초록 ▼

The catheter assembly includes an expandable member mounted to the distal end of a placement catheter, for delivery of a therapeutic device in one of the branch vessels of a bifurcated vessel. The catheter assembly includes lumens for a tracking guide wire and a positioning guide member for placemen

The catheter assembly includes an expandable member mounted to the distal end of a placement catheter, for delivery of a therapeutic device in one of the branch vessels of a bifurcated vessel. The catheter assembly includes lumens for a tracking guide wire and a positioning guide member for placement of the therapeutic device. The therapeutic device is mounted on the expandable member, the tracking guide wire is placed into the target branch vessel, and the placement catheter is then introduced over the tracking guide wire. A positioning guide member is introduced through the catheter, extended through an exit port in the catheter proximal to the expandable member, and then placed in another branch vessel of the bifurcation. The placement catheter then is advanced until the positioning guide member engages the vessel carina between the branch vessels, and the therapeutic device then may be placed accurately in the target branch vessel. In another form of the catheter assembly, a secondary catheter member is mounted to the placement catheter and adapted to receive the positioning guide member for placement of the positioning guide member in the vessel branch not to be treated. An elongated angle member is mounted to the secondary catheter member for engagement with the vessel carina.

대표청구항 ▼

The catheter assembly includes an expandable member mounted to the distal end of a placement catheter, for delivery of a therapeutic device in one of the branch vessels of a bifurcated vessel. The catheter assembly includes lumens for a tracking guide wire and a positioning guide member for placemen

