DMC Controls, Digital Controls, SUVA Sensor, Myoelectric Various controls cover a broad spectrum of indications. In the modern DMC Control (Dynamic Mode Control), the grip speed and grip force are controlled by the intensity of the muscle signal. Two independent mensuration and control systems ensure the hand switches to grip force mode when an object is gripped and the grip force is exerted in proportion to the muscle signal. In implementing the control, special attention was paid to the fact that (as in the natural hand) the muscle contraction, and thus also the electrical muscle potential, is not directly proportional to the build-up of grip force and grip speed. This makes the gripping process more physiological and permits gentle gripping of even small and fragile objects.
There is a third variant besides digital and DMC controls. EVO (Electronic Voluntary Opening) is an especially simple control designed to permit fitting as early as possible. Fitting patients as younger as two years old helps promote high acceptance of the prosthesis and successful integration in the body. The opening function of the hand is controlled via an electrode. No more muscle signals are received, the motor closes the hand automatically. In the classic Digital Control System, the grip speed remains the same even if the level of the muscle signal varies.
The grip force depends on the duration of the muscle signal. Another important advance in fitting is the Sensor Hand with SUVA Sensor*. Any shifts in the weight center of balance of the object being gripped are detected by the sensor and the grip force is readjusted automatically if necessary. The SUVA Sensor Technology also makes it possible for two totally new, innovative, single-electrode control concepts. Auto Control: The hand closes at maximum speed and grips an object with the least amount of grip force ( 10 N ). If the sensor senses a change in position, it automatically causes the grip to increase up to the maximum grip force ( 100 N ). VarioControl: With this control mode, the opening speed is determined by the level and speed of the muscle signal. The closing speed depends on the reduction in the muscle tension. Prior to fitting, sufficient electrical voltages must be localized and analyzed on the skin. A MyoBoy is used for this and for specific patient training.
The electrical voltage must be at least 15 nV.The myotrainer also helps with training specific muscles. It permits analysis of the muscle signals amplified by the electrodes and makes patient training reproducible. What is important, however, is not only advanced technology, but also the extent to which the patient succeeds in mastering this technology and integrating the prosthesis in his or her personal body image.