Bluetooth wireless technology formally celebrated its 20th anniversary last year, and its use to transmit medical data was understood almost from the beginning. Today it is clearly established as a key technology for use in many medical devices and systems. The vision for the next 20 years is clearly exciting.
Wireless patient monitoring can trace its beginnings with the NASA Gemini mission in 1965, and the first terrestrial (hospital) systems followed soon after using proprietary wireless technologies. Patient monitoring in the US was allocated a ‘reserved’ band in 2000 by the FCC (Federal Communications Commission), creating the “Wireless Medical Telemetry Service.”
Also in 2000, I demonstrated a system utilizing Bluetooth wireless technology to transmit patient data from a defibrillator through a GSM telephone to a hospital computer system. A “crystal ball” slide from that demonstration outlined a rich field of medical applications including in-home remote patient monitoring and implanted devices, and predicted that wireless communications would replace medical cabling and that Bluetooth would be a key technology. By 2003, the first Bluetooth-enabled medical device was cleared by the US Food and Drug Administration (FDA) for sale by Stryker Endoscopy. This system incorporated Bluetooth Serial Port adapter modules from connectBlue AB (now u-blox) to replace RS-232 cabling between devices in hospital operating rooms.
Wireless and medical today
The medical device field challenges all technologies with critical demands for reliability, security, power usage, and compatibility. At the same time, the systems require long-term availability and reasonable costs. Medical devices are subject to the scrutiny of government agencies, for example the FDA in the US and European Medicines Agency (EMA) in the EU.
Wireless technology provides distinct advantages over cabling for many medical use models. It allows patient mobility while maintaining electrical isolation, low cost, and low power. It is a link to the cloud for use by patients and their caregivers via both mobile and fixed gateways. Because Bluetooth technology is included worldwide in allsmartphones, tablets, and computers, medical systems can utilize available compute engines and user interfaces to enable excellent user experience and provide value to their patients and customers around the world.
In the past 20 years, Bluetooth has risen to the challenges and become the short-range wireless technology of choice for medical devices, especially outside the hospital. The Bluetooth SIG has helped enable this through its development of standard profiles and services for many common medical devices ranging from glucometers to thermometers. The use of common low-level Profiles (GAP and GATT) in Bluetooth low energy enable device manufacturers to develop customized communications protocols for non-standard devices including implanted pacemakers and pain management systems. Bluetooth continues to displace other wireless technologies formerly used in these devices due to its lower costs for materials and lower costs maintaining the previous proprietary technology.
The past 20 years have seen both maturity and exciting new modalities starting from its ‘killer market’ as a headset cable replacement for cellphones to the data-intensive medical and industrial markets. Bluetooth technology has continued to develop with improvements from Bluetooth 4.0 including low energy, beacons, and mesh.
Bluetooth has matured to coexist and combine in complementary ways with other technologies, especially Wi-Fi. It is used in complementary combination with longer range cellular technologies and location technologies to provide greater mobility and seamless coverage and enable flexibility of patient movement and coverage.
Emerging use models for devices ranging from hearing aids to stethoscopes are showing great interest in the most recent developments of low-energy audio technology. Markets for health and wellness solutions are growing. These devices incorporate medical-like monitoring capabilities at a lower cost with seamless integration into healthy lifestyle needs and have relaxed regulatory requirements. At the same time, consumer devices such as the Apple Watch have begun to include sophisticated medical device functions such as ECG/EKG arrhythmia analysis and warnings.
What will the next 20 years bring? In many ways, it feels like the future of medical and wireless is already here. A perfect example is provided by external ‘artificial pancreas’ systems. People with type 1 diabetes must constantly monitor their blood sugar levels and manage food, medication, and injections of insulin to maintain their health. In the past, separate devices have provided monitoring (often Bluetooth enabled) and insulin delivery. Complete systems have been approved that provide automatic ‘closedloop’ operation, integrating the data from continuous glucose monitor devices with wearable insulin pumps and associated algorithms to keep healthy, stable blood sugar levels, resulting in better long-term health.
The future will bring more hybrid and integrated systems like the above example that will greatly improve quality of life for those with chronic diseases. Systems will include implantable component devices, and machine learning will enable those with neurological damage to move or even walk by combining implanted sensors with artificial nerves and external assistance from motors or artificial muscles. Medical device systems will become less visible and more connected. Technologies with their roots in today’s Bluetooth and 5G will combine in new and less-intrusive ways to provide seamless communication between system components and between those systems and the cloud. Wireless technologies and server-less computing will provide data interchange and blend into the cloud for computing. These systems will include artificial intelligence acting on that data to provide automatic adjustments and decision support to physicians. If the above vision seems too far off to happen in the next 20 years, please consider what has happened in the past 20 years, and apply your own 20/20 vision.
William Saltzstein has been innovating in engineering and product design for over 35 years, the last 20 of them associated with Bluetooth wireless technology and medical devices. After working for companies including HP Medical and Medtronic, he founded Code Blue Consulting in 2000 to provide expertise and experience to the wireless and medical device industry.
Bill is an inventor on 25 issued patents primarily associated with communications and battery-powered and portable medical devices. His active professional memberships include AAMI, IEEE, and Bluetooth SIG. Bill’s academic career includes a Bachelor of Science in Electrical Engineering from University of Rochester.