Abstract: A disposable cassette for use with a main infusion pump unit is disclosed which contains both a disposable pump and a battery, thereby requiring the simultaneous replacement of both the pump and the battery. The controller contained in the main pump unit includes a timer which prevents the cassette from being used for longer than a predetermined time, which is substantially less than the life of the battery. An interlock prevents a cassette from being reinstalled following a single use.

Abstract: An enclosure for use to safely secure a water-sensitive medical or electronic device such as a medication infusion pump in a water-resistant manner is disclosed which utilizes a pouch made of a sheet of thin plastic material to store the apparatus, the pouch being adhesively sealable to secure the device. The enclosure also includes a perforated area which may be opened to form a strap to carry or hang the device, and is constructed inexpensively to be of a disposable nature.

Abstract: A device for use in conjunction with a pulse generator is disclosed which provides a variable pulsing rate in response to short term variations in arterial blood pressure, like the baroreceptor system of the healthy body's cardiovascular system. The system utilizes a pressure transducer implanted together with the pacemaker, the transducer is preferably located on the proximal axillary artery. The system features quick response based on physiological need, and also includes a reset feature which maintains a normal resting heart rate despite long term changes in blood pressure.

Abstract: A roller for use in the cargo bay of an aircraft is disclosed which is constructed with chopped fiber strands incorporated into the rubber and oriented in a substantially circumferential direction around the hub of the roller to provide reinforcement to the rubber portion of the roller.

Abstract: A conditioning circuit for use with a pressure transducer is disclosed which provides a digitally readable electronic output signal indicative of capacitance sensed by the pressure transducer. The circuitry of the present invention utilizes an R-C charge/discharge circuit, thereby enabling the circuitry to be substantially more compact than previously utilized L-C circuits. The circuitry is usable with either pressure transducers having a single capacitance or those including a reference capacitance, and the circuitry provides a high resolution, high precision output.

Abstract: An injection set for delivering a fluid to a subcutaneous injection location in a patient is disclosed which has a soft cannula projecting from a bottom surface of a holding pad. An insertion needle is initially inserted through a septum located between a catheter hub and a retaining cap mounted on the holding pad. The insertion needle extends through a fluid chamber defined by the septum and the catheter hub and then through a lumen of the soft cannula, with the sharpened tip of the insertion needle extending beyond the end of the soft cannula when the insertion needle is fully inserted. The insertion needle, which allows priming of the injection set, may be removed following installation of the injection set without kinking of the soft catheter, and fluid may be supplied to the injection set for delivery to the patient.

Abstract: An injection set for use with an external infusion source of fluid such as insulin is disclosed which injection set is constructed using multiwall tubing. The interior of the multiwall tubing is made of a material which is completely insulin compatible, while the exterior of the multiwall tubing is made of a material which may be solvent bonded. The multiwall tubing facilitates solvent bonding installation of an insert molded needle assembly and a connector to the ends of the tubing without necessitating the use of and incurring the disadvantages of epoxy bonding.

Abstract: A valve for use in medical applications is disclosed which is a highly precise, passive, one-way valve which makes an excellent inlet valve or outlet valve in a drug infusion pump. The valve operates with a very small forward pressure, requires only a small amount of fluid in the valve chamber, and operates in a positive and predictable fashion, even after an extended shelf life. The valve, may be inexpensively molded in one piece, thereby facilitating construction of a disposable pump, and may be installed with the portion of the pump housing contacting the top surface of the valve being flat, thereby further reducing manufacturing costs.

Abstract: A stator for use with a permanent magnet rotor electrical machine is disclosed which stator eliminates ferromagnetic teeth previously used in stator cores. The stator of the present invention uses a winding support structure made of non-magnetizable, non-conductive material to support the stator windings, which may advantageously be prewound prior to installation on the winding support structure. The stator is easily adaptable to liquid cooling, and has substantially reduced losses due to its toothless design.

Abstract: A quartz pressure transducer is disclosed which includes four or five elements, three of which are diaphragms containing deposited metal electrodes on both sides thereof. Since the electrodes are all on the diaphragms, the transducer disclosed herein is highly resistant to errors caused by changes in temperature, while retaining excellent resistance to errors caused by acceleration or vibration forces. The transducer may be constructed as either an absolute pressure sensor or as a differential pressure sensor, and in the primary embodiment contains a reference capacitance which may be used by appropriate electronic circuitry to provide compensation for acceleration or vibration forces, making the output of the pressure transducer of the present invention a highly accurate, highly sensitive indication of pressure sensed.

