Systems and methods for aspiration and monitoring

Abstract

To provide an aspiration system for removing undesired matter such as thrombus from a lumen of the body such as a blood vessel.SOLUTION: A system for aspiration includes an aspiration catheter including an elongate shaft including an aspiration lumen, and an open distal end, an extension tube, a peristaltic pump, a compressible portion disposed between the distal end and the proximal end of the extension tube, the compressible portion configured to be coupled to the peristaltic pump, such that operation of the peristaltic pump drives fluid from the aspiration lumen from the distal end of the extension tube to the proximal end of the extension tube, and a controller configured to receive a first signal from a first sensor and configured to vary the operation of the peristaltic pump based at least in part on a first signal received from the first sensor coupled to the aspiration lumen or extension tube related to a change in the characteristic of flow.SELECTED DRAWING: Figure 38

Description

[Technical field]

[0001]

[0001] The field of the invention relates generally to aspiration systems for removing undesirable material, such as thrombi, from bodily lumens, such as blood vessels, including fluid carrying cavities, ducts, sinuses, or tubes in the brain, or in any space of the body, whether or not intended to carry a fluid, by aspiration. [Background technology]

[0002]

[0002] A therapeutic method for removing undesirable material, such as a thrombus, from a patient's blood vessel involves the use of an aspiration catheter having an elongated shaft formed with an aspiration lumen extending therethrough. The aspiration catheter may also include a guidewire lumen for placement of a guidewire used to guide the aspiration catheter to a target site within the body. By applying a vacuum or negative pressure to the proximal end of the aspiration lumen, for example with a syringe having a hub connected to the proximal end of the aspiration catheter, material may be aspirated into an aspiration port at the distal end of the aspiration catheter and into the aspiration lumen, and thus removed from the patient. Summary of the Invention

[0003]

[0003] In one embodiment of the present disclosure, a system for catheter-based aspiration includes an aspiration catheter including an elongated shaft configured for placement within a vasculature of a subject, the shaft including an aspiration lumen having a proximal end and an open distal end; an extension tube having a distal end and a proximal end and a lumen extending therebetween, the lumen of the extension tube being configured to be hydraulically connected to the aspiration lumen of the aspiration catheter; a peristaltic pump configured to drive fluid through the extension tube, the peristaltic pump including a pump base having a pressure shoe, and a rotatable head, the rotatable head including two or more compression elements arranged around the periphery thereof; and a pump base and a rotatable head configured to connect the distal end and proximal end of the extension tube to a pressure shoe. a compressible tubular portion disposed between the pressure shoe and the rotatable head of the peristaltic pump, the compressible tubular portion configured to be connected to the pressure shoe and the rotatable head of the peristaltic pump such that operation of the peristaltic pump rotates the rotatable head such that the two or more compression elements drive fluid from the aspiration lumen of the aspiration catheter through the dilation tube from the distal end of the dilation tube to the proximal end of the dilation tube; a first sensor configured to measure a characteristic of flow through at least one of the aspiration lumen or the lumen of the dilation tube; and a controller configured to receive a first signal from the first sensor and to vary operation of the peristaltic pump based at least in part on the first signal received from the first sensor associated with a change in the characteristic of the flow. The "characteristic of the flow" may include pressure, flow rate, flow velocity, or a variation or disturbance of any of these. The "characteristic of the flow" may even be a state of laminar or turbulent flow, or a change therebetween.

[0004]

[0004] In another embodiment of the present disclosure, a method for performing a thrombectomy procedure includes the steps of providing an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen and an infusion lumen, the aspiration lumen having open distal and proximal ends, the infusion lumen extending into the aspiration lumen and having distal and proximal ends, the distal end of the infusion lumen being located within the aspiration lumen near the open distal end of the aspiration lumen, the aspiration catheter further including an orifice at the distal end of the infusion lumen configured to generate one or more jets when pressurized fluid is injected through the infusion lumen; placing at least a distal portion of the elongated shaft within the blood vessel of the subject, the orifice extending between the distal and proximal ends. the step of positioning a dilation tube having a compressible lumen, the dilation tube configured to be hydraulically connected to the suction lumen of the suction catheter in a roller pump such that a compressible portion of the dilation tube disposed between a distal end and a proximal end of the dilation tube is engageable by two or more rollers of a rotatable head of the roller pump; injecting pressurized fluid through the infusion lumen of the suction catheter from the proximal end to the distal end, causing it to enter the suction lumen through an orifice, thereby forcing a portion of the bodily fluid into the suction lumen of the suction catheter; and operating the roller pump such that the bodily fluid forced into the suction lumen of the suction catheter passes through the dilation tube from the distal end of the dilation tube to the proximal end of the dilation tube.

