Sensory Motor Transformations in Human Cortex
A Feasibility Study of the Ability of the Neural Prosthetic System 2 to Provide Direct Closed Loop Cortical Control of Extracorporeal Devices Through the Use of Intracortical Microstimulation in Patients With Quadriplegia
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interventional
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1 country
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Brief Summary
This research study is being conducted to develop a brain controlled medical device, called a brain-machine interface. The device will provide people with a spinal cord injury some ability to control an external device such as a computer cursor or robotic limb by using their thoughts along with sensory feedback. Development of a brain-machine interface is very difficult and currently only limited technology exists in this area of neuroscience. Other studies have shown that people with high spinal cord injury still have intact brain areas capable of planning movements and grasps, but are not able to execute the movement plans. The device in this study involves implanting very fine recording electrodes into areas of the brain that are known to create arm movement plans and provide hand grasping information and sense feeling in the hand and fingers. These movement and grasp plans would then normally be sent to other regions of the brain to execute the actual movements. By tying into those pathways and sending the movement plan signals to a computer instead, the investigators can translate the movement plans into actual movements by a computer cursor or robotic limb. A key part of this study is to electrically stimulate the brain by introducing a small amount of electrical current into the electrodes in the sensory area of the brain. This will result in the sensation of touch in the hand and/or fingers. This stimulation to the brain will occur when the robotic limb touches the object, thereby allowing the brain to "feel" what the robotic arm is touching. The device being used in this study is called the Neuroport Array and is surgically implanted in the brain. This device and the implantation procedure are experimental which means that it has not been approved by the Food and Drug Administration (FDA). One Neuroport Array consists of a small grid of electrodes that will be implanted in brain tissue and a small cable that runs from the electrode grid to a small hourglass-shaped pedestal. This pedestal is designed to be attached to the skull and protrude through the scalp to allow for connection with the computer equipment. The top portion of the pedestal has a protective cover that will be in place when the pedestal is not in use. The top of this pedestal and its protective cover will be visible on the outside of the head. Three Neuroport Arrays and pedestals will be implanted in this study so three of these protective covers will be visible outside of the head. It will be possible to cover these exposed portions of the device with a hat or scarf. The investigators hope to learn how safe and effective the Neuroport array plus stimulation is in controlling computer generated images and real world objects, such as a robotic arm, using imagined movements of the arms and hands.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at below P25 for not_applicable
Started Nov 2013
Longer than P75 for not_applicable
4 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
October 15, 2013
CompletedFirst Posted
Study publicly available on registry
October 17, 2013
CompletedStudy Start
First participant enrolled
November 1, 2013
CompletedPrimary Completion
Last participant's last visit for primary outcome
July 31, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
January 31, 2027
May 22, 2025
May 1, 2025
12.8 years
October 15, 2013
May 20, 2025
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
Patient control over the end effector (virtual or physical)
The primary effectiveness objective of this study is to evaluate the effectiveness of the NPS2 in controlling virtual or physical end effectors. Signals from posterior parietal cortex will allow the subject to control the end effector with accuracy significantly greater than chance; the subject will be able to perceive and discriminate ICMS above the level of chance; and,incorporating stimulation will improve the subject's control over the end effector. We will evaluate the effectiveness of the NPS2 primarily by calculating the accuracy of the subjects' control over the end effector with and without ICMS, and comparing these different accuracies to the chance level, and to each other. Each subject will serve as his or her own control.
Nine years after array implantation
Absence of infection or irritation
The primary objective of this study is to evaluate the safety of the NPS2. Implantation will not be associated with infection or irritation, and that the serious adverse event rate will not rise above 1%. We will evaluate the safety of the NPS2 by inspecting the subjects' scalps for evidence of reddening or discharge, by performing regularly scheduled neurologic history and physical exam, and by obtaining feedback from the subjects. The condition of the area will be compared with its condition on previous visits, history will be obtained regarding new symptoms and neurological and physical exam will be compared to baseline exams.
Nine years after array implantation
Study Arms (1)
Neural Prosthetic System 2
EXPERIMENTALThe Neural Prosthetic System 2 consists of three Neuroport Arrays, which are described in detail in the intervention description. Two of the three Neuroport Arrays are inserted into the posterior parietal cortex, an area of the brain used in reach and grasp planning. The third Neuroport Array is inserted into somatosensory cortex, specifically S1 which represents sensory feedback for the hand and fingers. The arrays are inserted and the percutaneous pedestal is attached to the skull during a surgical procedure. Following surgical recovery the subject will participate in study sessions 3-5 times per week in which they will learn to control an end effector by thought augmented with sensory feedback via intracortical microstimulation. They will then use the end effector to perform various reach and grasp tasks.
