Archives for category: Brain Computer Interface

BCI neurotech

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How much effort goes into picking up a spoon? The planning and anticipation of which hand to use, where to place the hand, when to open and close the fingers, and how much weight to anticipate is complex and requires much coordination of the nervous and musculoskeletal systems.

In a normally functioning nervous system, movement of the extremities occurs when electrical impulses from the brain trigger a response which is sent to muscles. The central nervous system (brain and spinal cord) passes along electrical signals to the peripheral nervous system, and the nerves in the peripheral nervous system respond by communicating with their corresponding muscles.

When a person has a neurological injury causing paralysis, the signals between the central nervous system and peripheral nervous system are interrupted. Suddenly, simple every day tasks become complicated. An injury such as a fall causing quadriplegia can leave a person struggling to figure out how to move around and perform previously effortless everyday tasks such as eating and getting dressed. The aspiration with medical technology, then, is to make the transition from injury to adjustment as smooth as possible.

Neuroprosthetics are medical devices intended to assist with injuries to the nervous system. In recent years, there has been much growth with this technology using brain-computer interface (BCI), robotics, and exoskeleton technology. The challenge with neurological injuries, however, is that it is very difficult to replicate the intricate and precise workings of the brain and nervous system.

The team from BrainGate recently published a study following a quadriplegic subject in which they ultimately allowed him to use his brain to successfully control the movement in his arms to be able to feed himself. This amazing coordination of technology was achieved by implanting electrodes into his brain which picked up electrical signals and transfer these signals to Functional Electrical Stimulation (FES).

In this study, the electrodes implanted in the motor cortex picked up the electrical signals as he planned to use his upper extremities. The BrainGate system is able to decipher the signals from the brain activity and transfer it to the FES system through electrical pulses. These electrical pulses stimulated the muscles in his arm, creating the desired movement which the participant had planned for. Specifically, the man was able to feed himself using his hand for the first time in 8 years.

Still an investigational device, the BrainGate system is so promising in providing independence and versatility of movement, and the team is now working with the Harvard Wyss Center. The hope is that someday individuals will be able to implement neurotechnology such as this as soon as possible after injury, allowing for adjustment before the deleterious effects of immobility set in.

Watch the video below for more insight into this amazing work:

 

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Those with spinal cord injuries (SCI’s) know that medicine still has a long way toward a successful solution for their injury.  Spinal cord injuries often occur as a result of trauma, such as a fall or gunshot wound. The initial physical compression and loss of blood supply to the spinal cord, followed by secondary edema and swelling cause a death of the spinal nerves which control our movement. In short, this type of injury usually takes away a person’s ability to walk and stand on their own.

SCI’s are normally classified in ASIA grades from complete (A) to normal (E), with incomplete injuries in between. Complete injuries involved complete loss of movement and sensation below the level of injury, while incomplete injuries maintain some preservation of sensation or motor control. Unfortunately, the rate of spontaneous recovery for those with complete injuries is low, while incomplete injuries have a slightly better success rate of recovery.

One project working toward a solution for spinal cord injuries by combining technology and rehabilitation is the Walk Again Project. Working toward a protocol for SCI recovery, this group has recently published research combining virtual reality and robotic assistance with variable gait training. And, it has shown promise of providing some recovery even for paralyzed individuals with complete SCI’s.

In the publication, the project demonstrates a partial return of neurological function in complete SCI’s by combining several methods of treatment. As the person controlled movement via a robotic exoskeleton with their brain using virtual reality for guidance, they also received some physical feedback from their environment. This physical feedback was applied to areas such as their feet or forearms in response to certain movements.

The results of this involved, year-long training are novel and incredible. People with previous complete loss of muscle and sensory function were able to regain some motor control, sensation, and proprioception after training. This is a novel publication by the length of the study and methods of guidance which lead those with SCI’s back toward recovery. The combination of brain machine interface, robotics, and rehabilitation provides a groundwork for future treatment options.

The effectiveness of this training may partly be explained by the idea that by forcing the body to walk and waking up the part of the brain which controls movement, the motor cortex, motor function is partially restored. Additionally, the physical movement may activate CPG’s (central pattern generators) in the spinal cord, which generate rhythmic movement. There may still be a long way to go toward medicine in SCI treatment, but this project provides solutions and hope through combined methods. Watch the video below for more insight into this amazing project:

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In the past, having a neurological injury which left someone with quadriplegia was a life sentence. With research and developing technology has emerged new hope for people left with minimal use of their arms and legs after an event such as severe stroke or spinal cord injury. Current applications are combining the use of virtual reality and electrical signals from the brain to increase people’s function and potential through brain-computer interface (BCI).

In light of the upcoming Cybathlon as well as BCI Meeting 2016, I would like to highlight a company creating much opportunity through research and development. g.tec is a biomedical engineering company that both creates products and conducts research for BCI. While many of the company’s products are inspiring and impressive, it is their BCI research system which is brilliant.

In a BCI system, a person is able to control a target by thinking, and thus using the electrical signals from their brain which are converted into electrical signals which a computer can detect and use to perform tasks. This task can either be something on a computer screen such as a game or computer application, or a robotic device which is able to pick up these signals and move in response. Much like our bodies can use our brain as the command center to tell us to pick up a pen using our left hand, a BCI system can potentially do the same, replacing a biological hand with a robotic limb.

In order for someone to control a target with their brain, there must be multiple working components. A person wears a cap with electroencephalography (EEG) electrodes, and can use motor imagery to plan a task. The electrical signals in the brain which occur while the person is planning this activity are picked up up by the EEG electrodes, amplified, and converted to electrical signals which the computer system uses to carry out the task. It is an incredibly complex and amazing feat to connect biological and computer systems seamlessly to carry out a task.

As the g.tec website elaborates, the electrical conversion from human brain to computer leads to a number of amazing applications. There is, for example, a motor rehabilitation system where a system is controlled by thought directing virtual hand activity, allowing users to control a prosthesis, wheelchair, or virtual reality environment with their mind. In essence, a person can think that they are using their right hand to spell out a word, and the computer spells out this word in response.

Another application of BCI which g.tec is working toward researching is motor rehabilitation through virtual limbs. In this system, a user imagines a limb moving, and is able to visualize this limb in virtual form on a screen. In essence, this system would allow someone with left sided paralysis after a stroke to visualize moving their left arm on a screen. This is incredibly valuable for recovery from a neurological event such as stroke, where decreased activity in the brain of controlling a limb can lead to permanent difficulty of extremity control. “Use it or lose it” unfortunately can prove to be an accurate description of limb use after a debilitating stroke.

While this technology is still emerging and by no means has reached its full potential, g.tec presents us with a diverse platform for research and development of products which will have a huge impact on those who are affected by stroke and other neurological injuries. Anyone who has observed someone with such an injury understands the frustration, disappointment, and loss of independence that such an event brings.

The BCI research system is just one of many groundbreaking products that g.tec is developing. Their site outlines many more products which perform a variety of functions, from cortical mapping to assisting people with communication limitations.