[0005]

[0005] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen and an infusion lumen, the aspiration lumen having open distal and proximal ends, the infusion lumen extending into the aspiration lumen and having a distal and proximal end, the distal end of the infusion lumen being located within the aspiration lumen near the open distal end of the aspiration lumen, an orifice at the distal end of the infusion lumen configured to generate one or more jets when pressurized fluid is infused through the infusion lumen, and a catheter assembly including a catheter having a distal end and a proximal end and a catheter member configured to connect the distal end and the proximal end of the catheter to the catheter. an extension tube having a lumen extending therebetween, a distal end of the extension tube configured to be hydraulically connected to the aspiration lumen of the aspiration catheter, the extension tube further having a compressible portion disposed between the distal and proximal ends of the extension tube, the compressible portion configured for placement within a peristaltic pump such that operation of the peristaltic pump moves fluid from the aspiration lumen of the aspiration catheter through the extension tube from the distal end of the extension tube to the proximal end of the extension tube; and a return conduit hydraulically connected to the extension tube and configured to return to the vascular system of a subject fluid that has passed through the extension tube from the distal to the proximal end.

[0006]

[0006] In yet another embodiment of the present disclosure, a system for catheter aspiration includes a peristaltic pump and an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen and an infusion lumen, the aspiration lumen having open distal and proximal ends, the infusion lumen extending into the aspiration lumen and having a distal and proximal end, the distal end of the infusion lumen being located within the aspiration lumen near the open distal end of the aspiration lumen, an orifice at the distal end of the infusion lumen being configured to generate one or more jets when pressurized fluid is infused through the infusion lumen, and a lubricant comprising: a peristaltic pump; a dilation tube having a compressible portion and a compressible portion configured for placement within a peristaltic pump such that operation of the peristaltic pump moves fluid from the suction lumen of the suction catheter through the dilation tube from the distal end of the dilation tube to the proximal end of the dilation tube; and a filter disposed in a conduit including the suction lumen of the suction catheter and the lumen of the dilation tube, the filter being disposed between the orifice and the compressible portion of the dilation tube.

[0007]

[0007] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen and an infusion lumen, the aspiration lumen having open distal and proximal ends, the infusion lumen extending into the aspiration lumen and having distal and proximal ends, the distal end of the infusion lumen being located within the aspiration lumen near the open distal end of the aspiration lumen, an orifice at the distal end of the infusion lumen being configured to generate one or more jets when pressurized fluid is infused through the infusion lumen, and an extension tube having distal and proximal ends and a lumen extending therebetween, the distal end of the extension tube extending between the aspiration catheter and the proximal end of the extension tube, the dilation tube configured to be hydraulically connected to an aspiration lumen of the aspiration catheter, the dilation tube further having a compressible portion disposed between a distal end and a proximal end of the dilation tube, the compressible portion configured for placement within the peristaltic pump such that operation of the peristaltic pump moves fluid from the aspiration lumen of the aspiration catheter through the dilation tube from the distal end of the dilation tube to the proximal end of the dilation tube; a controller configured to operate a piston pump configured to pressurize fluid through the infusion lumen; and a sensor configured to sense the presence of air in the pressurized fluid injected into or through the infusion lumen, the sensor configured to output a signal to the controller.

[0008]

[0008] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen with open distal and proximal ends; an expansion tube having distal and proximal ends and a lumen extending therebetween, the distal end of the expansion tube configured to be hydraulically connected to the aspiration lumen of the aspiration catheter, the expansion tube further having a compressible portion disposed between the distal and proximal ends of the expansion tube, the compressible portion configured for placement within the roller pump such that operation of the roller pump causes fluid from the aspiration lumen of the aspiration catheter to move through the expansion tube from the distal end of the expansion tube to the proximal end of the expansion tube; a pressure sensor configured for placement in fluid communication with a conduit including the lumen of the expansion tube and the aspiration lumen of the catheter; a measurement device connected to the pressure sensor and configured to measure a deviation in fluid pressure; and a communication device connected to the measurement device and configured to generate a signal related to the deviation in fluid pressure.

