Wireless in telehealth: Critical considerations for technology adoption: Q&A with Mark D. Benson, Director of Software Strategy, Logic PD
Improvements in wireless telehealth: Advances in standards, reductions in power. Mark D. Benson, Director of Software Strategy, Logic PD, gives his perspective in a conversation with Embedded Computing Design.
As telehealth home care continues to evolve, the wireless and medical device industries face numerous challenges. Mark explores technology, patient, and standards considerations, in addition to the necessary improvements to wireless technology – all factors critical to the ultimate success of in-home health care management.
ECD: What are the primary challenges involved in using wireless technologies when designing in-home telehealth devices?
BENSON: Primary challenges include wireless coexistence, data integrity, and security.
More and more devices (both medical and nonmedical) now include wireless radios. This creates a potential for competition between devices when they operate within the same RF spectrums. To counter this effect, medical devices that include RF must be designed to behave nicely toward other devices (RF emissions) and must be tolerant of other poorly behaved devices (RF immunity) when operating in close proximity.
For example, Wi-Fi-enabled devices, cordless phones, cell phones, and wireless video transmitters all claim to be able to coexist in a small physical space such as a residence or apartment. The reality is that many of these consumer devices are built without much front-end filtering to save component costs and design time, making them susceptible to electromagnetic interference.
RF coexistence issues can cause unintended negative user experiences that have nothing to do with the medical device’s fundamental operation. For example, consider a patient whose wireless router at home stops working every time he or she uses a wireless blood pressure cuff to collect data. While this might not be considered a failure by the medical device manufacturer during software verification and validation testing, it would be a significant drawback and perhaps constitute failure in the eyes of the user.
To help mitigate potential RF coexistence issues, following consensus standards can help. For example, “IEC 60601-1-2:2001 Medical Electrical Equipment – Part 1: General Requirements for Safety; Electromagnetic Compatibility – Requirements and Tests” and “IEC 61326 Electrical Equipment for Measurement, Control, and Laboratory Use – EMC Requirements” provide requirements and tests for verifying electromagnetic compatibility and serve as a guide for handling electromagnetic compatibility issues in a design.
Accurate and on-time data transmission is essential for many medical devices. Because error rates and data transmission latency can increase when devices using the same spectrum are in the same location, it’s important to use techniques such as frequency hopping to ensure that critical control signals are transmitted and received reliably and without error, as the data might be used for making diagnoses and medical treatment decisions.
It is impossible to underestimate the role security plays in home telehealth devices. Security means more than patient privacy and protection from wireless eavesdropping or malicious hacking. Perceived security by the user is equally important, as it affects the patient’s willingness to use the device and trust it with private medical data.
The idea of perceived security carries the notion that if a user does not believe the data is secure, it doesn’t really matter how secure the device actually is since the user won’t use it. Conversely, if the patient perceives the wireless in-home telehealth device to be secure (and reliable, safe, effective, and useful), they will likely use the device regardless of how secure the device actually is. A significant factor in perceived security lies within the boundaries of the brand, but might be influenced by the device design or the marketing material that accompanies it.
Perceived security, which can influence user adoption and overall business success, is not a replacement for actual security (encrypting patient data, plugging security holes). Only by employing a wide range of technical, business, and user-centered design techniques can we ensure the overall security of a wireless medical device (example shown in Figure 1).
ECD: What important concerns regarding patient care should drive the design of a preventive in-home telehealth device?
BENSON: In terms of patient care, the most important considerations are usability and cost.
Many users of in-home telehealth devices are elderly and perhaps not tech-savvy. In addition, users might have cognitive impairments, difficulty hearing, poor sight, or trouble using fine motor skills to navigate complicated touch-screen user interfaces.
For these reasons and many others, usability is becoming more important. In fact, the FDA is showing a growing interest in the human factors of medical devices as key device design elements. The FDA recognizes that even though a device might be bulletproof from a technical perspective, usability issues can cause confusion and increase the probability of errors.
The general approach for success here is to follow a user-centered design approach that is empathetic and nonassuming.
As health care insurance providers evolve their position on reimbursement for in-home telehealth products, some devices might not yet have assigned reimbursement codes. When a patient pays for a device, the cost of a device can be a sensitive issue, and its perceived value is eminently critical. Although device cost is always important from a business and profit-margin perspective, in this case it is acutely important when the patient is paying for the device out of pocket.
ECD: What wireless technology advancements are needed to improve telehealth systems?
BENSON: Two important areas for improvement are standards and low power.
There are many brands and models of in-home telemonitoring sensors, including blood pressure cuffs, weight scales, pulse oximeters, and blood glucose monitors. Unfortunately for the designers of base stations or gateway devices that collect and relay data, the telemonitoring sensor market is fragmented and there is no clear wireless standard for achieving true interoperability across a majority of devices. For example, USB, RS-232, Bluetooth, and proprietary wired and wireless protocols are all in widespread use today.
Some organizations such as the Continua Health Alliance and American Telemedicine Association are working hard to create and support wireless medical communications standards. However, until ubiquitous standards become widely adopted, this will remain a challenging area for any in-home telehealth device, sensors and gateways alike.
As wireless radios and the software that enables them become less power-hungry, it will open doors to new use cases. With smaller batteries, longer battery life, lighter weight devices, and better overall performance, users will be more apt to carry a sensor like a wireless portable blood glucose monitor around with them all day instead of leaving it at home. Semiconductor fabrication technology, digital and analog circuit design, and software integration all have a part to play in the future development of lower-power wireless medical devices.
ECD: How can designers select the most appropriate wireless technologies and gain rapid FDA approval for their telehealth device designs?
BENSON: Follow the FDA’s RF guidance as closely as possible throughout the entire design process. Pay special attention to the items the FDA considers particularly critical to the safe and effective use of wireless technology: wireless coexistence, performance, data integrity, security, and electromagnetic compatibility.
In addition to following the FDA’s guidance documents closely, choosing commercial off-the-shelf technologies, managing and mitigating RF risk throughout the entire program, and paying special attention to security issues that have the potential to cause accidental exposure of sensitive data can help designers accelerate approvals.
Logic PD 612-436-5115Twitter: @markbenson