Tekscan, Inc.

Charles Malacaria

Christopher George

Thomas Papakostas

Mark Lowe

Boris Oreper

Boris Dubinsky

Jay Winters

Charles McWilliams

Gary Loomis

Anthony Coviello

Janet Lefko

A control circuit for scanning a pressure or force responsive sensor array is disclosed. Pressure or force sensors formed of an array of pressure or force responsive sensor elements can be used to acquire pressure or force measurements in response to an applied load. The control circuit can sample signals from the sensor elements to detect the pressure or force at one or more sensor elements of the sensor array. The circuit herein may provide for relatively faster scan rates. A user may define a subset or subsets of sensor elements of the sensor array to be scanned. Various methods and related circuitry for adjusting for sensor characteristics are also disclosed.

Control circuit for sensor array and related methods

A sensor for measuring a parameter applied to a surface is provided. The sensor includes at least one substrate layer, a plurality of individual sensor elements operatively arranged with respect to the substrate layer, and a conductive trace disposed on the substrate layer. The conductive trace is electrically coupled to an individual sensor element and wraps around at least a portion of the sensor element in a spiral-like manner. Further, by employing slits or cut-outs of material between sensor elements, a sensor element may move independent of an adjacent sensor element, thereby allowing the sensor to conform to an irregularly shaped surface or otherwise when subject to relatively large deflections. The sensor may be employed to detect force distribution of a seating surface, such as a seat cushion of a wheelchair.

Sensor with a plurality of sensor elements arranged with respect to a substrate

A system and method for equilibrating and calibrating a pressure or force sensor is provided. The system includes a flexible bag arranged to receive the sensor, and a vacuum source, connectable with the flexible bag, adapted to reduce the pressure within the flexible bag. By reducing the pressure within the flexible bag, such that the pressure inside of the bag is less than the pressure outside of the bag, the resultant uniform pressure acting on the sensor is used to calibrate and equilibrate the sensor. The system may include a porous material in the flexible bag to facilitate the evacuation of air from within the flexible bag as the pressure is reduced. The system may also include an opening, such that when the sensor is placed in the bag, a portion of the sensor extends outside of the bag to communicate with a controller. The opening may be provided either on the flexible bag, or on a clamp attached to the flexible bag. The system and method for calibrating and equilibrating a sensor may be employed to correct for sensor variations and/or to correlate sensor output to force or pressure.

Sensor equilibration and calibration system and method

Sensor with plurality of sensor elements arranged with respect to a substrate

This invention relates to apparatus for detecting the contact or nip width between two contacting surfaces. The apparatus includes first and second insulating substrates each of which has a pattern of conductive material formed on a facing inner surface thereof, which substrates are adapted to be fitted between the contacting surfaces. For a first embodiment, the pattern of conductive material on one substrate includes a pair of conductive terminals spaced by a distance greater than the contact width to be measured and the conductive pattern on the other substrate includes a conductor which extends over at least a distance greater than the maximum width W to be measured. A resistance path is provided between the conductive terminals having a resistance R0 which is higher than that of the conductor and material is provided in the space between the conductor and the resistance path which material substantially permits current flow therethrough between the conductor and the resistance path in areas where the contacting surfaces are not in contact and which has a resistance less than R0 permitting current flow therethrough in areas where the contact surfaces are in contact. Circuitry is also provided for applying current to one of the terminals and for utilizing the difference in current flow between the terminals to determine contact width. For a second embodiment, the conductive pattern on one substrate includes N substantially parallel and evenly spaced conductive columns and the pattern on the other substrate is a plurality of substantially parallel and evenly spaced rows. The columns are divided into M groups, where M is an integer which is at least 2, and each of the rows is at an angle &thgr; to a line perpendicular to the columns when extending across alternate ones of the groups and at an angle &minus;&thgr; when extending across the remaining groups. The number of columns in each group is selected to achieve a desired resolution, and &thgr; is selected so that the distance in the direction of the columns between the ends of a row for each group is substantially equal to the spacing between adjacent rows.

Contact width sensors

Growing community of inventors

Medfield, MA, United States of America

Charles Malacaria