[0009] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen with open distal and proximal ends; an expansion tube having distal and proximal ends and a lumen extending therebetween, the distal end of the expansion tube configured to be hydraulically connected to the aspiration lumen of the aspiration catheter, the expansion tube further having a compressible portion disposed between the distal and proximal ends of the expansion tube, the compressible portion configured for placement within a peristaltic pump such that operation of the peristaltic pump causes fluid from the aspiration lumen of the aspiration catheter to move through the expansion tube from the distal end of the expansion tube to the proximal end of the expansion tube; a pressure sensor configured for placement in fluid communication with a conduit including the lumen of the expansion tube and the aspiration lumen of the catheter; a measurement device connected to the pressure sensor and configured to measure a deviation in fluid pressure; and a communication device connected to the measurement device and configured to generate a signal related to the deviation in fluid pressure.

[0010]

[0010] In yet another embodiment of the present disclosure, a method for performing a thrombectomy procedure includes the steps of providing an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen with open distal and proximal ends; placing at least a distal portion of the elongated shaft within the blood vessel of the subject; placing an dilation tube having distal and proximal ends and a lumen extending therebetween, the dilation tube being configured to be hydraulically connected to the aspiration lumen of the aspiration catheter within a roller pump such that a compressible portion of the dilation tube disposed between the distal and proximal ends of the dilation tube is engageable by two or more rollers of a rotatable head of the roller pump; and operating the roller pump such that bodily fluid forced into the aspiration lumen of the aspiration catheter passes through the dilation tube from the distal end of the dilation tube to the proximal end of the dilation tube.

[0011]

[0011] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a vasculature of a subject, the shaft having an aspiration lumen with open distal and proximal ends; an extension tube having distal and proximal ends and a lumen extending therebetween, the distal end of the extension tube configured to be hydraulically connected to the aspiration lumen of the aspiration catheter, the extension tube further having a compressible portion disposed between the distal and proximal ends of the extension tube, the compressible portion configured for placement within a peristaltic pump such that operation of the peristaltic pump causes fluid from the aspiration lumen of the aspiration catheter to move through the extension tube from the distal end of the extension tube to the proximal end of the extension tube; and a return conduit hydraulically connected to the extension tube and configured to return to the vasculature of the subject fluid that has passed through the extension tube from the distal to proximal end.

[0012]

[0012] In yet another embodiment of the present disclosure, a system for catheter aspiration includes a centrifugal pump, an aspiration catheter including an elongated shaft configured for placement within a subject's blood vessel, the shaft having an aspiration lumen having an open distal end and a proximal end, and a controller configured to operate the centrifugal pump.

[0013]

[0013] In yet another embodiment of the present disclosure, a system for real-time monitoring of catheter aspiration includes an ultrasonic sensor configured to be placed in fluid communication with a lumen that at least partially comprises the aspiration lumen of the catheter, where the aspiration lumen is configured to connect to a negative pressure source and where the ultrasonic sensor is configured to output a signal; a measurement device connected to the ultrasonic sensor and configured to count the number of times N during a predetermined time period P that the signal output by the ultrasonic sensor exceeds a predetermined threshold amplitude A, where the measurement device is further configured to determine whether the number of times N is less than or equal to a predetermined value V, or whether the number of times N exceeds or is equal to or greater than the predetermined value V; and a communication device connected to the measurement device and configured to enter a first communication mode when the number of times N is less than or equal to the predetermined value V, and to enter a second communication mode when the number of times N exceeds the predetermined value V or is equal to or greater than the predetermined value V.

[0014]

[0014] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft including an aspiration lumen having open distal and proximal ends; an dilation tube having distal and proximal ends and a lumen extending therebetween, the distal end of the dilation tube configured to be hydraulically connected to the proximal end of the aspiration lumen of the aspiration catheter; a receptacle having an internal volume, the proximal end of the dilation tube configured to deliver material flowing from the lumen of the dilation tube to the internal volume of the receptacle; a scale configured to weigh at least the material contained within the receptacle; and a communication element configured to indicate to a user a change in mass of the material contained within the receptacle over time.

