Harnessing haptics to help rehab


Imagine stroke patients undergoing rehabilitation in the comfort of their homes, with robotic devices – instead of physiotherapists – to help them exercise.

This may soon be a pervasive practice thanks to haptics – an emerging technology with wide-ranging applications that simulates “touch sensations” including force, vibration, motion, elasticity and more.

The technology has recently been used to develop a prototype robotic device that could eliminate the need for physiotherapists to monitor patients.

This device, along with others also based on haptics, were unveiled last month by Markham-based Quanser Inc., a developer and manufacturer of robotic and mechatronic systems.

The prototypes put on display can be used for advances in robotic surgery, rehabilitation, and surgical training, says Jakob Apkarian, chief technology officer (CTO) and founder of Quanser. “We wanted to take our technology to a broader audience – and expose the world to its potential applications in the medical industry,” he says.

Quanser has been spending around 30 – 40 per cent of its R&D dollars on haptic technology, which it has been developing over the past three years. “Over that time, we’ve come to realize one of the areas with the biggest potential for commercial use of haptics is the medical field,” Apkarian says.

Prototypes unveiled by Quanser include the Autonomous Upper-Limb Stroke Rehabilitation (AUSR) device.

Designed for post-stroke patients in need of limb rehabilitation, AUSR does away with what Apkarian calls “ad-hoc approaches to therapy using objects that were never designed for rehabilitation.” For instance, patients often use balls and stools to tilt back and forth so they can exercise certain body parts.

AUSR is a combination of advanced robotic and haptic technology, together with sensory feedback algorithms integrated with a graphical computer interface similar to a video game.

Besides programming AUSR for a variety of physiotherapy tasks that eliminate the need for an onsite therapist, the device acts as an incentive for patients to do such exercises.

What makes this exciting, is the virtual environment that allows the creation of different games to keep the patient interested, says Paul Gilbert, CEO of Quanser.

The company wants to develop interfaces that are age and gender- specific, he says. “A 60-year-old woman might be interested in gardening exercises, whereas a 25-year-old who just had a motorcycle accident might be interested in something completely different.”

Furthermore, the system automatically monitors patient progress, increasing resistance and level of difficulty if required.

Also launched by Quanser, is the 5 Degrees of Freedom Robotic Telepresence System. This system allows surgeries to be performed by robots that convey sensory stimulation from the operating table to the doctor controlling the robot.

The Telepresence system is operated by a surgeon with a handheld device connected to the robot through a local area network.

By including the sense of touch, another layer of perception is added to the system, says Gilbert. “If a brain surgeon is going through one membrane, and doesn’t want to cut the second, the surgeon would have to feel that.”

With haptic robotics capable of such precision, the hope is similar technology can be developed for minimally-invasive surgery, such as the kind that requires little cutting, says the CEO. That way, patients can expect a shorter hospital stay, and less pain and bleeding.

The Haptic Needle Insertion Training Simulator was another prototype unveiled by Quanser. This doctor training system allows medical professionals to practice the basic skill of inserting a needle in a patient, such as when administering epidurals.

The simulator mimics the behaviour of human tissue in a virtual environment, via a haptic device manipulated by the doctor. It can also assess the performance of the surgeon, while eliminating damage or risk to a live patient.

Currently, says Apkarian, training procedures involve using real patients, pigs or cadavers. But there are drawbacks: real patients present a real risk; pigs for surgical training cost $2,000; and, cadavers are getting harder to come by.

According to the CTO, the Training Simulator offers real-time response to actions of the surgeon and robot – as opposed to pseudo real-time effects that other devices may offer.

Quanser hopes to continue developing haptic simulation technology for simple medical procedures, such as administering epidurals and intubation. Simulators that mimic complex procedures, such as the removal of a gall bladder, tend to be more expensive, says Apkarian, and therefore less accessible to medical institutions.

Also, with a simulation, trainees can undergo the virtual procedure as many times as they like, with no additional cost, adds Gilbert.

These prototypes and others unveiled by Quanser are still undergoing development, and are up against the barrage of technological challenges facing haptic robotics.

“Technological solutions can be found given what we have,” says Apkarian, “but it’s very expensive, ‘so, how do we produce a high-fidelity haptic device at a reduced cost?'”

Besides cost, mimicking the dynamic characteristics of human tissue requires extensive research. To that end, Quanser has worked in tandem with medical institutions for valuable input on real-world issues influencing development, says the CEO.

The cost of producing haptic robotics for the area of medicine remains a hurdle, agrees Ted Kirkpatrick, assistant professor at Simon Fraser University’s school of computing science in Burnaby, Vancouver.

“That slows down acceptance of patient rehabilitation more than surgeon training,” says Kirkpatrick, adding that a system that enhances a surgeon’s skills will be more apt to receive funding. In addition, he says, fewer surgeon training systems are required than those for physiotherapy.

At this point, says Kirkpatrick, haptic robotics for medicine is still in its infancy, undergoing research and clinical trials. Most research and development has taken place in the areas of laparoscopic surgery, or minimally-invasive surgery, given the restricted range of motion required by the simulator, he says.

Conversely, complex procedures, such as open surgeries, would involve mimicking a wider range of motion and multiple tissue textures, says Kirkpatrick. “I think [complex simulators] are substantially more challenging and it won’t happen probably for a considerable longer time.”

Kirkpatrick says there currently exists medical training devices in use, but they are purely graphical, with no sensory perception.

Actually, the lukewarm welcome haptic robotics receives from the medical field is the result of an ongoing controversy, according to Kirkpatrick. “The question is, ‘how much better training would you get if you added haptic feedback?'”

Controversy aside, Kirkpatrick thinks Quanser’s focus on simulating simple medical procedures is a good direction to take. “I think they can more confidently produce a higher quality simulation because they’re designing a mechanically simpler system.”

“Let’s focus on something simple but valuable and do the best quality implementation we can,” he says.

Haptic robotics is gaining acceptance by doctors, even if this may not appear to be the case, says Emil Petriu, professor and university research chair at University of Ottawa’s School of Information Technology