Apparatus and methods for controlled clot aspiration
An aspiration thrombectomy system including an aspiration catheter, a vacuum source to provide negative pressure to the aspiration thrombectomy system, connection tubing to place the vacuum source and the aspiration catheter in fluid communication, controllable valves to control a level of negative pressure provided by the vacuum source, acoustic flow sensors to detect acoustic signals in the connection tubing, and a controller to receive, from the acoustic flow sensors, acoustic signals during a thrombectomy procedure, determine, based on the acoustic signals, whether occlusive material from a vasculature of a patient is lodged within the connection tubing or the aspiration catheter, and operate, automatically in response to determining that occlusive material is lodged based on the first acoustic signals, the aspiration thrombectomy system in a pulsed aspiration cycle by modulating one or more of the controllable valves to generate cyclical pressure pulses in the connection tubing and the aspiration catheter.
1 . An aspiration thrombectomy system, comprising:
an aspiration catheter;
a vacuum source configured to provide negative pressure to the aspiration thrombectomy system;
connection tubing configured to place the vacuum source and the aspiration catheter in fluid communication;
one or more controllable valves configured to control a level of negative pressure provided by the vacuum source;
one or more acoustic flow sensors configured to detect acoustic signals in the connection tubing or the aspiration catheter; and
a controller configured to:
receive, from one or more of the acoustic flow sensors, one or more first acoustic signals during a thrombectomy procedure;
determine, based on the first acoustic signals, a current flow state in the connection tubing or the aspiration catheter; and
operate, automatically in response to determining the current flow state based on the first acoustic signals, via one or more of the controllable valves, the aspiration thrombectomy system in a first operating mode of a plurality of operating modes comprising at least an extraction mode and a full vacuum mode.
2 . The aspiration thrombectomy system of claim 1 , wherein the current flow state is one of a plurality of flow states comprising a clogged flow state, a partially clogged flow state, or an unrestricted flow state.
3 . The aspiration thrombectomy system of claim 2 , wherein the extraction mode comprises generating a plurality of pressure pulses, and wherein one or more of the pressure pulses generates one or more pressure differentials within the connection tubing or the aspiration catheter.
4 . The aspiration thrombectomy system of claim 3 , wherein the extraction mode further comprises modulating one or more of the controllable valves in a first pressure pulse protocol to generate the plurality of pressure pulses.
5 . The aspiration thrombectomy system of claim 4 , wherein the first pressure pulse protocol is based on the one or more first acoustic signals.
6 . The aspiration thrombectomy system of claim 5 , wherein the first pressure pulse protocol is predetermined from a library of pressure pulse protocols.
7 . The aspiration thrombectomy system of claim 6 , wherein the library of pressure pulse protocols is associated with specified time periods corresponding to each of the plurality of operating modes.
8 . The aspiration thrombectomy system of claim 2 , wherein the one or more controllable valves comprise a vacuum valve and a vent valve, wherein the vacuum valve is positioned between the vacuum source and the connection tubing, and wherein the vent valve is positioned between a pressure source and the connection tubing.
9 . The aspiration thrombectomy system of claim 8 , wherein opening the vacuum valve provides negative pressure from the vacuum source to the aspiration thrombectomy system, and wherein opening the vent valve provides positive pressure from the pressure source to the aspiration thrombectomy system.
10 . The aspiration thrombectomy system of claim 9 , wherein the extraction mode comprises cyclically opening and closing the vacuum valve and the vent valve to change a level of positive pressure and negative pressure in the aspiration catheter or the connection tubing.
11 . The aspiration thrombectomy system of claim 10 , wherein the extraction mode further comprises changing a level of positive pressure and negative pressure in the aspiration catheter or the connection tubing in a first pressure pulse protocol.
12 . The aspiration thrombectomy system of claim 11 , wherein the first pressure pulse protocol is based on the one or more first acoustic signals.
13 . The aspiration thrombectomy system of claim 12 , wherein the first pressure pulse protocol is predetermined from a library of pressure pulse protocols.
14 . The aspiration thrombectomy system of claim 13 , wherein the first pressure pulse protocol comprises cyclically opening and closing the vacuum valve and the vent valve at a predetermined frequency.
15 . The aspiration thrombectomy system of claim 13 , wherein the library of pressure pulse protocols is associated with specified time periods corresponding to each of the plurality of operating modes.
16 . The aspiration thrombectomy system of claim 9 , wherein the full vacuum mode comprises holding the vacuum valve open, and wherein the negative pressure provided by the vacuum source is substantially greater than the positive pressure provided by the pressure source.
17 . The aspiration thrombectomy system of claim 16 , wherein the current flow state is determined to be a clogged state, and wherein the controller operates the aspiration thrombectomy system in the full vacuum mode based on a determination that the current flow state is a clogged state.
18 . The aspiration thrombectomy system of claim 9 , wherein the pressure source has a pressure level greater than an atmospheric pressure level.
19 . The aspiration thrombectomy system of claim 1 , wherein one or more of the acoustic flow sensors are ultrasonic flow sensors.
20 . The aspiration thrombectomy system of claim 1 , wherein the one or more acoustic flow sensors comprise at least a first acoustic flow sensor and a second acoustic flow sensor, and wherein the current flow state is determined based on the first acoustic signals from each of the first acoustic flow sensor and the second acoustic flow sensor.