[0015]

[0015] In yet another embodiment of the present disclosure, a method for performing a thrombectomy procedure includes the steps of providing a system for aspiration including an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen with open distal and proximal ends, an extension tube having distal and proximal ends and a lumen extending therebetween, the distal end of the extension tube configured to be hydraulically connected to the proximal end of the aspiration lumen of the aspiration catheter, a receptacle having an internal volume, the proximal end of the extension tube configured to deliver material flowing from the lumen of the extension tube to the internal volume of the receptacle, and a scale configured to weigh at least the material contained within the receptacle; placing at least a distal portion of the elongated shaft in the blood vessel of the subject; causing at least a portion of the thrombus to be aspirated from the blood vessel of the subject, through the aspiration lumen of the aspiration catheter, through the lumen of the extension tube and into the internal volume of the receptacle; and monitoring a change in mass of the material in the receptacle over time.

[0016]

[0016] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter including an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen, the aspiration lumen having an open distal end and a proximal end; an injection tube having an injection lumen extending therethrough, the injection tube configured to extend into the aspiration lumen and having distal and proximal ends, the distal end of the injection tube configured to be positioned within the aspiration lumen near the open distal end of the aspiration lumen; a micro-machined cap externally covering an outer periphery of the distal end of the injection tube to provide a seal; and an orifice in at least one of the micro-machined cap or the injection tube proximal to the micro-machined cap, the orifice configured to generate one or more jets in the aspiration lumen when pressurized fluid is injected through the injection lumen.

[0017]

[0017] In yet another embodiment of the present disclosure, a method for aspirating a thrombus includes the steps of providing an aspiration catheter having an elongated shaft with an aspiration lumen having a proximal end and an open distal end, and an infusion tube extending into the aspiration lumen and having a proximal end, a closed distal end, and an infusion lumen having an orifice at or adjacent to the closed distal end, attaching a pressurizable fluid source to the proximal end of the infusion lumen, connecting a pump to the proximal end of the aspiration lumen configured to aspirate fluid through the aspiration lumen in a distal to proximal direction, and positioning the aspiration catheter such that the open distal end of the aspiration lumen is at or adjacent to the thrombus. The method includes inserting a distal region of the shaft into the patient's vasculature; determining that a combination of injecting pressurized fluid through the infusion lumen and aspiration by the pump through the aspiration lumen is not sufficient to cause aspiration of the thrombus; advancing the aspiration catheter until the open distal end of the aspiration lumen is distal to the thrombus; injecting pressurized fluid through the infusion lumen without activating the pump at the aspiration lumen such that the pressurized fluid passes through and enters the aspiration lumen and enters the space distal to the thrombus from the open distal end of the aspiration lumen; and aspirating at least a portion of the thrombus by injecting pressurized fluid while activating the pump at the aspiration lumen.

[0018]

[0018] In yet another embodiment of the present disclosure, a system for catheter aspiration includes an aspiration catheter having an elongated shaft configured for placement within a blood vessel of a subject, the shaft having an aspiration lumen, the aspiration lumen having an open distal end and a proximal end; an injection tube having an infusion lumen extending therethrough, the injection tube extending into the aspiration lumen and being longitudinally adjustable relative to the elongated shaft, the injection lumen having open distal and proximal ends, the open distal end of the injection lumen configured to extend distally from the open distal end of the aspiration lumen; and an orifice through a wall of the injection tube proximal to the open distal end of the injection lumen, the orifice configured to generate one or more jets in the aspiration lumen when pressurized fluid is injected through the injection lumen and when the injection lumen of the injection tube is occluded distal to the orifice through the wall of the injection tube. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a plan view of a system for aspiration according to one embodiment of the present disclosure.

[0020] [Figure 2A] FIG. 1 is a diagram of a suction monitoring system according to a first embodiment of the present disclosure.

[0021] [Figure 2B] FIG. 2 is a diagram of a suction monitoring system according to a second embodiment of the present disclosure.

[0022] [Diagram 3] FIG. 13 is a diagram of a suction monitoring system according to a third embodiment of the present disclosure.

[0023] [Figure 4A] FIG. 1 is a cross-sectional view of an aspiration catheter within a blood vessel prior to contact with a thrombus.

[0024] [Figure 4B] FIG. 1 is a cross-sectional view of an aspiration catheter within a blood vessel upon contact with a thrombus.

[0025] [Figure 4C] FIG. 1 is a cross-sectional view of the suction catheter during reduction of vacuum.

