brain-computerinterface-SUBHAM KAR
- 1. Pratishruti Jain 1 Presented by: SUBHAM KAR Steam-ECE Class Roll-83 MAKAUT Roll-
- 2. CONTENTS: What is Brain-Computer Interface? Principle behind BCI Objective of BCI Types of BCIs History Implementation Software behind BCI Applications Limitations Future Concerns Conclusion References Brain-Computer Interface 2
- 3. What is Brain-Computer Interface? Brain Computer Interface is a direct technological interface between a brain & a computer system not requires a motor output from the user. It is abbreviated as BCI. It is also known as Direct Neural Interface (DNI) & Brain – Machine Interface (BMI). Brain-Computer Interface 3
- 4. Continued Brain-computer interface is an electrode chip which can be implemented in the brain through surgical procedure. • When it is implemented in brain the electrical signal exchanged by neurons within the brain are sent to the computer and then the computer is controlled by person. Brain-Computer Interface 4
- 5. Principle Behind BCI This technology is based on to sense, transmit, analyze and apply the language of neurons. It consist of a sensor that is implanted in the motor cortex of the brain and a device that analyses brain signals. The signals generated by brain are interpreted and translated into cursor movement on computer screen to control the computer. It consists of a silicon array about the size of an Aspirin tablet that contains about 100 electrodes each thinner than a human hair. Brain-Computer Interface 5
- 7. KEY ISSUES IN BCI RESEARCH AND USERS Target users: Researchers - clinical researchers, neuroscientists, signal processing experts, etc. Technical operators - caregivers, therapists who are in charge of training someone on BCI operation. End-users -people with disabilities who rely on the system for communication Casual end-users -those who use a BCI as an alternative input for entertainment devices.
- 8. STRUCTURE OF A BCI :-
- 9. Structure of a BCI 1) Signal Acquisition: the EEG signals are obtained from the brain through invasive or non-invasive methods (for example, electrodes). After, the signal is amplified and sampled. 2) Signal Pre-Processing: once the signals are acquired, it is necessary to clean them. 3) Signal Classification: once the signals are cleaned, they will be processed and classified to find out which kind of mental task the subject is performing. 4) Computer Interaction: once the signals are classified, they will be used by an appropriate algorithm for the development of a certain application.
- 12. BCI vs Neuroprosthetics Neuroprosthetics typically connect the nervous system to a device, whereas BCIs usually connect the nervous system with a computer system. Practical neuroprosthetics can be linked to any part of the nervous system—for example, peripheral nerves While the term "BCI" usually designates a narrower class of systems which interface with the central nervous system.Brain-Computer Interface 12
- 13. Objective of BCI: The goal of the Brain-Computer Interface is to develop a fast and reliable connection between the brain of a severely disabled person and a personal computer . The ‘Brain Gate’ device can provide paralysed or motor-impaired patients a mode of communication through the translation of thought into direct computer control. Brain-Computer Interface 13
- 14. Types of BCIs: • Invasive BCI Invasive BCIs are implanted directly into the grey matter of the brain during neurosurgery. • Non Invasive BCI Non-Invasive BCIs do not involve neurosurgery. They are just like wearable virtual reality devices. • Partially Invasive BCI Partially invasive BCI devices are implanted inside the skull but rest outside the brain rather than within the grey matter. Brain-Computer Interface 14
- 15. History- Discovering the Basics 1924: Hans Berger discovers the EEG Analyses the interrelation of EEG and brain diseases. 1970: First developments to use brain waves as input ARPA has vision of enhanced human First step in the right direction
- 16. History of BCI: • Research on BCIs has been going on for more than 20 years, but from the mid-1990s there has been a dramatic increase in working experimental implants. • Brain-Computer Interface was commercially developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. Brain-Computer Interface 16
- 17. BCI Research On Animals: At first, rats were implanted with BCI . Signals recorded from the cerebral cortex of rat operate BCI to carry out the movement. Brain-Computer Interface 17
- 18. Contd… • Researchers at the University of Pittsburgh had demonstrated on a monkey that can feed itself with a robotic arm simply by using signals from its brain. Brain-Computer Interface 18
- 19. Functionality of BCI Steps for the function of BCI. 1.user wired to a multi-electrode EEG skin cap, which is connected to a pc running BCI2000. 2.user of the signal asked to generate a series of signals. 3.EEG potential record and analyze the signal 4.the software attempt to match these signal to previous recorded signals. 5.at last identified words are wrapped on output devices like-screen or speech synthesizer.
