EIT-Based Fabric Pressure Sensing

This paper presents EIT-based fabric sensors that aim to provide a pressure mapping using the current carrying and voltage sensing electrodes attached to the boundary of the fabric patch. Pressure-induced shape change over the sensor area makes a change in the conductivity distribution which can be conveyed to the change of boundary current-voltage data. This boundary data is obtained through electrode measurements in EIT system. The corresponding inverse problem is to reconstruct the pressure and deformation map from the relationship between the applied current and the measured voltage on the fabric boundary. Taking advantage of EIT in providing dynamical images of conductivity changes due to pressure induced shape change, the pressure map can be estimated. In this paper, the EIT-based fabric sensor was presented for circular and rectangular sensor geometry. A stretch sensitive fabric was used in circular sensor with 16 electrodes and a pressure sensitive fabric was used in a rectangular sensor with 32 electrodes. A preliminary human test was carried out with the rectangular sensor for foot pressure mapping showing promising results.

[1]  G F Harris,et al.  An optoelectric plantar "shear" sensing transducer: design, validation, and preliminary subject tests. , 1996, IEEE transactions on rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society.

[2]  E. Somersalo,et al.  Existence and uniqueness for electrode models for electric current computed tomography , 1992 .

[3]  Masahiro Inoue,et al.  A flexible and stretchable tactile sensor utilizing static electricity , 2007, 2007 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[4]  Tsuyoshi Kato,et al.  Capacitive Sensing of Electrocardiographic Potential Through Cloth From the Dorsal Surface of the Body in a Supine Position: A Preliminary Study , 2007, IEEE Transactions on Biomedical Engineering.

[5]  Mark G. Arnold,et al.  Reconfigurable multi-component sensors built from MEMS payloads carried by micro-robots , 2010, 2010 IEEE Sensors Applications Symposium (SAS).

[6]  Yoon Keun Kwak,et al.  High sensitivity inductive sensing system for position measurement , 2000, Proceedings of the 17th IEEE Instrumentation and Measurement Technology Conference [Cat. No. 00CH37066].

[7]  G.Y. Yang,et al.  Mechanically robust micro-fabricated strain gauges for use on bones , 2005, 2005 3rd IEEE/EMBS Special Topic Conference on Microtechnology in Medicine and Biology.

[8]  Morten Willatzen,et al.  Dynamic coupling of piezoelectric effects, spontaneous polarization, and strain in lattice-mismatched semiconductor quantum-well heterostructures , 2006 .

[9]  Danilo De Rossi,et al.  Electroactive polymer-based devices for e-textiles in biomedicine , 2005, IEEE Transactions on Information Technology in Biomedicine.

[10]  K. S. Jaichandar,et al.  Intelli-sense bed patient movement sensing and anti-sweating system for bed sore prevention in a clinical environment , 2011, 2011 8th International Conference on Information, Communications & Signal Processing.

[11]  R. T. Lipczynski,et al.  Body-support pressure measurement using electrical impedance tomography , 1993, Proceedings of the 15th Annual International Conference of the IEEE Engineering in Medicine and Biology Societ.

[12]  Sejin Kwon,et al.  Thin Polysilicon Gauge for Strain Measurement of Structural Elements , 2010, IEEE Sensors Journal.

[13]  Yasuo Kuniyoshi,et al.  A tactile distribution sensor which enables stable measurement under high and dynamic stretch , 2009, 2009 IEEE Symposium on 3D User Interfaces.

[14]  Thomas Wunderer,et al.  Piezoelectric polarization of semipolar and polar GaInN quantum wells grown on strained GaN templates , 2010 .

[15]  Heinrich Ruser,et al.  Smartlow-cost weather sensor as an example for `multi-component' sensors , 2006, 2006 IEEE International Conference on Multisensor Fusion and Integration for Intelligent Systems.

[16]  P. Rochon,et al.  Preventing Pressure Ulcers: A Systematic Review , 2007 .

[17]  Walied A. Moussa,et al.  On the Feasibility of a New Approach for Developing a Piezoresistive 3D Stress Sensing Rosette , 2011, IEEE Sensors Journal.

[18]  T. Dias,et al.  Capacitive fiber-meshed transducers for touch and proximity-sensing applications , 2005, IEEE Sensors Journal.

[19]  Beth L Pruitt,et al.  Design optimization of piezoresistive cantilevers for force sensing in air and water. , 2009, Journal of applied physics.

[20]  Andrei Drumea,et al.  Modelling and simulation of an inductive displacement sensor for mechatronic systems , 2010, 33rd International Spring Seminar on Electronics Technology, ISSE 2010.

[21]  M. Soleimani,et al.  A pressure mapping imaging device based on electrical impedance tomography of conductive fabrics , 2012 .