Interventions
The NPS2 comprises 3 NeuroPort Arrays (SIROF). The tip of the electrodes are sputtered iridium oxide film (SIROF). Each array is comprised of 100 1.5 mm microelectrodes organized on a 4mm x 4mm silicon base that is 0.25 mm thick. Each microelectrode is insulated with Parylene-C polymer and is electrically isolated from neighboring electrodes by non-conducting glass. Of the 100 electrodes, 96 are wire bonded using 25m gold alloy insulated wires sealed with a silicone elastomer. The wire bundle is potted to a printed circuit board with epoxy, the circuit board is inserted into the Patient Pedestal (percutaneous connector), and then the Patient Pedestal is filled with silicone elastomer. Two fine platinum reference wires are also attached to the Patient Pedestal. The Patient Pedestal is 19 mm wide at the skin interface.
Eligibility Criteria
You may qualify if:
- High cervical spinal lesion
- Age 22-65
- Able to provide informed consent
- Able to understand and comply with instructions in English
- Communicate via speech
- Surgical clearance
- Life expectancy greater than 12 months
- Travel up to 60 miles to study locations up to five days per week
- Caregiver monitor for surgical site complications and behavioral changes on a daily basis
- Psychosocial support system
You may not qualify if:
- Presence of memory problems
- Intellectual impairment
- Psychotic illness or chronic psychiatric disorder, including major depression if untreated
- Poor visual acuity
- Pregnancy
- Active infection or unexplained fever
- Scalp lesions or skin breakdown
- HIV or AIDS infection
- Active cancer or chemotherapy
- Diabetes
- Autonomic dysreflexia
- History of seizure
- Implanted hydrocephalus shunt
- Previous neurosurgical history affecting parietal lobe function
- Medical conditions contraindicating surgery and chronic implantation of a medical device
- +9 more criteria
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Richard A. Andersen, PhDlead
- University of Southern Californiacollaborator
- Rancho Los Amigos National Rehabilitation Centercollaborator
- University of Colorado, Denvercollaborator
Study Sites (4)
Rancho Los Amigos National Rehabilitation Center
Downey, California, 90242, United States
University of Southern California
Los Angeles, California, 90033, United States
Richard Andersen
Pasadena, California, 91125, United States
University of Colorado Anschutz Medical Campus
Aurora, Colorado, 80045, United States
Related Publications (2)
Bashford L, Rosenthal IA, Kellis S, Bjanes D, Pejsa K, Brunton BW, Andersen RA. Neural subspaces of imagined movements in parietal cortex remain stable over several years in humans. J Neural Eng. 2024 Aug 28;21(4):046059. doi: 10.1088/1741-2552/ad6e19.
PMID: 39134021DERIVEDArmenta Salas M, Bashford L, Kellis S, Jafari M, Jo H, Kramer D, Shanfield K, Pejsa K, Lee B, Liu CY, Andersen RA. Proprioceptive and cutaneous sensations in humans elicited by intracortical microstimulation. Elife. 2018 Apr 10;7:e32904. doi: 10.7554/eLife.32904.
PMID: 29633714DERIVED
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Richard A Andersen, PhD
California Institute of Technology
- PRINCIPAL INVESTIGATOR
Charles Liu, MD, PhD
University of Southern California, Rancho Los Amigos Rehabilitation Center
- PRINCIPAL INVESTIGATOR
Dan Kramer, MD
University of Colorado, Denver
- PRINCIPAL INVESTIGATOR
Luke Bashford, PhD
University of Colorado, Denver
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- NA
- Masking
- NONE
- Purpose
- BASIC SCIENCE
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR INVESTIGATOR
- PI Title
- James G. Boswell Professor of Neuroscience
Study Record Dates
First Submitted
October 15, 2013
First Posted
October 17, 2013
Study Start
November 1, 2013
Primary Completion (Estimated)
July 31, 2026
Study Completion (Estimated)
January 31, 2027
Last Updated
May 22, 2025
Record last verified: 2025-05