brain computer interface for cervical injury patient

Syeda N TashrifaSofia Ashraf Michael Oduro Tuffour Salma Sirajee Jurinus Lesporis Aimee Tavarez

Using Brain Computer Interface(BCI) to Help Improve Life of aCervical Injury Patient

A BCI is a computer-based system that acquires brain signals, analyzes them, and translates them into commands that are relayed to an output device to carry out a desired action .

Introduction:

What is a BCI?

Jerry J. Shih, Dean J. Krusienski, Jonathan R. Wolpaw. “Brain-Computer Interfaces in Medicine”. Mayo Clin Proc. 2012 March; 87(3): 268–279. doi: 10.1016/j.mayocp.2011.12.008 PMCID: PMC3497935

How BCI works

Figure 1. Basic design and operation of a BCI system

http://deliveryimages.acm.org/10.1145/1950000/1941506/figs/f1.jpg

Biomedical Engineers revealed a long-term BCI device that is called electrocorticographic (ECoG). ECoG is acquired by placing electrodes underneath the skull, either above (epidural) or below (subdural) the dura mater (see Fig. 1).

Device and Anatomy of the Brain

Fig. 1. Recording domains: from single-unit recordings within the brain to EEG recordings on the surface of the scalp. From .

Schalk G, Leuthardt EC. “Brain-Computer Interfaces Using Electrocorticographic Signals”. IEEE Rev Biomed Eng. 2011;4:140-54. doi: 10.1109/RBME.2011.2172408.

Electrocorticographic (ECoG)

Fig. 2. Micro and macro ECoG arrays. A-B: Microgrid arrays. C: Schematic of microgrid array. D: Standard clinical macrogrid. E: Surgical placement of macrogrid.Jerry J. Shih, Dean J. Krusienski, Jonathan R. Wolpaw. “Brain-Computer Interfaces in Medicine”. Mayo Clin Proc. 2012 March; 87(3): 268–279. doi: 10.1016/j.mayocp.2011.12.008 PMCID: PMC3497935

People who cannot move their ● finger hand● arm or ● conversation with other people.

ECoG is needed for

ECoG is used for

http://digital-outcasts.com/2012/05/mind-controlled-video-games/

● ECoG can control brain by using computer with 1- or 2-dimensional cursor movements of motor or to select characters using motor-imagery.

Illustration of an ECoG (electrocorticographic) implant by Tom Giesler of the New York Times.

● An ECoG-based BCI can control a prosthetic hand.

http://lifesciences.ieee.org/articles/82-toward-electrocorticographic-control-of-a-dexterous-upper-limb-prosthesis

Figure shows ECoG signals in a prosthetic hand.

ECoG is used for

● ECoG signals measured over speech cortex during overt or imagined phoneme and word articulation were used for online cursor control.

Spoken or imaginary sounds generate brain waves which are recorded by ECoG electrodes and sent to a computer to control the movements of a cursor.

http://singularityhub.com/2011/04/25/patients-control-computer-using-only-their-minds-video/

ECoG is used for

Current Devices of BCI

•EEG(electroencephalogram)

* noninvasive device

•Single-neuron activity* invasive device

•ECoG(electrocorticograph)* invasive device

Parts of brain and three techniques• electrodes placed in different parts of the head

• http://www.youtube.com/watch?v=mFWnTONOvVo

EEG, Single nuron activity, and ECOG

http://www.etsu.edu/cas/bcilab/pictures/Leuthardt.jpg

Different BCI

Disadvantages of these techniques

• EEG produces signal noises • limited numbers of commands for control• required the extensive training

BCI with ECoG

Why ECoG?

Specialty of Our BCI

Experimental Design

Experimental Design

Experimental Design

Experimental Design

Experimental Design

Experimental Design

• Working Hypothesis:

Patients using our new BCI system will respond and perform more and better than commonly used BCI systems in market.

Future Attempts:•Movement of patients’ left and right hand

•Movement of patients’ left and right feet

•Make them capable to move their wheelchair

•In the long run help them in their speech

Problem/ Pathology

Cervical Injury--> Nerve Root/Brachial --> Neurotmesis

Neurotmesis: is where the entire nerve is ruptured and axonal continuity cannot be restored. (Mayo Clinic)

Our Device

ECoG based BCI with:• Artificial Intelligence• Multi-Channel Neural Recording

Our Device Advantage is focused in two Areas:1. Maintenance 2. Speed and Efficacy

Maintenance

Most BCI devices need constant recalibration and retraining as their performance degrades.

- Using permanently based ECoG removes the need for recalibration

-With Artificial Intelligence our device promises to improve with use instead of needing retraining

Speed and EfficacyECoG:Multichannel Neural Recording: this allows Artificial Intelligence: the device will be able to

make predictions, learn what usually

Experimental Design

The experimental design is very important as BCI systems experimental assessment is very subjective.

Experiment Broken Into Three Parts:1. Home Environment Observation2. Upper Limb Movement3. Electric Wheelchair Operation

Home Environment

Subjects are observed in standard smart home environment for 2 Weeks.

They are randomly assigned a caregiver daily.Caregiver will complete Barthel Index daily.

(Only 2nd Week of Results will be considered)

Upper Limb MovementBall Drops: Subject will be directed to pick up an assortment of balls

(different sizes and compressibility) and place them in different size bins. A scorecard for balls in and time it took will be recorded.

Pointer-to-Center:A pointer Laser is attached to hand of subject and they are

to move it from their lap to point it to the center of wall bulleyes layout.

Distance away from center will be taken after 30 seconds (Repeated 10 times)

Electric Wheelchair Operation

Cone Drive:Subject will drive from one point to another

point through a coned pathway.Starting with total points and points minused for

knocked over cones, time to complete pathway also recorded)

Study GroupsThree Study Groups:

Control Group: Industry Standard Device1st Experimental Group: Subject Before Device2nd Experimental Group: Subject After Device

Statistical AnalysisAnalysis of outcome between Experimental

Groups with our device. [p<.05]

Parametric Paired T-test

Nonparametric Wilcoxon rank sum test

Statistical Analysis

After analyzing whether there is a difference in time with our device.

Nonparametric