Abstract: A system for analyzing aerosols incorporates a corona discharge ion generator with a positively or negatively charged corona discharge needle formed of platinum or a platinum alloy. A high speed (40-210 meter per second) air flow sweeps the ions away from the corona discharge, and propels the ions into a mixing chamber in a turbulent jet that encounters an aerosol, also provided to the mixing chamber. In one version of the ion generator, the ions are carried into the mixing chamber through an orifice formed in a positively or negatively biased plate. In another alternative, the aerosol droplets are electrostatically generated, and propelled into the mixing chamber as an aerosol jet that confronts the ion jet to enhance a mixing of the charged droplets and the ions. In this version the droplets are advantageously neutralized to leave predominantly singly charged positive and negative particles, to provide a neutralized aerosol particularly well suited for analysis with a mass spectrometer.

Abstract: A system for analyzing aerosols incorporates a corona discharge ion generator with a positively or negatively charged corona discharge needle formed of platinum or a platinum alloy. A high speed (40-210 meter per second) air flow sweeps the ions away from the corona discharge, and propels the ions into a mixing chamber in a turbulent jet that encounters an aerosol, also provided to the mixing chamber. In one version of the ion generator, the ions are carried into the mixing chamber through an orifice formed in a positively or negatively biased plate. In another alternative, the aerosol droplets are electrostatically generated, and propelled into the mixing chamber as an aerosol jet that confronts the ion jet to enhance a mixing of the charged droplets and the ions. In this version the droplets are advantageously neutralized to leave predominantly singly charged positive and negative particles, to provide a neutralized aerosol particularly well suited for analysis with a mass spectrometer.

Abstract: A biological fluid transport device comprises a cutwater at the junction of at least two blood flow paths. The cutwater is substantially straight, substantially vertical, or both. At least one of the fluid paths may be tubular, and in some embodiments all of the fluid paths are tubular. The shear sensitive fluid may be, without limitation, blood, blood-based combinations, cell culture media, cell suspensions, proteins, and microcapsule suspensions. The device may be part of an extracorporeal circuit (e.g., blood during heart-lung bypass procedures or blood processing), but it need not be. Preferred embodiments of the device include, without limitation, kinetic pumps, mass transfer devices, filters, reservoirs, and heat exchangers.

Abstract: A biological fluid transport device comprises a cutwater at the junction of at least two blood flow paths. The cutwater is substantially straight, substantially vertical, or both. At least one of the fluid paths may be tubular, and in some embodiments all of the fluid paths are tubular. The shear sensitive fluid may be, without limitation, blood, blood-based combinations, cell culture media, cell suspensions, proteins, and microcapsule suspensions. The device may be part of an extracorporeal circuit (e.g., blood during heart-lung bypass procedures or blood processing), but it need not be. Preferred embodiments of the device include, without limitation, kinetic pumps, mass transfer devices, filters, reservoirs, and heat exchangers.

Abstract: An aerodynamic particle size measuring device includes a laser energy source and beam splitting, shaping and polarizing optics for forming two parallel, peripherally overlapping beams. The beams are caused to intersect a gas stream perpendicular to the direction of gas flow, thus to form a measuring volume at the intersection of the beams and flow. Single particles are carried through the measuring volume with the gas flow, each particle scattering and extinguishing light according to the beam profile, as predetermined by the degree of beam overlap and the Gaussian intensity distribution of each beam. A photodetector, responsive either to scattered light or light extinction, generates a time-dependent voltage profile that tends to replicate the intensity profile. The resulting electrical signal is processed to determine an amplitude, set a threshold for minimally acceptable amplitudes, and to derive two negative-going zero crossings for an unambiguous time/velocity determination.

Abstract: An electromagnetic flow meter for measuring the flow of blood through a conduit. Flow rate is measured by applying an electromagnetic field around the conduit, with the moving electrolytic blood inducing a current that is sensed by electrodes. The flow meter includes a substantially "E"-shaped magnetic core structure as well as an "E"-shaped hinged cover piece for defining a complete flux loop. In the circuitry, a floating ground arrangement is provided for enhancing the stability and sensitivity of the meter and to ensure appropriate patient isolation. A strong magnetic field, covering the sensing region and with little flux leakage, is alternately switched in polarity. The magnetic coil driver circuit employs an arrangement of switches for facilitating very fast polarity reversal. A two-level current source in the coil current driver greatly enhances the meter's efficiency and power dissipation characteristics.

