Electric linear actuators are seeing more medical use every day, often replacing older pneumatic and hydraulic systems. Their applications are varied, and can range from the tiny (2" stroke actuators) to the large (24" stroke actuators). There are four main reasons that electric actuator usage is on the rise in the medical field:

1. They are small, especially when compared similar strength hydraulic devices.
2. They are quiet. There's none of the hiss and gurgle as found in current pneumatic/hydraulic solutions.
3. They are precise. Pneumatic pistons can only be accurately positioned at either full extension or retraction.
4. They are essentially maintenance free. Due to their design, linear actuators have fewer moving parts, and have less parts under pressure. There are simply fewer points of failure.

Motorized Wheelchairs and other Power Assisted Seating

Actuators are being used in increasing quantities for motorized wheelchairs and electric mobility devices, taking the place of traditional pistons and gears. The actuators used are commonly mini linear actuators for reasons of space efficiency and low power requirements. Actuators can be used to power these features:

• Height Adjustment: Powerful linear actuators under the seat can raise or lower it on demand.
• Arm/Leg Adjustment: Some chairs offer the ability to specifically place the arm and leg rests individually. Electric linear actuators are good for this purpose because of their accuracy and high lock force.
• Control Systems: Many chairs that require sensitive control from hands, mouths, or feet, use actuators to multiply the force of the controlling movement. Because of their high accuracy and precision actuators are an ideal match.

Hospital Beds and Chairs

Given their size and relative power for that size, linear actuators are popular in adjustable hospital beds, which give their occupants the power to raise or lower certain parts of the bed as they see fit. Some configurations can even 'twist' to one side or another, making it easier to get into and out of the bed. Traditionally these devices were powered by hydraulic or pneumatic systems, but as actuator technology has progressed and become cheaper in price it has become the preferred solution. Actuators are so commonplace that some beds in the home are starting to incorporate these features as well.

Medical chairs also benefit from the application of actuators. Dentist chairs, surgical chairs, and even examination tables are all able to rise and fall due to their presence.

Given their quiet operation, precise movement, and high lock strength, linear actuators have quietly taken over a host of operations normally reserved for mechanical or hydraulic systems. As progress marches on there are certain to be even more applications of this useful technology.