| abstract |
A suspension of a therapeutic substance (e.g., embolic beads) dispersed within a liquid can be delivered via a catheter by using a bidirectional pump to rapidly draw the mixture of the therapeutic substance and liquid from an external syringe into an internal reservoir, then rapidly push the mixture back out into the external syringe. The rapid operation of the bidirectional pump mixes the two constituents so that the therapeutic substance is temporarily suspended within the liquid. Then, a low-speed pump is used to inject the mixture out via the catheter. In some embodiments, the parameters of the low-speed pump are controlled so that the fluid exiting the catheter will experience laminar flow. When the therapeutic substance comprises embolic beads, this can advantageously prevent reflux of the embolic beads, which can be dangerous. |