Abstract: A vascular access system (20) utilizing a catheter (22) having at least one lumen with a bidirectional check valve assembly (24).

Abstract: A method and apparatus for catheterization is provided. The method and apparatus are particularly suited for bone catheterization, i.e. access to an internal cavity of an animal, by means of a bone associated therewith. The preferred apparatus includes a tap arrangement and a cannula arrangement, provided in fluid flow communication with one another. The tap arrangement is constructed and arranged for anchoring within a bone, in fluid flow communication with the cavity. The cannula is preferably oriented for fluid flow access therewith, from a remote location. In preferred applications, the cannula arrangement is provided in communication with a medical access port and/or infusion pump arrangement. A preferred tool is described, for implanting the apparatus in a bone of the subject.

Abstract: A particle flux counter apparatus utilizing light extinction. The apparatus utilizes two oppositely disposed cylindrical mirrors (21a, 21b) to bounce a beam back and forth between them, the beam traversing the length of the cylindrical mirrors (21a, 21b) in incremental steps. A plane mirror (22) is cooperatively located to reflect the beam back between the system to traverse the length of the cylindrical mirrors (21a, 21b) a second time in incremented steps. The two sets of steps interleaving such that the beam forms a sheet of light. A detector (60) monitors the intensity of the beam. As particles in a sample aerosol intersect the beam, the light is extinguished and the beam intensity changes. The detector (60) transmits a signal to a microprocessor (108) analyzation. The apparatus also utilizes a feedback circuit (300) to regulate the beam intensity and alternatively provides for modulating the beam to provide for higher peak power into the detector (60) and elimination of common mode noise.

Abstract: A method and apparatus for catheterization is provided. The method and apparatus are particularly suited for bone catheterization, i.e. access to an internal cavity of an animal, by means of a bone associated therewith. The preferred apparatus includes a tap arrangement and a cannula arrangement, provided in fluid flow communication with one another. The tap arrangement is constructed and arranged for anchoring within a bone, in fluid flow communication with the cavity. The cannula is preferably oriented for fluid flow access therewith, from a remote location. In preferred applications, the cannula arrangement is provided in communication with a medical access port and/or infusion pump arrangement. A preferred tool is described, for implanting the apparatus in a bone of the subject.

Abstract: An apparatus and method for determining the concentration of macromolecules and colloids in a liquid sample is disclosed. The apparatus preferably includes an electrospray apparatus 16 for forming droplets from the sample. Liquid is removed from the droplets by drying in the electrospray apparatus 16, thereby forming an aerosol. The aerosol of a size greater than a predetermined size is then counted by a condensation nucleus counter 52. In this manner, the target macromolecules and colloids are counted. This apparatus is capable of detecting very small macromolecules and colloids of a wide range of materials in a liquid, for example, individual molecules having molecular weight as small as 10,000.

Abstract: A zero net external displacement implantable pump for the transfer of accumulated body fluids, such as transfer of ascites fluid from the peritoneum to the vasculative system. The pump includes a pair of bellows type displacement chambers which are alternately compressed and expanded by action of a pivoted rocker member. The fluid to be transferred is drawn into the chambers on the expansion strokes and expelled on the compression strokes. The rocker member may be operated manually or power driven. Single action and double action pumps are disclosed.

Abstract: Methods and apparatus for enhancing the accuracy of laser optical measuring instruments using fringe pattern spacing are disclosed. The apparatus in one embodiment includes a laser beam source 10, a beam splitter 14, and mirrors 22 to deflect the beams 18, 20 emitted from the beam splitter 14 to a sensing volume. Alternative embodiments include prisms 42, 44, gratings 62 or other optical devices in lieu of mirrors 22. Objects passing through the sensing volume scatter light which is detected by the instrument to determine, among other things, the velocity of the object. The emitted beams 18, 20 are automatically deflected in response to wavelength changes of the laser beam 16 such that variations in the fringe spacing, due to variations in laser beam 16 wavelength, are compensated by variations in the closing angle K of the emitted, deflected beams. The fringe pattern spacing is thereby held more nearly constant enhancing the accuracy of the instrument.

