Pulsating suction system using a static vacuum source with intermittent injection of pressure pulses

Abstract

Disclosed herein is a pulsating aspiration system including a catheter and a pump system. The catheter includes an outer wall, a proximal portion, a distal portion, and an inner wall dividing the proximal portion into a central main lumen and an auxiliary lumen. The pump system is in fluid communication with the catheter and independently controls negative and positive fluid pressures within the central main and auxiliary lumens to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure. The maximum aspiration pressure can be generated at the distal end of the catheter when the resulting pressure is solely negative fluid pressure, and the maximum positive pressure can be generated at the distal end of the catheter when the positive fluid pressure balances the negative fluid pressure.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 447,506, filed February 22, 2023, the disclosure of which is incorporated herein by reference in its entirety.

[0002] FIELD OF THE INVENTION The present disclosure relates generally to systems and methods used during thrombectomy procedures for capturing and removing occlusions or blood clots. Specifically, the present disclosure relates to a pulsating aspiration system for capturing and removing occlusions or blood clots within a vessel, where the pulsating aspiration pressure waveform includes a static vacuum pressure generated using a static vacuum source and a pressure pulse injected by a positive pressure source. [Background technology]

[0003] Blood clots are essentially living polymers, comprising a matrix of entangled and cross-linked fibrin strands within which reside red and white blood cells, platelets, and numerous other proteins and components. The mechanical properties of a clot are strongly influenced by the relative proportions of fibrin and red blood cells, with clots with a high (and highly organized) fibrin content and a low red blood cell content tending to be much stronger and more cohesive than clots with a high red blood cell content. Such clots have also been found to have a higher coefficient of friction, or in other words, to be "stickier." Removal of these strong and cohesive clots from blood vessels can be a significant challenge.

[0004] Clots with low fibrin content and high red blood cell content can be less cohesive and more fragile, and have been found to have a lower coefficient of friction than the more organized, fibrin-rich clots described above. These properties mean that such clots are easily pulled from the occlusion but tend to break apart during the retrieval process, with the consequent risk of losing clot fragments into distal or new vascular regions.

[0005] Attempting to aspirate such clots into a catheter can be very challenging because the clot must be deformed to fit the catheter lumen, and the energy required to deform such clots is not easily achieved by suction. The high coefficient of friction of these clot types makes it even more difficult to aspirate them into the distal opening of the catheter. Holding a suction grip or sheath over such a clot so that it can be pulled into a more proximal conductor safety device is very difficult because these tough clots do not tend to easily deform and reform, and therefore do not readily conform to the shape of the catheter tip to affect the seal and subsequently the suction grip.

[0006] Unlike static aspiration, which applies a constant vacuum pressure to the distal tip or end of the aspiration catheter, pulsating aspiration applies a static vacuum pressure and pressure waves having a pressure higher than the static vacuum pressure. During cycles under static vacuum pressure, the clot is drawn proximally and trapped at the distal tip of the aspiration catheter, while during cycles of pressure waves, the pressure at the distal tip increases.

[0007] One challenge associated with the use of pulsatile aspiration in capturing and removing clots is the damping effect on the waveform along the length of the catheter (due to the catheter's length and inner diameter). Ideally, the vacuum waveform would vary at high frequency from, for example, ambient pressure to full vacuum pressure, but this is not possible in conventional systems due to damping effects. One option is to generate the pressure waveform at the distal tip of the catheter, but this is difficult to do, especially while simultaneously maintaining the flexibility and other performance requirements needed from the catheter. Summary of the Invention [Problem to be solved by the invention]

[0008] It is therefore desirable to develop an improved pulsating suction system that has as few active components as possible, which reduces the aforementioned damping effects and allows maximizing the circulation frequency. [Means for solving the problem]

[0009] According to the disclosed technology, a pulsating aspiration system is provided, comprising a catheter and a pump system. The catheter includes an outer wall, a proximal portion, a distal portion, and an inner wall. The outer wall extends longitudinally from a proximal end to an opposite distal end and defines a passageway therethrough. The proximal portion has an associated proximal portion of the passageway. The distal portion is disposed distally relative to the proximal portion and has an associated distal portion of the passageway. The inner wall extends longitudinally through the passageway and divides the proximal portion of the passageway into (i) a central main lumen defined radially inward relative to the inner wall and (ii) an auxiliary lumen defined at least partially within the outer wall by the inner wall. The central main lumen, capable of receiving a first fluid therethrough, is configured to generate one of a negative fluid pressure or a positive fluid pressure therein. The auxiliary lumen, capable of receiving a second fluid therethrough, is configured to generate the other of a positive fluid pressure or a negative fluid pressure therein. The distal portions of the central main lumen and the auxiliary lumen are in fluid communication with each other, and negative and positive fluid pressures combine as a resultant pressure within the distal portion of the passageway. A pump system is in fluid communication with the catheter and independently controls the negative and positive fluid pressures within the central main and auxiliary lumens to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure. A maximum aspiration pressure can be generated at the distal end of the catheter when the resultant pressure is solely negative fluid pressure, and a maximum positive pressure can be generated at the distal end of the catheter when the positive fluid pressure balances the maximum positive pressure of the negative fluid pressure.

[0010] The disclosed technology also provides a method for operating a pulsatile aspiration system including a catheter. The catheter has an outer wall extending longitudinally from a proximal end to an opposite distal end. The outer wall defines a passageway therethrough. The catheter includes a proximal portion having an associated proximal portion of the passageway and a distal portion disposed distally of the proximal portion and having an associated distal portion of the passageway. The proximal portion of the passageway is divided by an inner wall extending longitudinally through the passageway. The proximal portion of the passageway is divided into (i) a central main lumen defined radially inward relative to the inner wall and (ii) an auxiliary lumen at least partially defined by the inner wall. The central main lumen, capable of receiving a first fluid therethrough, is configured to generate one of a negative fluid pressure or a positive fluid pressure therein. The auxiliary lumen, capable of receiving a second fluid therethrough, is configured to generate the other of a negative fluid pressure or a positive fluid pressure therein. The distal ends of the central main lumen and the auxiliary lumen are in fluid communication with each other, and the negative and positive fluid pressures combine as a resultant pressure within the distal portion of the passageway. The pulsating aspiration system further includes a pump system in fluid communication with the catheter. The method includes independently controlling the negative and positive fluid pressures within the central main and auxiliary lumens to generate a pulsating aspiration waveform that is variable between a maximum aspiration pressure and a maximum positive pressure at the distal end of the catheter. A maximum aspiration pressure can be generated at the distal end of the catheter when the resultant pressure is solely negative fluid pressure, while a maximum positive pressure can be generated at the distal end of the catheter when the positive fluid pressure balances the maximum positive pressure of the negative fluid pressure. [Brief explanation of the drawings]

[0011] The above and further aspects of the technology disclosed in the present invention will be further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in the various drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosed technology. The figures depict one or more implementations of the device of the present invention by way of example only, and not by way of limitation. [Figure 1A] 1A and 1B schematically depict a perspective view of an example of a distal tip of a catheter of a pulsatile aspiration system in accordance with the disclosed technology. [Figure 1B] 1B is a schematic depiction of a cross-sectional view of the distal tip of FIG. 1A taken along line I of FIG. 1A in accordance with the disclosed technology; [Figure 1C] 1B is a schematic depiction of another cross-sectional view of the distal tip of FIG. 1A taken along line II of FIG. 1A in accordance with the disclosed technology; [Figure 2A] 10A and 10B schematically depict a perspective view of another example of a distal tip of a catheter of a pulsatile aspiration system in accordance with the disclosed technology. [Figure 2B] 2B is a schematic depiction of a cross-sectional view of the distal tip of FIG. 2A taken along line III of FIG. 2A in accordance with the disclosed technology; [Figure 2C] 4A is a schematic depiction of another cross-sectional view of the distal tip of FIG. 2A taken along line IV of FIG. 2A in accordance with the disclosed technology; [Figure 3] 1B is a schematic depiction of an example of a pulsating aspiration system shown with a distal tip in FIG. 1A in accordance with the disclosed technology; [Figure 4] 10A and 10B are graphs illustrating exemplary pressure waveforms at the distal tip of a catheter in accordance with the disclosed technology; [Figure 5A] 1 depicts a pulsating suction method according to the disclosed technology. [Figure 5B] 1 depicts a pulsating suction method according to the disclosed technology. DETAILED DESCRIPTION OF THE INVENTION

[0012] As used herein, the term "about" or "approximately" in connection with any numerical value or numerical range indicates a suitable dimensional tolerance that enables a portion of a component or a collection of components to function for its intended purpose as described herein. More specifically, "about" or "approximately" may refer to a range of values ​​of ±20% of the recited value; for example, "about 90%" may refer to a range of values ​​of 71% to 99%.

