Abstract: Systems, kits, and methods for establishing vascular access are described. A system typically includes a radially expandable sleeve, a dilator, and a guidewire. The methods comprise positioning the guidewire through an initial tissue tract, passing the radially expandable sleeve over the guidewire through the tissue tract to a target blood vessel, and thereafter passing the dilator over the guidewire and through the radially expandable sleeve to effect radial expansion of the sleeve. Use of the sleeve reduces the risk of injuring tissue surrounding the tissue tract by lessening the axial forces imparted to the tissue. Kits comprise at least the radially expandable sleeve together with instructions for use.

Abstract: An apparatus and method for forming and enlarging percutaneous penetrations comprises an elongate dilation member which receives an elongate expansion member in an axial lumen thereof. The dilation tube includes a tubular braid which usually comprises a mesh of non-elastic filaments which are radially expandable from a small diameter configuration to a large diameter configuration and which is optionally covered by a removable sheath. The dilation tube is percutaneously introduced to a target site within a patient's body, usually within the abdomen in a laparoscopic procedure. The sheath (if present) is then removed, and the tubular braid thereafter radially expanded by axial insertion of the expansion member through its lumen. The tubular braid is anchored by axial shortening of the mesh and remains in place to permit subsequent exchange of dilation members to provide for different diameter access lumens.

Abstract: A folding tray assembly is provided and includes a support member and a tray member, whereby the tray member is pivotably supported by the support member and moveable relative thereto between a use position and a stowed position. The folding tray assembly further includes a locking mechanism operable to selectively lock the tray member to the support member in one of either the use position or the stowed position. The locking mechanism is housed within the tray member such that the mechanism is not visible or accessible by an occupant, but rather remotely actuated by a handle or lever. In addition, the tray assembly eliminates external supports by providing support within the tray member, thereby providing an open space below the tray member and giving the tray assembly a generally L-shape in the use position.

Abstract: Systems, kits, and methods for establishing vascular access are described. A system may include a needle, a radially expandable sleeve and a dilator. The methods include creating an initial tissue tract to a target blood vessel with a radially expandable sleeve mounted on a needle. Upon removal of the needle, the dilator is then passed through the radially expandable sleeve to effect radial expansion of the sleeve. Use of the sleeve reduces the risk of injuring tissue surrounding the tissue tract by lessening the axial forces imparted to the tissue. Kits comprise at least the radially expandable sleeve together with instructions for use.

Abstract: Systems, kits, and methods for establishing vascular access are described. A system may include a needle, a radially expandable sleeve and a dilator. The methods include creating an initial tissue tract to a target blood vessel with a radially expandable sleeve mounted on a needle. Upon removal of the needle, the dilator is then passed through the radially expandable sleeve to effect radial expansion of the sleeve. Use of the sleeve reduces the risk of injuring tissue surrounding the tissue tract by lessening the axial forces imparted to the tissue. Kits comprise at least the radially expandable sleeve together with instructions for use.

Abstract: An apparatus and method for forming and enlarging percutaneous penetrations comprises an elongate dilation member which receives an elongate expansion member in an axial lumen thereof. The dilation tube includes a tubular braid which usually comprises a mesh of non-elastic filaments which are radially expandable from a small diameter configuration to a large diameter configuration and which is optionally covered by a removable sheath. The dilation tube is percutaneously introduced to a target site within a patient's body, usually within the abdomen in a laparoscopic procedure. The sheath (if present) is then removed, and the tubular braid thereafter radially expanded by axial insertion of the expansion member through its lumen. The tubular braid is anchored by axial shortening of the mesh and remains in place to permit subsequent exchange of dilation members to provide for different diameter access lumens.

Abstract: An apparatus and method for forming and enlarging percutaneous penetrations comprises an elongate dilation member which receives an elongate expansion member in an axial lumen thereof. The dilation tube includes a tubular braid which usually comprises a mesh of non-elastic filaments which are radially expandable from a small diameter configuration to a large diameter configuration and which is optionally covered by a removable sheath. The dilation tube is percutaneously introduced to a target site within a patient's body, usually within the abdomen in a laparoscopic procedure. The sheath (if present) is then removed, and the tubular braid thereafter radially expanded by axial insertion of the expansion member through its lumen. The tubular braid is anchored by axial shortening of the mesh and remains in place to permit subsequent exchange of dilation members to provide for different diameter access lumens.

