Still in development

ExoArm

ExoArm is Focal's most advanced dynamic arm support. ExoArm is the outcome of a development trajectory of more than ten years. A range of knowledge institutes, universities and companies were involved. From this period the working title McArm is known in many places. ExoArm was launched after another two years of development and production preparation in september 2016.

ExoArm finds its origin in the wish already expressed in 2005 by Focal’s visionary founder Paul Groenland to come to an intelligent arm support that adapts to the wishes and needs of the user. In that period potential users with very limited capabilities could not be served with then existing arm supports. Focal released many innovative arm supports such as Darwing or Gowing during the last few years. Nevertheless the need to come up with a robotized arm support that can bridge the gap between high- end conventional dynamic arm supports and robot manipulators remained. Such intelligent armsupports should possibly postpone the use of stand alone robots and keep users active and independent as long as possible.

The working principle of ExoArm is based on robot technology with the architecture of a dynamic arm support. This means that the device commonly is attached to an electric wheelchair which supplies electrical energy and carries the weight of the support and the human arm. On the other end ExoArm is attached to the lower arm of its user. The device moves in an intelligently coordinated way along with the human shoulder and arm and bears the weight of the arm. Through its complex sensor technology and electromotors it assists in lifting and moving in all directions but in particular against gravity. It constantly adapts its performance after the observed and measured needs of the user. Hence the entitlement exoskeleton. During its operation there is no need for the user to push buttons or do other control tasks. ExoArm can however considerably be configured and adapted to individual needs and characteristics of its user. This is commonly done by its supplier, but the user is also able to change many of its behaviours him- or herself. For this purpose an accessible User Interface is present.

ExoArm usage

Once individually programmed ExoArm is easy to use. The arm is placed in the forearm splint, without the need for it to be secured in any way. Movement in all directions hardly requires any effort anymore. In the course of the day or depending fatigue or the requirements of specific task the user may adapt ExoArm’s performance. This is done through the User Interface. However while executing a certain taks the arm support and movement process is fully automated.

ExoArm technique

ExoArm operates on the basis of robot technology. The system measures the intentions of the user to move his/her arm in a certain direction by using a sensor that is attached to the arm rest. This makes that the arm rest functions as a measuring scale. Movements measured may be any horizontal or vertical movement and through computinf also the rotations of the lower arm (pro- and supination) are measured. Input signals do not only concern directions, but also masses being the weight of the arm and eventually the load that has to be lifted (motion control). The input signals are receiver by the CPU of the device where on the basis of complex control technologies the required forces to move in any direction are calculated taking into account the forces that already are exerted by the user. Calculated required forces and directions then result in outpur signals and through its actuators the ExoArm will support the user in his task execution followng the principle of ‘Assist-as- Needed’. Consequently the user will still be as active as possible.

During the movements a control loop is present that registers the proceedings of the movements as well as any deviations in weight or direction in milliseconds. The system instantly adapts to this which allows the user to stay in control, steer the movements and accomplish the task.

ExoArm is to a considerable extend adaptable to individual characteristics and needs. It might Based on such needs it may have specifik kinematic feaures. The progamming of its individual charactitics is done by its supplier. But that’s not all. ExoArm is an arm support that allows the user to himself make adjustments with regard to the degree of compensation and all kinds of other settings. For this purpose an accessible interface is present.

Currently, there are no user experiences described for ExoArm.

Photos:

For ExoArm, downloadable documentation is available.
Click here to view the documentation.

 

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