| 摘要 |
A catheter has: a treatment channel 11 to introduce a treatment substance into the body of a patient; a catheter tip 10 which surrounds an end of the treatment channel; and a cleaning channel 12. The cleaning channel joins the treatment channel at a connection 13 which may be a valve (figures 11a,12a) operable by a pneumatic, hydraulic or electric control line (13_2, figure 13). In use a cleaning substance is circulated through the cleaning channel and through the treatment channel in the direction away from the catheter tip. The connection between the channels may locate inside or outside of the patients body. Filters (31,32 figures 3a-3c) may reside in either or both channels. The channels may be coaxial or one may be located in the wall of the catheter. There may be multiple lumens in the wall of the catheter (figure 7). Lumen collapse may be prevented by supports (8, figure 8). Pressure, flow or pH sensors may be included and the cleaning process ceased if leakage into the body is indicated. |
