SoC designs crack the code on connected medical devices

By Adrie Van Meijeren, product marketing group manager, low power connectivity, Dialog Semiconductor

In the medical and pharmaceutical space, the internet of things (IoT) has the potential to radically reshape how medical devices serve doctors, nurses, and hospitals and improve quality of life and medical care for patients. And it’s only recently that advances in system-on-chip (SoC) designs have empowered engineers and designers to finally crack the code on connected medical devices.

Some of those advancements in SoC design include new integrated circuits that simultaneously reduce the power footprint, shrink the amount of board space needed for components, and lower component costs. The addition of disposable batteries to IoT medical devices has been another major leap forward, necessary for component integration and footprint reasons as well as addressing the safe disposability of the medical devices themselves. Both of these developments have made connected medical device engineering more feasible in terms of bill of materials (BOM), power consumption, and manufacturing logistics.

Image: Pixabay

How connected medical devices improve patient outcomes

The IoT is already creating new opportunities for medical devices to better serve doctors and patients by adding connectivity to traditionally offline devices.

Look at connected glucose meters. Patients wear these like a patch, with the needle under the skin measuring blood sugar and then transmitting that information to an app on the user’s smartphone. Not only is this a pain-free, longer-lasting alternative for diabetics who no longer need to constantly prick their fingers for blood, but it also provides a new way to gather and store data about patients’ glucose levels in real time, made conveniently accessible on their phones for easy reference later on.

Smart inhalers are another innovative application of connectivity in medical devices. With traditional inhalers, asthma patients are instructed to wait about 30-60 seconds between puffs for the medication to be most effective. But a study published earlier this year found that 84% of patients weren’t waiting 30 seconds (the bare minimum recommended time) between inhalations.

In fact, 54% didn’t even wait 15 seconds. When patients don’t use the inhaler correctly, they aren’t receiving the proper dosage of medicine. Consequently, the devices aren’t as effective as they could be and need to be. And, of course, the patient has no idea they’re not using the inhaler correctly because a doctor isn’t right there providing that feedback.

Adding connectivity to the inhaler addresses this problem directly. Smart inhalers measure the device’s usage in real-time, giving patients immediate feedback about the effectiveness of their inhalations, the dosage they’re receiving, how frequently they’re receiving it, and so on. That’s useful information for patients because it gives them in-the-moment reminders about when and how to use their inhalers to get the full effect. But it’s also useful for the pharmaceutical companies. Instead of gauging how effective their devices are by relying on user questionnaires (which are often filled out by patients based on how they think they’re using the inhaler rather than their actual behavior), the companies get immediate and accurate data on user behavior and can adjust as needed. 

Blood pressure (BP) meters are another example of medical devices that have been improved by making them smarter. Typically, if you need your blood pressure measured, you have it done at the doctor’s office. But for many patients, a trip to the doctor’s office is a stressful time. Just being in a doctor’s office or hospital might elevate a person’s BP reading higher than usual, resulting in an inaccurate number. Using a connected blood pressure meter at home can help ensure a more typical at-rest BP reading, which is then transmitted to the cloud for the doctor’s office to access. That’s higher-quality information for both the doctor and the patient, leading to more accurate diagnoses and prescriptions.

If there’s a common thread to these and other connected medical device applications, such as continuous thermometer patches or smart injection devices, it’s this: More and better data improves patient care. Smart medical devices empower pharmaceutical and medical companies to build up huge databases that collect high-quality, real-time patient feedback on everything from medicine effectiveness to how disciplined patient usage is. That database is fed by real-time user behavior information provided by connected devices, which, in turn, gives doctors more accurate insights into how to treat their patients and empowers those patients to make adjustments to their own treatment plans (e.g., informing them if they aren’t taking enough of the intended dosage from an inhaler or aren’t taking it regularly enough).

Overcoming design challenges

While connectivity and smart medical devices are a game-changer for patients and doctors, they’re a relatively recent trend. For years, medical device engineers have been restrained by a number of prohibitive factors.

Cost, as usual, is one of the big challenges. The bill of materials, for both the SoC and external components needed to design a smart blood pressure meter or smart inhaler, has been a major roadblock for engineers trying to deliver meaningful connectivity for these applications.

Power consumption and shelf life have also been major design hurdles. Medical devices often have long shelf lives, lasting anywhere from 18 months to four years. That’s a long time to be in use, and if the SoC is not consuming power efficiently, it simply won’t be able to keep up with user needs. What good is a smart glucose meter to someone with diabetes if the battery can’t last more than a few months before depleting?

Only by addressing both the cost and footprint issues can engineers broaden the reach and availability of connected medical devices. Integrating silver-oxide batteries as part of the chip design is one way forward. Their small, thin design makes them easier to integrate onto the chip. Their low capacity, when coupled with a DC/DC converter, reduces voltage and ensures that battery capacity is capable of running for that 18-month to four-year window, with juice to spare. Their disposable nature means patients can safely throw away their inhalers or injectors, including the battery, after use. And their affordability helps reduce overall BOM costs for the device, too.

A sea change for medical devices and the IoT

While the medical device industry may not be known for its speedy review cycles, it’s hard not to see how quickly the ground is shifting beneath these engineers’ feet. We’re still in the early days for smart, connected medical devices, but the roadmap is clear: New SoC solutions that optimize component integration, lower BOM costs, and cut power consumption in half — coupled with the explosion of cloud storage and big data — have created a more fertile market than ever for smart medical devices to take off and provide real-time feedback to patients about medicine effectiveness and to help improve overall quality of life.