How Energy Harvesting is Enabling New Possibilities for Medical Wearable Devices
November 19, 2020
Healthcare facilities and hospitals use connected IoT devices for a wide range of use cases, including giving wearable medical devices to patients as an easy way to monitor their from anywhere.
The IoT has transformed the healthcare industry. Healthcare facilities and hospitals use connected IoT devices for a wide range of use cases, including giving wearable medical devices to patients as an easy way to monitor their vitals from anywhere. Additionally, connected beacons can be used to track the whereabouts of patients while they are at a facility, an important feature for large campuses. These types of solutions are especially helpful given that the healthcare industry is facing staffing shortages.
While the advances in healthcare technologies are exciting, there are still a number of challenges with using battery-operated connected devices for medical applications. The costs of replacing batteries can add up quickly, and harmful materials can leech into the environment when batteries are improperly thrown out. Luckily, over the past few years, there have been some new technologies that are helping to significantly extend the battery life of healthcare wearables, and even enable some medical devices to operate without any batteries at all.
One way that connected devices can achieve prolonged battery life is with a low power radio implementation that supports the latest Bluetooth 5.0 standard. The implementation of Bluetooth 5.0 can help extend the battery life of a connected device by decreasing its power consumption by 5 - 10 times. This allows devices to operate much more efficiently. Additionally, controlled energy harvesting can be used to significantly extend the battery life of IoT applications. Energy harvesting is the process of capturing and storing small amounts of energy from external sources, such as RF, photovoltaic, thermal and motion. This energy is then converted to electricity in place of, or as a supplement to, battery power.
By combining circuit-level and system-level innovations, power consumption can be reduced to such a low level that energy harvesting becomes a genuinely viable power source. This type of energy harvesting technology is designed to operate with microwatt active power and microwatt-level average power in low-duty cycle applications. The energy gathered from the environment can supply a regular trickle of current to a battery so that the device can operate much longer between charges, enabling forever battery life so batteries last the entire lifetime of a device. What’s even more exciting is that some applications can run entirely off of harvested ambient energy from the environment, and do not require any batteries to operate.
Wearables with energy harvesting are ideal for non-critical patient monitoring, such as badges or wrist-bands that incorporate sensors to capture data about a person’s vitals to share over Bluetooth. In some cases, the patient could even be sent home with the monitoring device to help healthcare staff continue tracking their vitals. The first few days after a hospital stay can be crucial as the patient transitions to life back at home or in another type of a care facility.
Another interesting use case for wearable medical devices is continuous glucose monitoring, a method of tracking the real-time effects of food and exercise on one’s blood glucose levels. To use a continuous glucose monitor (CGM) one inserts a sensor under the skin that measures glucose readings continuously day and night. A wireless transmitter is attached to the sensor via Bluetooth and sends glucose levels to a display device which shows the user their blood sugar levels and can alert the patient when these levels are too low or high. The challenge presented with traditional CGM applications is that the transmitter, pump and charger batteries need to be charged regularly since they are in constant use.
This problem can be solved with the use of controlled energy harvesting technology to enable forever battery life. This means that CGMs using energy harvesting won’t need to be charged – and the batteries wouldn’t need to be replaced – for the lifetime of the device. CGMs with forever battery life can help put the minds of patients at ease, as they wouldn’t need to worry about their devices running low on batteries and thus missing critical health information. Plus, devices with support for Bluetooth 5.0 can enable the possibility for remote monitoring. Bluetooth 5.0 can increase the range of connected devices by four times the range of previous Bluetooth generations, enabling doctors to monitor patients from greater distances via a browser or smartphone application.
By extending the battery life of medical wearable devices, both patients and practitioners can use these vital connected applications more efficiently, and without worrying about missing critical information due to a dead battery. Furthermore, extended battery life reduces the costs of battery maintenance and also helps reduce environmental waste along the way.
About the Author
Srinivas has over 20 years of experience in wireless and other communication technologies. He has held a variety of business development and marketing roles in Mobile, Computing, Consumer Electronics, IoT, and Networking segments with Synaptics, Qualcomm, Atheros and NXP. He is an entrepreneur, having owned and operated Skyscape Aviation. Srinivas earned a Master’s Degree in Electrical Engineering from Oregon State University and an MBA from Santa Clara University.