Research Profile: The Robotics Institute

Introduction:

Welcome to one of SciTech’s two new sections: Research Profiles. To help you get better acquainted with the exciting research being conducted right under your noses, the SciTech staff put together this section. This way, you may get a better sense of the kind of research or profession you might want to get into after college or the kind of undergrad research you might want to pursue here at CMU.

This week and next, SciTech will be featuring the Robotics Institute. Dr. Yoky Matsuoka is an assistant professor in the Robotics Institute. Her lab focuses on research and development in neural control of movement, brain-machine interface, and devices for rehabilitation, motor enhancement, and entertainment.

The research projects described in this feature are amazing — the Matsuoka lab is standing at the crossroads of biology and technology, making technological devices that will enhance human life. To be able to use robotics to enhance human sensory and neurological systems seems almost imaginary, like something out of science fiction.

This research would not be possible if it did not incorporate the knowledge and skills of multiple disciplines. “In the Neurobotics lab we aim to help patients with neurological injury through robotic rehabilitation, direct neural interface, and neurally-based prosthetic control. This involves the collaboration of electical, mechanical, and biomedical engineers; medical doctors; and many others,” said Pedram Afshar, an MD/PhD student in the Neurobotics lab.

“People who do best are those that want to learn more about other disciplines. They can really integrate each other’s knowledge,” said Mike Vande Weghe, a research programmer. “Even if no one person has the necessary skills, having the curiosity to be open and learn from people with other skills makes it much more fun. You get much more out of it. Sometimes you don’t know how well you know something until you have to explain it — this lab has really shown me that.”

The research being conducted in this lab is very promising for patients with physical disabilities. As Matsuoka put it, “My work will allow disabled and elderly people to live richer and more independent lives. Those who have physical paralysis will be rehabilitated under virtual robotic environment. Those who cannot be rehabilitated will be provided with assistive devices that allow them to reach and manipulate objects better. Those with primitive prosthetic devices may be given an opportunity to use much more natural replacement of their limbs. Maybe those disabled and elderly people can one day participate in sports or go back to work where it wouldn’t have been possible without the neurobotics technology.”

Read on to find out more about the various technologies being developed in the Matsuoka lab.

Neurobotics Laboratory

CMU’s Neurobotics Laboratory focuses primarily on building robot-human closed-loop systems that alter the neural control of movement as a way to rehabilitate, assist, and enhance human motor control and learning capabilities. The beneficiaries of the research that goes on here are people with strokes, spinal cord injuries, traumatic brain injuries, and other injuries that inhibit daily activities. Besides these, the Neurobotics Laboratory’s work also has applications in sports medicine, the military, and entertainment.

Currently, efforts are focused on developing a passive rehabilitation device to help stroke patients. The idea behind such a device stems from the fact that neural pathways will start to regrow after an accident or time of dormancy if they are stimulated. Stroke patients tend to give up using the affected body part. Doing so, however, could dramatically increase the time it takes to recover from the stroke. “Instead of people learning to work around a disability and never regaining control, this device will help them to regain functionality. Their recovery would be sped up by a safe, passive robot that could guide them,” said Wegh.

This device would tie in with the ongoing Feedback Distortion for Rehabilitation project, which combines the repetitive movements of robotic therapy with visual feedback distortion. Simply speaking, when an individual performs a task repeatedly, his or her performance on a given attempt is predicted largely by the previous performance. If feedback received by the individual is distorted so that the level of performance appears less than the level previously achieved, the individual will improve performance until the feedback indicates that the previous performance level has been reached.

The lab’s current projects also include Sensory Transfer Systems for the Sensory Impaired. The purpose of this project is to construct a sensory transfer system to assist and enhance the manipulation abilities of the sensory impaired. This system consists of two parts — an array of sensors worn on the arm and an array of actuators worn on the face or neck. The system senses the pressure exerted on the hand by various objects and transfers that pressure to a location from which a patient still receives sensory information.

The Silicon/Neuron Interface is another project that focuses on creating chronically implantable neural interfaces that may be used to control external devices and replace lost sensory input. Research currently focuses on conductive polymer coatings, to promote more intimate connections between cells and metal electrodes, that could eventually lead to a device that would be safe for long-term use and that would produce low-noise chronic single-unit recording.

Researchers working for the Neurobotics lab are also working to gain a better understanding of neuromuscular control. One way of doing this is through reading electrical signals from the brain and doing experiments to better understand how the brain manages motor control. In this regard, Alik Widge has been working on the development of biologically-friendly materials that make up the neuron detectors. These detectors can serve as bi-directional transmitters, allowing the user to read incoming electrical signals from the body and also send electrical signals of their own.

