Lifehand2’s years of preparation have culminated in the implant surgery of intraneural electrodes, which were followed by nearly three weeks of exercises required in order to teach the patient to use the neural circuit and eight days of experimental usage of the prosthesis

19th – 24th January 2013: Pre-surgery and Experimentation

The patient, who arrived in Rome 18th January 2013, was subjected to pre-surgery screening at the University Policlinico ‘Agostino Gemelli’ aimed at assessing his health and monitor the reorganization of his cerebral regions and functions following the amputation of his left hand in 2004. listed below are the tests which were carried out:

  • Blood tests;
  • electrocardiogram;
  • Chest x-ray;
  • 32 Channel electroencephalogram (eeg) while resting and with peripheral stimulation;
  • sensory evoked Potentials (seP) with motor imagery;
  • electroneurography (eng) and echography of the nerves in the stump and intact limb;
  • Transcranial Magnetic stimulation (TMs);
  • eeg/TMs of three different cortical areas (frontal, central, posterior); 
  • functional Magnetic Resonance (fMRi) with motor and sensory cortex mapping;
  • Clinical evaluation of missing limb syndrome pain levels;
  • neuropsychological Personality tests.

26th January: Surgery

surgery to implant the four TIME intraneural electrodes in the median and ulnar nerves of the left arm of the patient was performed at the the University Policlinico ‘Agostino Gemelli’, Rome. The operation began at 8.30 in the morning and lasted over seven hours. neurosurgeon Professor Eduardo Marcos Fernandez and his team inserted the electrodes – placed in distal and proximal positions, two for the median nerve and two for the ulnar nerve, in the stump – transversally to the nervous fascicle. Four exit points in the patient’s arm were created for the electrode wires, in order to enable them to be connected to experimental equipment during tests over the following weeks.

Surgery, carried out under general anaesthesia, required an incision approximately 15 cm long to be made on the inner side of the left arm, well away from the traumatic edge of the stump. Once the two nerves had been isolated from the muscular and adipose tissues, the implantation was carried out using a surgical microscope. The part of the electrode containing contact points used for transmitting signals was placed inside the nervous tissue via guided-needle. The remainder of the microscopic filaments was connected to the nerve and micro-stitched in order to guarantee greater stability.

Straight away in the operating theatre and with the patient still under anaesthetic, the stimulation system was tested as well as the correct functioning of the 64 contacts (or sites) located on the inserted electrodes (16 for each of the four electrodes) while their impedance was gauged. The patient was discharged from hospital two days after surgery so as to begin the prosthesis educational and experimenting phase.

30th January – 14th February: Training

The patient spent nearly three weeks with researchers, every day training for several hours in order to learn how to recognise and classify electric impulses, delivered via the intraneural electrodes, with characteristics identical to those which would be transmitted by the biomechatronic hand during experimentation.

16th – 23rd February: Experimentation with prosthesis

experimentation with prosthesis lasted eight days, during which the patient faced two daily sessions of about four hours each. During sessions, he undertook tactile recognition exercises of objects and grasps. The objects were of different shapes and consistency. During the course of the exercises, the patient was blindfolded and acoustically insulated. In this way, researchers were able to assess the patient’s ability to correctly perceive and handle objects solely relying on sensory information sent to his brain by the sensors positioned on the prosthesis, without the aid of sight or sounds in
recognising their shape, consistency and position. The bidirectional communication flow between prosthesis and brain was recorded during the course of the sessions using appropriate equipment, providing data which was later studied by the researchers.

To create the bidirectional communication circuit from the prosthesis to the brain (sensory) and vice versa (movement and grasp intent), two algorithms were developed by researchers:

  • one capable of “reading” the output from the tactile sensors of the robotic fingers and sending it to the nervous system through the intraneural electrodes in the form of electric impulses

  • the other capable of receiving, processing and decoding the surface electromyographic electrodes (sEMG) signals located on the patient’s stump muscles and transforming them into appropriate motor commands for the robotic hand.

On 24th February 2013, after the 30 days which had been authorized for the implant of the four electrodes in the patient’s nerves, surgery was performed for their removal.