[0013] The present disclosure is directed to an improved pulsatile aspiration system and method of use with reduced damping effects that allows for increased cyclic frequency of aspiration (vacuum pull) and maximum positive pressure. The system described herein provides a highly flexible catheter with high frequency variable pulsatile aspiration.

[0014] It should be noted that as used herein, "suction pressure" refers to a vacuum or negative pressure. Thus, "maximum suction pressure" is similarly synonymous with "maximum vacuum force."

[0015] The catheter contains two lumens that are connected to a programmable pump system. One lumen is used for vacuum aspiration, and the other for ambient or positive pressure fluid flow. By controlling the pressure within each lumen, greater amplitudes and frequencies of pulsatile waveforms at the distal tip can be achieved than by simply connecting the proximal end of the catheter to a pump.

[0016] In accordance with the disclosed technology, the two lumen configuration provides dual lumens in the proximal and intermediate sections of the catheter, with a single lumen at the distal tip of the catheter.

[0017] According to the disclosed technology, control sensors can be integrated with and used with the stentreaver, if desired. For example, a pressure sensor at the distal tip can be used to monitor pressure and provide a feedback loop to the pump / control system to ensure optimal pulsatile parameters are achieved. Furthermore, the pressure sensor also ensures that a net positive pressure is not achieved at the distal tip, as this could push the clot further distally within the vessel (rather than pulling the clot toward the distal tip).

[0018] In use, vacuum pressure is applied to the first of the two lumens. In addition to the novel techniques described herein, this lumen can be used in conjunction with standard aspiration techniques. To apply a pulsating vacuum to the distal tip, vacuum pressure can be varied within this lumen, and positive fluid pulses can be applied through the second of the two lumens. The positive pressure combines with the negative pressure from the first lumen to create a net maximum air pressure. In some instances, this is approximately ambient atmospheric pressure.

[0019] By using two lumens, rapid changes in pressure at the distal tip can be achieved by injecting a positive fluid pulse in the second lumen, because the negative pressure in the first lumen does not need to change significantly or at all. Thus, only a small amount of added / injected fluid needs to be injected into a single lumen at the distal tip of the catheter to achieve a full vacuum to a net maximum (e.g., ambient) pressure. The control system can calculate the volume of the injected positive fluid pulse based on the applied vacuum pressure level and the pressure measurement at the distal tip, ensuring that the distal tip pressure does not exceed the net maximum pressure.

[0020] Other features of the techniques of this disclosure include, but are not limited to:

[0021] A clot sensor can be provided at the funnel tip to identify the mechanical properties of the clot and determine the waveform parameters applied by the pump. These parameters can vary along the length of the clot when mechanical properties (e.g., fibrin content, red blood cell (RBC) content, or clot impedance) vary.

[0022] In certain catheter examples, inner and outer catheters can be provided that advance and / or retract independently of one another. For example, as discussed in more detail below, the outer catheter can be first advanced to the clot surface, and then the inner catheter can be advanced into position without affecting the ability to track the outer catheter. In this example, the diameter of the inner catheter can be optimized for use with a microcatheter and / or stentreaver.

[0023] Additionally, one of the lumens can be positioned so that there is a receiving space for the clot to be entrapped. The pressure sensor can identify when the clot is fully entrapped, for example, by detecting a change in the pressure waveform, which serves as an indicator to the physician that the catheter can be removed.

[0024] Based on the principles discussed above, a specific illustrative example of a pulsating aspiration system in accordance with the techniques of this disclosure will now be described.

[0025] Different exemplary configurations of pulsating suction systems are described in this disclosure, all of which include a suction catheter connected via a proximal hub. A static vacuum source, such as a vacuum pump, is in fluid communication with the proximal hub, either directly or via an inlet tube. In addition, the pulsating suction system further includes a positive pressure source that generates positive pressure pulses.

[0026] FIG. 1A depicts a perspective view of an example of a distal tip of a catheter of a pulsating aspiration system. FIG. 1B depicts a cross-sectional view of the distal tip of FIG. 1A taken along line I in FIG. 1A. FIG. 1C depicts a cross-sectional view of the distal tip of FIG. 1A taken along line II in FIG. 1A. FIG. 3 schematically depicts an example of a pulsating aspiration system shown with the distal tip of FIG. 1A.

[0027] 1A-1C and 3, there is shown the distal tip of a catheter 105 forming a portion of a pulsatile aspiration system 100 (FIG. 3). The catheter 105 has an outer wall extending longitudinally along a longitudinal axis 60 from a proximal end 110 to an opposite free distal end 115, with a passageway 105A defined therethrough. Referring to FIG. 1A in conjunction with FIG. 3, the proximal end 110 is connected to a hub 160, which will be described in more detail below. The catheter 105 further includes a proximal portion 120 associated with proximal portions 135, 140 of the passageway 105A and a distal portion 125 disposed distally thereto, the distal portion 125 being associated with a distal portion 143 of the passageway 105A and terminating at the distal end 115. In some examples, distal portion 125 can vary in length from approximately 0 centimeters (distal portion 125 is essentially an extension of proximal portion 120, extending almost to free distal end 115, but optimally extending at least a few millimeters therefrom) to 5 centimeters. In some examples, distal portion 125 can include radiopaque markers 150 for tracking the location of the distal tip within the patient's body.

[0028] As particularly seen in FIG. 1C , the proximal portion 135, 140 of the passageway 105A includes an inner wall 130 extending longitudinally proximally through the passageway 105A. The inner wall 130 divides the proximal portion 135, 140 of the passageway 105A into a central main lumen 135 and an auxiliary lumen 140, both of which are capable of receiving a fluid therethrough. The central main lumen 135 is at least partially defined by the inner wall 130 so as to be defined on one side of the inner wall 130 (e.g., radially inward relative to the inner wall 130 toward the longitudinal axis 60) and is sized to receive a stentreaver. The auxiliary lumen 140 is at least partially defined by the inner wall 130 so as to be disposed on another side of the inner wall 130 (e.g., radially outward relative to the longitudinal axis 60 from the inner wall 130). Inner wall 130 is designed so that, in cross section, the areas of central main lumen 135 and auxiliary lumen 140 have a predetermined ratio relative to one another to maximize space for clot entrapment. In some instances, the ratio of central main lumen area to auxiliary lumen area is at least 70:30, e.g., 90:10 or 95:5. In contrast, as seen particularly in FIG. 1B , distal portion 143 of passageway 105A is not divided. However, as noted above, it will be understood that in some instances, distal portion 125 / 143 (as shown) can be configured essentially the same as proximal portion 120 by extending inner wall 130 all the way to free distal end 115.

[0029] In this example, the auxiliary lumen 140 is positioned eccentrically from the central main lumen 135. Additionally, the inner wall 130 is permanently fixed in place within the proximal portion of the passageway 105A of the catheter 105, radially dividing the proximal portion of the passageway 105A of the catheter 105 into the central main lumen 135 and the auxiliary lumen 140 on either side of the inner wall 130.

