Introduction

Active joint prosthesis, configured to control the rotation of a robotic limb (for example, a portion of an upper limb such as an arm) connected to a second element, such as a trunk or an additional limb (for example, a portion of an upper limb such as a forearm). In particular, the described joint prosthesis represents a prosthetic elbow. Most joint prostheses (or prosthetic joints) and, specifically, the prosthetic elbows currently available, are cosmetic or “body-powered”. The few active prosthetic elbows offer poor functionality and high weights. This invention, thanks to a transmission mechanism based on two parallel kinematic chains, aims to offer high performance in small footprints.

Technical features

Prosthesis composed of two segments (arm and forearm), configured to rotate each other. The first compensates the weight of the prosthesis thus minimizing the footprint given by the gear motor, the second instead offers propulsion to the system through a series of ad-hoc reductions, with the ability to offer, at the same time, the maintenance of the configuration states without requiring energy use. It consists of: a first attachment to the first prosthesis (biceps side); a second attachment to the second prosthesis (hand side); a pin that defines the axis of rotation of the attachments; a motor configured to apply a lifting force, creating the reciprocal rotation of the previously mentioned segments; and a compensator, which applies a torque to the pin, variable depending on the angular opening between the attachments and which significantly reduces the torque to be applied to the pin to obtain this reciprocal rotation. The joint prosthesis can include a control panel in connection with the motor for the operation of the entire prosthesis, using EMG sensors. TRL 7.

Possible Applications

• Active joint prosthesis, configured to control the rotation of a robotic limb connected to a second element

Advantages

• Responsive and intuitive controls, providing the patient with an experience as close as possible to the missing limb.
• Affordable, light and comfortable to wear.
• Produces little noise and has low power consumption.