Abstract: A reference receiver has a biased, strobed sampling system that is tuned to provide the predominant frequency response of the reference receiver allowing for the removal of the discrete reference receiver filter. The reference receiver has a photodiode optical-to-electrical converter that is configured to effectively utilize the current output of the high impedance source in that the converter is not reverse terminated to the characteristic impedance of a transmission coupled to the electrical output of the converter. The electrical output of the converter is coupled to a sampling circuit that receives biasing voltages and gating strobe pulses for producing an approximate Bessel-Thompson filter response from the sampling circuit. The combination of the unterminated optical-to-electrical converter and the tuned sampling circuit results in a reference receiver having higher gain and narrower reference receiver tolerance limits.

Abstract: Systems, kits, and methods for establishing vascular access are described. A system typically includes a radially expandable sleeve, a dilator, and a guidewire. The methods comprise positioning the guidewire through an initial tissue tract, passing the radially expandable sleeve over the guidewire through the tissue tract to a target blood vessel, and thereafter passing the dilator over the guidewire and through the radially expandable sleeve to effect radial expansion of the sleeve. Use of the sleeve reduces the risk of injuring tissue surrounding the tissue tract by lessening the axial forces imparted to the tissue. Kits comprise at least the radially expandable sleeve together with instructions for use.

Abstract: An apparatus and method for forming and enlarging percutaneous penetrations comprises an elongate dilation member which receives an elongate expansion member in an axial lumen thereof. The dilation tube includes a tubular braid which usually comprises a mesh of non-elastic filaments which are radially expandable from a small diameter configuration to a large diameter configuration and which is optionally covered by a removable sheath. The dilation tube is percutaneously introduced to a target site within a patient's body, usually within the abdomen in a laparoscopic procedure. The sheath (if present) is then removed, and the tubular braid thereafter radially expanded by axial insertion of the expansion member through its lumen. The tubular braid is anchored by axial shortening of the mesh and remains in place to permit subsequent exchange of dilation members to provide for different diameter access lumens.

Abstract: An apparatus and method for forming and enlarging percutaneous penetrations comprises an elongate dilation member which receives an elongate expansion member in an axial lumen thereof. The dilation tube includes a tubular braid which usually comprises a mesh of non-elastic filaments which are radially expandable from a small diameter configuration to a large diameter configuration and which is optionally covered by a removable sheath. The dilation tube is percutaneously introduced to a target site within a patient's body, usually within the abdomen in a laparoscopic procedure. The sheath (if present) is then removed, and the tubular braid thereafter radially expanded by axial insertion of the expansion member through its lumen. The tubular braid is anchored by axial shortening of the mesh and remains in place to permit subsequent exchange of dilation members to provide for different diameter access lumens.

Abstract: An output amplifier for a strobed sampling circuit has first and second operational amplifiers coupled to receive the sampled output from the sampling circuit. The operational amplifiers each have a RC circuit having a high ohmic value resistor that is coupled from its inverting input terminal to its output terminal. The non-inverting input terminals receive biasing voltages that are coupled to the sampling circuit. The gating strobes to the sampling circuit produces a DC current through the feedback resistor as a result of strobe pulses being integrated by the RC circuit. Respective electronic switches are coupled in parallel with the RC circuits of the operational amplifiers and are closed at a predetermined time interval after each strobe pulse to discharge the stored charge on the capacitors prior to the next strobe pulse. The output signals from the operational amplifiers are summed in a summing amplifier.

Abstract: Systems, kits, and methods for establishing vascular access are described. A system may include a needle, a radially expandable sleeve and a dilator. The methods include creating an initial tissue tract to a target blood vessel with a radially expandable sleeve mounted on a needle. Upon removal of the needle, the dilator is then passed through the radially expandable sleeve to effect radial expansion of the sleeve. Use of the sleeve reduces the risk of injuring tissue surrounding the tissue tract by lessening the axial forces imparted to the tissue. Kits comprise at least the radially expandable sleeve together with instructions for use.

