Prosthesis With Sensations
Condition: Amputation; Phantom Limb Pain; Sensory Deficit
MeSH terms: Phantom Limb
Study type: Interventional

Summary: 
      Lower limb amputees suffer complete lack of sensory feedback of current available prostheses,
      which excludes the central nervous system from the correct sensory-motor integration. It
      causes serious problems as: falls due to unexpected perturbations, asymmetric walking, low
      mobility, higher power consumption, feeling the prosthesis as a foreign body, high cognitive
      burden, and phantom limb pain occurrence.

      Investigators will provide amputees with a prosthesis restoring sensory feedback and will
      assess its benefits on the users.
    

Detailed description: 
      The clinical investigation described here aims at evaluating the benefit of a lower limb
      prosthesis providing sensory feedback (bidirectional prosthesis), in selected transfemoral
      amputees. The device is constituted by i) Rheo Knee XC, Pro Flex foot and customized
      socket/liner structure from OSSUR. Rheo Knee embedded already an encoder coupled with a
      Bluetooth unit, which is used to make communication with devices external to the knee itself;
      ii) nerve stimulating system constituted by implantable intraneural electrodes from IMTEK,
      iii) an external neurostimulator from AXONIC, and iv) sensorized sole from SensArs
      Neuroprosthetics to apply under the prosthetic foot and driving the stimulating system. The
      readout of the sensorized insole are transmitted via Bluetooth, together with the encoder
      readout, to an external controller, which transduces it in parameters of stimulation. These
      parameters are sent to the stimulator, which injects current into the intraneural electrodes.
      As final result, the subject perceives sensory feedback from the prosthesis when using it.

      Investigators call SENSY the sensory feedback restoration system. The subjects will use the
      prosthesis with and without sensory feedback to execute walking tasks. The average change of
      kinematics (including falls), metabolic cost, embodiment, and cognitive burden (EEG) when
      intraneural stimulation is provided will be compared to the case in which there is no sensory
      feedback. Standard clinical tests (as PEQ and CB&MS) will be executed with and without
      sensory feedback. Also, when the subjects will report attacks of phantom pain, they will
      undergo a 10-minutes-stimulation session. Only stimulation without prosthesis is used in this
      intervention.

      Finally, imaging of the cortical activity will be executed through functional magnetic
      resonance imaging (fMRI). This procedure will be only observational since no prosthesis or
      sensory feedback will be used by the subjects.
    

Intervention name(s): SENSY
Intervention type(s): Device
Intervention description(s): The sensory feedback will be delivered by SENSY with or without the leg prosthesis. Benefits connected to the stimulation of sensory nerves will be assessed.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment