Two-way outdwelling slit valving of medical liquid flow through a cannula and methods

摘要

A novel cardiovascular outdwelling, normally closed, pressure-responsive slit valve liquid flow control (10) and related methods wherein a diaphragm (124) having a slit (146) therein is flexed distally by hydrostatic pressure and proximally by negative pressure at different points in time to selectively open the slit and accommodate the flow of IV solution to a medical patient through a cannula (14) and blood sampling from the cardiovascular system of the patient through the cannula in such a way as to prevent bleed-back and clotting of blood within the cannula.