PIKESH PRASOON | 1104150 | ETC-III

SCHOOL OF ELECTRONICS ENGINEERING, KIIT

From human limitations, to potentials

BIONICS

Introduction

▪ Since time immemorial, human has done inventions to mimic the Mother Nature. Necessities has forced him to discover technologies to help the ailing society. So, it must be accepted that if social disabilities persist, the person is not crippled; rather the technology is crippled, broken. A century ago, Tuberculosis had no cure. Surely, technology that time was crippled!

▪ Many people around us challenge the physical disabilities like deafness, blindness, amputations, etc. But we are not bestowed with regeneration capabilities to overcome these. The technology remained crippled for many years until research in STEM CELLS, BIONICS, and SENSORY SUBSTITUTION took place.

▪ Bionics has been practically implemented and many people have overcome their disability to much extent by this technology.

What is ‘Bionics’?

▪ Bionics - as the name suggests is the interplay of ‘BIOlogy’ and ‘electrONICS’. By dictionary, bionics means “comprising or made up of artificial body parts that enhance or substitute for a natural biological capability”[1]. Generally, a mechatronic prosthetic system is interfaced to the biological body to overcome the disability.

▪ It is seen in most of the cases that even if the body part is not working well (say the ear, eye or body part is amputated), the part of brain responsible for controlling it, works fine. So, if one is amputated, his brain’s motor cortex works fine. Bionics exploits this idea. As ideology, it believes that the signals from the brain could be extracted, deciphered and then implemented by mechatronic prosthetic system . Even more, it believes sending back the feedback/stimulus to brain, say by the prosthetic system.

History[2]

1958 : The first artificial pacemaker by Wilson Greatbatch

1971 : Bausch & Lomb develop the world’s first soft contact lens.

1978 : The multi-channel cochlear implant, which allows the recipient to hear by mimicking the function of the cochlea, is first used.

1983 : A person born blind implanted with bionic eye by Joao Lobo Antunes

2000 : An artificial silicon retina is implanted into a human eye. The artificial retina is made from silicon microchips which contain thousands of tiny light-converting units.

2001 : Amputee Jesse Sullivan receives a fully robotic arm developed by the Rehabilitation Institute of Chicago. The arm has a nerve muscle graft which allows him to use his own thoughts to move the artificial limb.

2002 : Argus I, Bionic Eye, clinically tested on 6 patients

2002 : Project Cyborg - Array of 100 Electrodes implanted to nervous system of Kevin Warwick. The signal produced was transmitted, and felicitated a prosthetic arm to mimic Warwick’s hand movements. Later Warwick’s nervous system was connected to internet.

2004 : The Rheo Knee, Hugh Herr, Bionic Knee for walking, running.

2006 : Argus II, Bionic Eye, approved for commercial use in Europe.

PROSTHETIC LIMB

Human Limitation: Due to accidents in military scenarios, road, trekking, etc 10 million people worldwide[3] has been victimized to amputation (till September, 2008). Due to this moral, physical, social, and economic life of the victim gets affected and slowed.

Technological Milestones 1Human potential : Bionics based Prosthetic Limb

Bionics in Prosthesis

HOW DOES THE MOTION IN HUMAN OCCUR ACTUALLY ?

Upper motor neurons(Cortico-spinal) inter-neurons arise from the motor cortex and descend to the spinal cord. They activate the lower motor-neurons through synapses. These lower motor neurons innervate the muscles. The alpha motor neurons innervate the extrafusal muscle fibers. These muscle fibers cause fast and rough motion. The gamma motor neurons are responsible for precise motion.

HOW DOES BIONICS INCORPORATE IT ?

Bionics uses the fact that even if a part is amputated, the concerned brain portion works fine. In case of amputated hand/legs or other locomotors, the MOTOR CORTEX works fine. It exploits this fact that lower motor neurons innervate the muscle fibers. So if some mechanism is involved that could get signals from these innervated nerves (that cause motion) prosthesis could be given a new dimension.

HOW DOES BIONICS INCORPORATE IT ? contd..

Using surface electrodes, EMG, EEG sensors that could read the signals from nerve. They are generally stickered to human body muscle (hand/leg/thighs). In some cases they could be injected inside the body. In Project Cyborg 100 electrodes were implanted in the nervous system.

