine module, also called MedWand, which is designed to monitor fitness and health. It may look more like a big computer mouse than a magic wand but its numerous sensors have no effect on PC operations. Instead, it conjures up the user’s key medical data. MedWand charges a monthly subscription for its service and also provides data access to doctors once they set up an account. Unlike fitness equipment, the highly versatile wand must be used according to a doctor’s instructions so that a diagnosis can be reached step by step. The wand has several adaptations to allow a fairly comprehensive examination to be made remotely. Placed on the chest, it serves as an electronic stethoscope to listen to the heart and lungs. Move it down to the abdo-men and the doctor can listen for anything unusual. It can also measure temperature and the oxygen saturation of the blood. The electrical sensors can provide a single-channel ECG and the built-in camera can be transformed for use as an otoscope, ophthalmoscope, or dermatoscope by using the supplied accessories. In addition to remote general health care and acute care for patients living in places where a doctor is not within reach, such as in crisis areas, mountain huts, ships, or on oil platforms, the wand is also intended to be used in postoperative follow-ups or in the rehabilitation of stroke sufferers.

Visit www.medvand.com for more information.

AI & IoT in Healthcare

The robot Will see You now

In Thailand, IoT-supported robots have been deployed to help protect shopping center employees and customers from Covid-19. A ‘Robot for Care’ (ROC) and thermal scanners are employed to identify potentially ill people as they enter the enormous CentralWorld shopping mall in Bangkok. Once inside the complex, customers are kept as safe as possible with the help of automatic disinfectors that use ultraviolet light to keep the escalator handrails sterilised. In addition, a dog-like robot roams the ground-floor area with an automatic hand disinfectant dispenser on its back to make it easier for customers to keep their hands clean. The ultraviolet (UV) LED-based sanitizer for disinfecting the escalator handrails can also be used for masks, control elements and medical equipment. In Asia, such light sources are being fitted to AI-controlled robots to irradiate indoor areas when people are not around. A light source of only 1.3 mm to 5 mm in size destroys Covid-19 pathogens completely without chemicals. The light used is in the UV-C range which, in this case, has wavelengths between 260 nm and 265 nm, shorter than the light used in sunbeds. It carries enough energy to reliably destroy the DNA of viruses, bacteria and fungi and has also been successfully used against MRSA germs in hospitals. From 2025 onwards, healthcare is expected to be one of the most important applications for AI and IoT in China which has a shortage of doctors. The reasons for this are obvious, especially in rural areas where there are even fewer doctors available and there is a considerable lack of healthcare facilities of all kinds.

Maxim

Hearable Wearable

Modern in-ear hearing aids and cochlear implants enable patients with extreme hearing loss to connect wirelessly to smartphones or conference systems. More sensors are now being added to these aids to provide health data. A number of patents have already been applied for which enable electroencephalography (EEG), the electrical measurement of brain waves, using sensors on the hearing device. The measurement of vital functions, such as temperature, pulse, and heart rate, are also conceivable and, if the hearing aids are worn regularly, will open up an expanded therapy spectrum. Size is a limiting factor for in-ear technology and some of the circuit boards have four layers but only have a total thickness of 0.15 mm. The Maxim Integrated MAXM86161 chip, for example, is an optical biosensor that carries a complete optical data acquisition system. The sensor is extremely low-power and is specially designed for medical in-ear applications. It detects oxygen saturation, heart rate, and heart rate variability to clinical standards of measurement. Its organic land grid array (OLGA) package only measures 2.9 mm × 4.3 mm × 1.4 mm yet it does not fit into a standard in-ear hearing aid. The potential benefits of the technology will put pressure on hearing aid manufacturers to make their devices even more compact.

Visit www.maximintegrated.com for more information.

Massachusetts Institute of Technology

Smart Diaper

Modern diapers for babies and senior citizens contain a highly absorbent hydrogel and it’s not always immediately apparent when a change is necessary. Both target groups are dependent on external help and often have difficulty articulating themselves. Researchers at MIT have developed a technology to inform nursing staff about the condition of the diaper. The system relies on a networked base station that monitors an RFID chip over a distance of up to one meter. The information is transmitted to the nursing station computer or sends information to a smartphone. MIT is using a type of hydrogel that can act as the antenna element for the RFID tag when it gets wet. The tags costs less than two cents and can therefore be disposed of with the diaper – unlike currently available systems that need batteries and must be reused due to their higher price.

Visit www.mit.com for more information.

Abbott FreeStyle Libre

Sugar Snapshot

The FreeStyle Libre Sensor adheres to an area of skin on the back of the upper arm. A thin, flexible, sterile filament is pushed directly under the skin and taps off a tiny amount of blood (0.3 μL). Within four seconds the sensor determines the exact blood sugar value and sends it to a handheld reader. The patch needs to be changed every 12 weeks. The values collected and stored by a proprietary reader provide a snapshot of a typical day’s levels but long-term average values are also calculated. The software thus helps the patient to understand patterns and fluctuations in sugar levels better. The sensor is waterproof enough to survive when taking a shower or even a short bath (maximum 30 minutes).

Visit www.freestylelibre.de for more information.

Withings

Heart Flutter

One of the most beautiful IoMT digital applications comes, ironically, in an analog wristwatch from Withings. The Move ECG watch has a built-in, one-channel ECG for detection of heart palpitations. It re-cords tiny glitches in pulse rates with the help of a medical-quality ECG and sends the information to a smartphone. One in four adults suffers from atrial fibrillation but it occurs episodically and is therefore difficult to detect. It would be pure coincidence if it occurred precisely when the patient was with the doctor and connected to ECG equipment. Move ECG has two electrodes on the back of its case which can record the ECG results as soon as the patient touches the watch’s front bezel if they feel unwell. The record stays on the watch until it can be transferred to the smartphone app for analysis. If the attack is considered serious enough, the wearer is recommended to visit their doctor and, in preparation, a PDF document is sent so the doctor is aware of what happened.

Visit www.withthings.de for more information.

SteadySense

Fever Patch

femSense reliably detects the increase in body temperature associated with ovulation and can also be used for patient monitoring dur-ing an illness or after surgery.SteadySense, an Austrian start-up, has come up with a tiny sensor in a patch that is attached under the armpit to continually mea-sure temperature, for example in postopera-tive care where the system can check around the clock for fevers triggered by infections. The patch continuously stores temperature values at preset time intervals and uses near-field communication (NFC) to transmit the record to a smartphone. Those medical uses will be a future spin-off because the sensor has been designed as the femSense Ovula-tion patch. Ovulation is accompanied by an increase in temperature and women can use the information from the patch to determine the perfect days for fertilization. The data is downloaded over NFC to a smartphone where the app delivers its conclusions.

Visit www.steadysence.at for more information.

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