[0026] [Figure 4D] FIG. 1 is a cross-sectional view of a thrombus being aspirated through an aspiration catheter.

[0027] [Figure 5A] 4B is a graph of pressure versus time for the condition of FIG. 4A.

[0028] [Figure 5B] 4C is a graph of pressure versus time for the condition of FIG. 4B.

[0029] [Figure 5C] 4D is a graph of pressure versus time for the condition of FIG. 4C.

[0030] [Figure 5D] 4E is a graph of pressure versus time for the condition of FIG. 4D.

[0031] [Figure 6] 1 is a graph of pressure and output sound amplitude versus time for one embodiment of a suction monitoring system.

[0032] [Figure 7] 1 is a graph of pressure and output sound amplitude versus time for one embodiment of a suction monitoring system.

[0033] [Figure 8] 1 is a graph of pressure and output sound frequency versus time for one embodiment of a suction monitoring system.

[0034] [Figure 9] 1 is a graph of pressure and output sound frequency versus time for one embodiment of a suction monitoring system.

[0035] [Figure 10] FIG. 13 is a plan view of a system for aspiration according to another embodiment of the present disclosure.

[0036] [Figure 11] FIG. 13 is a plan view of a system for aspiration according to another embodiment of the present disclosure.

[0037] [Figure 12] FIG. 12 is a detailed view of the suction monitoring system of the suction system of FIG. 11.

[0038] [Figure 13] FIG. 13 is a plan view of a system for aspiration according to another embodiment of the present disclosure.

[0039] [Figure 14] FIG. 14 is a detailed view of the suction monitoring system of the system for suction of FIG. 13.

[0040] [Figure 15] FIG. 1 is a schematic diagram of a system for aspirating thrombus, according to one embodiment of the present disclosure.

[0041] [Figure 16] FIG. 16 is a schematic diagram showing the proximal portion of the system for aspirating thrombus of FIG. 15 in more detail.

[0042] [Figure 17] FIG. 16 is a schematic diagram of a distal end portion of the system for aspirating thrombus of FIG. 15.

[0043] [Figure 18] FIG. 1 is a plan view of a portion of a multi-purpose system according to one embodiment of the present disclosure.

[0044] [Figure 19] FIG. 19 is a perspective view of a proximal portion of the multi-purpose system of FIG.

[0045] [Figure 20] FIG. 1 is a plan view of a portion of a multi-purpose system according to one embodiment of the present disclosure.

[0046] [Figure 21] FIG. 21 is a detailed view of the distal end of the multi-purpose catheter of the multi-purpose system of FIG. 20.

[0047] [Figure 22] FIG. 21 is a perspective view of a proximal portion of the multi-purpose system of FIG.

[0048] [Diagram 23] FIG. 21 is a plan view of the proximal portion of the multi-purpose system of FIG.

[0049] [Figure 24] FIG. 21 is a perspective view of a portion of the multi-purpose system of FIG.

[0050] [Diagram 25] FIG. 1 is a plan view of an aspiration catheter according to one embodiment of the present disclosure.

[0051] [Figure 26] FIG. 1 is a top view of a tubeset according to one embodiment of the present disclosure.

[0052] [Figure 27] FIG. 1 is a plan view of a stopcock according to one embodiment of the present disclosure.

[0053] [Figure 28] FIG. 1 is a plan view of a stopcock according to one embodiment of the present disclosure.

[0054] [Figure 29] FIG. 2 is a plan view of a vacuum source according to one embodiment of the present disclosure.

[0055] [Diagram 30] FIG. 1 is a plan view of an aspiration system according to one embodiment of the present disclosure.

[0056] [Diagram 31] FIG. 1 is a top view of an aspiration system according to one embodiment of the present disclosure.

[0057] [Diagram 32] FIG. 1 is a top view of an aspiration system according to one embodiment of the present disclosure.

[0058] [Diagram 33] FIG. 1 is a top view of an aspiration system according to one embodiment of the present disclosure.

[0059] [Diagram 34] FIG. 1 is a partial cross-sectional view of an embodiment of a saline infusion aspiration (thrombectomy) catheter with a guidewire in place, according to an embodiment of the present disclosure.

[0060] [Diagram 35] FIG. 2 is a plan view of the proximal end of a guide catheter having an aspiration catheter disposed therein.

[0061] [Diagram 36] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure.