Analysis of advancement:

▪ Many nerves innervate the muscles responsible for control and precision of movement. Still among the many electrical signals sent from brain for motion, we make use of few that gives the prosthetic design to function roughly. For more preciseness we need to decipher among many electrical signals and noise, the meaning of instructions.

▪ The hand has 27 degrees of freedom naturally. Still, we are not able to achieve the number. The system remains underactuated.

▪ Research work is under process to use other muscles to control body parts. Ex: neck muscles could control the movement of prosthetic hand. This needs rigorous training and research.

▪ Sensing, or sending stimulations back to brain is still under research.

COCHLEAR IMPLANT

Human Limitation: Many persons worldwide are profoundly deaf due to damage to sensory hair cells in the Cochleas. More than 4 lacs people worldwide are deaf by this cause.

Technological Milestones 2Human Potential : Cochlear Implant

Bionics in Cochlear Implant

HOW DOES HEARING IN HUMAN OCCUR ACTUALLY ?

Ear is made of thousands of hair cells. They get stimulated by sound and begin to vibrate, thereby passing electrical impulses to cochlear/auditory nerve.

HOW DOES BIONICS INCORPORATE IT ?

In many cases of deafness (sensorineural), the hair cells do not function well, and thus could not send signals to brain. Bionics, which sees brain working fine, tries to sort out the issue with hair cells. An external stimulator is used to stimulate the cochlear nerve.

HOW DOES BIONICS INCORPORATE IT ? Contd..

As stated the hair cells do not function properly. As a solution, a lead of electrodes is implanted in the ear. This help in replication of what hair cells do. The implantation may contain from 1 to 22 electrodes, each being stimulated for different frequencies and pitches. These electrodes then stimulate the nerves, thereby sending signals to brain. The electrodes are wound through the cochlea.

External System: •Microphone : Receives the sound frequencies.•Speech processor : Acts on the frequencies received, filters out the audio frequency, divides the filtered output in channel and send to the transmitter.•Transmitter : Sends the channelized output to internally placed receiver.

Internal System: (Implanted Inside the ear)•Receiver : It receives the signal transmitted externally.•Stimulator: It converts the signal into electrical impulses and sends them via internal cable to electrodes.•Electrodes : They send the impulse to the cochlear nerve.

Analysis of advancement:

▪ The sound quality is not natural, as no o f electrodes used limit the natural quality.

▪ Research is still going on how the brain interprets loudness, quality, direction of sound, and pitch of sound. Further advancements will lead to improved efficiency in performance of Implants.

▪ It is able to send feedback signal to brain as compared to prosthetic limb.

BIONIC EYE (VISUAL PROSTHESIS)

Human Limitation : Many persons lose their vision partially or fully due to degraded photoreceptors. Disabilities like Retinitis pigmentosa, choroideremia cause human to lose their vision.

Technological Milestones 4Human Potential : Bionic Eye (Ex : Argus II)

Bionics in Bionic Eye

•The biocompatibility of the implant and the human host is still under research.

•The stimulation caused by the ARCC (Artificial Retina Component Chip) could affect the retinal and cortical tissue because of the intensity needed to stimulate the nerve endings in order for a retinal response.

•Many further projects[4] are being researched for improvement in retinal prosthesis.

Analysis of advancement:

References

• Jeffrey Fox, Kim Edginton, Jennifer Wightman, Rebuilding the body with bionics, http://www.cem.msu.edu/~cem181fp/brain/index.html • [1] Medical Dictionary, Merriam Webster,

http://www.merriam-webster.com/dictionary/bionic• [2] Lloyd Emma, The history of bionics, http://www.healthguideinfo.com/prosthetics-

bionics/p9070/, Project Cyborg, http://en.wikipedia.org/wiki/Kevin_Warwick#Project_Cyborg, Argus , http://en.wikipedia.org/wiki/Argus_retinal_prosthesis#History• [3] Maurice LeBlanc, https://web.stanford.edu/class/engr110/2011/LeBlanc-03a.pdf• [4] Visual Prosthesis/Ongoing Projects,

http://en.wikipedia.org/wiki/Visual_prosthesis#Ongoing_projects

THANK YOU !!!!!