| 摘要 |
An apparatus for measuring distensibility of a vessel, lumen or sphincter includes a balloon catheter having a balloon located adjacent a distal end of a catheter for inserting in, for example, the sphincter, the distensibility of which is to be determined. The balloon is inflated to respective first and second pressures to distend the sphincter to respective first and second transverse cross-sectional areas which are measured. The first and second pressures are selected so that the relationship between the pressure and the cross-sectional area of the sphincter is linear. The distensibility of the sphincter is determined as a distensibility index, which is the value of c from the equation of a line y=mx+c containing the values of the first and second pressures and areas, where x represents pressure and y represents area. |
| 主权项 |
1. A method for determining the distensibility of one of a vessel wall, a lumen wall and a sphincter, the method comprising:
providing a balloon catheter comprising an elongated catheter extending between a proximal end and a distal end, and an inflatable element defining a hollow interior region when inflated located on the catheter, the inflatable element being adapted for locating in the one of the vessel, the lumen and the sphincter, locating the inflatable element of the balloon catheter in the one of the vessel, the lumen and the sphincter, inflating the inflatable element to a first pressure sufficient to distend the one of the vessel wall, the lumen wall and the sphincter, determining a first transverse cross-sectional area adjacent a portion of the one of the vessel wall, the lumen wall and the sphincter, at which the distensibility is to be determined when the inflatable element is inflated to the first pressure, inflating the inflatable element to a second pressure sufficient to distend the one of the vessel wall, the lumen wall and the sphincter, determining a second transverse cross-sectional area adjacent the portion of the one of the vessel wall, the lumen wall and the sphincter, at which the distensibility is to be determined when the inflatable element is inflated to the second pressure sufficient to distend the one of the vessel wall, the lumen wall and the sphincter, the values of the first and second pressures being different and being values at which the relationship between the transverse cross-sectional area of the inflatable element adjacent the portion of the one of the vessel wall, the lumen wall and the sphincter, at which the distensibility is to be determined and the pressure of an inflating medium in the inflatable element is a linear relationship, determining a linear equation of a line containing the values of the first and second transverse cross-sectional areas of the inflatable element adjacent the portion of the one of the vessel wall, the lumen wall and the sphincter, at which the distensibility is to be determined and the values of the first and second pressures of the inflating medium in the inflatable element corresponding to the first and second values of the transverse cross-sectional area thereof, the line being a plot of the values of the transverse cross-sectional area of the inflatable element adjacent the portion of the one of the vessel wall, the lumen wall and the sphincter, at which the distensibility is to be determined against the values of the corresponding pressure of the inflating medium in the inflatable element, and determining the distensibility of the one of the vessel wall, the lumen wall and the sphincter as a distensibility index, the distensibility index being the value of a point of intersection of the axis on which one of the transverse cross-sectional area and the pressure is plotted by the line, the equation of which contains the values of the first and second transverse cross-sectional areas of the inflatable element and the corresponding values of the first and second pressures of the inflating medium in the inflatable element. |