[0030] In some instances, in the proximal portion 120, the central main lumen 135 generates a negative fluid pressure therein by a fluid (e.g., blood) and a pump system, which will be described in more detail below. In these instances, the auxiliary lumen 140 generates a positive fluid pressure therein by a biocompatible fluid and a pump system, which will be described in more detail below.

[0031] In other examples, it will be appreciated that the positive and negative pressures can be reversed such that negative fluid pressure is generated in the auxiliary lumen 140 and positive fluid pressure is generated in the main lumen 135 in accordance with the techniques of the present disclosure.

[0032] As indicated by the dashed line in FIG. 1A, the distal ends of the central main lumen 135 and the auxiliary lumen 140 are in fluid communication with each other, and the negative and positive fluid pressures combine as a resultant pressure within a single lumen at the distal portion 143 of the passageway 105A (see waveform in FIG. 4).

[0033] As mentioned above, and with reference to FIG. 3 , a pulsatile pump system is in fluid communication with catheter 105 and independently controls negative (suction) fluid pressure in central main lumen 135 and positive fluid pressure in auxiliary lumen 140. Those skilled in the art will appreciate that at least intermittent, continuous pressure in one lumen need not necessarily be provided to counteract pressure in the other lumen (discussed in more detail below). The pump system includes a programmable controller 183, tubing 175, a fluid collection chamber / canister 180, and a proximal hub 160. Controller 183 includes a positive pressure source (e.g., a positive pressure pump or a pressurized fluid reservoir with an on-off valve) with a pressure exchange PX port and a vacuum pump with a vacuum VAC port. In some examples, proximal hub 160 is a dual-side port proximal hub with a negative fluid pressure port 165 and a positive fluid pressure port 170. Negative fluid pressure port 165 is in fluid communication with central main lumen 135 and positive fluid pressure port 170 is in fluid communication with auxiliary lumen 140 .

[0034] 3 illustrates a schematic representation of a vacuum pump coupled to a circuit with a positive pressure source. This circuit is then connected to the proximal end of catheter 105 via negative fluid pressure port 165 and positive fluid pressure port 170. A fluid collection container 180 in the aspiration circuit collects any contents aspirated from the patient's body. In some examples, the vacuum source of the controller is operable to evacuate fluid collection container 180.

[0035] The suction circuit tubing 175 and the positive pressure circuit tubing 175 are joined to the proximal end of the catheter 105 via respective ports 165, 170 of the proximal hub 160. In the suction circuit, the tubing 175 is discontinuous to provide a fluid collection container 180, while in the positive pressure circuit, the tubing 175 may be continuous from the positive pressure port 170 to the PX port on the controller.

[0036] As illustrated by the waveform in FIG. 4, the controller 183 independently controls the positive pressure source and the vacuum pump to generate a resulting pressure at the distal end 115 of the catheter 105 with a pulsating suction waveform that fluctuates between a maximum suction pressure (see the valleys of the waveform in FIG. 4) and a maximum positive pressure (see the peaks of the waveform in FIG. 4).

[0037] Note that "0" on the y-axis may be atmospheric pressure, or the patient's systolic or diastolic blood pressure. It will be understood that the peak maximum pressure may be set above or below this line. Furthermore, it may be set below a particular pressure determined to be safe or unsafe (e.g., about 50 Kpa above the patient's blood pressure).

[0038] The maximum suction pressure can be generated at the distal end 115 of the catheter 105 when the resulting pressure is exclusively negative fluid pressure through the central main lumen 135. In this scenario, the positive pressure source does not inject fluid to cause an increase in pressure. Similarly, the maximum positive pressure can be generated at the distal end 115 of the catheter 105 when the controller 183 controls the positive pressure source to inject a biocompatible fluid (e.g., saline) through the auxiliary lumen 140. In some examples, the biocompatible fluid is injected into the auxiliary lumen 140 in a direction generally parallel to the longitudinal axis 60. In other examples, the biocompatible fluid can be injected at an angle (e.g., between 0 and 90 degrees) relative to the longitudinal axis. The maximum positive pressure (of the resulting pressure) can be generated by positive fluid pressure from the positive pressure source at least partially offsetting the negative fluid pressure from the vacuum pump.

[0039] As alluded to above, in another example, a positive pressure source with a pressure exchange PX port and a vacuum pump with a vacuum VAC port can be reversed with the central main lumen 135 and the auxiliary lumen 140, resulting in a negative fluid pressure being generated in the auxiliary lumen 140 and a positive fluid pressure being generated in the central main lumen 135.

[0040] In some examples, the maximum positive pressure is less than ambient atmospheric pressure. In other examples, the maximum positive pressure is about ambient atmospheric pressure. In further examples, the maximum positive pressure can exceed ambient atmospheric pressure without departing from the spirit and scope of the present disclosure. By way of example, the maximum positive pressure can be above atmospheric pressure but below the patient's diastolic blood pressure, or can be between the patient's diastolic and systolic blood pressures, or can exceed the patient's systolic blood pressure.

[0041] A pressure sensor 145 is disposed on the inner surface of the outer wall of the distal portion 125 of the catheter 105 to monitor the resultant pressure at the distal tip of the catheter 105. The pressure sensor 145 monitors the resultant pressure within the distal portion 143 of the passageway 105A of the catheter 105. By monitoring the pressure and providing a feedback loop with the controller 183, at least one waveform parameter (in terms of positive and / or negative pressure) of the maximum pulsatile aspiration waveform (see FIG. 4 ) generated at the distal end 115 of the catheter 105 can be maximized. This is done by controlling the controller 183 based on the resultant pressure monitored by the pressure sensor 145, and the controller 183 is operable to adjust the rate, volume, and / or frequency of the positive pressure injection of fluid through the auxiliary lumen 140.

[0042] Additionally, when the resultant pressure within the distal portion of the catheter passageway, as monitored by pressure sensor 145, exceeds a predetermined threshold, system 100 is operable to perform several functions. For example, an indicator can be activated to alert the physician of the pressure reading, and / or controller 183 can be controlled to adjust the positive pressure fluid (by varying the volume of biocompatible fluid infused) through auxiliary lumen 140 such that the monitored resultant pressure returns below the predetermined threshold. By way of example, the predetermined threshold may be ambient atmospheric pressure, the patient's diastolic blood pressure, the patient's systolic blood pressure, etc.

[0043] By implementing the pulsatile aspiration system 100 in this manner, cycling between maximum aspiration pressure and maximum positive pressure within the distal portion 125 of the catheter 105 can be performed at a very high frequency, with only small amounts of biocompatible fluid injection required. The dual lumen 135, 140 structure keeps the negative and positive pressure pulses separate, minimizing the damping effect on the pulsatile aspiration waveform (FIG. 4) because the negative pressure within the central main lumen 135 does not need to change significantly, thereby enabling the aforementioned rapid pressure changes within the distal portion 125.

[0044] Further to the above, in accordance with the techniques of the present disclosure, the above-described pulsating suction system 100 enables the following method 500 to be performed, as shown in FIG. 5A.

[0045] Negative fluid pressure is independently controlled in one of the central main lumen 135, the auxiliary lumen 140, and the positive fluid pressure in the auxiliary lumen 140 to generate a maximum pulsating aspiration waveform that is variable between maximum aspiration pressure and maximum positive pressure at the distal end 115 of the catheter 105 (step 502). Maximum aspiration pressure can be generated at the distal end 115 of the catheter 105 when the resulting pressure is negative fluid pressure alone, while maximum fluid pressure can be generated at the distal end 115 of the catheter 105 when the positive fluid pressure (via the auxiliary lumen 140 or the central main lumen 135, as discussed above) balances with that of the negative fluid pressure (via the other of the central main lumen 135 and the auxiliary lumen 135, as discussed above).

[0046] The method 500 further includes step 504 of maximizing at least one waveform parameter of the pulsating pressure waveform generated at the distal end 115 of the catheter 105 by controlling the pump system based on the resulting pressure monitored by the pressure sensor 145.

