The United States of America As Represented by the Administrator of the

Other

Virginia Commonwealth University

Center for Innovative Technology

Harlan K Holmes

Thomas C Moore

Bruce J Holmes

Devendra S Parmar

Debra L Carraway

Ray E Clouse

Domenic A Bellino

Andrew J Fantl

The system includes an array of transducers that simultaneously senses multiple intralumenal pressures, a data acquisition module that acquires and stores samples of the measured pressures, software routines for signal analysis, a software module for multi-dimensional data display presentations, and a software module to perform pattern recognition on the acquired data set to identify potential maladies that may be indicated by the analysis. The transduction elements are cylindrical segments that deform according to the circumferential pressures encountered. Distributing a quantity of these sensor segments at desired locations along a flexible support structure and providing a flexible sheath over the entire length forms the sensor array. Measuring the sensor deformation provides an electrical analog of the pressure causing the deformation. Acquiring these measurements in a suitable data acquisition and processing unit, including a display, printing, and plotting capability, completes the hardware elements. Integrated software modules complete the system.

Motility analysis, display, and interpretation system

A pressure sensor includes a liquid crystal positioned between transparent, electrically conductive films (18 and 20), that are biased by a voltage (V) which induces an electric field (E) that causes the liquid crystal to assume a first state of orientation. Application of pressure (P) to a flexible, transparent film (24) causes the conductive film (20) to move closer to or farther from the conductive film (18), thereby causing a change in the electric field (E'(P)) which causes the liquid crystal to assume a second state of orientation. Polarized light (P.sub.1) is directed into the liquid crystal and transmitted or reflected to an analyzer (A or 30). Changes in the state of orientation of the liquid crystal induced by applied pressure (P) result in a different light intensity being detected at the analyzer (A or 30) as a function of the applied pressure (P). In particular embodiments, the liquid crystal is present as droplets (10) in a polymer matrix (12) or in cells (14) in a polymeric or dielectric grid (16) material in the form of a layer (13) between the electrically conductive films (18 and 20). The liquid crystal fills the open wells in the polymer matrix (12) or grid (16) only partially.

Pressure sensor using liquid crystals

A probe for measuring circumferential pressures inside a body cavity. In the preferred embodiment, a urodynamic pressure measurement probe for evaluating human urinary sphincter function is disclosed. Along the length of the probe are disposed a multiplicity of deformable wall sensors (15) which typically comprise support tube sections (55) with flexible side wall areas (57, 16). These are arranged along the length of the probe in two areas, one just proximal to the tip (13) for the sensing of fluid pressure inside the bladder, and five in a sensing section (14) which is positioned within the urethra at the point at which the urinary sphincter constricts to control the flow of urine. The remainder of the length of the probe comprises multiple rigid support tube sections (10) interspersed with flexible support tube sections in the form of bellows (58) to provide flexibility.

Circumferential pressure probe

A crossflow vorticity sensor is provided for the detection of crossflow vorticity characteristics. The crossflow vorticity sensor is comprised of crossflow sensors (10) which are non-invasively adhered to swept wing laminar surface (12) either singularly, in multi-element strips (11), in polar patterns (40), or orthogonal patterns (41). These crossflow sensors (10) are comprised of hot-film sensor elements (18) which operate as a constant temperature anemometer circuit to detect heat transfer rate changes. Accordingly, crossflow vorticity characteristics are determined via cross-correlation. In addition, the crossflow sensors (10) have a thickness which does not exceed a maximum value h in order to avoid contamination of downstream crossflow sensors (10).

Crossflow vorticity sensor

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Newport News, VA, United States of America

Harlan K Holmes