Proportional control, intended as a method of controlling the movement of a prosthetic hand with direct myoelectric control, consists in providing the user with the possibility of directly managing the speed and the closing / opening force of the prosthetic hand, modulating the strength of the prosthetic hand muscle contractions exerted to perform a given movement.
Thanks to the integrated system based on machine learning and Artificial Intelligence techniques with which Adam’s Hand is equipped, it was possible to implement these features without altering the primary characteristics that distinguish our prosthetic hand, namely intuitiveness and ease to use.
Adam’s Hand gripping force modulation
But why we equipped our Adam’s Hand prosthesis with this functionality? In everyday life it often happens to grab, hold, move, lift objects of various shapes and different weights.
These actions, although conceptually very similar, bring with them substantial differences in the speed and strength with which the action itself is carried out. If we also take into account the physical characteristics of each individual object, such as weight, fragility, strength and consistency, it becomes clear how profound the differences are between the various actions performed.
Grasping a paper cup or disposable tableware, taking an egg gently without breaking its shell, grasping a plastic or glass bottle are all actions that, thanks to the proportional control, the user can perform extremely naturally.
In fact, in order to control speed and grip strength, Adam’s Hand analyzes the EMG signal taken during the user’s muscle contractions and, if these are mild, the device will perform movements at reduced speed, applying a gentle grip.
Conversely, in order to firmly grasp a work tool, lift a fitness dumbbell or perform any other action that requires a firmer grip and greater strength, the user simply has to contract the muscles with greater decision which he activates the movement and the prosthetic hand will be activated according to the indications and the required performances.
Proportional control configuration and management
This mode, like all the other features of Adam’s Hand and all its accessories, is designed to be extremely easy to use, so it does not require a more complex calibration process or the setting of particular parameters, but the users more experts can decide to manage their settings in detail through the MyoLogic and MyoLogic Pro apps.
Specifically, proportional control can be enabled and disabled at any time by the user using the physical button on the back of Adam’s Hand, according to his specific needs, so that the user-device interconnection is always optimal.
Furthermore, to guide the user in learning and make the most of this feature, in the “Calibration” screen of the MyoLogic Pro app there are numerous visual feedbacks: a progress bar that indicates the intensity of muscle activation and dynamic size icons they provide immediate visual information during the training phases.
As already happened in the past, the implementation of this functionality was also achieved thanks to the constant collaboration with our users and with the orthopedic technicians of our network: with their suggestions we continue to work to improve our products and make Adam’s Hand always more adaptive and user-friendly, putting technology increasingly at the service of the user.