Abstract: A pressure transducer calibration device is disclosed having a housing which defines a first and second chamber separated by a compliant barrier. Two ports are in fluid communication with the first chamber, and one port is in fluid communication with the second chamber. The first chamber is configured to be filled with fluid and connected, via a three-way stopcock, to a pressure monitoring line. The second chamber is configured to be connected in fluid communication with a pressure generation device. In operation, the transducer is isolated from the monitored pressure source. Fluid communication is established between the first chamber and the transducer. A known fluid pressure is applied to the second chamber such that the known fluid pressure is also applied to the first chamber through the compliant barrier. The pressure transducer is then calibrated based upon the known fluid pressure within the first chamber.

Abstract: A pressure transducer calibration device is disclosed having a housing which defines a first and second chamber separated by a compliant barrier. Two ports are in fluid communication with the first chamber, and one port is in fluid communication with the second chamber. The first chamber is configured to be filled with fluid and connected, via a three-way stopcock, to a pressure monitoring line. The second chamber is configured to be connected in fluid communication with a pressure generation device. In operation, the transducer is isolated from the monitored pressure source. Fluid communication is established between the first chamber and the transducer. A known fluid pressure is applied to the second chamber such that the known fluid pressure is also applied to the first chamber through the compliant barrier. The pressure transducer is then calibrated based upon the known fluid pressure within the first chamber.

Abstract: A cannula that is usable to remove blood from a patient during an operation such as bypass surgery where the cannula has a pressure sensor in the form of an electronic piezoresistive chip located at or adjacent the location within the heart where the blood is being removed. The crystal has a sensing side and a reference side that is exposed to a reference pressure that is known. The piezoresistive chip is mounted at the distal end of the cannula such that its sensing side faces outwardly away from the central bore of the cannula that is transporting the blood that is being removed and thus is isolated from the dynamic effects of the moving blood. In addition, the pressure sensor has a characteristic drift based on temperature and the sensor is therefore standardized at body temperature, 36 degrees Centigrade, so that the pressure sensor is standardized at the temperature at which it will be used when positioned within the patient.

Abstract: A sealed coupler includes a splined pin that moves axially inside orifices formed in the two or more members, and a rotating actuator. The actuator can be threaded to engage a threaded end of the pin, or it can include one or more cams to engage one or more cam followers coupled to the pin to move the pin inside the orifices. The pin moves axially between a locking position, where the members are rotationally locked, and an unlocking position, where the members are free to rotate relative to each other, in response to rotation of the actuator.

Abstract: A modular tool system includes a tool head, a handle, and an intermediate piece disposed therebetween. The handle includes a first pin for coupling the handle to the intermediate piece and the intermediate piece includes a second pin for coupling the intermediate piece to the tool head. The first and second pins each include a splined portion for engaging splined orifices in the handle and intermediate pieces, respectively, and a shank for removably engaging shank-receiving orifices in the intermediate piece and the tool head, respectively. When the shanks are engaged with their respective shank-receiving orifices, the handle can be moved along the first pin to selectively lock the handle to the intermediate piece and the intermediate piece can be moved along the second pin to selectively lock the intermediate piece to the tool head.

Abstract: An adjustable tool with a locking hinge mechanism is disclosed which is movable between a plurality of selectable positions. A hinge pin splined along substantially its entire length holds the portions of the tool together, and is movable between an unlocked position and a locked position. In the unlocked position, the tool is adjustable, and in the locked position the tool is fixed in position and suitable for use.

Abstract: A blood aspiration assembly and method has proximal, intermediate and distal tubing, an adjustable volume reservoir and an aspirator receiver. The receiver has a housing with a rigid casing and a resilient plug, and a liquid flow chamber. The resilient plug has a slit or perforation to allow passage of a blunt needle therethrough. The plug can have two parts of different compliance, which aligned slits or perforations. The blunt needle tip can be rounded or flat, with a side opening for the needle bore. The contour of the needle tip and the design of the plug are correlated such that the working force required to penetrate the needle tip into the plug perforation is considerably less than the force required for said needle tip to penetrate normal intact human skin of the hands or arms.

Abstract: An aspirator receiver forms part of a blood aspiration system for injecting fluid into a patient and withdrawing undiluted blood. The aspirator receiver has a housing with a passage occluded by a septum and in communication with the blood flow channel through the aspirator system. An aspirator comprises a cannula having a blunt tip surrounded by a shroud, the cannula being in communication with a blood receiving receptacle. The aspirator is applied to the housing with the shroud centering the cannula about and for penetration through the septum of the housing whereby undiluted blood may be withdrawn from the flow channel into the receptacle. Upon removal of the aspirator, the septum occluding the end of a standard vacuum-filled container is penetrated by the cannula whereby blood from the receptacle may be transferred into the container.

Abstract: A ratchet wrench comprises a ratchet head having a conventional ratchet system for rotating a shank about an axis. A generally cylindrically shaped connecting pin aligned along an axis parallel to the shank axis is attached to the ratchet head. The connecting pin extends through a splined orifice in a handle, thereby connecting the handle to the ratchet head. The handle is slidable between a locked position and a unlocked position on the connecting pin. When the handle is in the locked position, the ratchet wrench can be used to rotate a nut or bolt in a conventional manner. When the handle is in the unlocked position, and the ratchet wrench can be used to rapidly rotate a nut or bolt by moving the handle in a reciprocating manner. When a nut or bolt to be rotated is near an obstruction, the handle can be unlocked, rotated about the connecting pin axis, then locked, thereby adjusting the angle between the longitudinal axis of the handle and the longitudinal axis of the ratchet head.