The catheter assembly includes an expandable member mounted to the distal end of a placement catheter, for delivery of a therapeutic device in one of the branch vessels of a bifurcated vessel. The catheter assembly includes lumens for a tracking guide wire and a positioning guide member for placement of the therapeutic device. The therapeutic device is mounted on the expandable member, the tracking guide wire is placed into the target branch vessel, and the placement catheter is then introduced over the tracking guide wire. A positioning guide member is introduced through the catheter, extended through an exit port in the catheter proximal to the expandable member, and then placed in another branch vessel of the bifurcation. The placement catheter then is advanced until the positioning guide member engages the vessel carina between the branch vessels, and the therapeutic device then may be placed accurately in the target branch vessel. In another form of the catheter assembly, a secondary catheter member is mounted to the placement catheter and adapted to receive the positioning guide member for placement of the positioning guide member in the vessel branch not to be treated. An elongated angle member is mounted to the secondary catheter member for engagement with the vessel carina. the end tidal concentration of a gas in a subject's breath, comprising: a first sensor, said first sensor generating a first output signal corresponding to the concentration of a first gas in said subject's breath; a second sensor, said second sensor generating a second output signal corresponding to the concentration of a second gas in said subject's breath; a microprocessor, said microprocessor receiving said first output signal and said second output signal, and having means for computing a plurality of local end tidal concentrations of the first gas based on said first and second output signals; and means for determining the subject's overall concentration of the first gas based on said local end tidal concentrations of the first gas. 3. The apparatus according to claim 1 or 2, wherein said microprocessor additionally comprises means for filtering said second output signal to match the characteristics of said first output signal. 4. The apparatus according to claim 2, wherein said first gas is hydrogen. 5. A method for determining a subject's end tidal carbon monoxide concentration, comprising the steps of: obtaining samples of the subject's breath; taking carbon dioxide measurements and carbon monoxide measurements from said samples; determining inhaled carbon monoxide levels from said carbon monoxide measurements, and excluding the effect of said inhaled carbon monoxide; calculating local end tidal carbon monoxide measurements from the carbon dioxide measurements and the carbon monoxide measurements; and calculating the subject's overall end tidal carbon monoxide concentration from the local end tidal carbon monoxide concentrations. 6. A method for determining the concentration of a gas in a subject's end tidal breath, comprising the steps of: obtaining samples of the subject's breath; taking measurements of a first gas and a second gas from said samples; determining inhaled levels of said first gas from said measurements of said first gas, and excluding the effect of said inhaled first gas; calculating local end tidal concentrations of said first gas from said measurements of first gas and said second gas; and calculating the subject's overall concentration of said first gas from said local end tidal concentrations of said first gas. 7. A method for determining a subject's end tidal carbon monoxide concentration, comprising the steps of: obtaining samples of the subject's breath; obtaining a first output signal corresponding to the concentration of carbon monoxide in the subject's breath; obtaining a second output signal corresponding to the concentration of carbon dioxide in the subject's breath; determining inhaled carbon monoxide levels from said first output signal, and excluding the effect of said inhaled carbon monoxide; calculating a carbon monoxide concentration from the first output signal; calculating a local end tidal carbon dioxide concentration from the second output signal; calculating a filtered carbon dioxide concentration from the second output signal; calculating a local end tidal carbon monoxide concentration based on said local end tidal carbon dioxide concentration, said filtered carbon dioxide concentration, and said carbon monoxide concentration; and calculating said subject's overall end tidal carbon monoxide concentration from said local end tidal carbon monoxide concentration. 8. The method according to claim 7, wherein the step of calculating a filtered carbon dioxide concentration from said second output signal comprises the steps of: filtering said second output signal to match the characteristics of said first output signal; and calculating carbon dioxide concentration from said filtered second output signal. 9. The method according to claim 7 or 8, wherein the step of calculating a local end tidal carbon monoxide concentration based on said local end tidal carbon dioxide concentration, said filtered carbon dioxide concentration, and said carb on monoxide concentration comprises multiplying the carbon monoxide concentration by the ratio of the local end tidal carbon dioxide concentration to the filtered carbon dioxide concentration. 10. A method for determining gas concentration in a subject, comprising the steps of: obtaining samples of the subject's breath; obtaining a first output signal corresponding to the concentration of a first gas in the subject's breath; obtaining a second output signal corresponding to the concentration of a second gas in the subject's breath; determining inhaled levels of said first gas from said first output signal, and excluding the effect of said inhaled first gas; calculating a concentration of said first gas from the first output signal; calculating a local end tidal concentration of said second gas from the second output signal; calculating a filtered concentration of said second gas from the second output signal; calculating a local end tidal concentration of said first gas based on said local end tidal concentration of said second gas, said filtered concentration of said second gas, and said concentration of said first gas; and calculating said subject's overall end tidal concentration of said first gas from said local end tidal concentration of said first gas. 11. The method according to claim 10, wherein the step of calculating a filtered concentration of said second gas from said second output signal comprises the steps of: filtering said second output signal to match the characteristics of said first output signal; and calculating the concentration of said second gas from said filtered second output signal. 12. The method according to claim 10 or 11, wherein the step of calculating a local end tidal concentration of said first gas based on said local end tidal concentration of said second gas, said filtered concentration of said second gas, and said concentration of said first gas comprises multiplying the concentration of said first gas by the ratio of the local end tidal concentration of said second gas to the filtered concentration of said second gas. 13. A method for determining a subject's end tidal carbon monoxide concentration, comprising the steps of: obtaining samples of the subject's breath; obtaining a first output signal corresponding to the concentration of carbon monoxide in the subject's breath; obtaining a second output signal corresponding to the concentration of an other gas in the subject's breath; determining inhaled levels of carbon monoxide from said first output signal, and excluding the effect of said inhaled carbon monoxide; determining that a subject has entered an exhalation phase based upon increases in the second output signal, and that a subject is ending an exhalation phase based upon decreases in the second output signal; computing a corrected concentration of said other gas over time from said second output signal, by determining concentration of said other gas over time from said second signal, and by adjusting said concentration of said other gas over time so that the rate of reduction in concentration of said other gas during an exhalation phase is limited in proportion to the rate of increase during the same exhalation phase; calculating a carbon monoxide concentration from the first output signal; calculating a local end tidal concentration of said other gas from the second output signal; calculating a local end tidal carbon monoxide concentration based on said local end tidal concentration of said other gas, said corrected concentration of said other gas, and said carbon monoxide concentration; and calculating said subject's overall end tidal carbon monoxide concentration from said local end tidal carbon monoxide concentrations. 14. The method according to claim 13, wherein said other gas is carbon dioxide. 15. An apparatus for determining a subject's end tidal carbon monoxide concentration, comprising: a first sensor, said first sensor generating a fi rst output signal corresponding to the carbon monoxide concentration in the subject's breath; a second sensor, said second sensor generating a second output signal corresponding to the carbon dioxide concentration in the subject's breath; a microprocessor, said microprocessor receiving said first output signal and said second output signal, and said microprocessor having means for excluding the effect of inhaled carbon monoxide; means for determining carbon dioxide concentration over time from said second output signal; means for determining end tidal breath phases based on peaks in said carbon dioxide concentration; means for adjusting carbon dioxide concentration after said peaks so that any decrease in carbon dioxide concentration during an end tidal phase is limited in proportion to the rate of increase in the end tidal phase; means for computing a plurality of local carbon monoxide concentrations based on said first output signal and said adjusted carbon dioxide concentration; and means for determining the subject's overall end tidal carbon monoxide concentration based on said local end tidal carbon monoxide concentrations. 16. An apparatus for determining a subject's end tidal carbon monoxide concentration, comprising: a first sensor, said first sensor generating a first output signal corresponding to the carbon monoxide concentration in said subject's breath; a second sensor, said second sensor generating a second output signal corresponding to the concentration of an other gas in said subject's breath; a microprocessor, said microprocessor receiving said first output signal and said second output signal, and having means for excluding the effect of inhaled levels of the first gas; means for determining a filtered concentration of said other gas and an end tidal concentration of said other gas; means for determining excessive breath variability whenever the variation among a plurality of samples of the ratio between the end tidal concentration of said other gas to the concentration of the other gas exceeds a threshold; means for computing a plurality of local end tidal carbon monoxide concentrations based on said first and second output signals; and means for determining the subject's overall end tidal carbon monoxide concentration based on said local end tidal carbon monoxide concentrations. 17. The apparatus according to claim 16, wherein the predetermined threshold is expressed in the formula, wherein g2represents the concentration of said other gas. 18. The apparatus according to claim 17, wherein said other gas is carbon dioxide. 19. A method for determining a subject's end tidal carbon monoxide concentration, comprising the steps of: obtaining samples of the subject's breath; obtaining a first output signal corresponding to the concentration of carbon monoxide in the subject's breath; obtaining a second output signal corresponding to the concentration of an other gas in the subject's breath; determining inhaled levels of carbon monoxide from said first output signal, and excluding the effect of said inhaled carbon monoxide; calculating a carbon monoxide concentration from the first output signal; calculating a local end tidal concentration of said other gas from the second output signal; calculating a filtered concentration of said other gas from the second output signal; determining excessive breath variability whenever the variation among a plurality of samples of the ratio between the end tidal concentration of said other gas to the filtered concentration of said other gas exceeds a predetermined threshold; computing a plurality of local end tidal carbon monoxide concentrations based on said first and second.output signals; and calculating said subject's overall end tidal carbon monoxide concentration from said local end tidal carbon monoxide concentrations. 20. The method according to claim 19, wherein the predetermined threshold is expressed in the formula: