Keeping a steady hand is vitally important for many professions where the use of a static or purely mechanical handrest just isn’t practical or possible. A new computer-controlled, motorized hand and arm support will let doctors, artists, machinists and others precisely control scalpels, brushes and tools over a wider area than otherwise possible, and with less fatigue. A person using the Active Handrest puts their wrist on a support that can slide horizontally in any direction. The user's wrist sits on a round wrist pad on an arm that is attached to a motorized base that can move from side to side and back and forth to re-center the hand. Under the wrist rest is a force sensor similar to a bathroom weight scale. The base also is attached to an elbow rest.
The system includes a personal computer to control the handrest. The computer detects the position or force of the user’s wrist and decides how the armrest should move. Meanwhile, with position control the device monitors the tool motion and repositions the handrest to follow the tool’s motion.
In this way the handrest allows a person to maintain a steady hand while it senses the position of a hand-grasped tool or the force exerted by the hand - or both. Then, the device's computer software moves the handrest so it constantly re-centers the user’s fingertips in the center of their dexterous workspace – that is the range over which users can move their fingers and be very precise.
For example, if a person places their arm on a desk to write, their hand is able to move the pen about 4 inches in any direction, but precise writing is practical only within a 1-inch wide "dexterous workspace," says Provancher.
Posts
No comments:
Post a Comment