Knees that talk the walk: Making implants “smart” for real-time feedback
CEO: William Hunter, M.D.
Based: Vancouver, Canada
The scoop: Canary Medical is bringing the Internet of Things to medical devices, starting with artificial knees. Its smart implants are designed to provide real-time feedback on how they’re working and how patients are healing.
Eventually, when the company has collected enough data from enough patients, it plans to use machine learning to recognize patterns that could help physicians catch problems, such as infection or loosening of the joints, before they get worse.
Canary’s approach provides data from the implants themselves, rather than through secondhand means. Today, physicians gather data from imaging—MRIs, CT scans or X-rays—as well as from post-operative visits and patient reports, and the latter are often unreliable.
Meanwhile, skeptics have asked Canary CEO Bill Hunter why they can’t get the same kind of data from a wearable device, like a Fitbit.
“No disrespect to wearables, but what’s going on in my left wrist can only tell me so much about my right knee,” Hunter said. “Data from within my right knee provides a level of detail and understanding that are difficult to achieve elsewise.”
What makes Canary fierce: A longtime medical device executive, Hunter found himself wondering why mundane machines like refrigerators were connected to the internet, but lifesaving medical devices weren’t. The question reminds him of his earlier work developing drug-eluting stents.
“I spent the first part of my career putting drugs on devices... I used to get that question a lot: drugs are around, devices are around, why don’t we put them together?” he said.
“The answer was they’re very different industries that don’t routinely talk to each other. It’s not that the technology doesn’t exist,” Hunter said. The same goes for smart implants.
“The typical medical device company hasn’t traditionally spent a lot of time thinking about artificial intelligence and sensor technology, with the exception of companies making active implantables, like pacemakers, pumps, glucose monitors. The rest of the devices were inert,” he added.
Some have tried to overcome that problem with Fitbits and other wearables. But this method requires patient cooperation—“It's asking a lot of somebody to wear it over and over, charge it, download the data,” Hunter said—and there’s only so much a device worn outside the body can tell physicians about another device that’s inside the body.
Wearables are part of the first wave of implant monitoring, Hunter said. Canary Medical wants to usher in the next: the wave from within. It's a much more complicated ask, given how long an implant stays in a patient’s body.
“We’ve taken what was known about active implants and adapted it to become active implants that provide feedback,” Hunter said. “We’re using existing technology to serve a different end.”
Canary’s device, dubbed Canturio, fits into the “dead space” of an artificial knee, encased in the part of the implant that extends into the tibia, or shin bone. It contains FDA-approved technology, including pacemaker batteries, tiny sensors based on micro electro-mechanical systems, and wireless data transmitters.
It measures motion, including a patient’s gait and the range of their new joint—metrics doctors are interested in and are usually captured in snapshots during post-operative physical exams.
“We’re trying to provide the types of things that clinicians have been relying on for a long period of time, but instead of getting them only on the six-week and three-month visit, they’ll get it three times a day, every day, to fill in those data points,” Hunter said. The extra information could help doctors identify patients who might benefit from additional physiotherapy or another intervention, such as a revision procedure.
“That in and of itself is an important step forward,” he said. But there’s more. The Canturio isn’t just a way to get better data on traditional measures, but also a means to access new data that doctors couldn’t get before.
“The quality and fidelity of the data we’re picking up is extraordinarily high: We can see very small motions, or micromotions in the joint. We can see different parts of the prosthesis moving, which gives different ideas on anatomy and gait disturbances,” Hunter said.
“It turns out when you have a front-row seat to what’s going on, you start to see things you didn’t imagine you could see. With enough patients and enough machine learning, we could crack things like infection detection.”
Canary’s Canturio implant is currently under FDA review, with approval and launch expected in the next few months. The company has teamed up with Zimmer Biomet to offer the device with the latter’s knee replacement, the Persona Total Knee Arthroplasty. Over time, the company wants to make the device widely available, Hunter said.
And though Canary’s team has deep expertise in cardiovascular disease, it started with knees for practical reasons.
“If we could, we would probably have built a cardiovascular device first,” Hunter said. “But at least, for our first-generation product, we had some limitations. The battery had to be a certain size.”
As far as medical devices go, orthopedic implants like knees are pretty big, with the space for a device like Canturio to fit into and convert them into smart devices. Canary hopes to move into artificial hips and then shoulders within the next couple of years, before branching out into trauma screws and vascular implants, such as heart valves or stents.
These devices may be different in size and function, but they’re fundamentally based on three components: a power source, a transmitter and a sensor array. Canary will tweak each part to fit each device’s purpose.
“A knee you’ll need to monitor for 20 years, so it needs a significant battery. Something like a trauma screw, you only need to monitor for eight or 12 weeks, so we can use a different power source,” Hunter said. “We wanted to do the same three [components] over and over so we don’t need to reinvent for every single project.”
Investors: Kobuck Ltd., BioSicence Managers L.P., Quark Ventures and Relentless Partners Limited Partnership.