[0047] If the resulting pressure monitored by pressure sensor 145 exceeds a predetermined threshold (e.g., ambient pressure, diastolic or systolic pressure, etc., as discussed above), method 500 further includes step 506 of setting an adjusted level of positive fluid pressure (in auxiliary lumen 140 or, alternatively, central main lumen 135) via the pump system such that the resulting pressure monitored by pressure sensor 145 is reduced to below the predetermined threshold.

[0048] Similarly, when the resulting pressure in the distal portion 125 of the passageway 105A of the catheter 105 monitored by the pressure sensor 145 exceeds a predetermined threshold, the method 500 further includes step 508 of activating an indicator, and / or (ii) adjusting at least one waveform parameter of the positive pressure fluid by the pump system (via the auxiliary lumen 140 of the central main lumen 135, as discussed above) so that the monitored resulting pressure is reduced to below the predetermined threshold.

[0049] The method 500 further includes the step 510 of introducing a stentriever through the central main lumen 135 of the catheter 105 .

[0050] Figure 2A depicts a perspective view of another embodiment of a distal tip of a catheter for a pulsating aspiration system. Figure 2B depicts a cross-sectional view of the distal tip of Figure 2A taken along line III in Figure 2A. Figure 2C depicts a cross-sectional view of the distal tip of Figure 2A taken along line IV in Figure 2A. Figure 3 illustrates the distal tip of Figure 1A, but represents the following description of a pulsating aspiration system 200.

[0051] 2A-2C and 3, there is shown the distal tip of catheter 205, which forms part of pulsatile aspiration system 200 (FIG. 3). Catheter 205 has an outer wall extending longitudinally along longitudinal axis 60 from proximal end 210 to opposite free distal end 215, with passageway 205A defined therethrough. Referring to FIG. 2A in conjunction with FIG. 3, as in the previous example, proximal end 210 is connected to hub 160, which will be described in more detail below. Catheter 205 further includes proximal portion 220 associated with proximal portions 235, 240 of passageway 205A and distally disposed distal portion 225, which is associated with distal portion 243 of passageway 205A and terminates at distal end 215. In some examples, distal portion 225 can vary in length between approximately 0 centimeters (distal portion 225 is essentially an extension of proximal portion 220, which extends almost to free distal end 215, but optimally extends at least a few millimeters therefrom) and 5 centimeters. In some examples, similar to the distal portions described above, distal portion 225 can include a radiopaque marker (not shown) for tracking the location of the distal tip within the patient's body.

[0052] As seen particularly in FIG. 2C , the proximal portion 235, 240 of the passageway 105A includes an inner wall 230 extending longitudinally through the passageway 205A. The inner wall 230 divides the proximal portion 235, 240 of the passageway 205A into a central main lumen 235 and an auxiliary lumen 240, both of which can receive fluid. The central main lumen 235 is at least partially defined by the inner wall 230 so as to be defined on one side of the inner wall 230 (e.g., radially inward relative to the inner wall 230 toward the longitudinal axis 60) and is sized to receive a stentriever. The auxiliary lumen 240 is at least partially defined by the inner wall so as to be disposed on another side of the inner wall 230 (e.g., radially outward from the longitudinal axis 60 relative to the inner wall 230). Inner wall 230 is designed so that, in cross section, central main lumen 235 and auxiliary lumen 240 have a predetermined ratio of area relative to one another to maximize clot entrapment. Depending on the lumens used for negative and positive fluid pressure, respectively (and discussed in more detail below), the ratio of negative fluid pressure lumen to positive pressure lumen area can be at least 70:30, e.g., 90:10 or 95:5. In contrast, and as seen particularly in FIG. 2B , distal portion 243 of passageway 205A is not divided. However, as alluded to above, it will be understood that in some instances, distal portion 225 / 243 (shown in each figure) can be configured essentially the same as proximal portion 220 by extending inner wall 230 all the way to free distal end 215.

[0053] In this example, the central main lumen 235 and the auxiliary lumen 240 are concentrically disposed about the longitudinal axis 60. More specifically, in this example, the inner wall 230 is an inner catheter 230 that is concentrically disposed within the proximal portion 220 of the passageway 205A of the catheter 205 and is longitudinally slidable independently of the catheter 205 (i.e., independently of the auxiliary lumen 240). However, it will be understood that in other examples, the central main lumen 235 may be eccentrically / offset relative to the longitudinal axis 60. The inner catheter 230 has a longitudinal channel defined therein that serves as the central main lumen 235 of the proximal portion 220 of the passageway 205A of the catheter 205, while the region radially defined between the inner catheter 230 and the proximal portion 220 of the catheter 205 serves as the auxiliary lumen 240.

[0054] In some instances, in the proximal portion 220, the central main lumen 235 generates a negative fluid pressure therein via a fluid (e.g., blood) and a pump system, described in more detail below. In these instances, the auxiliary lumen 240 generates a positive fluid pressure therein via a biocompatible fluid and a pump system, described in more detail below.

[0055] It will be appreciated that in other examples, the positive and negative pressures can be reversed in accordance with the techniques of the present disclosure, such that a negative fluid pressure is generated in the auxiliary lumen 240 and a positive fluid pressure is generated in the main lumen 235. In the example shown in FIG. 2A, this can be particularly advantageous because the suction can be applied along the inner circumference of the catheter 205, thereby maximizing the clot entrapment volume.

[0056] As indicated by the dashed line in FIG. 2A, the distal ends of central main lumen 235 and auxiliary lumen 240 are in fluid communication with each other, and the negative and positive fluid pressures combine as a resultant pressure within a single lumen at distal portion 243 of passage 205A (see waveform in FIG. 4).

[0057] As mentioned above and with reference to FIG. 3 , the pulsatile pump system is in fluid communication with the catheter 205 and independently controls negative (suction) fluid pressure in the central main lumen 235 and positive fluid pressure in the auxiliary lumen 240. Those skilled in the art will appreciate that at least intermittent, continuous pressure in one lumen need not necessarily be provided to counteract the pressure in the other lumen (discussed in more detail below). The pump system includes a programmable controller 183, tubing 175, a fluid collection chamber 180, and a proximal hub 160. The controller 183 includes a positive pressure source (e.g., a positive pressure pump or a pressurized fluid reservoir with an on-off valve) having a pressure exchange PX port and a vacuum pump having a vacuum VAC port. In some examples, the proximal hub 160 is a dual-side port proximal hub having a negative fluid pressure port 165 and a positive fluid pressure port 170. The negative fluid pressure port 165 is in fluid communication with the central main lumen 235 and the positive fluid pressure port 170 is in fluid communication with the auxiliary lumen 240 .

[0058] As discussed above, Figure 3 illustrates a schematic diagram of a vacuum pump coupled in circuit with a positive pressure source. This circuit is connected to the proximal end of catheter 205 via negative fluid pressure port 165 and positive fluid pressure port 170. A fluid collection container 180 in the aspiration circuit collects any contents aspirated from the patient's body.

[0059] Tubing 175 in the aspiration circuit as well as tubing 175 in the positive pressure circuit are joined to the proximal end of catheter 205 via respective ports 165, 170 of proximal hub 160. In the aspiration circuit, tubing 175 is discontinuous to provide for fluid collection container 180, while in the positive pressure circuit, tubing 175 may be continuous from positive pressure port 170 to a PX port on the controller.

[0060] As illustrated by the waveform in FIG. 4, the controller 183 independently controls the positive pressure source and the vacuum pump to generate a resulting pressure at the distal end 215 of the catheter 205 with a pulsating suction waveform that fluctuates between a maximum suction pressure (see the valleys of the waveform in FIG. 4) and a maximum positive pressure (see the peaks of the waveform in FIG. 4).

[0061] The maximum suction pressure can be generated at the distal end 215 of the catheter 205 when the resulting pressure is exclusively negative fluid pressure through the central main lumen 235. In this scenario, the positive pressure source does not inject fluid to cause an increase in pressure. Similarly, the maximum positive pressure can be generated at the distal end 215 of the catheter 205 when the controller 183 controls the positive pressure source to inject a biocompatible fluid (e.g., saline) through the auxiliary lumen 240. In some examples, the biocompatible fluid is injected into the auxiliary lumen 140 in a direction generally parallel to the longitudinal axis 60. In other examples, the biocompatible fluid can be injected at an angle (e.g., between 0 and 90 degrees) relative to the longitudinal axis. The maximum positive pressure (of the resulting pressure) can be generated by positive fluid pressure from the positive pressure source at least partially offsetting the negative fluid pressure from the vacuum pump.

[0062] As mentioned above, in another example, a positive pressure source with a pressure exchange PX port and a vacuum pump with a vacuum VAC port can be reversed with the central main lumen 235 and the auxiliary lumen 240, resulting in a negative fluid pressure being generated in the auxiliary lumen 240 and a positive fluid pressure being generated in the central main lumen 235.

[0063] In some examples, the maximum positive pressure is less than ambient atmospheric pressure. In other examples, the maximum positive pressure is about ambient atmospheric pressure. In further examples, the maximum positive pressure can exceed ambient atmospheric pressure without departing from the spirit and scope of the present disclosure. By way of example, the maximum positive pressure can be above atmospheric pressure but below the patient's diastolic blood pressure, or can be between the patient's diastolic and systolic blood pressures, or can exceed the patient's systolic blood pressure.

[0064] A pressure sensor 245 is disposed on the inner surface of the outer wall of the distal portion 225 of the catheter 205 to monitor the resultant pressure at the distal tip of the catheter 205. The pressure sensor 245 monitors the resultant pressure within the distal portion 243 of the passageway 205A of the catheter 205. By monitoring the pressure and providing a feedback loop with the controller 183, at least one waveform parameter (in terms of positive and / or negative pressure) of the maximum pulsatile aspiration waveform (see FIG. 4 ) generated at the distal end 215 of the catheter 205 can be maximized. This is done by controlling the controller 183 based on the resultant pressure monitored by the pressure sensor 245, and the controller 183 is operable to adjust the rate, volume, and / or frequency of the positive pressure injection of fluid through the auxiliary lumen 240.

[0065] Additionally, when the resultant pressure within the distal portion of the catheter passageway, as monitored by pressure sensor 245, exceeds a predetermined threshold, system 200 is operable to perform several functions. For example, an indicator can be activated to alert the physician of the pressure reading, and / or controller 183 can be controlled to adjust the positive pressure fluid (by varying the volume of biocompatible fluid infused) through auxiliary lumen 240 such that the monitored resultant pressure returns below the predetermined threshold. By way of example, the predetermined threshold may be ambient atmospheric pressure, the patient's diastolic blood pressure, the patient's systolic blood pressure, etc.

[0066] 2A can further include a funnel-shaped portion 290 within the distal portion 225 of the catheter 205, the funnel-shaped portion 290 having a free distal end / port 291 and an opposite proximal end 292 attached to the distal portion of the catheter 205. As shown, the free distal end 291 of the funnel-shaped portion 290 has a larger diameter D1 compared to the diameter D2 of the proximal end 292 of the funnel-shaped portion 290 to accommodate a clot. A second sensor 295 is disposed on the inner surface of the funnel-shaped portion 290. The second sensor 295 detects a clot parameter (e.g., dependent on fibrin content, RBC content, or impedance) of a clot that can be captured within the funnel-shaped portion 290. By way of example, the second sensor 295 can be an impedance-based sensor or an optical sensor using visible or near-infrared light. In another example, second sensor 295 may be a second pressure sensor that provides supplemental feedback to controller 183 and may be used (similar to pressure sensor 245) to adjust at least one waveform parameter for controlling the pump system. As one skilled in the art will appreciate, funnel portion 290 and second sensor 295, while described with respect to the example of Figures 2A-2C, may of course be employed in the initially described example of Figures 1A-1C without departing from the spirit and scope of the present disclosure.

[0067] By implementing the pulsatile aspiration system 200 in this manner, cycling between maximum aspiration pressure and maximum positive pressure within the distal portion 225 of the catheter 105 can be performed at a very high frequency, with only small amounts of biocompatible fluid injection required. Because the dual lumen 235, 240 structure keeps the negative and positive pressure pulses separate, the negative pressure within the central main lumen 235 does not need to change significantly, thereby enabling the aforementioned rapid pressure changes within the distal portion 225, thereby minimizing the damping effect on the pulsatile aspiration waveform (FIG. 4).

[0068] Further to the above, in accordance with the techniques of the present disclosure, the above-described pulsating suction system 200 enables the following method 500 to be performed, as shown in FIGS. 5A and 5B.

[0069] Negative air pressure is independently controlled in one of the central main lumen 235, the auxiliary lumen 240, and the positive fluid pressure in the auxiliary lumen 240 to generate a maximum pulsating aspiration waveform that is variable between a maximum aspiration pressure and a maximum positive pressure at the distal end 215 of the catheter 205 (step 502). Maximum aspiration pressure can be generated at the distal end 215 of the catheter 205 when the resulting pressure is negative fluid pressure only, while maximum fluid pressure can be generated at the distal end 215 of the catheter 205 when positive fluid pressure (via the auxiliary lumen 240 or the central main lumen 235, as discussed above) balances with that of negative fluid pressure (via the other of the central main lumen 235 and the auxiliary lumen 135, as discussed above).

[0070] The method 500 further includes step 504 of maximizing at least one waveform parameter of the pulsating pressure waveform generated at the distal end 215 of the catheter 205 by controlling the pump system based on the resulting pressure monitored by the pressure sensor 245.

[0071] If the resulting pressure monitored by pressure sensor 245 exceeds a predetermined threshold (e.g., ambient pressure, diastolic or systolic pressure as discussed above, etc.), method 500 further includes step 506 of setting an adjusted level of positive fluid pressure (in auxiliary lumen 240 or, alternatively, central main lumen 235) via the pump system such that the resulting pressure monitored by pressure sensor 245 is reduced to below the predetermined threshold.

[0072] Similarly, when the resulting pressure in the distal portion 225 of the passageway 205A of the catheter 205 monitored by the pressure sensor 245 exceeds a predetermined threshold, the method 500 further includes step 508 of activating an indicator, and / or (ii) adjusting at least one waveform parameter of the positive pressure fluid by the pump system (via the auxiliary lumen 240 of the central main lumen 235, as discussed above) so that the monitored resulting pressure is reduced to below the predetermined threshold.

[0073] The method 500 further includes the step 510 of introducing a stentriever through the central main lumen 235 of the catheter 205 .

[0074] Referring to FIG. 5B, the method 500 further includes a step 512 of capturing the target clot within a funnel-shaped portion 290 disposed on the distal end 215 of the catheter 205, the distal end 291 of the funnel-shaped portion 290 having a larger diameter D1 compared to a diameter D2 of the proximal end 292 of the funnel-shaped portion 290.

[0075] The method 500 further includes detecting 514 a parameter of the target clot via a second sensor 295 disposed on the interior surface of the funnel-shaped portion 290. By way of non-limiting example, the parameter may be a mechanical property of the clot, such as fibrin content, RBC content, clot impedance, and / or a combination thereof.

[0076] The method 500 further includes adjusting 516 at least one waveform parameter for controlling the pump system based on the detected parameter of the captured target clot.

[0077] The method 500 further includes step 518 of repeatedly determining detected parameters of the captured target clot at different positions along its longitudinal length by the second sensor 295 as the captured target clot is drawn proximally into the passage 205A of the catheter 205.

[0078] In some examples, the second sensor 295 can repeatedly determine other parameters (not necessarily the measured clot properties) to determine when and how much clot is entrapped. This information can be used, for example, to switch from periodic suction to continuous suction and vice versa.

