Empirical Technologies Corporation

University of Virginia Patent Foundation

Sperry Marine Inc.

Charles M Adkins

David W Gerdt

Martin Baruch

Doris Wilsdorf

James R Brazell

Marin Baruch

Heinz G Wilsdorf

Henry C Stacey

Gerard T Mayer

A system for detecting dehydration, hemorrhaging, and increases in blood volume comprising monitors the time difference between the arrival of the primary left ventricular ejection pulse (pulse T1) and the arrival of the iliac reflection (pulse T3) to determine an arterial pulse parameter which is the time difference between T1 T3. Changes in T3 minus T1 are indicative of something happening to blood volume. If the T1-3 value goes up and the patient is on an infusion system, it can be an indication of having too much fluid pumped and if T1-3 is lower than it should be for an individual, they are either dehydrated (which can result in decreases in blood volume), they are hemorrhaging, or they have hemorrhaged. A downtrend in T13 can tell whether someone is continuing to hemorrhage.

Detection of progressive central hypovolemia

A fiberoptic sensing apparatus comprises a fiberoptic coupler in which a plurality of optical fibers are joined through a fused coupling region, the optical fibers including at least one input optical fiber and a plurality of output optical fibers, the fiberoptic coupler distributing light incident to the input optical fiber among the plurality of output optical fibers. The coupler is mounted to a support member and configured such that at least a portion of the coupling region can be deflected to change the light distribution among the output fibers without putting the coupling region under tension. A fluid column is cooperative with a deflection member disposed to deflect the portion of the coupling region.

Sensing apparatus employing variable coupler fiberoptic sensor

A variable coupler fiberoptic sensor utilizes a coupler having a fused coupling region that can be deflected to change the light distribution to a plurality of output fibers without putting the coupling region under tension. A compact, rugged, and highly sensitive sensor design is achieved by use of a coupler having a fused coupling region arranged substantially in a U-shape to allow the input and output fiberoptic leads to extend from the same side of the sensor structure.

Variable coupler fiberoptic sensor and sensing apparatus using the sensor

In a method of measuring pulse transit time of a living subject, first and second pulse wave signals are produced by sensing the pulse at first and second pulse points, respectively, the first and second pulse points being spaced from one another. The first and second pulse wave signals are differentiated, and based on the results, corresponding points of the first and second pulse wave signals are selected (e.g., points of maximum slope). The time delay between the selected points is determined, thus yielding the pulse transit time. A preferred apparatus measures pulse transit time using at least one fiberoptic pulse sensor including a fused-fiber coupling region having at least a portion that can be deflected without putting the coupling region under tension.

Apparatus and method for measuring pulse transit time

A sensing pad assembly for monitoring acoustic activity or motion of an object supported on the pad utilizes an improved fiberoptic sensor as a pressure transducing element to convert pressure fluctuations due to the acoustic activity or motion to an output that changes in accordance with the pressure fluctuations. The sensor has an improved design that permits deflection of the coupler fusion region without accompanying tension. In a preferred embodiment, the coupler fusion region is arranged substantially in a U-shape so that the fiberoptic leads of the sensor may be located adjacent to each other at one side of the sensor.

Sensing pad assembly employing variable coupler fiberoptic sensor

The invention relates broadly to a fiber optic sensor device, advantageously, a refractive index measurement device. A light emitting member transmits light, preferably coherent light, to a light splitter. The light splitter splits the light into a first portion that is transmitted to a first fiber optic coupler having an input optical fiber member and an optical fiber member having a waist region. A first output optical fiber member emerges from the first fiber optic coupler waist region. The light splitter is positioned to insert light into the first fiber optic coupler input optical fiber member. A reference fiber optic coupler includes an input optical fiber member and an optical fiber member having a waist region. The reference fiber optic coupler is enclosed in a potting medium stable reference of constant refractive index. A reference output optical fiber member emerges from the reference fiber optic coupler waist region. The light splitter member inserts a second portion of the split light into the reference fiber optic coupler input optical fiber member. A sum difference device processes the measured light emitted from the first output optical fiber member and from the reference output optical fiber member whereby the value derived said measured light emitted from said first output optical fiber member is independent of variations in light from said light emitting member.

Single mode fiber optic evanescent wave refractometer

A dynamic vibration absorber for reducing vibrations of a platform induced by an oscillating mass mounted thereon is provided by mounting a mass of equal mechanical resonant frequency as that of the oscillating mass and oscillating this mass in a manner to establish an equal and opposite vibration of the platform, thereby cancelling the vibrations induced by the oscillating mass. In one embodiment, a signal from the oscillating mass representative of the frequency and amplitude of its mechanical oscillation is phase shifted and utilized as a driving signal to the drive motor of the absorber mass. In another embodiment, electrical signals representative of the platform vibrations are detected to provide phase and amplitude vibration error signals. These error signals are applied to a reference signal coupled to the drive motor of the canceller mass causing the oscillations of the canceller mass to induce vibrations in the platform which counter the vibrations induced by the oscillating mass.

Method and apparatus for countering vibrations of a platform

A multifiber electrical brush formed of an electrically conductive matrix material having plural electrically conducting fiber wires embedded therein and extending therefrom, wherein the fiber wires have a diameter varying from 1 to 120.mu.m, a length on the order of 100 times greater than the diameter thereof, and a packing density between 1-25%. Suitable materials for the fiber wires are platinum, gold, silver, copper, palladium, or niobium which may be embedded in a copper, silver, or other suitable matrix material, or copper embedded in an aluminum matrix. The fiber wires may be provided with a coating of a suitable barrier material on the lateral surfaces thereof as may be required to protect the fiber wires from etching during removal of the matrix material, or to prevent and/or retard interdiffusion between the matrix material and the fiber wire material during annealing or hot-forming of brush stock, and/or to impart improved electrical performance to the resultant electrical brush. The electrical brush is fabricated typically by drawing, cutting, bundling and redrawing metal fiber wires, with or without a coating or casing of a barrier material, packed in a tube of matrix material, whereupon after shaping of the multi-filamentary ends to the shape of an object to which the brush is to make contact, the matrix is etched away to a predetermined length, preferably under high centrifugal forces in a centrifuge and/or with the application of ultrasound.

Growing community of inventors

Charlottesville, VA, United States of America

Charles M Adkins