[0062] [Figure 37] FIG. 1 is a perspective view of a subject being reinfused with blood according to one embodiment of the present disclosure.

[0063] [Figure 38] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure.

[0064] [Figure 39] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure.

[0065] [Diagram 40] FIG. 1 is a perspective view of an ultrasonic sensor for use with an aspiration system according to one embodiment of the present disclosure.

[0066] [Diagram 41] FIG. 41 is a plan view of an aspiration system having a y-connector with the ultrasonic sensor of FIG. 40 disposed therein.

[0067] [Diagram 42] FIG. 42 is a perspective view of the console of the aspiration system of FIG. 41.

[0068] [Diagram 43] FIG. 1 is a plan view of an aspiration system according to one embodiment of the present disclosure.

[0069] [Diagram 44] FIG. 44 is a detailed diagram of the weight-based suction monitoring system of the system of FIG. 43.

[0070] [Diagram 45] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure.

[0071] [Figure 46] FIG. 13 is a detailed view of another weight-based suction monitoring system of the system.

[0072] [Figure 47] FIG. 1 is a plan view of an aspiration system according to one embodiment of the present disclosure.

[0073] [Figure 48] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure.

[0074] [Figure 49] FIG. 2 is a cross-sectional view of a distal end of an aspiration catheter according to an embodiment of the present disclosure.

[0075] [Figure 50] FIG. 2 is a cross-sectional view of a distal end of an aspiration catheter according to an embodiment of the present disclosure.

[0076] [Figure 51] FIG. 2 is a cross-sectional view of a distal end of an aspiration catheter according to an embodiment of the present disclosure.

[0077] [Figure 52] FIG. 2 is a cross-sectional view of a distal end of an aspiration catheter according to an embodiment of the present disclosure.

[0078] [Figure 53] FIG. 1 is a plan view of a microcatheter being tracked over a guidewire in a first step.

[0079] [Figure 54] FIG. 13 is a plan view of the insertion of an insertable injection tube and cap being inserted into a microcatheter in a second step according to one embodiment of the present disclosure.

[0080] [Figure 55] FIG. 13 is a plan view of the insertable injection tube and cap advancing through the lumen of the microcatheter in a third step.

[0081] [Figure 56] FIG. 13 is a plan view of the insertable injection tube and cap in a fully inserted position within the microcatheter in a fourth step.

[0082] [Figure 57] FIG. 13 is a perspective cross-sectional view of a distal end of an insertable injection tube and cap with a spline inserted into a microcatheter according to one embodiment of the present disclosure.

[0083] [Figure 58] FIG. 58 is a perspective view of the insertable fill tube and cap with splines of FIG. 57.

[0084] [Figure 59] FIG. 13 is a perspective cross-sectional view of a distal end of an insertable injection tube and cap with a spline inserted into a microcatheter according to one embodiment of the present disclosure.

[0085] [Figure 60] FIG. 1 illustrates one form of a method for treating a patient using an aspiration catheter and system according to one embodiment of the present disclosure. [Figure 61] FIG. 13 is another diagram illustrating a method for treating a patient using a suction catheter and system according to an embodiment of the present disclosure. [Figure 62] FIG. 13 is yet another diagram illustrating a method for treating a patient using an aspiration catheter and system according to an embodiment of the present disclosure. [Figure 63] FIG. 13 is yet another diagram illustrating a method for treating a patient using an aspiration catheter and system according to an embodiment of the present disclosure.

[0086] [Figure 64] FIG. 1 illustrates one form of a method for treating a patient using an aspiration catheter and system according to one embodiment of the present disclosure. [Figure 65] FIG. 13 is another diagram illustrating a method for treating a patient using a suction catheter and system according to an embodiment of the present disclosure.

[0087] [Figure 66] FIG. 1 illustrates one form of a method for treating a patient using an aspiration catheter and system according to one embodiment of the present disclosure. [Figure 67] FIG. 13 is another diagram illustrating a method for treating a patient using a suction catheter and system according to an embodiment of the present disclosure. [Figure 68] FIG. 13 is yet another diagram illustrating a method for treating a patient using an aspiration catheter and system according to an embodiment of the present disclosure. [Figure 69] FIG. 13 is yet another diagram illustrating a method for treating a patient using an aspiration catheter and system according to an embodiment of the present disclosure.