- 20. Architecture
- 23. BCI On HUMANS In December 7, 2004, brain-computer interface had been clinically tested on a human by an American biotech company Cyberkinetics. The first participant in these trials was a 25-year-old man who had sustained a spinal cord injury leading to paralysis in all four limbs . Brain-Computer Interface 23
- 24. Contd… Over a period of nine months, he took part in 57 sessions during which the implanted Brain Gate sensor recorded activity in his motor cortex region while he imagined moving his paralyzed limbs and then used that imagined motion for several computer- based tasks such as, moving a computer cursor to open e-mail, draw shapes and play simple video games. Brain-Computer Interface 24
- 25. How BCI Implements? A more difficult task is interpreting the brain signals for movement in someone who can't physically move his own arm. With a task like that, the subject must "train" to use the device. With an implant in place, the subject would visualize closing his or her disabled hand. After many trials, the software can learn to recognize the signals associated with the thought of hand-closing. Software connected to a robotic hand is programmed to receive the "close hand" signal and interpret it to mean that the robotic hand should close. At that point, when the subject thinks about closing the hand, the signals are sent and the robotic hand closes. Brain-Computer Interface 25
- 27. Contd… This could even be accomplished without the "robotic" part of the device. Signals could be sent to the appropriate motor control nerves in the hands, bypassing a damaged section of the spinal cord and allowing actual movement of the subject's own hands. Brain-Computer Interface 27
- 28. Software behind BCI • The technology is comprised of four main components; a signal capture system, a signal processing system, a pattern recognition system, and a device control system. • The signal capture system includes the electrodes themselves and the isolated electronic amplifiers Brain-Computer Interface 28
- 29. Contd… The signal processing system includes the algorithms for the linear prediction of the signal. The pattern recognition system often used to be composed of neural networks as to recognize which neurons are producing these signals. Interfaces have been developed to control different devices . Brain - Computer Interface 29
- 30. Applications One of the most exciting areas of BCI research is the development of devices that can be controlled by thoughts. For a quadriplegic, something as basic as controlling a computer cursor via mental commands would represent a revolutionary improvement in quality of life. Some of the applications of this technology are also frivolous, such as the ability to control a video game by thought , ability to change TV channels with your mind etc. Brain-Computer Interface 30
- 31. Limitations At present ,the biggest impediment of BCI technology is the lack of sensor modality that provides safe, accurate, and robust access to brain signals. It is very expensive. • Information transformation rate is limited to 20 bits/min. • Difficulty in adaptation and learning. Brain-Computer Interface 31
- 32. Future Concerns Light Reactive Imaging BCI devices are still in the realm of theory. This would involve implanting a laser inside the skull. The laser would be focussed on a single neuron and the neuron’s reflectance is measured by a separate sensor. • When the neuron fires, the light pattern and wavelength it reflects would change slightly . This would allow the researchers to monitor a single neuron and require less contact with the tissue. Researchers of the Carleton University , Canada believe that the same interface could form the basis of a mind- controlled password system. Brain-Computer Interface 32
- 33. Conclusion • The results of BCI are spectacular and almost unbelievable. • BCI can help paralyzed people to move by controlling their own electric wheelchairs, to communicate by using e-mail and Internet-based phone systems, and to be independent by controlling items such as televisions and electrical appliances. • Conclusively, BCI has proved to be a boon for paralyzed patients . Brain-Computer Interface 33
- 35. ACKNOWLEDGEMENT Most importantly, I would like to thank GB ma’am for giving technical based topics which helped us in a big way to get to know more of the core concepts. Pratishruti Jain 35