Pedram Afshar’s research into understanding how the brain controls the human hand uses a different method with the same underlying principles. “I am working on the neural control of movement project,” Afshar said. “My research has two goals: (1) figure out how the brain solves the problem of human hand control and (2) design engineering strategies for brain controlled hand prosthetics.”

Hands Devices

It is midnight. You just finished writing a lab report, but your happiness is short-lived as you remember that you also have a paper due tomorrow. In times like these, you wish you had another hand that could do work for you. Well, this dream is not as bizarre as it seems.

The Neurobotics lab is currently involved in three projects that focus on the hand. These projects will benefit those whose ability to use the hand is lost due to physical injury or illness. One of these projects is called the Anatomically Correct Testbed Hand (ACTH). Begun in 2002, the project’s goal is to devise a hand that could serve as a model to better understand the coordination of the hand via brain signaling. The ACTH could also serve to detect Hutchinson’s disease, the first symptom of which is the impairment of motor abilities.

The ACTH could one day serve as a device that emulates the hand movements and functions for prosthetics and remote operations. But more importantly, it will serve as a physical model for surgeons to test surgical reconstruction techniques for impaired hands. Where this hand differs from most robotic hands is that it also emulates the biomechanical aspects of the body that are pivotal for the proper functioning of the hand via the control signals that act like neural commands. In other words, the hand is made to mimic a real human hand as much as possible. “There would be a lot less to do with the software design and mechanical settings if the dynamics of the hand were right. Movement of the hand would come naturally,” said Weghe, who is working as a research programmer for this project.

The biggest challenge the Matsuoka lab faces in developing the ACTH is finding the right materials to use. It is crucial to know which parts are vital for the hand to function and which serve no significant purpose. In addition to engineering the tendons to match the tendons that are present in the actual hand, they have also been successful in devising an actuator that mimics the active and passive mechanics of the human muscles. It could be used in the ACTH as long as it does not interfere with the size and weight of the hand by altering the tendon structure of the hand. In order to simulate the active and passive muscle activity and contractions, a custom-made spring and a motor were installed.

The second project in the Neurobotics lab is a hand exoskeleton. The primary difference between the two projects is that the exoskeleton would be more like a glove and could be used for people whose hands have impaired functions. The exoskeleton is intended for simple tasks such as pinching, pointing, and grasping. The device is controlled by the user’s own muscle signals by using surface electromyography sensors attached to the arm. This hand could also be attached and removed as required.

In order to better understand the control and coordination of the brain over the hand, the Neurobotics lab has devised another project to study neuromuscular hand control. The project has two goals: to understand how the brain solves the problem of human hand control and to design prosthetics that can be controlled by the brain.

To achieve the above goals, the Matsuoka lab is currently putting visual markers on human fingers and using the data to understand how the body controls the hand, in order to devise a more realistic model of the hand. An electrical brain interface is also used to detect electrical signals from the brain. However, the material used in the interface is incompatible with the neurons. Due to this, the device fails to detect signals from the neurons after a while. Researchers are currently working on developing biologically-friendly materials to detect neurons in order to combat this problem.

Based on current research, the future could see a prosthetic hand controlled entirely by the brain. In the words of Weghe: “This device will be able to transmit past damage. It could perhaps be able to bypass numb parts of an injured arm, for example. The brain will eventually learn which nerves to use.”

The scope of these projects is immense. “There are rehabilitative institutes that may benefit from our published research, as well as small companies or other institutes that could pick it up,” said Weghe. “This research will help to understand body function, what kind of things we can do. It will lay the groundwork for the application and development of many techniques and devices.”

Conclusion:

For those of you interested in pursuing an MD/PhD, have you ever thought of combining medicine and engineering? Afshar’s message might just make you consider it: “I believe that the most interesting and challenging problems today are at the interface between medical science and engineering. To solve these problems requires both a thorough understanding of patients and medicine and the technical ability to identify and solve the underlying scientific questions. This is exactly the aim of the MSTP [Medical Scientist Training Program, a program at UPMC]: to train students with passion to help humanity and skills to create new science.”

So now that you have a good sense of the kind of research being conducted in this lab, Pedram Afshar is giving you a chance to participate in his research!

“The goal of my project is to determine how neural activity going to finger muscles creates finger movement. I recruit participants who are right-handed with no history of neurologic disease. The participants will play with a robot while I measure the neural activity to their muscles and their index finger. The experiment lasts about three hours and pays $10 per hour.”