Abstract: A lumen wall of a blood vessel, such as a coronary artery, is imaged by inserting a catheter into the vessel and emitting near-IR radiation toward the lumen wall through a side window formed in the catheter. Blood flowing through the vessel is caused to react with a fin arrangement formed on a body of the catheter to displace the window toward a region of the lumen wall opposing the window in order to minimize the amount of blood that is interposed between the window and the lumen wall. Thus, the amount of radiation that is scattered or absorbed by the blood is minimized.

Abstract: A roller pump including a stator and a rotor assembly disposed within the stator. The rotor assembly includes a rotor hub, a first roller slide and a second roller slide slidingly disposed within the rotor hub. Each of the roller slides rotatably supports a roller. An occlusion adjustment knob for adjusting a radial position of the first and second roller slides and a magnetic detent assembly for providing an audible indicator as the occlusion adjustment knob is rotated.

Abstract: A lumen wall of a blood vessel, such as a coronary artery, is imaged by inserting a catheter into the vessel and emitting near-IR radiation toward the lumen wall through a side window formed in the catheter. Blood flowing through the vessel is caused to react with a fin arrangement formed on a body of the catheter to displace the window toward a region of the lumen wall opposing the window in order to minimize the amount of blood that is interposed between the window and the lumen wall. Thus, the amount of radiation that is scattered or absorbed by the blood is minimized.

Abstract: The present invention involves a dynamic brake for use in a peristaltic (i.e., roller) pump. The dynamic brake avoids backlash, due to counter rotation. In addition, it does not preclude the option of hand operating the roller pump. This is achieved by initiating the braking operation after the roller pump set-point has been set to zero and only after the roller pump has decelerated below a predefined speed (e.g., 20 rpm). In addition, the braking operation is activated for only a very brief period of time (i.e., a period of time required for the pressure in the roller pump fluid conduit to subside).

Abstract: A roller pump including a stator and a rotor assembly disposed within the stator. The rotor assembly includes a rotor hub, a first roller slide and a second roller slide slidingly disposed within the rotor hub. Each of the roller slides rotatably supports a roller. An occlusion adjustment knob for adjusting a radial position of the first and second roller slides and a magnetic detent assembly for providing an audible indicator as the occlusion adjustment knob is rotated.

Abstract: A network communication and messaging protocol for use in a medical perfusion system, provides the rules which govern how, among other things, information and data is conveyed between the various devices which are connect to the network. The rules define the different types of messages that are used in conveying information and data, as well as the formatting for each of those message types. The various messages provide the ability to configure the perfusion system devices, establish links between the perfusion system devices, and convey various types of information and data, even when the main network controller is unavailable.

Abstract: A self-contained pack assembly includes all of the disposable components of an extracorporeal support circuit for cardiac bypass surgery. The pack assembly comprises a blood reservoir, a blood oxygenator, and a carrier for mounting the blood reservoir and blood oxygenator. One or more trays may be releasably attached to the carrier to serve as storage containers for coiled tubing used in the support circuit. Pre-made connections can also be formed between the tubing and the blood reservoir and blood and oxygenator as may be desired.

Abstract: Fluid pump control modes in a medical perfusion system include a Back Off Response Mode, a Flow Servo Mode, a Pressure Servo Mode, and a Master-Slave Servo Mode. In the Back Off Response Mode, pump's speed is decremented to a new speed when an excessive flow rate or pressure condition is detected. The new speed is maintained until an additional decrement is required or until the Back Off Response Mode is exited. In the Flow Servo Mode, a pump's speed is controlled to maintain a fluid flow rate indicated by a user as a setpoint. In the Pressure Servo Mode, a pump's speed is controlled to maintain a pressure indicated by the user as a setpoint. In the Master-Slave Servo Mode, a slave pump receives an indication of a master pump's speed, and the slave pump speed is controlled to maintain a specified percentage of the master pump's speed.

Abstract: The present invention involves a dynamic brake for use in a peristaltic (i.e., roller) pump. The dynamic brake avoids backlash, due to counter rotation. In addition, it does not preclude the option of hand operating the roller pump. This is achieved by initiating the braking operation after the roller pump set-point has been set to zero and only after the roller pump has decelerated below a predefined speed (e.g., 20 rpm). In addition, the braking operation is activated for only a very brief period of time (i.e., a period of time required for the pressure in the roller pump fluid conduit to subside).

Abstract: A self-contained pack assembly includes all of the disposable components of an extracorporeal support circuit for cardiac bypass surgery. The pack assembly comprises a blood reservoir, a blood oxygenator, and a carrier for vertically mounting the blood reservoir and blood oxygenator. Trays may be releasably attached to the carrier to serve as containers for coiled tubing used in the support circuit.

