Muscles Put Medical Devices into Motion

Redesigned for use with overweight patients, an imaging table required rails with a high load capacity and extended stroke

January 15, 2008

2 Min Read
Muscles Put Medical Devices into Motion

Originally Published MPMN January/February 2008


Muscles Put Medical Devices into Motion

Shana Leonard

A two-phase actuator is based on electroactive polymer artificial muscle technology.

Improved actuation of medical devices could be as simple as swapping motors for muscles, according to Artificial Muscle Inc. (Menlo Park, CA). The company’s novel line of actuators do not run on sheer brawn, however. Instead, its actuators are made from polymers that behave like a human muscle.

A spin-off from nonprofit independent research institute SRI International, three-year-old Artificial Muscle develops products based on electroactive polymer artificial muscle (EPAM) technology. Performing much like a human muscle, electroactive polymers expand and contract based on variable voltage input levels.

EPAM technology consists of the application of a thin layer of mechanically compliant electrode material to both faces of a dielectric elastomer film, which results in what John Bashkin, business development director of the Artificial Muscle medical sector, describes as an Oreo cookie–like structure. Applying a voltage across the two faces of the polymer causes the electrode layers to squeeze the film “filling,” which, in turn, gets increasingly thinner and subsequently expands in area. “You have this conversion of electrostatic potential into the mechanical work of this film physically deforming,” Bashkin explains. “If you then put this film into a frame and do the engineering properly, you can capture that physical deformation and create a device that does useful work.”

Using this technology as a platform, Artificial Muscle has produced smartMove actuators. Advantages of the actuators over traditional electromagnetic actuators or solenoid valves include lighter weight, better power efficiency, and virtually no heat generation, according to Bashkin. He adds that electric motors necessitate numerous parts for motion control in devices, whereas the smartMove actuator is based solely on the single actuator muscle.

“[This technology] creates a whole new set of design rules for engineers. They’re no longer hemmed in by the traditional kinds of actuators,” Bashkin says. “Now, they can imagine actuators that have completely different shapes, sizes, and form factors.”

In addition to offering design flexibility and cost effectiveness to OEMs, the EPAM-based products can provide benefits to patients as well. Smaller sizes and lighter weights achieved by employing the actuator enhance mobility. Furthermore, the actuators operate silently for an unobtrusive presence.

The Artificial Muscle actuator is suited for use in medical equipment and devices such as blood pressure cuffs, endoscopic surgical actuators, endoscopic surgery cameras and lens positioners, haptic feedback devices, infusion pumps, surgical tools, drug-delivery pumps, ventilator pumps, and proportional valves.

Booth #676

Copyright ©2008 Medical Product Manufacturing News

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