[0088] [Figure 70]FIG. 70 is a cross-sectional view of the translatable occluder of the suction system of FIGS. 66-69 in a first position according to one embodiment of the present disclosure.

[0089] [Figure 71] FIG. 70 is a cross-sectional view of the translatable occluder of the suction system of FIGS. 66-69 in a second position.

[0090] [Figure 72] FIG. 70 illustrates an optional blocking step in the method of FIGS. 66-69, according to one embodiment of the present disclosure.

[0091] [Figure 73] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure.

[0092] [Figure 74] FIG. 1 is a perspective view of an aspiration system according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0093]

[0093] The present disclosure relates to an aspiration catheter system including an aspiration system for removing thrombi from a patient's vasculature, and a monitoring, alert and communication system for the aspiration catheter system. Such vasculature may include veins and arteries, including coronary, carotid, cerebral, and other arteries of the head and neck. Clogged aspiration catheters, for example by large thrombi, are a common concern for users. Techniques for avoiding clogging / occlusion of material within the catheter often involve quickly and aggressively advancing the aspiration catheter, or gently picking at the edge of the clot to ensure that only a small piece or portion is introduced at a time, the piece being small enough not to clog or occlude the aspiration lumen. If the device becomes clogged during use, there is an increased likelihood of accidental dislodgement of the clot downstream; this is referred to as peripheral embolization. Because this type of aspiration procedure is often used in highly technical emergency settings, early detection of a clogged aspiration catheter for the user during aspiration can contribute to the success of the procedure and clinical outcomes. Several sources report that up to 50% of used suction catheters become clogged during use.

[0094]

[0094] A user may have difficulty determining whether there is a vacuum or negative pressure in the system. For example, a user may have difficulty determining whether there is a vacuum or negative pressure (e.g., whether the vacuum source has been turned on or off). Additionally, a user may have difficulty determining whether there has been a vacuum loss in the system, for example, due to a syringe (or other vacuum source) filled with fluid or because of a leak in the system. Blood is relatively opaque and can coat the walls of the syringe, making it difficult to determine when the syringe is filled. This makes it difficult to determine whether sufficient vacuum or negative pressure has been applied to the aspiration catheter. The negative pressure gradient may change to an unacceptable level even before the syringe is filled. An extension tube or other tubes may also cause a vacuum loss or a decrease in negative pressure in the system. Certain tube kinks may be difficult for a user to see or identify. It is also difficult to determine whether there is an air leak in the system, which can be another cause for a vacuum loss or a decrease in negative pressure, even before the syringe is filled with the aspiration fluid.

[0095] During aspiration of a clot with a suction catheter, it is difficult to determine when the clot is being actively aspirated or when blood is simply being aspirated. In general, it is desirable not to aspirate large amounts of normal blood from a blood vessel, since it is important to maintain normal blood volume and blood pressure. However, when tracking the tip of the suction catheter in the vicinity of a clot, it is difficult to know whether the suction catheter has actively engaged the clot, whether the suction catheter has aspirated at least a portion of the clot, or whether the suction catheter has not engaged the clot and has only aspirated blood. While some suction catheters, such as those used in peripheral blood vessels or arteriovenous fistulas, may be about 50 cm or less, the tip of the suction catheter may be more than 90 cm away from the user's hand, or as far as 135 cm away from the user's hand, or even as far as 150 cm away in some cases, and the specific state of the aspiration capability at the tip of the catheter is often not known to the user. Thus, the user may essentially be poking the catheter blindly without any significant and useful sensory feedback. The outer diameter of the catheter may be up to 6 French or more, and the height may be 10 French or more. The increased catheter outer diameter may raise concerns of potential intravascular trauma. The use of suction catheters is therefore inefficient and does not minimize the length of the user's treatment as desired, and may cause blood loss, requiring transfusion in severe cases. Also, the increase in the normal volume of blood being aspirated means that the vacuum source (e.g., syringe) fills in a shorter time, thus necessitating more frequent replacement of the vacuum source. If the negative pressure gradient is not sufficient and is not yet recognized by the user, peripheral embolism may occur.

