Zarlink Semiconductor (Toronto/San Diego) this week introduced what it called the world’s only transceiver chip designed exclusively for wireless communication systems that link implanted medical devices with base stations.
The new chip, the ZL70100, enables an implanted device/ base station link up to a distance of 2 meters, according to Steve Swift, senior vice president and general manager, Ultra Low-Power Communications, for Zarlink, thus greatly extending the range of the most advanced previous generations of this general type of communication system in the device arena.
Until now, the most advanced versions of the technologies linking implantable devices to an outside-the-body receiver have had a range of just a few centimeters, Swift told Medical Device Daily. And they come with a variety of limiting disadvantages, he said.
Among the most obvious of these is the need for place-ment of a system coil on a patient’s skin, placing it too close to – or even within – the sterile field during an implant procedure.
Besides having 10 times the range of previous chips, the new Zarlink device offers a much higher data rate but with “half the power consumption,” according to Swift.
He said that since most implanted medical devices do not require constant communication, and instead transmit data on a scheduled or as-required basis, the average “sleep” current is a key design factor of the ZL70100. Its radio transceiver contains an ultra-low-power wake-up system with an average current demand of just 200 nanoamps. It also consumes less than 5 milliamps of supply current while active, a feature that Zarlink describes as “industry-leading.”
While the ZL70100 allows implanted devices to quickly transmit large amounts of patient health and device performance data, it has only “minimum impact on the battery life of the implanted device,” according to the company.
Perhaps for device manufacturers, the best-known use of Zarlink’s technology thus far – and sharing the same platform with the ZL70100 – is the radio frequency transmitter used in the PillCam from Given Imaging (Yokneam, Israel), an ingestible capsule using a tiny camera to survey the small intestine to diagnose Crohn’s disease, celiac disease and other disorders.
While providing a variety of technicalities for its use in the camera pill, Swift said these all boil down to the chip being “the thing that does all the timing control inside the capsule, collects data from the imager and [packages] it.”
While official rollout of the chip/transceiver system for implantable devices came yesterday, Swift said that “samples” of the chips along with “data sheets” already have been provided to “all the major medical device manufacturers” in the U.S. and Europe.
Those companies – including what Swift called the “big boys” – Medtronic (Minneapolis), Guidant (Indianapolis) and St. Jude Medical (St. Paul, Minnesota) – are testing the chip technology “to make sure it meets the claims we’ve made for it,” he said.
He added that the device is “not customized for anybody,” but instead is a “catalog product” that can then be adapted to the various uses required by a range of companies making implantable products. “They can design our technology into their products,” Swift said, in a succinct restatement of the idea.
In general, he compared the technology to “an Onstar for a patient,” Onstar being the system that links an automobile to a base station and is highly usable in an emergency, as we’ve heard in the many radio advertisements of that product.
Zarlink’s technology offers a parallel life-saving possibility – and even more broadly, important quality-of-life advantages – for the increasing numbers of elderly and the increasing numbers with medical implants, he noted.
“Any medical device implantable in the body is a potential candidate” for utilizing the ZL70100 system, Swift said, citing an application range from neuro-stimulation devices to bladder controllers to the oncoming variety of implanted glucose sensors. The potential numbers of these and associated uses will expand exponentially as baby boomers “get a bit long in the tooth,” he said.
Swift noted also that, unlike other communication bands that aren’t compatible from country to country – for instance, for cellphones – the ZL70100 uses the medical implantable communication services (MICS) 402-405 MHz frequency band specifically designated to promote compatibility worldwide. He says MICS was first defined by the Federal Communications Commission in the late 1990s for medical devices, then “rolled out to other countries” and now is “almost universal.”
During surgery, a physician can use the higher data rates and longer communication range afforded by MICS technology to program the performance of an implanted device outside of the sterile surgical environment, the company noted.
Zarlink said this compares to previous implanted communication systems relying on magnetic coupling between coils in an in-body device and a base station, with data transmission rates of just a few tens of kb/s.
Advances in ultra-low-power radio expertise and global adoption of the MICS band opens the door for advanced telemedicine applications that extend patient health monitoring beyond the traditional clinical setting, Zarlink said.
As an example, it provided the following scenario:
“An ultra-low-power RF transceiver in a pacemaker can wirelessly send patient health and device performance data to a bedside base station in the home. Data is then forwarded over the telephone or Internet to a physician’s office. If a problem is detected the patient goes to the hospital where the high-speed, two-way RF link can be used to easily monitor and adjust device performance.
“Potentially, a pacemaker could also use the high-speed wireless link to directly contact emergency services during a cardiac event.”
Swift said that while Zarlink has been focused on short-range, lower-power data communication” systems for the past 30 years for a variety of uses and applications, it began focusing on such a system for the implantable medical sector about 3-1/2 years ago.
Zarlink termed the industrial-grade ZL70100 transceiver chip for base stations “the first device in a product platform designed specifically to meet the performance, power and size requirements of implanted communication systems.”
And the ZL70100 is just the beginning, Swift said.
“We’re continuing to develop a whole range of these devices” for rollout over the coming months and years, he promised.