[0079] The method 500 further includes a step 520 of adjusting at least one waveform parameter for controlling positive fluid pressure by the pump system for each determined parameter at different locations along the longitudinal length of the captured target clot.

[0080] The techniques of the present disclosure described herein can be further understood in accordance with the following clauses.

[0081] Clause 1. A catheter comprising: an outer wall extending longitudinally from a proximal end to an opposite distal end and defining a passageway therethrough; a proximal portion having an associated proximal portion of the passageway; a distal portion disposed distal to the proximal portion and having an associated distal portion of the passageway; and an inner wall, the inner wall extending longitudinally through the passageway and dividing the proximal portion of the passageway into (i) a central main lumen defined radially inwardly relative to the inner wall, and (ii) an auxiliary lumen defined at least in part by the inner wall and interior to the outer wall, the central main lumen capable of receiving a first fluid therethrough and configured to generate one of a negative fluid pressure or a positive fluid pressure, and the auxiliary lumen capable of receiving a second fluid therethrough and generating the other of a positive fluid pressure or a negative fluid pressure. a catheter configured to apply a negative fluid pressure to a distal portion of the central main lumen and a distal portion of the auxiliary lumen in fluid communication with each other, wherein the negative fluid pressure and the positive fluid pressure combine as a resultant pressure in the distal portion of the passage; and a pump system in fluid communication with the catheter that independently controls the negative fluid pressure and the positive fluid pressure in the central main lumen and the auxiliary lumen to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure, wherein the maximum aspiration pressure can be generated at the distal end of the catheter when the resultant pressure is solely negative fluid pressure, and the maximum positive pressure can be generated at the distal end of the catheter when the positive fluid pressure balances the pressure of the negative fluid pressure.

[0082] Clause 2. The pulsating suction system of clause 1, wherein the auxiliary lumen is positioned eccentrically from the central main lumen.

[0083] Clause 3. A pulsating suction system as described in clause 2, wherein the inner wall is permanently fixed in place within the proximal portion of the catheter passageway and radially divides the proximal portion of the catheter passageway into a central main lumen and an auxiliary lumen on either side of the inner wall.

[0084] Clause 4. The pulsating suction system of clause 1, wherein the central main lumen and the auxiliary lumen are concentrically arranged.

[0085] Clause 5. A pulsating suction system as described in clause 1, wherein the inner wall is an inner catheter disposed within a proximal portion of the catheter passage and is longitudinally slidable independently of the catheter, the inner catheter having a longitudinal channel defined therein, the channel serving as a central main lumen of the proximal portion of the catheter passage, while a radially defined region between the inner catheter and the outer wall of the proximal portion of the catheter serves as an auxiliary lumen.

[0086] Clause 6. A pulsating suction system as described in any one of clauses 1 to 5, further comprising a pressure sensor disposed on the inner surface of the outer wall of the distal portion of the catheter, the pressure sensor monitoring the resulting pressure within the distal portion of the catheter passage, and at least one parameter of the pulsating suction waveform generated at the distal end of the catheter being adjusted by controlling the pump system based on the resulting pressure monitored by the pressure sensor.

[0087] Clause 7. A pulsating suction system as described in Clause 6, wherein when the resulting pressure in the distal portion of the catheter passage monitored by the pressure sensor exceeds a predetermined threshold, (i) an indicator can be activated, and / or (ii) the pump system is controllable to adjust positive pressure fluid through the central main lumen or the auxiliary lumen so that the monitored resulting pressure is reduced to below the predetermined threshold.

[0088] Clause 8. A device described in any one of clauses 1 to 7, comprising a funnel-shaped portion having a free distal end and an opposite proximal end attached to the distal end of the catheter, the free distal end of the funnel-shaped portion having a larger diameter compared to the proximal end of the funnel-shaped portion, and a second sensor disposed on an inner surface of the funnel-shaped portion for detecting a parameter of the clot associated with the fibrin content of the clot that can be captured within the funnel-shaped portion.

[0089] Clause 9. The pulsatile aspiration system of any one of clauses 1 to 8, wherein the stentriever is receivable within the central main lumen of the catheter.

[0090] Clause 10. A pulsating suction system according to any one of clauses 1 to 9, wherein the distal portion of the passage is unsegmented.

[0091] Clause 11. A method for operating a pulsatile aspiration system including a catheter having an outer wall extending longitudinally from a proximal end to an opposite distal end and defining a passageway therethrough, the catheter including a proximal portion having an associated proximal portion of the passageway, and a distal portion disposed distally of the proximal portion and having an associated distal portion of the passageway, the proximal portion of the passageway being divided by an inner wall extending longitudinally through the passageway into a central main lumen defined radially inwardly relative to the inner wall and an auxiliary lumen at least partially defined by the inner wall, the central main lumen capable of receiving a first fluid therethrough being configured to generate one of a negative fluid pressure or a positive fluid pressure therein, while the auxiliary lumen capable of receiving a second fluid therethrough being configured to generate one of a negative fluid pressure or a positive fluid pressure therein. the catheter is configured to generate one of the two pressures internally, the other of which is a negative fluid pressure, the distal end of the central main lumen and the distal end of the auxiliary lumen being in fluid communication with each other, the negative fluid pressure and the positive fluid pressure combining as a resultant pressure within the distal portion of the passageway, the pulsating aspiration system further comprising a pump system in fluid communication with the catheter, the method including the step of independently controlling the negative fluid pressure and the positive fluid pressure within the central main lumen and the auxiliary lumen to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure, the maximum aspiration pressure being generateable at the distal end of the catheter when the resultant pressure is solely negative fluid pressure, while the maximum positive pressure being generateable at the distal end of the catheter when the positive fluid pressure balances the pressure of the negative fluid pressure.

[0092] Clause 12. The method of clause 11, further comprising maximizing at least one waveform parameter of the pulsating pressure waveform generated at the distal end of the catheter by controlling the pump system based on the resulting pressure monitored by the pressure sensor.

[0093] Clause 13. The method of clause 12, further comprising the step of setting an adjusted level of positive fluid pressure via the pump system such that, if the resultant pressure monitored by the pressure sensor exceeds a predetermined threshold, the resultant pressure monitored by the pressure sensor is reduced to below the predetermined threshold.

[0094] Clause 14. A method according to any one of clauses 11 to 13, comprising the steps of capturing a target clot within a funnel-shaped portion disposed on the distal end of the catheter, the distal end of the funnel-shaped portion having a larger diameter compared to the proximal end of the funnel-shaped portion, detecting a parameter of the target clot via a second sensor disposed on an inner surface of the funnel-shaped portion, and adjusting at least one waveform parameter for controlling the pump system based on the detected parameter.

[0095] Clause 15. The method of any one of clauses 11-14, further comprising positioning the auxiliary lumen eccentrically from the central main lumen.

[0096] Clause 16. The method of clause 15, further comprising permanently fixing an inner wall in place within a proximal portion of the catheter passageway, radially dividing the proximal portion of the catheter passageway into a central main lumen and an auxiliary lumen on either side of the inner wall.

[0097] Clause 17. The method of any one of clauses 11-14, further comprising concentrically arranging the central main lumen and the auxiliary lumen.

[0098] Clause 18. The method of clause 17, further comprising: disposing the inner wall as an inner catheter within a proximal portion of the catheter passageway and longitudinally slidable independently of the catheter; and forming an internally defined longitudinal channel within the inner catheter, wherein the channel serves as a central main lumen of the proximal portion of the catheter passageway, while a radially defined region between the inner catheter and the proximal portion of the catheter serves as an auxiliary lumen.

[0099] Clause 19. The method of any one of clauses 11 to 18, further comprising the step of (i) activating an indicator when the resulting pressure in the distal portion of the catheter passage monitored by the pressure sensor exceeds a predetermined threshold, and / or (ii) adjusting at least one waveform parameter of the positive pressure fluid via the pump system so that the monitored resulting pressure falls below the predetermined threshold.

