Otto Bock hands

Tendon or residual muscle movement has been used to actuate pneumatic sensors when interposed between a prosthetic socket and the superficial tendons and/or muscle. These sensors can be used for prosthesis control. The Vaduz hand, which was developed by a German team headed by Dr. Edmund Wilms in Vaduz, Liechtenstein, following World War II, used muscle bulge to increase pneumatic pressure to operate a switch-controlled, voluntary-closing, position-servo hand. This hand can be considered to be a forerunner of the pneumatic Otto Bock Hands of the 1970s and the electrically powered Otto Bock Hands of today. 

Otto Bock Sensor Hand provides secure grasps of various objects. The system frees the user from constant watch on the objects in the hand since the automatic grasping feature senses when an object is about to slip and makes necessary adjustments. The Flexi-Grip function gives the amputee a natural look and flexible grip. The hand is controlled by volitional contraction of muscles that are touching the socket. 

FIGURE 42.6 The Michelangelo Bionic Hand. (Otto Bock Healthcare, GmbH, Duderstadt, Germany.)... 

Standard operating voltages used in prosthetics are 4.8, 6, 9, and 12 V depending on the manufacturer and component to be driven. All Otto Bock System 2000 children s hands (Fig. 32.14) (Otto... 

FIGURE 32.12 Otto Bock System Electrohand (Otto Bock Orthopedic Industry. Inc., Dud-erstadt, Gmnany). The hand consists of a mechanism over which a liner is placed. A cosmetic glove is then pulled over the liner. (Note Otto Bock does not provide silicone gloves.) Liner creases have been placed in the finger thumb web space in an effort to reduce its elastic resistance. Also shown is a pair of tweezers that are provided with each hand to make tip prehension possible. Prosthetic hands have very poor tip prehension without the aid of some sort of extra tool such as these tweezers. 

RSLSteeper Ltd. (Roehampton, England), and Cen-tri (Sweden) also manufacture single-DOF devices for the adult. Single-DOF child-size hands are also available from Variety Village, Otto Bock Orthopaedic, Inc., and RSLSteeper Ltd., among others. Michael (1986) provides a nice overview of the commercially available powered-hand mechanisms of the day, whereas Heck-athome (1992) provides in-depth descriptions and technical specifications of all the externally-powered components available at the time of writing. 

For prosthetic arms to be more than just position controllers for portable vices, multifunctional mechanisms that have the ability to have multiple degrees of freedom controlled simultaneously (in parallel) in a subconscious manner need to be developed. Current commercially available multifunctional controllers are generally sequential in nature and take the form of two site, three state multifunctional controllers. Motion Control, Inc., in the ProControl hand-wrist controller, uses rapid cocontraction of the forearm extensors and flexors to switch control between hand opening and closing to wrist rotation. Otto Bock uses a similar control strategy in its wrist-hand controller. Motion Control, Inc., in its elbow controller, uses dwell time (parking) to switch from elbow flexion and extension to hand opening and closure and cocontraction of biceps and triceps to switch control from the hand back to elbow. 

Otto Bock has a hand that has a microprocessor-controlled slip detector (Otto Bock SensorHand). The thumb has a sensor that detects slippage of an object grasped by the prehensor and automatically... 

Otolith transfer function, 64-6 Otolithic organs, in vestibular system, 64-1 Otten, E, 22-12 Otto Bock Sensor Hand, in... 

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