A Low Cost Bidirectional Human-Computer Interface

Authors: Alexey Borisenko, Lukash Monczak, Ikvir S Samra, Ovidiu Draghici, Daniel Shapiro, Voicu Groza

Overview

Objectives Motivation Neuroplasticity HCI state-of-art Approach Results Conclusion & Future

work

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Objectives

• Non-invasive bidirectional human-computer interface

• Low-cost (< $20)• Faster training time

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Motivation

• HCI devices used by hospitals to alleviate suffering of patients that have lost vision, balance, or mobility.

• HCI devices very expensive• Neuroplasticity

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mclasen.com

Neuroplasticity

Property of the brain to reorganize itself• Phantom limbs• Treatment of brain damage• Treatment of learning difficulties

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brainline.org

HCI State-of-art

• Brainport [Danilov05]

• BCI 2000 [Schalk08]

• BCCI[Walter09]

• Oral Tactile Interface[Tang06]

periodistadigital.com

gtec.at

met.usc.edu

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Designed Prototype (BHCI):

Approach taken

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Human FPGA TDU

Pushbuttons

VGA Serial Data

Balance Data*

*Wicab has applied for provisional patents for the use of balance data for TDUs.

Tongue Display Unit (TDU)

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• A TDU actuates signals onto the tongue using an electrode array

• Data is received by the brain and interpreted

• Signals such as balance [Danilov05] and tactile information [Tang06] are observed

Advantages

• Low cost• Simple architecture• Flexible software

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Safety Issues and Considerations

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Murphy and His Law•We naturally assume that any system plugged into the wall should not be connected to a person.No Human Testing, Not Yet•For now we are doing testing with a digital oscilloscope and a multimeter.Wireless is the Future•[Danilov05] and [Tang06], started with wired designs and left wireless as future work.

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Computer-Human Interface

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Sensory Perception•What humans feel

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Current (mA) 1 second Feeling *

1 Tingling

5 Maximum harmless current

10-20 Muscular contraction (pain, unsafe)

100-300 Ventricular Fibrillation (can kill)

6000 Defibrillation (respiratory paralysis and burns if sustained)

*http://www.highvoltageconnection.com/articles/ElectricShockQuestions.htm

Computer-Human Interface

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Actuating Signals Onto the Tongue•12th cranial nerve [Lin09].•Resistance of tongue [Faes99].•Approaches to signal actuation:

• Capacitive conductor (grayscale)• Time multiplexing (row, column) • Roof of the mouth [Tang06]• Surface of tongue (BHCI, Brainport)

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Results

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Low Cost and Proper Operation

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The design does not go near the current limit and was designed with very low cost components. *

http://www.youtube.com/user/uottawaBHCI#p/a/u/0/Sm0DINKrUHg

Conclusion & Future workCARG 2010

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• Human testing may follow, eventually.• Open collector ICs are required to fix fluctuating

output voltage.• An upgrade to wireless is needed to approval for

human testing.• Cleaning protocol• Plastic sealant

A low cost HCI was designed, implemented, and tested in the lab.

References• [Danilov05] Y. Danilov and M. Tyler, “Brainport: an alternative input to the brain.”Journal of integrative neuroscience, vol. 4, no. 4, p. 537, 2005.• [Tang06] H. Tang and D. Beebe, “An oral tactile interface for blind navigation,”Neural Systems and Rehabilitation Engineering, IEEE Transactions on, vol. 14, no. 1, pp.

116 –123, march 2006.• [Lin09] H. Lin, P. Barkhaus, “Cranial Nerve XII: The Hypoglossal Nerve”, Seminars in

Neurology, vol. 29, no. 1, p.45-52.• [Faes99] T. J. C. Faes, H. A. van der Meij, J. C. de Munck, and R. M.Heethaar, “The electric resistivity of human tissues (100 hz-10 mhz): a meta-analysis

of review studies,” Physiological Measurement, vol. 20, no. 4, p. R1, 1999.• [Borisenko10] A.Borisenko, L. Monczak, I. S. Samra, O. Draghici, D. Shapiro, V.

Groza, “A Low Cost Bidirectional Human-Computer Interface,” Medical Measurements and Applications (MeMeA), Apr. 2010.