The Carbonhand and weak grip

The Carbonhand uses a glove and servo unit linked by an umbilical cord

The Carbonhand uses a glove and servo unit linked by an umbilical cord

In our last article we gave our view on approaches to hand and arm rehabilitation and outlined the RehaDigit product from Hasomed. The second product we deal with is the Carbonhand from Bioservo Technologies. The Carbonhand is an evolution from the original SEM Glove (Smart Extra Muscle) product and a significant step forward. We were excited to work with this product as it represents “soft-robotic” technology that we feel will develop to have significant benefits in rehabilitation.

The Carbonhand, like the SEM Glove aims to assist persons with a weak grip but who have an ability to flex and extend the fingers. The Carbonhand however has an improved glove design making it easier to don and significantly improved software that makes the product useful for a wider range of people.

Of course, grip problems are a result of many conditions including stroke and spinal cord injury. However, many of these persons affected by stroke and spinal cord injury do not have an ability to both flex and extend the digits and therefore the glove could not work for them.

An app gives great control over all aspects of operation

An app gives great control over all aspects of operation

The glove design uses pressure sensors in the thumb and two fingers of the glove and these had to be brought into contact with the object to be gripped. Once a small amount of pressure is applied to one of the sensors then this is detected and the fingers of the glove are made to grip the object.

This relies upon a clever design that uses small motors held in a belt unit to pull on slender cords that extend along an “umbilical” cord and into the fingers of the glove. In order to get the motors to release the object again, the user must have some ability to extend the fingers. The unit detects the change in pressure applied and the motors release the tension on the cords and the grip relaxes.

The original SEM Glove had a very narrow range of application and this to some extent has been improved by the Carbonhand. First of all, the glove design has improved making it much easier for a disabled person to get on the glove. Secondly there is an App that gives significantly greater control over how the unit operates.

We still find that some persons expect that the unit will give them back all the function they have lost and can disappointed if this is not the case. We find the persons who do best with this unit are those who have a more balanced attitude to the assistive technology and modifiy their behaviour to some extent.

We have developed a smart webform that allows us to predict whether a client is likely to be able to take advantage of the Carbonhand.