Abstract: A cDNA molecule encoding coniferin beta-glucosidase is disclosed. This enzyme catalyzes one of the last steps in the synthesis of lignin in plants. Plants having modified lignin content may be produced by transformation with this cDNA (or parts of the cDNA), for example, in either sense or antisense orientation. The invention includes methods of altering-lignin content in plants using this cDNA, as well as transformed plants, such as conifers, having modified lignin content.

Abstract: Devices and methods for providing access to a body cavity without substantial loss of inflation gas therein. The device comprises an access assembly 10 that may have a tubular member 12, at least one sleeve 16 coaxially disposed over the tubular member, a pneumostasis valve 13 attached to the tubular member, and an obturator 11 removably received in the tubular member. Sleeve 16 comprises expandable region 19 capable of forming an anchor 30 upon axial compression. A method to provide access using assembly 10 comprises insertion of the assembly 10 into the body cavity, expanding region 19, and insufflating the cavity with gas. Expandable region 19 on assembly 10 is axially compressed to form anchor 30 to seal against an interior wall of the body cavity. The method may further comprise either a second expanded anchor 50 or a non-expanding anchor 40 which clamps against an exterior wall of the body cavity to securely position and seal the access assembly 10.

Abstract: An access system comprises a radially expandable sleeve, a pneumoperitoneum needle, a cannula assembly, and an obturator. Methods for reconstructing and reusing the access system comprise replacing the radially expandable sleeve and cannula valve cap components of the system, both of which are disposable. All remaining system components may be sterilized and reused one or more times. The pneumoperitoneum needle can be separated into tubular needle body and needle stylet components, which may be separately replaced or sterilized and reused. Similarly the cannula comprises both a cannula hub and a cannula tube, where the hub and tube may be separately replaced or sterilized.

Abstract: A step generator for producing steps having constant edge parameters while driving varying loads includes a pair of DC coupled low speed diode switches for slowly switching the output load current. A pair of capacitors provide an AC coupled high speed input for rapidly, but temporarily, switching the output load current until the sustaining action of the low speed diode switch has occurred. A pair of resistor divider circuits in each of the low speed diode switches maintains a relatively constant reverse bias voltage across the diodes coupled to the capacitors. The high speed switching threshold is maintained at a relatively constant level which produces an output voltage step with constant edge parameters and no overshoot.

Abstract: A pulse generator utilizes a pair of current sources acting through a pair of Schottky diode switches to provide load currents in opposite directions through a load resistor to produce an output voltage across the load resistor of magnitude proportional to the difference between the load current magnitudes. The pulse generator output voltage is abruptly driven to zero potential by applying balanced, rapid slewing voltage pulses to the Schottky diode switches, causing the switches to simultaneously divert the load currents from the load resistor. The balanced voltage pulses are developed at the terminals of a step-recovery diode by switching the step-recovery diode from forward to reverse bias state.

Abstract: A dual channel time domain reflectometer includes a pair of input lines connected at respective nodes to a reference flat current pulse generator and a traveling wave sampling gate, respectively. The sampling gates are actuated by a balanced strobe generator which includes a waveguide coupler for coupling a high amplitude fast rise time pulse to each of the gates simultaneously. Pulses of requisite amplitude and shape are generated by a circuit responsive to a strobe trigger input which drives a step recovery diode.

Abstract: Firm gel structures are formed from hot aqueous radioactive waste solutions containing boric acid by adding powdered magnesium oxide or magnesium hydroxide followed by addition of calcium oxide or calcium hydroxide. Cement may be introduced after addition of the magnesium compound without interfering with subsequent gel reactions. Product rigidity imparted by the gel enables reduction of typical cement usage up to 50% or more in the processing of radioactive boric acid concentrates. This results in more waste being solidified per container, less exothermic heat generation, greater shipping efficiency, and improved resistance to aqueous leaching of radionuclides.