Abstract: An aspirator receiver forms part of a blood aspiration system for injecting fluid into a patient and withdrawing undiluted blood. The aspirator receiver has a housing with a passage occluded by a septum and in communication with the blood flow channel through the aspirator system. An aspirator comprises a cannula having a blunt tip surrounded by a shroud, the cannula being in communication with a blood receiving receptacle. The aspirator is applied to the housing with the shroud centering the cannula about and for penetration through the septum of the housing whereby undiluted blood may be withdrawn from the flow channel into the receptacle. Upon removal of the aspirator, the septum occluding the end of a standard vacuum-filled container is penetrated by the cannula whereby blood from the receptacle may be transferred into the container.

Abstract: A blood aspiration assembly has an aspirator receiver. The receiver has a housing with a rigid casing and a resilient plug, and a liquid flow chamber. The chamber has an offset lower wall surface, to create turbulence to remove air bubbles during initial set up. The offset wall can be elevated with an intermediate part of larger cross section to accommodate the blunt needle. The plug has a slit or perforation to allow passage of a blunt needle therethrough. The plug can have two parts of different compliance, with aligned slits or perforations. The blunt needle tip can be rounded or flat, with a side opening for the needle bore. The contour of the needle tip and the design of the plug are correlated such that the working force required to penetrate the needle tip into the plug perforation is considerably less than the force required for said needle tip to penetrate normal intact human skin of the hands or arms. A stop prevents the needle from contacting the aspiration chamber wall.

Abstract: A resilient valve core, biased against its seat in a molded body, controls large flow volumes for flushing. A small resilient tube embedded in the core bypasses the valve to provide smaller flow volumes for IV-fluid drip. For flushing, the core is deformed, rather than bodily moved, relative to the body. A fluid-flow channel is recessed along one side of the valve cavity, and the valve seat forms a short barrier across this channel. The core is a T-shaped unitary member; the center of the "upper" surface of the T crossbar is biased against the seat, and the extrema of the crossbar are hermetically sealed against the valve body, while the stem of the T extends outward from the body. A user squeezes a cowling mounted outside the body to start and control flushing. The cowling itself deforms to pull the stem of the T outward, deforming the T and separating the middle of its crossbar portion from the valve seat. A user can elect to grasp and pull the stem directly.

Abstract: An apparatus bushing is fixed to a support wall or the wall of the apparatus housing and is electrically coupled to the apparatus within. A high voltage cable is fixed to the single leg of a 600-Amp "T" connector and is supported only by a bracket extending from said apparatus bushing to one of the "T" legs. A removable pin-and-socket applied link member selectively couples the remaining "T" leg to the apparatus bushing whereby power passes between the apparatus and high voltage cable only when said link is present and isolates said cable and apparatus when it is absent. A novel operating assembly assures proper contact between the link sockets and the pins of the apparatus bushing extender and the 600-Amp "T" connector and can be arranged to positively separate the link assembly. The operating assembly can also be used to install and remove a cap assembly when the electrical link is not in place.

Abstract: A damping device for use in conjunction with a circulatory pressure measuring system to attenuate resonant pressure waves therein includes a series connector for connection to the pressure measuring system. An integrally connected parallel portion includes a capillary tube fluid resistance element in communication with the series connector. A flexible membrane isolates the capillary tube from a fixed volume gas chamber located adjacent the flexible membrane.

Abstract: An improved conduit (50) communicating between a pressurized source (10) of solution and a partially filled reservoir (34) associated with a drip chamber (24) in a continuous-flush system. The conduit comprises a tube (54,56) that is bent at approximately a 45 degree angle so that solution discharging from the conduit (50) is diverted to impinge against the interior wall (58) of the reservoir (34) before interfacing with the solution (62) accumulated therein. The arrangement reduces bubble formation normally associated with turbulent discharge flow during filling and flushing of the system.

Abstract: A physiological pressure sensing and monitoring system including a sterile throwaway pressure transducing device. The device includes a pressure transducer mounted together with a flow control valve in a housing. The device includes a first connector for connecting the device to a source of sterile solution, a second connector for electrically connecting the pressure transducer to a monitoring device, and a third connector for selectively connecting the device to a catheter inserted into a patient's circulatory system. The device, including the connectors, is made to be low cost so as to permit the entire device to be installed and discarded as a unit so as to constitute a throwaway pressure sensing and flow regulating means.

Abstract: This invention relates to novel nitramine propellant compositions for guns nd rockets.

Abstract: A tool for use by an operator in the field in attaching and securing a bushing assembly within an electrical connector and subsequently connecting or disconnecting the electrical connector and a terminal of an electrical apparatus to establish a connection from a remote location through the use of an insulated implement, such as a hot-stick. The tool includes an operating member with a wrenching configuration for engaging a complementary wrenching arrangement in the bushing assembly, a wrenching portion for direct wrenching of the operating member and a torque responsive device through which the insulated implement is coupled to the operating member to enable rotation of the insulated implement relative to the operating member upon exceeding a predetermined torque indicative of the appropriate seating of the electrical connector upon the terminal so that such relative rotation serves as an indication to the operator that the connection is complete.

Abstract: A flow control apparatus is disclosed which is particularly useful in liquid flow systems for blood pressure monitoring in humans and other animals. A resiliently biased valve plunger is provided with a marine bore capillary passage extending from one side of the plunger seating area to the other, thus establishing a first, low flow path. When the plunger is moved from its seat, a second, high flow path is established which flushes the apparatus. In one embodiment, the apparatus is combined with a pressure transmitting diaphragm assembly used to transmit pressure to instrumentation, the flush flow then serving to sweep air from the plenum above the diaphragm.