Abstract: A sensor probe for in-situ measurement of pH in a human tissue (e.g., cardiovascular) environment comprises a hollow needle having a tip and a back end. The tip is insertable into the tissue. An optic cable comprises a light conduit surrounded by a cladding. A first end of the light conduit is inserted from the back end of the needle and extends to within a predetermined distance of the tip to define a cavity within the tip. A porous dye layer is contained within the cavity, wherein the dye layer has a response to excitation light delivered through the light conduit that varies according to the pH of the tissue environment. An overcoat layer is deposited on the dye layer, wherein the overcoat layer is ionically permeable and substantially opaque at a light wavelength corresponding to the variable response of the dye layer.

Abstract: A NIRS sensor device for brain monitoring is small in size, provides reliable attachment to a patient, blocks ambient light, is easy to use, is hygienic, and supports data integration with surgical and monitoring systems. The sensor device is coupled to a remote near infrared light source via a hybrid cable. Since the light source is remotely located, a source adapted for providing high energy, short pulses can easily be used so that there is less chance of interference by superficial non-brain tissues and less interference from ambient light. In addition, the remote location avoids changes in output of local light sources experienced in the prior art during hypothermia procedures (e.g., bandwidth shifts in LEDs as a result of lowered temperature). The higher energy may be achieved by the use of laser diodes as opposed to locally-mounted LEDs typically used in the prior art.

Abstract: An emboli detector device receives a blood flow in a perfusion circuit. The connector-like device has a rigid plastic smooth body hermetically sealed from the blood. There is a calculated thin, but rigid window formed as part of the flow-through tubing wall to allow ultrasonic waves to interrogate the flowing blood. A dampening material is included in the ultrasound path to adjust the acoustic levels to an applicable range to monitor emboli. The device incorporates a mechanism to securely hold the transducer during operation and a sensing system for automatically informing a control system of which one of several standard perfusion circuit tubing diameters is being used. The ultrasound echoes detected by the transducer are provided to a controller which detects the emboli and provides a detection signal to warn the surgeon or other operating room personnel of the embolic event.

Abstract: A sensor probe for in-situ measurement of pH in a human tissue (e.g., cardiovascular) environment comprises a hollow needle having a tip and a back end. The tip is insertable through tissue into the tissue environment. An optic cable comprises a light conduit surrounded by a cladding. A first end of the light conduit not covered by the cladding is inserted from the back end of the needle and extends to within a predetermined distance of the tip to define a cavity within the tip. A porous dye layer is contained within the cavity adjacent to the first end of the light conduit, wherein the dye layer has a response to excitation light delivered through the light conduit that varies according to the pH of the tissue environment. An overcoat layer is deposited on the dye layer, wherein the overcoat layer is ionically permeable and substantially opaque at a light wavelength corresponding to the variable response of the dye layer.

Abstract: A blood parameter measurement device especially useful for surgical procedures includes a compact housing with a light source, light detector and signal converter contained within the housing. In use, the device is releasably coupled to a cassette that can be either used as an in-line cell in series with a cardiopulmonary by-pass circuit, or in another passageway that shunts the cardiopulmonary by-pass circuit. Preferably, the housing of the device has a longitudinal axis that extends in a direction generally parallel to the direction of blood flowing through the cassette.

Abstract: A cassette useful for measuring one or more parameters of blood in, for example, a cardiopulmonary bypass circuit has a convex coupling for releasable connection with a mating, concave coupling of a measuring device. The coupling of the cassette includes flexible leg portions that can be moved toward each other under the influence of finger pressure to detach the cassette from the measuring device. Optionally, the cassette includes a body carrying one or more sensors, and also includes a casing that can be detached from the body when desired. A shunt circuit arrangement enables the cassette to be connected to the bypass circuit either before or during a surgical procedure.

Abstract: A blood parameter measurement device especially useful for surgical procedures includes a compact housing with a light source, light detector and signal converter contained within the housing. In use, the device is releasably coupled to a cassette that can be either used as an in-line cell in series with a cardiopulmonary by-pass circuit, or in another passageway that shunts the cardiopulmonary by-pass circuit. Preferably, the housing of the device has a longitudinal axis that extends in a direction generally parallel to the direction of blood flowing through the cassette.

Abstract: A cassette for tonometric calibration especially useful for systems that measure one or more blood parameters includes a cassette having an elongated fluid chamber. In one embodiment of the invention, the fluid chamber includes an expansion region that reduces the likelihood of bubble coalescence of the calibration gas. In another embodiment, inner wall sections of the chamber are provided with a hydrophilic surface. Optionally, a fitting is non-releasably coupled to a casing of the cassette and is movable between a first position for closing a calibration gas outlet port and a second position for venting the calibration gas outlet port. In another embodiment, the cassette includes an elongated sparging tube that extends in a direction generally parallel to the longitudinal axis of the chamber.

Abstract: An assembly useful for retaining optical components such as lenses, optical filters and the like includes a block having a cavity and a pair of retainers received in the cavity. In certain embodiments, the cavity is cylindrical and each retainer has a semi-cylindrical configuration. Each retainer preferably includes integrally molded deformable ribs that shift the optical components when the retainers are closed to a position such that the optical axis of each component is collinear with the central axis of the optical chamber and the retainer cavity.

Abstract: A sensor cassette for use in measuring a compositional parameter of blood comprising a housing having a wall defining a passage which is adapted to receive blood. The wall is at least somewhat permeable to the compositional parameter. A support element, which is less permeable to the compositional parameter of blood than the housing, is carried by a region of the wall. A sensor is carried by the support element and provides a signal in response to the compositional parameter. The support element separates the sensor from at least a portion of such region of the wall so that the affect of the permeability of the housing to the compositional parameter on the signal from the sensor is reduced.