The i-limb ultra revolution is an externally powered prosthesis often controlled by myoelectric signals, meaning it uses muscle signals in the patient’s residual limb to move the device. Electrodes are placed on the user’s bare skin above two pre-selected muscle sites. When a user contracts these muscles, the electrodes pick up subtle changes in the electrical patterns and send these signals to a microprocessor which instructs the i-limb to open and close.
Muscle Triggers
The i-limb can open and close into several different grip patterns such as a lateral grip or precision pinch. Users can assign their most commonly used grip patterns to up to four different muscle triggers.
- `hold open’ (using the open signal for a set period of time)
- `double impulse’ (two quick open signals after the hand is fully open)
- `triple impulse’ (three quick open signals after the hand is fully open)
- `co-contraction’ (contracting both the open and close muscles simultaneously)
When the user activates any one of these triggers, the i-limb will move into the grip that has been assigned to it.
For example, a user can assign “tripod pinch” to a “hold open” trigger. After programming that feature and trigger, sustaining an open signal for a predetermined amount of time (usually a few seconds or less), will activate the tripod pinch mode that the user can then open and close. When the user contracts his/her muscle for closing, the hand will pinch closed. Likewise, when the user contracts his/her muscle for an open signal, the hand will open in this pinching motion.
The number of triggers programmed depends on each individual’s ability to control and activate the signals. As the user’s control and strength improves over time with practice, the user can assign more triggers to grips for improved dexterity and function.
quick gripstm – available with the i-limb ultra revolution
quick grips offer mobile control with instant access to up to 24 different grip patterns.
A user may want to use a wide variety of grips and gestures throughout the day, and utilize more features than what they are currently capable of using with muscle triggers alone. The user can simply open
the my i-limb app on their mobile device to access quick grips. Up to 24 different grips can be selected, allowing instant access to new grips with the tap of a button on the app screen. An additional 12 custom my grips may also be programmed offering the user up to 36 different grips or gestures.
grip chipstm – available with the i-limb ultra revolution
grip chips are small Bluetooth® enabled devices that allow users to enter any available grip pattern simply by moving their i-limb device close to an object where a grip chip is placed. By using the my i-limb app, users can program each grip chip with different settings.
For example, a user might place a grip chip near his or her laptop to activate a feature suitable for typing such as “index point.” Another grip chip might be placed by the plates in the kitchen to allow the hand to enter “lateral grip” for picking up plates with ease.
For details visit : http://www.touchbionics.com/products/active-prostheses/i-limb-ultra