October 4, 2022

Neurotechnology provides a direct connection of technical components with the nervous system. These technical components can vary from electrodes, intelligent prostheses to even computers. In addition, these components manipulate brain activity by applying electrical or optical stimuli. Another function of the components is to record signals from the brain and translate them into technical control commands. 

Developing brain or machine interfaces, therapeutics or academic research- these are some of the applications of Neurotechnology. 

ELECTROPHYSIOLOGY

Neurons communicate using electrical and chemical signals. 

Electrophysiology is a branch of neuroscience. Not only does it explore the electrical activity of living neurons. It also investigates the processes-  molecular and cellular. 

In other words, it is the use of electrodes to understand the electrical properties of neurons in the brain. 

  • Electrodes are conductors through which electricity can enter or leave.

In the 1780s, Luigi Galvani conducted an experiment with frogs’ legs. He noticed that the legs twitched when electric shocks were applied even when they were disconnected from the frog’s body and brain. Because of this discovery, a lot of research was instigated to learn about how neurons fire in response to stimuli.

Electroencephalogram

Electroencephalogram is an electrophysiological monitoring method, which is called EEG in short. It is used to record electrical activity of several neurons at once. No instruments go into the body so it is noninvasive. The electrodes are arranged in a cap and then placed over the scalp. The voltage fluctuations of the brain underneath the electrode cap are measured. 

Electroencephalogram is produced using electroencephalography. 

Brain cells communicate through electrical impulses. They are active all the time, including when asleep. This brain activity shows up as wavy lines on the EEG recording. 

Its main use is to detect abnormalities occurring neurally. It investigates epilepsy, which is a condition that causes continuous and repeated seizures. Epilepsy being of various types, an EEG helps in finding out which type of epilepsy the patient has and what may be triggering the seizures. This helps in giving the best treatment course for the patient. 

Electroencephalogram- instrument

Firstly, the EEG gives very little or no discomfort as the electrodes don’t transmit any sensations. Secondly, they only record the brain waves. But it doesn’t show if the patient has any damage or physical abnormalities in the brain. 

Electrocorticogram

Another aspect of electrophysiology is electrocorticogram, in short ECoG. This is invasive as it involves placing electrodes in direct contract with the surface of the brain. It measures the brain in the specific brain regions. It is used to map the epileptic regions of the brain which can lead to their safe removal. Since it is carried out in the course of a surgery, it is considered intraoperative. 

Clinical ECoG offers an opportunity to obtain invasive electrophysiological signals in awake and behaving humans.

Conditions diagnosed with an EEG or ECoG-

Seizure disorders

Sleep disorders

Brain tumours

Brain injuries

Dementia

Brain infections

Strokes

Attention disorders 

Behaviour disorders 

Development delays

Above all, all these conditions have a direct or indirect connection to the brain activities that take place. 

DEEP BRAIN STIMULATION

It is a technique that involves implanting electrodes into specific parts of the brain surgically. It helps to modulate the way the brain works. These electrodes regulate the abnormal neuronal activity in the patient by producing electrical impulses. 

The stimulation delivered to the brain is regulated by a pacemaker-like device. It is connected to the electrodes through a wire that runs under the skin. The process is highly invasive but has not many side effects.

A DBS system has 3 parts that are implanted in the body. The pacemaker is programmable and battery powered. This creates electric pulses. It is placed under the skin of the chest below the collarbone or in the abdomen.

Moreover, it is used to treat movement disorders like Parkinson disease, tremor and dystonia.  

Placement of DBS System

DBS was first developed in 1987 by a team treating patients with essential tremor and Parkinson Disease at Grenoble, France. 

“Over eight years of observation, most of our study participants experienced an antidepressant response to the deep brain stimulation of Area 25 that was robust and sustained. Given that patients with treatment-resistant depression are highly susceptible to recurrent depressive episodes, the ability of DBS to support long-term maintenance of an antidepressant response and prevention of relapse is a treatment advance that can mean the difference between getting on with your life or always looking over your shoulder for your next debilitating depressive episode.”

Dr. Mayberg

The future of DBS looks promising and holds the potential to contribute in improving the quality of life of people. 

BRAIN COMPUTER INTERFACES

Brain computer interface is a computer-based system. It receives brain signals, analyzes those signals and translates them into commands for devices. This device produces the desired output. 

It helps in restoring normal neuromuscular function in patients with disorders. Some of these disorders are amyotrophic lateral sclerosis, cerebral palsy, stroke and spinal cord injury.

Computer Interface

In 2015, some researchers at the University Of Houston made an amputee control his prosthetic hand just by using his mind. Above all, it was done without any invasive brain implant.

He wore a 64-channel EEG headset that monitored brain activity across the motor, action observation and decision-making regions of the brain. As a result, it was found that neural activities in the above regions of the brain preceded the movement of the prosthetic hand by 50-90seconds. This proved that the brain already anticipated the movement of the prosthetic hand before it happened.

64-channel EEG

Doesn’t it sound like a fantasy that being able to type on the keyboard or move the cursor just using our brain is real?!

Certainly, as technology keeps evolving, it takes multiple industries with it to their rise. So, there are many more techniques and types of technology being encompassed in the field of neurotechnology. Ranging from being able to record the activity of a single neuron to being able to modulate the activity of the entire brain.

“I do foresee that in 20-30 years, these types of implants will be just as common and acceptable as cardiac pacemakers are today.”

Florien Solzbacher of Blackrock Neurotech

This shows that neurotechnology has changed the way we treat neurological and psychiatric conditions and will continue to do so. 

Epilogue

For now, that’s all from my side regarding neurotechnology. There are many more discoveries and inventions yet to come. Until my next post, stay tuned and check out The Startech

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