[0100] Clause 20. The method of any one of clauses 11 to 19, further comprising the step of introducing a stentriever through the central main lumen of the catheter.

[0101] Clause 21. The method of clause 14, wherein as the captured target clot is drawn proximally into the catheter passage, a second sensor repeatedly determines detected parameters of the captured target clot at different positions along its longitudinal length, and for each parameter determined at different positions along the longitudinal length of the captured target clot, the method further includes adjusting at least one waveform parameter for controlling the positive fluid pressure.

[0102] The documents incorporated by reference into this patent application are to be considered integral parts of this application, and except to the extent that any term is defined in these incorporated documents in a manner that is inconsistent with a definition expressly or impliedly given herein, only the definitions in this specification shall be considered.

[0103] The descriptions contained herein are examples of the disclosed technology and are not intended to limit the scope of the disclosed technology in any way. As described herein, the disclosed technology contemplates many variations and modifications of pulse generation mechanisms for producing pulsating aspiration pressure waveforms using a static vacuum source. Modifications and variations that are obvious to those skilled in the art in light of the teachings of the present disclosure are intended to be within the scope of the following claims.

[0104] [Embodiment] (1) A pulsating suction system, A catheter, an outer wall extending longitudinally from a proximal end to an opposite distal end and defining a passageway therethrough; a proximal portion having an associated proximal portion of the passageway; a distal portion disposed distally of the proximal portion and having an associated distal portion of the passageway; an inner wall extending longitudinally through the passage and dividing the proximal portion of the passage into (i) a central main lumen defined radially inward relative to the inner wall, and (ii) an auxiliary lumen at least partially defined by the inner wall and interior to the outer wall; the central main lumen capable of receiving a first fluid therethrough is configured to generate one of a negative fluid pressure or a positive fluid pressure therein; the auxiliary lumen capable of receiving a second fluid therethrough is configured to generate the other of the positive fluid pressure or the negative fluid pressure therein; a catheter, wherein a distal portion of the central main lumen and a distal portion of the auxiliary lumen are in fluid communication with each other, and the negative fluid pressure and the positive fluid pressure combine as a resultant pressure within the distal portion of the passage; a pump system in fluid communication with the catheter, the pump system independently controlling the negative and positive fluid pressures in the central main and auxiliary lumens to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure; the maximum suction pressure is producible at the distal end of the catheter when the resulting pressure is only negative fluid pressure; and A pulsatile aspiration system, wherein the maximum positive pressure is producible at the distal end of the catheter when the positive fluid pressure balances the pressure of the negative fluid pressure. (2) The pulsating suction system of embodiment 1, wherein the auxiliary lumen is positioned eccentrically from the central main lumen. (3) The pulsating suction system of claim 2, wherein the inner wall is permanently fixed in place within the proximal portion of the catheter passageway and radially divides the proximal portion of the catheter passageway into the central main lumen and the auxiliary lumen on either side of the inner wall. (4) A pulsating suction system as described in embodiment 1, wherein the central main lumen and the auxiliary lumen are arranged concentrically. (5) The pulsating suction system of embodiment 1, wherein the inner wall is an inner catheter disposed within the proximal portion of the catheter passage and is slidable in the longitudinal direction independently of the catheter, the inner catheter having the longitudinal channel defined therein, the channel functioning as the central main lumen of the proximal portion of the catheter passage, while a radially defined region between the inner catheter and the outer wall of the proximal portion of the catheter functions as the auxiliary lumen.

[0105] (6) further comprising a pressure sensor disposed on an interior surface of the outer wall of the distal portion of the catheter, the pressure sensor monitoring the resulting pressure within the distal portion of the passageway of the catheter; 2. The pulsating suction system of claim 1, wherein at least one parameter of the pulsating suction waveform generated at the distal end of the catheter is adjusted by controlling the pump system based on the resulting pressure monitored by the pressure sensor. (7) A pulsating suction system as described in embodiment 6, wherein when the resulting pressure in the distal portion of the passage of the catheter monitored by the pressure sensor exceeds a predetermined threshold, (i) an indicator can be activated, and / or (ii) the pump system can be controlled to adjust positive pressure fluid through the central main lumen or the auxiliary lumen so that the monitored resulting pressure is reduced below the predetermined threshold. (8) a funnel-shaped portion having a free distal end and an opposite proximal end attached to the distal end of the catheter, the free distal end of the funnel-shaped portion having a larger diameter compared to the proximal end of the funnel-shaped portion; 2. The pulsating suction system of claim 1, further comprising: a second sensor disposed on an inner surface of the funnel-shaped portion and configured to detect a parameter of the clot associated with the fibrin content of the clot that can be captured within the funnel-shaped portion. (9) The pulsating aspiration system of embodiment 1, wherein a stentriever is receivable within the central main lumen of the catheter. (10) The pulsating suction system of embodiment 1, wherein the distal portion of the passage is undivided.

[0106] (11) A method for operating a pulsatile aspiration system including a catheter having an outer wall extending longitudinally from a proximal end to an opposite distal end and defining a passageway therethrough, the catheter including a proximal portion having an associated proximal portion of the passageway, and a distal portion disposed distally of the proximal portion and having an associated distal portion of the passageway, the proximal portion of the passageway being divided by an inner wall extending longitudinally through the passageway into a central main lumen defined radially inward relative to the inner wall and an auxiliary lumen at least partially defined by the inner wall, and a first fluid being introduced therethrough. the central main lumen capable of receiving a second fluid therethrough is configured to generate one of a negative fluid pressure or a positive fluid pressure therein, while the auxiliary lumen capable of receiving a second fluid therethrough is configured to generate the other of the negative fluid pressure or the positive fluid pressure therein, a distal end of the central main lumen and a distal end of the auxiliary lumen are in fluid communication with each other, the negative fluid pressure and the positive fluid pressure combine as a resultant pressure within the distal portion of the passageway, and the pulsating suction system further includes a pump system in fluid communication with the catheter, and independently controlling the negative and positive fluid pressures in the central main and auxiliary lumens to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure, wherein the maximum aspiration pressure is generateable at the distal end of the catheter when the resulting pressure is solely negative fluid pressure, while the maximum positive pressure is generateable at the distal end of the catheter when the positive fluid pressure balances the pressure of the negative fluid pressure. (12) The method of embodiment 11, further comprising maximizing at least one waveform parameter of the pulsating suction waveform generated at the distal end of the catheter by controlling the pump system based on the resulting pressure monitored by a pressure sensor. (13) The method of claim 12, further comprising the step of setting an adjusted level of the positive fluid pressure via the pump system such that, if the resulting pressure monitored by the pressure sensor exceeds a predetermined threshold, the resulting pressure monitored by the pressure sensor is reduced to below the predetermined threshold. (14) capturing a target clot within a funnel-shaped portion disposed on the distal end of the catheter, the distal end of the funnel-shaped portion having a larger diameter compared to the proximal end of the funnel-shaped portion; detecting a parameter of the target clot via a second sensor disposed on an interior surface of the funnel-shaped portion; 12. The method of claim 11, further comprising adjusting at least one waveform parameter for controlling the pump system based on the detected parameter. 15. The method of claim 11, further comprising positioning the auxiliary lumen eccentrically from the central main lumen.

[0107] (16) The method of claim 15, further comprising permanently fixing the inner wall in place within the proximal portion of the catheter passageway and radially dividing the proximal portion of the catheter passageway into the central main lumen and the auxiliary lumen on either side of the inner wall. 17. The method of claim 11, further comprising concentrically disposing the central main lumen and the auxiliary lumen. (18) disposing the inner wall as an inner catheter within the proximal portion of the passage of the catheter and slidable in the longitudinal direction independently of the catheter; 18. The method of claim 17, further comprising forming an internally defined longitudinal channel within the inner catheter, the channel serving as the central main lumen of the proximal portion of the passage of the catheter, while a radially defined region between the inner catheter and the proximal portion of the catheter serves as the auxiliary lumen. (19) The method of embodiment 12, further comprising the step of: (i) activating an indicator when the resulting pressure in the distal portion of the passage of the catheter monitored by the pressure sensor exceeds a predetermined threshold; and / or (ii) adjusting at least one waveform parameter of positive pressure fluid via the pump system so that the monitored resulting pressure falls below the predetermined threshold. (20) The method of embodiment 11, further comprising the step of introducing a stentriever through the central main lumen of the catheter.

