US Patent 11259821 Aspiration system with accelerated response

An aspiration system exhibits an accelerated drop in negative pressure at the distal end of an aspiration catheter from the time of opening a valve. The system includes an aspiration pump in communication with a first chamber, and an aspiration catheter configured for placement into fluid communication with the first chamber by way of an elongate aspiration tube. A second chamber is provided between the aspiration tube and the catheter, and a valve is provided between the second chamber and the aspiration catheter. Upon opening of the valve with negative pressure at equilibrium in the first and second chambers, resistance to fluid flow between the second chamber and the distal end of the catheter is less than the resistance to fluid flow between the second chamber and the first chamber, causing a rapid aspiration into the second chamber.