Abstract: A hydrostatic finger cuff for blood flow property analysis is provided which includes an elongated substrate member having a pair of opposing long edges and a pair of opposing short edges. The hydrostatic finger cuff is configured to form a frustoconical shell when the ends of the cuff are overlapped and releasably connected together. The interior of the frustoconical shell conforms to the shape of the finger or thumb. One side of the elongated member has an inflatable member that has a pressurizable interior region. A tube is fixed to the inflatable member and is in pneumatic communication with the interior of the inflatable member inflatable to a maximum of no more than 60 mmHg. The inflatable member completely circumscribes the finger and provides substantially uniform contact across the entire length of a phalange.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A device for the application of artificial light to a user's retina is disclosed. A light source leads to a light focusing member that generates a light stream at, at least one transmission angle, to the user's retina, preventing the light from coming in contact with the user's fovea. In one embodiment, the light focusing member is a light ring containing a plurality of apertures around an outer periphery with light exiting through the apertures in a plurality of streams at a transmission angle. A vision aperture within the light ring has a periphery less than the outer periphery and is on a direct axis with the user's fovea to enable the user to maintain vision during chronotherapy. The light source can be distanced from the light focusing member and connect by a light transfer member, such as a optic fiber. In another embodiment, the light focusing member can be the frame of a pair of eyeglasses having lenses to enable user vision.

Abstract: A coupled pair of fiber optic fibers are used an immunoassay device. The fibers are first coupled and then drawn down to a single mode diameter. The coupler senses output ratio change due to chemical, biochemical, bioaffinity, immunogenic-type interactions and other molecular activity occuring within the evanescent field. The fusion joint of the coupler is coated with a first immunoassay component, and then surrounded with a second immunoassay component.

Abstract: The coupler includes a waist region formed by merging and fusing a plurality of optical fibers with the waist region encapsulated in photorefractive encapsulating material. The index of refraction of the encapsulating material is modulated by applying illumination thereto, so as to vary the coupler output ratio. The applied illumination can direct the coupler output from one output fiber to another output fiber thereby providing an optically actuated switch. The illumination applied to the encapsulating material can direct a large optical power signal applied to an input fiber from one output fiber to another output fiber thereby providing an optical amplifier analogous to a transistor. One of the output fibers of the element can be utilized to provide the encapsulating material illumination thereby providing an optical feedback oscillator.

Abstract: Cardiovascular sounds from a patient's body are monitored by placing a fiber optic coupler sensor at an appropriate location on the patient to sense the sounds. The sensor is comprised of all dielectric material having a variable coupler waist region encapsulated in material with index of refraction that varies with applied stress. Stress is induced in the encapsulating material in response to the cardiovascular sounds. Sensor configurations include encapsulating material membranes with curved surfaces to enhance sensitivity.

Abstract: The pulsed input light source of the fiber-optic sensor array is divided into a plurality of input light sources for the respective sensors of the array by a network of low-loss single mode fixed ratio fiber-optic couplers. The input light is applied to the input fiber of a first fixed ratio coupler, the output fibers thereof providing the input fibers of further fixed ratio couplers and so forth until the light is divided into the appropriate number of sources. The divided light sources are applied to the input fibers of the variable ratio fiber-optic coupler sensors of the array through differing lengths of optical fiber so that the input light pulses impinge upon the sensors of the array at different times. The output fibers of the sensors are coupled to multimode busses through low-loss taps.In an alternative embodiment for highly imbalanced ratio fiber-optic coupler sensors, the pulsed input light is applied to the input fiber of a first sensor.

Abstract: Temperature, pressure and liquid level parameters are sensed by the variable ratio fiber optic coupler sensor wherein the optical coupling ratio varies in accordance with stress applied to the coupler encapsulant resulting from application of the parameter being sensed. Such use of the coupler sensor is particularly advantageous in fuel tanks, which are subject to spark hazard. Vertical arrays of such sensors are utilized to determine levels of liquids in such fuel tanks. Various sensor configurations are disclosed.

Abstract: An optically driven signal generator utilizes optical switches having a common output port and input ports alternately coupled to first and second potentials of opposite polarities. Optical pulses, with interpulse periods commensurate with a desired output frequency, sequentially operate the switches so that electrical signals of opposite polarities are alternately coupled to a common output port in a manner to establish a continuous electrical signal at a frequency that is commensurate with the interpulse periods.

Abstract: The system includes a television camera or an optical viewer device with a gated image intensifier input. A short intense laser pulse is transmitted to illuminate the scene. The image intensifier is gated on after a time delay equal to the round trip transit time of the pulse from a range slice of interest. The image intensifier is gated on for a time interval equal to the width of the laser pulse. In the television camera embodiment, one laser pulse per frame is transmitted and successive range slices are observed during successive frames by successively increasing the time delay. The range slice images are stored in a buffer and read out to a television display. In the optical viewer device embodiment, a segmented horizontally sliced electro-optical shutter is disposed adjacent the phosphor output of the image intensifier to transmit successive range slice information to an eyepiece of the device for viewing by an observer.

Abstract: The microchannel plate current of a microchannel plate image intensifier is sensed to generate a pulse train applied to the image intensifier photocathode for gating the image intensifier on and off with an on period proportional to the light impinging thereon. The off periods of the pulse train are sufficiently positive to repair photocathode spot damage.

Abstract: An electric furnace for fusing optical fibers has a body made of insulating material. A fiber channel is provided wherein the fibers to be fused are positioned. To facilitate the insertion of the fibers a slot is provided which extends from the fiber channel to the surface of the body. Coil channels are provided around the fiber channel each having an opening to the fiber channel in the fusion area. During the fusion process the fibers are under tension to stretch the coupling region and the light coupling is monitored until the desired level is achieved.

Abstract: A variable coupler fiberoptic sensor in which a fused, tapered, biconical directional fiberoptic coupler is encapsulated in a stress birefringent medium whose index of refraction changes with applied stress.The ratio of power in the output fibers of the directional coupler varies with the change of index of refraction of the encapsulating medium as stress is applied to the medium.