Never have wireless technologies influenced and changed society as fast as in recent years. Bluetooth, mobile phones, AirPorts and Lan networks – they all enhance our everyday lifestyle and productivity in ways never imagined before.
The technologies and networks that connect people, data and devices wirelessly are plentiful and in recent years wireless medical devices have steadily grown. In the not too distant past, mobile computing in a hospital setting would have referred to a PC on a trolley. Improvements in wireless technology and mobile devices have changed that and the benefits for the medical field become more and more obvious. Freedom of movement, transportability and connectivity are only to mention a few.
Regulatory bodies have already taken steps to push the industry towards new wireless solutions. In Europe and in the US alike, programmes and funding have been set up to enhance the work on wireless medical devices.
In October 2010, the US Federal Communications Commission (FCC) and the Food and Drug Administration (FDA) have announced a partnership especially designed to promote wireless medical technology and to encourage investment in the field. In Europe, wireless healthcare solutions have increasingly received the necessary CE marking to be released on the European healthcare market.
Wireless health devices
"Wireless technology has given great new growth to some established product lines. It has enabled new features and functionality to the incorporated technologies," says the head of global medical technology practice at Cambridge Consultants, Andrew Diston.
The UK-headquartered company has recognised the future of wireless in healthcare and develops devices for the professional and semi-professional medical markets. Wireless health technology can include everything from pumps that deliver insulin for diabetes patients, to remote monitoring systems that measure the level of glucose in a patient’s body, to implants with sensors that send text messages to a doctor if a patient’s state changes.
In contrast with wired technologies, cordless devices rely fully on wireless networks. "You need good wireless understanding but the technical challenges are relatively low," says Diston. "The major challenges are intellectual property, ownership and achieving regulation, and getting approvals for the device, showing that device is safe when the wireless system doesn’t perform as expected."
When developing a wireless device, key performance factors such as frequency band, data rate, range, power consumption, interoperability and regulatory constraints must be considered. In addition, methods to ensure link quality, resilience to interference, latency and security must also be addressed.
"Generally, the wireless networks used are so-called proprietary networks, which are much higher security and have much higher functionality. A wireless network, like LAN, tends to be too high-power consumption for medical networks. So there tend to be custom-networks, which are then connected through to the hospital’s data LAN,"Diston explains.
Proprietary networks are customised wireless solutions for specific applications. Other relevant networks include Bluetooth, which is used to transmit smaller amounts of data close to a person or object, and ZigBee, a network optimised for low current consumption, which is able to self-configure and even self-heal in the event that a node fails.
Wi-Fi technology is optimised for data transmission, enabling higher data rates to be transmitted than for example with Bluetooth. Another technology is cellular, which allows transmission over large distances.
The last system is DECT, a connection-oriented technology, originally developed for the uninterrupted transmission of voice, providing high quality service for continuous data. Different devices use the different networks, depending on specific requirements.
Medical device smartphone
One exciting new opportunity comes with the use of smartphones as medical monitoring systems. In October 2009, cardiologist and director of the Scripps Translational Science Institute in La Jolla, California, US, Eric Topol, addressed his audience at ‘The Wireless Future of Medicine’ event with the following words: "You check your email while you’re sitting here. In the future you’re going to be checking all your vital signs, your heart rhythm, your blood pressure, your oxygen, your temperature."
Topol drew a picture of the future where people would monitor their health, their sleeping patterns and even the foetal heartbeat of an unborn child wirelessly with an app on their smartphone.
As exciting this future might sound, in reality wireless medical smartphone apps are still in their infancy. "They are not very reliable," comments Andrew Diston. Network failures and privacy problems also have to be addressed.
But the combination of smartphones and specialist devices opens up exciting opportunities with real benefits for patients and healthcare institutions. Home monitoring can be an improvement for the patient’s quality of life, for hospitals and other medical facilities, on the other hand, keeping patients at home helps them to cut the costs associated with patients visiting or staying overnight.
One major challenge for every device, however, is the reliability of the used network. "When you’re doing wireless development, you always have to make the assumption that the wireless link is not going to be 100% reliable," says Andrew Diston. "No wireless ever is and frequently people misunderstand the impact of the way that the failure of the wireless link has on the overall system.
"The developers and the marketers and the people that are looking at the overall product safety need to really understand how wireless systems operate in practice."
How real network failures can be was shown by the case of CareFusion, which had to recall approximately 17,000 insulin infusion pumps in October last year. The pumps had been classified as Class I by the FDA, which is only issued when there is a probability of the product causing serious health consequences or death. Under a certain wireless condition a communications error in the system could have occurred, which causes the unit to freeze. If this happened during the infusion and delayed or interrupted the therapy, it could lead to serious injury or death.
Another big concern with wireless is the issue of privacy. As more devices become controlled wirelessly, privacy could soon become a significant problem from the perspective of securing the patient’s information and active attacks on the systems themselves. "A wireless system obviously opens the door to people to temper with it," says Andrew Diston. "You have to put in all the extra features and functions you need for security."
That, however, has an effect on power consumption, the data, the access and the ease of use and up to now it is unclear to what extent usable privacy can be achieved for wireless medical devices. "There are issues that have to be addressed," says Diston.
Experts and industry members alike, however, forecast a healthy outlook for wireless medical devices, especially in the case of monitoring patients with chronic conditions such as cardiac diseases and diabetes. Doctors and patients will constantly be connected and wireless devices will be helping them to make educated decisions regarding a patient’s health.
Connectivity and 2.0 have not only become catchphrasesfor society but also for the medical device industry. Wireless technology has been and will be standing at the forefront of this new era.