Abstract: An implantable intravascular access system, including an implantable, catheter obturator controller manifold for use with an implantable intravascular catheter. The catheter includes a lumen, having an expanded state and a normal state, an obturator, and an obturator plenum having an inflated state and a contracted state. The lumen can be closed or opened by hydraulically actuating the expansion or contraction of the obturator plenum when the lumen is in its normal state. When the obturator plenum is expanded to its inflated state, the obturator substantially blocks the lumen such that substantially no fluid can pass through the lumen when the lumen is in its normal state. The manifold comprises a housing, a receiving mechanism for receiving the catheter, an actuating mechanism for hydraulically actuating the expansion or contraction of the plenum, and a first entry mechanism for entering the housing.

Abstract: An implantable infusion pump (20) for infusing drugs or other chemicals or solutions into the body. A flexible spring diaphragm (25) forms an outer back wall portion (26) of a housing (22) of the infusion pump (20). The spring diaphragm (25) applies substantially constant force over a range of displacement and communicating internal body pressure to the drug chamber (30) so as to maintain a substantially uniform pressure difference between the drug chamber (30) and the internal body pressure.

Abstract: An implantable infusion pump (20) for infusing drugs or other chemical or solutions into the body. A movable diaphragm (26) forming a variable volume drug chamber (22). A fluid piston (32) opposing the force exerted by the diaphragm (26) on the drug solution in the drug chamber (22). The pressure of the fluid piston (32) being controlled by a regulator (33) providing a reference pressure and in fluid communication with the fluid piston (32). The regulator (33) reducing the fluid pressure of the piston fluid (32) as drug solution is expelled from the drug chamber (22) so as to maintain a constant pressure differential between the drug chamber (22) and an infusion site in the body. The implantable infusion pump (20) being readily adaptable to variable or electronic flow control.

Abstract: A system for the measurement of a metabolite in a physiological fluid is disclosed which comprises a catheter which includes an internal metabolite sensor downstream from a semipermeable region where dynamic equilibrium is attained between the external metabolite and a higher concentration of the same metabolite contained in an infusate which is flowed through the catheter. The changing metabolite concentration also can open and close a chemical valve to control the codelivery of a drug through the catheter.

Abstract: A catheter having a tip which is resistant to plugging by blood components or other body fluids when used as a long term implant within a living body. A check valve is incorporated in the tip that is exposed to the blood stream or other body fluids. The central bore within the catheter is closed at its downstream end. A cross bore or port is provided immediately upstream from the closed end. This cross bore is covered by a thin elastic sleeve to create a check valve. The pressure developed by injected infusate through the catheter opens the valve against the elastic force of the outer sleeve. Fluids cannot enter the catheter either by diffusion against the high velocity exit flow or by suction applied to the proximal end of the catheter.

Abstract: A bone fixation device for securing adjacent and separated bone portions, such as at a joint or at a relatively clean, unsplintered break, comprises a pair of telescoping members which are pinned into the respective bone portions, and have internal actuating members to permit the telescoping parts to be moved together to bring the two bone portions to bear against one another at a desired level of pressure. After the telescoping members have been adjusted the members are permanently left in place to fix and hold the joint or break in a predetermined relationship. The adjusting members also remain in place as pins within the bone, which are accessible through incisions in the skin if later adjustment is necessary. The entire device is embedded, and is not external. The process of inserting is relatively simple to follow and rigidly fixes a joint or break between two abutting bone portions without having external members.

Abstract: An improved bridge-type hot-wire constant overheat anemometer having current controlled temperature compensation circuitry, whereby matched sensors may be employed. Independent voltage sensing and current supply paths along with high impedance cross-coupled velocity sensing circuitry assures device accuracy.