CECA 2020 has 4 scientific and technological objectives (OS).
OS1: Modular prosthesis for partial-hand amputation with sensory feedback system and integrated controlne
CECA2020 aims to develop a motorized finger prosthesis for partial-hand amputation, controlled in flexion-extension through muscular interfaces, sensorized and equipped with a sensory feedback system. This sensory feedback system will provide contact information based on DESC strategy (Discrete Event-driven sensory feedback Control), where discrete vibro-tactile stimulation is provided corresponding to the events of contact and release of objects. The integrated control system will be modular and adaptable to different levels of amputation will manage combined movements of multiple fingers.
OS2: Prosthesis for complete amputation of hand with integrated wrist with selectable stiffness
For cases of complete amputation of hand, the project aims to develop a multi-articulated trans-radial hand prosthesis, integrated with a wrist joint and a multimodal sensory system.
This wrist joint will be equipped with active flexion and extension or, alternatively, will be passive with selectable stiffness.
OS3: Bidirectional control interface
The bidirectional control interface is a processing system capable of converting biological signals into motion controls of the prosthesis and thus providing the subject with a sensory feedback.
The OS3 is divided into two sub-objectives described below.
OS3.1 Movement control of the prosthesis
To reduce the physical and cognitive effort of users, the project aims to study and develop algorithms and technologies that decode the motor intention and translate it in motion of the prosthesis.
The control electronics will not exceed the shape of the hand and the biological control signals will be acquired with a matrix of sensors measuring the pressure exerted by the residual muscles on the socket. For trans-carpal and trans-radial amputations, the control will be based on the decoding of surface electromyographic signals (sEMG).
OS3.2 Sensory feedback
Two tactile stimulation systems will be developed in this project: the first one based on the aforementioned DESC model, while the second is based on coherent multi-modal feedback, i.e. on feedback stimuli of the same mode as the input stimulus.
OS4: Instruments for pre-clinical and clinical evaluation of prosthetic systems
The final prototypes of the project will be evaluated on amputees through experiments designed to replicate daily life activities.
This evaluation will be conducted through tests commonly used in the prosthetic field (e.g. Southampton Hand Assessment Procedure, Box and Block test, 9 PEG in HOLE dexterity test, and others).
In addition to these tests, devices and procedures will be designed for simple and objective evaluations of the functionalities of prostheses and their bidirectional control interfaces. The Virtual Eggs Test (VET) and the Pick and Lift Test (PLT) will be developed and, possibly, integrated in a single instrumented object.
The first replicates the action of picking and replacing fragile cubic objects. The assessment is made based on the number of cubes transferred and the percentage of broken cubes in 1-minute trail.
The second replicates the action of picking, lifting, and replacing objects and consists of a rigid object in the shape of a parallelepiped, instrumented with load cells that measure the grip force and the load force that the object exerts when placed on a surface.