Silicone reshaping wearable medical devices

Silicone is changing the medical device world, one step at a time.

As more and more consumers flock toward Fitbits and iWatches, devices that can monitor fitness on a rudimentary level, more advanced wearable medical devices gradually are becoming increasingly prevalent in clinical settings. In time these devices could allow for hospitals to monitor patients remotely, reducing costs and increasing outpatient services.

“Wearable technology is huge,” said Luis Tissone, Life Sciences director for Trelleborg Sealing Solutions, North America. “Algorithms and sensors are so evolved at this point, but still in the very early stages of what we can achieve. These devices are going to be so intelligent that we're going to be able to proactively cure things rather than treating diseases.

“Wearable technology is evolving so fast, it just goes in line with the trends of smaller, more portable devices. It's definitely going to be one of the leading type of the devices and keep bringing the highest innovations in the industry in the years to come.”

And silicone is a big factor in pushing these devices to the next level. It is already a prevalent technology in wearable devices used for wound treatments because of its selective adhesion properties compared to other commonly used adhesives. Acrylic adhesives dominate the market primarily because they're the most cost-effective. Hydrogels and hydrocolloids are used in certain applications.

Kevin Pickett—medical products manager for Marian Inc., a converter of flexible material such as silicone into small die-cut parts—said of the four, silicone arguably is the most comfortable to wear on the skin. It doesn't pull hair off when removed, can be replaced multiple times, has strong waterproofing properties, is extremely pure and can be worn on the skin for a long period without irritation.

“Most silicones in health care have been used for wound dressing,” said Marie Crane, Dow Corning's global segment leader for medical devices. “Dow Corning has been active in that market for quite a number of years. The growth of silicones in wound dressing applications is actually displacing traditional acrylics because the market lends itself to them. The skin is very thin, so the compliancy and the move toward silicone are important because you're removing that trauma factor.

“I believe that bringing silicone into the market may change the way people traditionally use devices.”

Devices such as the iWatch or Fitbit are not considered a medical device, but they do monitor the body in basic ways—counting the number of steps or giving people a rough heart rate. To get readings accurate enough for clinical applications, the device can't slide up and down the patient's wrist; it must adhere to a certain spot.

Tissone, however, said these devices have pushed the market in other ways and still could have an impact on future developments. For starters, people are comfortable wearing devices that monitor the body, and as medical technology moves toward more outpatient monitoring, these devices could help give patients control of their treatments.

“The trend is now toward preventive medicine,” Crane said. “You want to try and measure and prevent a major incident. That impacts not only the quality of life, but the expense of keeping people healthy. That's why you're starting to hear wearables—it gets at prevention-type treatment.”

For example, insulin pumps utilize a handheld device to activate and program the different functions of the pump. Tissone said that device is disappearing progressively and turning into a phone app, which he eventually could see turning into an app for a device such as the iWatch or Fitbit.

Rudi Gall, managing director of Raumedic Inc., said in an email that medical device connectivity, where data is transferred from the patient's device to an analytical or diagnostic system, is a growing trend.

“I think it's going to be a big movement,” said Christine Weber, Dow Corning's medical device AETS team leader. “It helps with cost control. If you have to keep a patient in a hospital bed to monitor them, it's quite costly. That room and that bed are a big expense. If they're able to send patients home and monitor their vitals remotely, that helps reduce costs significantly.”

A direct skin contact adhesive with a high-end printed ink circuit attached to the skin could be used to provide patient data that's consistent and accurate. Pickett said instead of using many wired patches, hospitals could use one strong wearable to measure the patient and take the burden off nurses.

Hospital staff could monitor many hospital beds—or even entire wings—from one location, eliminating the need to wake patients in the middle of the night to take vitals.

Pickett said one wearable device could replace a half-dozen electrodes, reduce the workload of doctors and nurses, and even get to the point where patients could be monitored from home—increasing outpatient services.

“Imagine a neonatal unit in the hospital with all these premature babies,” Karen O'Keefe, Bluestar Silicones' elastomers business director, said at the recent MDM West conference in Anaheim, Calif. “Instead of having all these wires hooked up to them, they could have a little electrode patch that's diagnostic. It's a gentle silicone adhesion that goes on the fragile skin of the baby, and that enables doctors to monitor the baby without having all of those wires and tubes.”

Wearable devices already have the ability to administer treatment, and Tissone said this function is probably going to get more prevalent in the market.

For instance—a glucose monitoring device will have an adhesive attached to it that also attaches to the body so it can constantly monitor the patient's glucose levels. Some even include insulin pumps that not only monitor the patient, but also inject insulin when appropriate so the patient doesn't have to.

“The wearable device technology that we're seeing is specifically a device created to wear directly to your skin to be able to read physiological information,” Pickett said. “Be it blood pressure, heart rate, temperature—and the list goes on as they're being developed. Because the wearable device category is so new, we're seeing all different kinds of concepts. One of the most common that we're seeing is our skin contact adhesive being attached to a medical device.”

Tissone said microneedle patches could replace many drugs commonly administered using syringes. These patches are applied to the body, with the needles gently puncturing the skin to induce the drug.

A big advantage to these kinds of patches is anyone can apply them to the body, which makes them attractive for the military because it faces so many hazardous conditions where a medical expert is not readily available to administer a needle. The patient could apply the patch like a bandage.

Cosmetics also provide another big opportunity for wearables. Pickett said large cosmetic and consumer retail firms are working hard to perfect anti-aging patches, an evolution of the already existing scar treatment silicone patches. The patches are applied to the skin, and a special ingredient is transferred to the skin, such as a lotion designed to ease age discolorations and wrinkles. It also keeps the skin moist and heals like a bandage.

Eventually this technology could evolve into silicone masks used in-home for anti-aging and wrinkle treatment.

“You would put the silicone on your face, under your eyes and on your forehead, like a mask attached with a silicone gel adhesive,” Pickett said. “When you remove it, whatever is on that silicone has been transferred to the skin and makes it feel soft.”