Abstract: A programmable infusion pump apparatus having a power supply (4, 11), a first circuit (6) responsive to the and assisting the power supply (4), power generating circuit (8) for generating sufficient power to drive a pump drive mechanism (12), a power storage circuit (10) for storing the power generated by the power generating circuit (8), a sensing system (16) for sensing stored power levels and the condition of the power supply (11), a microprocessor (18); a plurality of actuators (24, 26, 28, 30) for display and changing parameter values stored in RAM of the microprocessor (18), a memory (34) operably connected to microprocessor (18); display screen (40) for displaying parameter values and other information concerning the apparatus and a tone transducer (22) for providing an audio output from the apparatus to indicate certain conditions.

Abstract: In an implantable device, transmission and reception of digital information is accomplished as well as the transmission and reception of analog information. The analog signal is FM modulated for transmission and the digital signal is phase modulated for transmission. The FM modulated signal is used as a clock in the phase encoding of the digital signal and thus provides a signal simultaneously carrying analog and digital information. Means for reception of the analog and digital information is taught. The use of PSK (phase shift keying) as the phase modulation scheme for transmission and reception is also taught.

Abstract: A solenoid drive apparatus for driving a lead screw of an External Infusion Pump (1) having a housing (302), solenoid winding (356) within the housing (302), a solenoid armature (358) which is driven by the field of the solenoid winding (356), push rod (362) which is driven by the armature (358), pawn (314) which is driven by push rod (362), a first pawl (320) which is driven by pawn (314) and a second pawl (326) which is an antibacklash device, a ratchet wheel (318) having teeth (319) around its periphery and engaged by the first pawl (320) and the second pawl (326) and the drive shaft (316) which is drawn by the ratchet of the ratchet wheel (318).

Abstract: An arrangement for supplying coolant flow to turbine blades in a gas turbine engine is disclosed which utilizes a preswirl assembly to impart a tangential velocity to the coolant flow substantially greater than the tangential velocity of the rotor at the point at which the air is supplied to the rotor. The overswirled air is injected radially inwardly into an internal passage contained in the rotor, and the coolant flow continues to be an overswirled condition within the internal passageway. The amount of overswirl imparted to the coolant flow is such that the tangential velocity of the coolant flow is greater than the tangential velocity of the blades at the location on the blades the coolant flow is supplied to the blades for blade cooling, thereby resulting in substantially improved efficiency in the cooling system.

Abstract: A bleed flow modulator is used in conjunction with pressure regulating valves regulating bleed air pressure from each engine to a common manifold. The bleed flow modulator monitors the pressure drop across a heat exchanger, which pressure drop is proportional to flow rate of bleed air through the heat exchanger. By providing a limited authority negative feedback signal to the pressure regulating valve from the bleed flow modulator, flow rate of bleed air from each engine to the common manifold is kept near a desired uniform value, thereby achieving balanced flow extraction of bleed air from the aircraft engines.

Abstract: A two pole permanent magnet rotor utilizes a single cylindrical two pole permanet magnet mounted between two end pieces and surrounded by a retaining hoop. The cylindrical two pole permanent magnet, which is made of high energy product material, is "straight through" diametrically magnetized to provide a sinusoidal air gap flux distribution which eliminates losses due to harmonics. The cylindrical two pole permanent magnet may be made of a plurality of smaller magnet blocks which are stacked and machined to form a cylindrical configuration.

Abstract: An electrical machine utilizes a consequent pole rotor with a polyphase stator assembly and a control coil to produce a widely variable voltage output. Either constant-speed--variable-voltage performance, or variable-speed--constant-voltage performance may be easily achieved by varying the magnitude and level of D.C. current supplied to the control coil. Single and double rotor embodiments are disclosed, with cogging being easily suppressible in the double rotor embodiments.

Abstract: A valve, suitable for use in small medical devices and which can readily be made of medical grade materials, comprises an elastic diaphragm stretched over a protruding surface, preferably of spherical or convex shape. The diaphragm has a ring of holes concentrically around a hole in the protruding surface. A mating recess, connected to a conduit, fits over the protruding surface. The elastic material is held in place at or near the opening of the recess. The holding structure may also serve to seal the valve. A dual arrangement provides an input and an output valve in combination.

Abstract: A rotor for an electrical machine has large permanent magnets located at half the pole locations, with alternating pole locations containing ferromagnetic projections which become consequent poles in the rotor. The permanent magnet poles have a high reluctance, while the ferromagnetic poles have a very low reluctance, thereby affording variable flux linkage between the rotor and a stator. Magnetic homogeneity is improved, while susceptibility to thermal degradation in the rotor is reduced substantially.

Abstract: A permanent magnet rotor having a unitary aluminum casting surrounding magnets mounted on the shaft which has favorable heat transfer, performance, and cost characteristics, and which may be constructed by the accompanying method. Spacers and rings surrounding the permanent magnets are eliminated by the aluminum casting. Pockets for the permanent magnets are cast into the aluminum. A non-magnetic outer sleeve overlies the shaft, magnets and aluminum layer.