UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Minimally Invasive Gathering of Body Context Information from Garment

Interactions

Lucy Dunne, Barry Smyth

Smart Media Institute, University College Dublin

Sarah Brady, Dermot Diamond

National Centre for Sensor Research, Dublin City

University

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Wearable Sensing

• Sensor-based user monitoring for Context awareness– Awareness of: user’s physiological state, environment, social setting– Reduces cognitive load of wearable technology– Minimizes necessary amount of integrated technology

• Garment Integration– Minimally invasive sensing (vs. standard body sensing technologies)– Minimizes degree of adaptation required by user– Maximizes user comfort (physical, social)

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Data Extraction from Garment Interactions

• Exploiting natural movements, garment features, and textile structures to obtain information– Detection of physical interactions between body and garment

• Using garment/textile as sensor– Intelligent textiles, monitoring of textile changes

• Minimizing foreign concepts/components– Eases user acceptance of innovation

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Pressure-Sensitive Foam

• Polyurethane foam, coated with conductive polypyrrole polymer

• Pressure results in detectable increase in conductance

• Soft, washable sensor

• Foam substrate allows detection of deformations of the structure: bends and compressive forces

• Does not rely on extension of fabric

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Garment Layout

Removable sensors/ circuits

2 layer garment: easy integration of

additional sensor

locations

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Breathing Monitor

Breathing

2.00E+03

3.00E+03

4.00E+03

0 200 400 600

Time (s)

Re

sis

tan

ce

(O

hm

s)

20% difference in relative resistance

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Shoulder Movement

Right Shoulder Lift

-5.00E+06

0.00E+00

5.00E+06

1.00E+07

0 100 200 300

Time (sec)

Re

sis

tan

ce

(O

hm

s)

100% difference in relative resistance

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Neck Movement/Posture

Neck Bends

-1.00E+06

0.00E+00

1.00E+06

2.00E+06

0 100 200 300 400 500

Time (s)

Re

sis

tan

ce

(o

hm

s)

Extension: 80% difference in relative resistance

Flexion: 30% difference in relative resistance

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Shoulder Blade Pressure

Shoulder Blade Pressure (lying down)

0.00E+00

5.00E+05

0 100 200 300

Time (s)

Re

sis

tan

ce

(o

hm

s)

60% difference in relative resistance

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Problems

• Sensor baseline drift: 26.6% of total resistance per minute, due to hysteresis in foam substrate (after 2 hr relax period resistance returns to “normal”)

• Sensor oxidation: gradual reduction in resistance over time due to oxidation of polymeric backbone

• Precision of sensor: presence of noise

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Future Directions

• Wireless sensor networks– Integration of pressure sensors into Mote networks

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Future Directions

• Activity monitoring– Coarse detection of arm position

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Future Directions

• Sensitive Sock for Neuropathy

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Future Directions

• Integration of additional sensor types– Contextual information from multiple sources– Agent-based collaboration between wireless sensor nodes– Determination of noise vs. signal

UNIVERSITY COLLEGE DUBLIN DUBLIN CITY UNIVERSITYSMI || NCSR || CDVP

Questions?

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