Abstract: A method of measuring temperature including the steps of calibrating a sensor disposed near one end of an optical fiber, the sensor having a source of light which irradiates light, the optical fiber being positioned at one end to receive light from the source of light; a transducer positioned near the other end of the optical fiber, the transducer being made up of at least two polymers that have refractive indices with different temperature dependencies and form a microphase separation structure; a reflection element for reflecting the irradiated light; and an arithmetic processing unit which receives the reflected light by exposing the sensor to two or more sources of heat whose values are known; and exposing the sensor to the portion whose temperature is to be measured.

Abstract: A blood pump comprising a pump mechanism having an outer sleeve, an inner sleeve, and an impeller. The pump mechanism is movable between a closed and preferably retracted position wherein one or both of an inlet port and an outlet port are sealed by the inner and/or outer sleeve for inserting the pump mechanism into the heart, and an open and preferably extended position wherein the inlet and outlet ports are open to allow the impeller to pump blood through the ports. The pump mechanism preferably retracts so that it has less length and is more readily maneuvered when it is in its closed position. Also disclosed are a bearing portion received within a cap of the impeller with a flow of lubricating liquid between the bearing portion and cap, and a method of using the pump.

Abstract: The present invention provides an optical fluorescence based sensor for measuring the concentration of a gas (e.g., CO2 or ammonia) in a medium such as blood which has superior dry web sensor performance, enhanced sensor consistency for transparent sensor calibration, improved autoclave stability and rapid rehydration of the sensor. In a preferred embodiment, the sensors of the present invention comprise microcompartments of an aqueous phase having a pH sensitive indicator component and a nonionic amphipathic surfactant within a hydrophobic barrier phase comprising a plurality of dispersed hydrophobic particles.

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: An apparatus for removing a biologically active agent from body fluid that includes an inlet for receiving body fluid, a substrate that includes the reaction product of a substantially water insoluble polymer and a polyalkylene imine, the polyalkylene imine being in a form capable of binding a biologically active agent in the body fluid, and an outlet through which the body fluid flows following contact with the substrate.

Abstract: A blood treatment system has a housing formed of transparent plastic material configured so that substantially the entire blood flow path is visible. A generally planar blood filtration media assembly divides a blood treatment chamber within the housing into first and second interior spaces that are visible through the transparent housing, with a cardiotomy manifold in fluid communication with the first interior space and a venous blood inlet in fluid communication with the second interior space. A generally planar blood defoamer media assembly is provided generally parallel with and spaced apart from the blood filtration media assembly. The blood defoamer media assembly divides the second interior space from the blood storage chamber. The blood flow path along each side of the blood filtration media assembly and each side of the blood defoamer media assembly is visible.

Abstract: A process for modifying a surface of an article that includes treating a surface with a solution that includes an organic solvent, and the reaction product of a substantially water insoluble polymer and a polyalkylene imine to form a modified surface.

Abstract: A volume controlling support for a flexible venous reservoir that permits the reservoir to have a clear flow passage from its inlet to its outlet which is visible and accessible to the perfusionist. The portion of the reservoir through which the major part of the blood flow is occurring can be manipulated if necessary, particularly for the purpose of manipulating the reservoir to improve the clearance of air bubbles in the blood. Preferred embodiments also enhance the convenience for the perfusionist by permitting right-handed or left-handed operation, and by providing an approximate read-out of the volume of blood contained in the reservoir.

Abstract: Tubular bundles are potted in a housing, such as in an oxygenator or a pheresis unit. Spacer material is placed into the housing to cover the first ends of the tubular elements. A layer of potting material is placed into the housing covering the spacer material, and then solidified in place to seal between each of the tubular elements and the housing. The spacer material is then removed from the housing to expose the first ends of the tubular elements. In the oxygenator, at least some of the tubes are gas exchange tubes having an interior lumen and a tube wall which is permeable for oxygen and carbon dioxide flow through the tube wall. The potting separates the housing into manifold chambers communicating with the interior of the tubes and a blood flow chamber sealed from the manifold chambers. Blood flows over the exterior surface of the tubes. Other tubes may be heat transfer tubes, such as for carrying a heat transfer fluid to control the temperature of the blood.

Abstract: A blood reservoir mounting bracket supports alternate sizes of blood reservoir assemblies. The reservoir mounting bracket has a reversible reservoir mounting frame, with mounting pins on one side thereof arranged in a first pattern for the mounting holes of one size of a blood reservoir assembly, and mounting pins on its other side arranged in a second pattern for the mounting holes of a second, different sized blood reservoir assembly. Alternatively, the reservoir mounting bracket has a reservoir mounting frame with retractable pins therein for use in adapting to differently arrayed holes on different sized blood reservoir assemblies. The reservoir mounting bracket further has an oxygenator holder which allows orientation of the oxygenator in a plurality of positions.