LTI Programmable VariGrip Controllers

Small, light-weight in-wrist design Adjustments made through graphical software Simultaneous control of two devices Controls up to four device motors (elbow, wrist, hand or gripper)

• Works with all popular terminal devices
• Accepts up to five inputs from electrodes, Touch Pads, linear transducers, and switches
• Ten standard control strategies, changed through software

LTI's Programmable VariGrip Multi-Device control system is a microprocessor-based circuits for controlling powered prosthetic devices. In the past, adjusting a prosthesis meant disassembling the unit, rewiring the hardware (possibly changing the circuit) and reassembling everything before you could test whether it worked! With the Programmable VariGrip technology, you now adapt the circuit to the user, not the user to the circuit! It's as simple as connecting the prosthesis to a computer, and changing the values in the software.

• A patient evaluation mode simplifies the process of finding the optimal muscle sites for myoelectric controls and eliminates the need for other evaluation devices.
• The ability to accept input signals from myoelectrodes, Touch Pads (force-sensitive resistors), servo transducers (linear variable resistors), or switches provides tremendous versatility.
• Control of up to four devices, like hands, wrist rotators, lock actuators, etc.
• Automatic gain setting allows the system to adjust the myoelectrode gain, eliminating the need for manual adjustments.
• Optional co-contraction switching allows the prosthetist to tailor the switching scheme to the patient's abilities when two or more devices are being controlled.
• Fabrication using Surface Mount Technology (SMT) ensures durability and reliable operation.
• The control system remains internal to the prosthesis with no unsightly bulges, even if a wrist rotator is used.
• A low-power circuit extends battery life.

Graphical Interface Software

The VariGrip's Graphical Interface software and interface unit are easy to use. Prosthetists can select a control strategy from the list of approximately ten standard strategies. These cover the common controls used for most prosthetic systems, consisting of single and two input sites using; switches, Touch Pads, myoelectrodes and servo control. If a unique control strategy is needed, Liberating Technologies, Inc. can provide this. Custom control strategies can be created to suit the needs of users with unusual requirements or capabilities.

Using our proprietary Graphical Interface Software, you can program the controller with any standard computer equipped with Windows 3.1 or Windows-95 and above. An LTI interface device is available to connect the computer to the prosthesis, ensuring the proper optical isolation to protect the patient during set-up.

Additional Information Product Catalog: Programmable VariGrip Controllers (PDF) Product Manuals: MyoWizard/MyoAssistant Software Guide (PDF) USB Interface Instructions (PDF) Promotional Information: LTI VariGrip Controller (PDF) VariGrip Article Reprint - O&P Edge (PDF) Other: Ulinks drivers (ZIP)