The STIMuGRIP ® was developed within the Healthy Aims project, the key objective of which was to develop a range of medical implants to help the ageing population and those with disabilities.
- STIMuGRIP ® system
- What is it?
- How does it work?
- The development of STIMuGRIP ®
- The Implant
- The External Controller
- Clinical Trials
- Current status of STIMuGRIP ®
What is it?
STIMuGRIP ® restores control of wrist extension and hand opening actions to users following:
- Spinal Cord Injury
- Cerebral Palsy
- Multiple Sclerosis
The system comprises two key parts:
The system uses an accelerometer integrated into the External Controller to trigger pre-programmed stimulation routines, an example is shown in the diagram below:
How does it work?
- The external controller is positioned over the site of the implant.
- The user selects one of the pre-programmed stimulation routines or the exercise program.
- The exercise program cycles through extending the rest, opening the hand, closing the hand and relaxing the wrist.
- The External Controller transmits power and control signals, when triggered, through the skin, to the Implant Receiver.
- The Implant Receiver converts the received signals into stimulation impulses which are delivered to the nerves/muscles at the electrodes, thereby causing the muscle to contract.
- The programs can use many different triggers to start and stop the stimulation giving a wide range of activities that can be undertaken.
The Development of STIMuGRIP ®
The system comprises two key parts:
The developments within these components are discussed below:
The STIMuGRIP ® implant comprises epimysial electrodes, Cooper cables and a receiver-stimulator.
This design improves upon technology and experience gained from development and manufacture of the Finetech-Brindley and STIMuSTEP ® implants.
The STIMuGRIP ® implant provides much greater immunity to crosstalk between the two independent channels and adds epimysial electrodes to the cuff (used intrathecally), wire-wound (used extradurally) and button electrodes (used for STIMuSTEP ®) that Finetech currently manufacture.
The images below show the electrodes and receiver-stimulator in various development stages:
The External Controller
The STIMuGRIP ® external controller made use of a number of technologies new to Finetech Medical including the use of mass produced accelerometers as a means of triggering stimulation sequences and rapid-prototyping of enclosures.
The custom enclosure design made use of a new, simpler, less bulky method for locking the strap to hold the controller on users' arms.
Some of the many design iterations of the Controller are shown in the images below:
Ethical approval for a clinical trial of the STIMuGRIP ® system was granted in the fourth year of the Healthy Aims project. The trial was planned to consist of five subjects who had suffered from stroke.
For the implantation of the STIMuGRIP ® implant, a new surgical stimulator and probes were developed (as shown on the right).
The images to the left show the surgical stimulator in action and the results of stimulating the targetted nerve and muscle.
Operations were conducted under general anaesthetic and typically lasted around an hour.
Following implantation and suturing up, the implants were tested using an external controller to prove all was working, as shown in the image below:
Three subjects were implanted with STIMuGRIP ® systems. All improved accross the entire range of assesment methods used and all users were delighted with the system.
Various articles and papers have been written covering the trials, some of which are listed below:
Current status of the STIMuGRIP ®
Following succesful implantations and improvements across the whole range of assesment methods used for the three subjects involved in the trial, Finetech Medical are interested in hearing from clinical centres who would be interested in conducting a further clinical trial in order to collect sufficient data to support a CE approval submission.
Until CE approval has been achieved, this system is unavailabe to patients. If you would like to receive updates on any changes in the status of this potential product, please register your interest using the Contact Us form.