Claims

1. 1. A pulsating suction system comprising: A catheter, an outer wall extending longitudinally from a proximal end to an opposite distal end and defining a passageway therethrough; a proximal portion having an associated proximal portion of the passageway; a distal portion disposed distally of the proximal portion and having an associated distal portion of the passageway; an inner wall extending longitudinally through the passage and dividing the proximal portion of the passage into (i) a central main lumen defined radially inward relative to the inner wall, and (ii) an auxiliary lumen at least partially defined by the inner wall and interior to the outer wall; the central main lumen capable of receiving a first fluid therethrough is configured to generate one of a negative fluid pressure or a positive fluid pressure therein; the auxiliary lumen capable of receiving a second fluid therethrough is configured to generate the other of the positive fluid pressure or the negative fluid pressure therein; a catheter, wherein a distal portion of the central main lumen and a distal portion of the auxiliary lumen are in fluid communication with each other, and the negative fluid pressure and the positive fluid pressure combine as a resultant pressure within the distal portion of the passage; a pump system in fluid communication with the catheter, the pump system independently controlling the negative and positive fluid pressures in the central main and auxiliary lumens to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure; the maximum suction pressure is producible at the distal end of the catheter when the resulting pressure is only negative fluid pressure; and A pulsatile aspiration system, wherein the maximum positive pressure is producible at the distal end of the catheter when the positive fluid pressure balances the pressure of the negative fluid pressure.

2. The pulsating aspiration system of claim 1 , wherein the auxiliary lumen is positioned eccentrically from the central main lumen.

3. 3. The pulsatile aspiration system of claim 2, wherein the inner wall is permanently fixed in place within the proximal portion of the catheter passageway and radially divides the proximal portion of the catheter passageway into the central main lumen and the auxiliary lumen on either side of the inner wall.

4. The pulsating aspiration system of claim 1 , wherein the central main lumen and the auxiliary lumen are concentrically arranged.

5. 2. The pulsatile aspiration system of claim 1, wherein the inner wall is an inner catheter disposed within the proximal portion of the catheter passage and slidable in the longitudinal direction independently of the catheter, the inner catheter having the longitudinal channel defined therein, the channel serving as the central main lumen of the proximal portion of the catheter passage, while a radially defined region between the inner catheter and the outer wall of the proximal portion of the catheter serves as the auxiliary lumen.

6. a pressure sensor disposed on an interior surface of the outer wall of the distal portion of the catheter, the pressure sensor monitoring the resulting pressure within the distal portion of the passageway of the catheter; 10. The pulsating aspiration system of claim 1, wherein at least one parameter of the pulsating aspiration waveform generated at the distal end of the catheter is adjusted by controlling the pump system based on the resulting pressure monitored by the pressure sensor.

7. 7. The pulsating aspiration system of claim 6, wherein when the resulting pressure in the distal portion of the passage of the catheter monitored by the pressure sensor exceeds a predetermined threshold, (i) an indicator is activatable, and / or (ii) the pump system is controllable to adjust positive pressure fluid through the central main lumen or the auxiliary lumen so that the monitored resulting pressure is reduced below the predetermined threshold.

8. a funnel-shaped portion having a free distal end and an opposite proximal end attached to the distal end of the catheter, the free distal end of the funnel-shaped portion having a larger diameter compared to the proximal end of the funnel-shaped portion; 10. The pulsatile aspiration system of claim 1, further comprising: a second sensor disposed on an inner surface of the funnel-shaped portion to detect a parameter of the clot associated with fibrin content of the clot that is captureable within the funnel-shaped portion.

9. The pulsatile aspiration system of claim 1 , wherein a stentriever is receivable within the central main lumen of the catheter.

10. The pulsating aspiration system of claim 1 , wherein the distal portion of the passageway is unsegmented.

11. 1. A method for operating a pulsatile aspiration system including a catheter having an outer wall extending longitudinally from a proximal end to an opposite distal end and defining a passageway therethrough, the catheter including a proximal portion having an associated proximal portion of the passageway, and a distal portion disposed distally of the proximal portion and having an associated distal portion of the passageway, the proximal portion of the passageway being divided by an inner wall extending longitudinally through the passageway into a central main lumen defined radially inward relative to the inner wall and an auxiliary lumen at least partially defined by the inner wall, and adapted to introduce a first fluid therethrough. the central main lumen capable of receiving a second fluid therethrough is configured to generate one of a negative fluid pressure or a positive fluid pressure therein, while the auxiliary lumen capable of receiving a second fluid therethrough is configured to generate the other of the negative fluid pressure or the positive fluid pressure therein, a distal end of the central main lumen and a distal end of the auxiliary lumen are in fluid communication with each other, the negative fluid pressure and the positive fluid pressure combine as a resultant pressure within the distal portion of the passageway, and the pulsating suction system further includes a pump system in fluid communication with the catheter, and independently controlling the negative and positive fluid pressures in the central main and auxiliary lumens to generate a pulsating aspiration waveform at the distal end of the catheter that is variable between a maximum aspiration pressure and a maximum positive pressure, wherein the maximum aspiration pressure is generateable at the distal end of the catheter when the resulting pressure is solely negative fluid pressure, while the maximum positive pressure is generateable at the distal end of the catheter when the positive fluid pressure balances the pressure of the negative fluid pressure.

12. 12. The method of claim 11, further comprising maximizing at least one waveform parameter of the pulsating aspiration waveform generated at the distal end of the catheter by controlling the pump system based on the resulting pressure monitored by a pressure sensor.

13. 13. The method of claim 12, further comprising the step of: if the resultant pressure monitored by the pressure sensor exceeds a predetermined threshold, setting an adjusted level of the positive fluid pressure via the pump system such that the resultant pressure monitored by the pressure sensor is reduced to below the predetermined threshold.

14. capturing a target clot within a funnel-shaped portion disposed on the distal end of the catheter, the distal end of the funnel-shaped portion having a larger diameter compared to the proximal end of the funnel-shaped portion; detecting a parameter of the target clot via a second sensor disposed on an interior surface of the funnel-shaped portion; The method of claim 11 , further comprising adjusting at least one waveform parameter for controlling the pump system based on the detected parameter.

15. The method of claim 11 , further comprising positioning the auxiliary lumen eccentrically from the central main lumen.

16. 16. The method of claim 15, further comprising permanently fixing the inner wall in place within the proximal portion of the catheter passageway, radially dividing the proximal portion of the catheter passageway into the central main lumen and the auxiliary lumen on either side of the inner wall.

17. The method of claim 11 , further comprising concentrically disposing the central main lumen and the auxiliary lumen.

18. disposing the inner wall as an inner catheter within the proximal portion of the passageway of the catheter and slidable in the longitudinal direction independently of the catheter; 18. The method of claim 17, further comprising forming the longitudinal channel defined therein within the inner catheter, the channel serving as the central main lumen of the proximal portion of the passageway of the catheter, while a radially defined region between the inner catheter and the proximal portion of the catheter serves as the auxiliary lumen.

19. 13. The method of claim 12, further comprising the step of: (i) activating an indicator when the resultant pressure in the distal portion of the passageway of the catheter monitored by the pressure sensor exceeds a predetermined threshold; and / or (ii) adjusting at least one waveform parameter of positive pressure fluid via the pump system such that the monitored resultant pressure falls below the predetermined threshold.

20. 12. The method of claim 11, further comprising the step of introducing a stentriever through the central main lumen of the catheter.

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