Periodic Reporting for period 4 - MYKI (A Bidirectional MyoKinetic Implanted Interface for Natural Control of Artificial Limbs)
Période du rapport: 2021-03-01 au 2023-02-28
The need/desire for functional replacement of a missing upper limb is an ancient one: historically humans have replaced a missing limb with a prosthesis for cosmetic, vocational, or personal autonomy reasons. In fact the loss of a hand causes severe physical and also mental illness. The inability to grasp and manipulate objects runs parallel with the inability to sense and explore the surrounding world as well as with the inability to use gestures to support speech and express emotions. Still today the restoration, following amputation, of dexterous control equivalent to that of the human hand is one of the major goals in applied neuroscience and bioengineering. To accomplish this requires achieving two important subgoals: the development of a multi-degree of freedom (DoF) artificial hand, and the implementation of an intuitive and effortless human–machine interface (HMI) that maps the sources of volition to the DoFs of the artificial hand, bi-directionally. Although MYKI targets this goal as a whole, is the HMI the primary focus of the project.
The overall objective of the MYKI project is to investigate, design, develop and clinically assess on one selected transradial amputee what we defined MyoKinetic interface, i.e. a magnetic field-based HMI with features beyond the state of the art, for the natural control and perception of a transradial hand prosthesis. This goal will be achieved by addressing the following technological objectives (TOs) and specific scientific objectives (SSOs):
TO1: Localizer of implantable magnets
SSO1: Efferent processing algorithms for MyoKinetic Interface
TO2: Remote actuation of implantable magnets
SSO2: Is it possible to convey physiologically appropriate touch information related to tactile events in the hand prosthesis through implanted magnets?
SSO3: Is it possible to convey physiologically appropriate proprioceptive information of a missing finger or DoF through implanted magnets?
TO3: Smart hand-wrist prosthesis with tactile sensors and shared control
TO4: Biocompatible packaging for implanted magnets
At conclusion of the project, all the foreseen Technological Objectives (TOs) were successfully accomplished. The first volunteer underwent surgery to receive the myokinetic implant on April 1st 2023. Six magnets were implanted in three forearm muscles through a minimally-invasive surgical procedure. Outcomes from the first implant will be available after the explant, set for May 13th 2023.
- the investigation, through simulations and a physical forearm mockup, of multi-magnet tracking systems capable to localize many more magnets than those described earlier.
- the development of dedicated hardware solutions for multi-magnet tracking suitable for integration on wearable devices.
- the development of different prototypes for the delivery of selective remote vibrations, at arbitrary frequencies and with different shapes, to multiple targets, an unprecedented tool to study proprioception in humans.
- The integration of the magnetic tracking and actuation technologies in a unique system so that controlled vibrations can be delivered in moving magnets.
- The identification of Parylene C as a safe coating for short-term implants in humans.
- The self-contained arm prosthesis with myokinetic control used for pilot clinical assessment with one patient.
- The first implantation of six magnets in humans for the myokinetic control of a arm prosthesis.
The development of the above mentioned key enabling technologies (TOs and SSOs) permitted MYKI to perform the first in-human implant of the MyoKinetic interface, that in turn will allow to assess the proposed control and sensory feedback strategies. Due to its nature the implant was minimally invasive. Interestingly, although it is being first clinically assessed with a transradial amputee (the most prevalent case), it is worth mentioning that the MyoKinetic interface concept adapts nicely to all cases of upper limb amputation (from partial hand amputations, to shoulder disarticulation) and could also find use in lower limb prostheses. Hence, the project could also have a major socioeconomic impact for disabled people in general by providing new interfacing solutions resulting in better quality of life.