NCT06391697

Magnetic Bead Tracking System and eOPRA Implant System With Bionic Prosthesis for Transtibial Amputees

A Feasibility Study Evaluating the Magnetic Bead Tracking System and Its Safety and Efficacy When Used With the e-OPRA Implant System and a Bionic External Prosthesis to Improve Prosthetic Controllability for Persons With Transtibial Amputation

• Status: Active Not Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 7 (estimated)
• Sponsor: Brigham and Women's Hospital · Academic / Other
• Sex: All
• Age: 22 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

The e-OPRA Implant System, is a further development of the OPRA (Osseointegrated Prostheses for the Rehabilitation of Amputees) Implant System. The e-OPRA Implant system is an implant system for direct skeletal anchorage of amputation prostheses. The added feature in the e-OPRA Implant system, is a bidirectional interface into the human body that allows permanent and reliable communication using implanted electrodes. These electrodes will provide long-term stable bioelectric signals for an improved control of the prosthetic limb. The Magnetic Bead Tracking System, which will be implanted and used in combination with the e-OPRA Implant system, is an investigational device that consists of pairs of magnetic beads, and a set of magnetic field sensors that measure and track the length of muscles and the speed at which they move in real-time. When the beads are implanted in muscle in the residual limb of an amputee, the muscle length signal is communicated to an investigational, robotic ankle-foot prosthesis. The purpose of the study is to evaluate the feasibility of a transtibial amputee with the e-OPRA Implant System and Magnetic Bead Tracking System exhibiting full neural control over a neuro-mechanical prosthetic system. A maximum of seven subjects will be enrolled. Each subject will undergo one or more surgeries where the e-OPRA Implant System and Magnetic Bead Tracking System will be implanted. The subjects will participate in follow-up sessions the last of which occurs approximately 24 months after the surgery. This is a prospective, non-randomized, uncontrolled study.

Detailed description

Normalization of function for individuals with limb amputation is within reach, and will be achieved by smart implants capable of bi-directional communication between brain and machine via bone-anchored, interactive, powered prosthetic components. Rehabilitation of patients with expected high physical activity level, such as after amputation due to trauma or cancer, is currently limited by dependence on an external socket for the mechanical attachment of the prosthesis to the residuum. Despite the use of advanced materials and fabrication methods, socket interfaces routinely cause sores, chafing, pain, increased energy expenditure, and a decreased quality of life. Novel surgical techniques using osseointegrated transdermal titanium implants, now validated in Europe for over 25 years, obviate the need for painful sockets by establishing a direct, load-bearing link between skeleton and prosthesis. This system also promises a transformative breakthrough in neuroprosthetics, because it allows for fully internal, high bandwidth, stable neural connections. In a paper recently published in Science Translational Medicine, implanted muscle and nerve cuff electrodes were added to the osseointegrated device, creating a bi- directional efferent-afferent interface utilizing a safe and immune-sealed osseo-conduit. Commenting on this work, the editor stated, "Osseointegration could revolutionize the field of neuroprosthetics, giving patients more intuitive control and more freedom of movement." Investigators have sought to advance bionic prostheses with sufficient degrees of freedom for performing natural tasks, such as manipulating objects in the case of upper-extremity prostheses, or walking and running for lower-extremity systems. Nonetheless, afferent feedback has not played a major role in any clinically-viable amputation prostheses, despite being critical for biomimetic control. This deficiency can, in large part, be attributed to a lack of clinically-available methodologies for sustained communication with the peripheral nervous system. There is no existing platform capable of invasive, robust, and permanent communication with the peripheral nervous system in a high-demand clinical set- ting. Only by bringing together critical technologies and expertise will it be possible to create a bionic limb replacement system with adequate suspension, load transmission, motor control, proprioceptive feedback, and external mechatronics that resemble the mass, volume and dynamics of the missing biological limb. To develop the most advanced clinically- viable artificial limb and achieve the next level of prosthetic technology integration, a multi-disciplinary scientific team has been assembled with members from Massachusetts Institute of Technology (MIT: Carty, Herr, Brånemark) and Brigham and Women's Hospital (BWH: Carty, Ferrone). With proprioceptive afferent feedback, we seek to demonstrate that a person with transtibial amputation can exhibit full volitional control over a neuro-mechanical prosthetic system where key walking metrics are normalized, including preferred speed, metabolism and joint dynamics. It is the view of the proposers that the scope of this research is fundamental wherein the results will be shared broadly within the scientific community.

Conditions

• Amputation

Interventions

Type	Name	Description
DEVICE	eOPRA Implant System for Transtibial Amputees and Magnetic Bead Tracking System	The Magnetic Bead Tracking System is an investigational device that consists of pairs of magnetic beads, and a set of magnetic field sensors that measure and track the length of muscles and the speed at which they move in real-time. When the beads are implanted in muscle in the residual limb of an amputee, the muscle length signal is communicated to an investigational, robotic ankle-foot prosthesis. The e-OPRA is an investigational implant system that lets a lower leg prosthesis attach securely to the remaining tibia bone. The e-OPRA device has been designed so that it can be implanted with an electrode set that consists of an electrical connector and electrodes to allow it to be used with both a neuro-mechanical (powered) prosthesis system, in addition to the standard prosthesis. The operation to implant these devices will represent a modification of the surgical technique currently employed for standard below knee amputation.

Timeline

• Start date: 2024-05-01
• Primary completion: 2026-05-02
• Completion: 2027-05-02
• First posted: 2024-04-30
• Last updated: 2025-10-20

Locations

2 sites across 1 country: United States

Regulatory

• FDA-regulated device study