[0096]

[0096] In some cases, a syringe that is completely or nearly full of blood and / or clot may still be used, but this condition results in an inefficient use of time and a longer procedure because there is not enough pressure to effectively aspirate the clot or undesirable material. In some cases, the user may not realize that the syringe plunger is not being pulled back (to vent the syringe) by mistake. In some cases, the syringe itself may be faulty and not provide enough negative pressure without the user realizing. In some cases, a kinked tube, line, or catheter may go unnoticed due to poor visibility in the procedure room or simply from the degree of concurrent activity. In many cases, the user's eyes are directed, i.e., focused, on a monitor, such as a fluoroscopy monitor or other imaging monitor, or a monitor with vital patient data. The user can see the flow through a clear or partially clear lumen (such as an expansion tube) with dim lighting associated with intermittent observation, but it is difficult to handle the flow of an opaque liquid (such as blood / clot) at the user's will. Even with good lighting and focusing of the eyes, the movement of fluid through the dilation tube may not give an accurate picture of the aspiration condition, since the visual flow effect may lag relative to the applied vacuum or negative pressure. Multiple medical equipment personnel may share sensory information with each other to build a current state of the aspiration procedure in each other's mind. When one user relies on another's interpretation, a false sense of status may occur, especially if either is multitasking. A syringe attached to an aspiration catheter may become kinked, for example, if placed on an uneven surface. The distal opening in the aspiration lumen of the aspiration catheter tends to aspirate directly against the vessel wall and may therefore temporarily impinge on the vessel wall and stop flow throughout the aspiration lumen. In some cases, too large a negative pressure gradient may be applied erroneously or inappropriately to the aspiration lumen of the aspiration catheter, limiting its effectiveness (e.g., if it collapses the wall surrounding the aspiration lumen, thereby significantly reducing flow through the aspiration lumen).Syringes that are sometimes used as vacuum sources to connect to the aspiration lumen of aspiration catheters can malfunction and not be fully actuated / evacuated. However, even when the syringe is functioning correctly, it tends to fill at moments that are difficult to predict, and therefore generally has periods of time when no negative pressure gradient is applied. If a portion of the clot / thrombus is being aspirated through the aspiration lumen, a significant pressure drop may occur at the current location of the clot, and therefore sufficient negative pressure may only exist from the proximal end of the aspiration lumen distally to the point of the clot. Thus, insufficient negative pressure may exist at the distal end of the aspiration lumen, e.g., the distal end of the aspiration catheter, causing insufficient aspiration. The same situation may occur if there is an actual blockage at some intermediate point in the aspiration lumen. In any of these conditions, there is a risk that the clot or embolus will be sent distal to the vasculature due to insufficient aspiration at the distal end of the aspiration lumen, which may cause an occlusion, stroke, pulmonary embolism, or other injury depending on the location of the intervention or procedure being performed. With current equipment and techniques, these conditions are extremely difficult to detect when they occur. It is estimated that as many as 50% of thrombus aspiration procedures fail.

[0097]

[0097] An aspiration system 2 is shown in FIG. 1 and is configured to allow real-time monitoring of catheter aspiration. The aspiration system 2 includes an aspiration catheter 4, a vacuum source 6, a valve 8, an extension tube 10, and an aspiration monitoring system 48 with an in-line pressure transducer 12. The aspiration catheter 4 has a proximal end 14 and a distal end 16, and an aspiration lumen 18 extending from the proximal end 14 to the distal end 16. The aspiration lumen 18 can be sized for aspiration of thrombus, and in some embodiments, the aspiration lumen 18 can have an inner diameter of about 0.38 millimeters (0.015 inches) to about 2.54 millimeters (0.100 inches). The aspiration catheter 4 includes a hub 20 at the proximal end of the aspiration catheter 4, which can include a female Luer connector 22. At the distal end 16 of the aspiration catheter 4, the aspiration lumen 18 can include an angled opening 24 to aid in tracking through tortuous or occluded vasculature. In some embodiments, the guidewire lumen 26 is connected to the distal end 16 of the aspiration catheter 4 and is configured to be tracked by the guidewire 28. The vacuum source 6 may include a syringe and may be sized from 5 ml to 100 ml, or 20 ml to 60 ml. The vacuum source 6 may include a VacLok® syringe manufactured by Merit Medical, Inc., South Jordan, Utah. The vacuum source 6 may include a barrel 30 and a plunger 32 with a lock 34 configured to hold the plunger 32 in a position relative to the barrel 30, such that, for example, a negative pressure (vacuum) is created within the barrel 30 when the plunger 32 is pulled back in direction D. In some embodiments, the vacuum source 6 may include any other type of evacuable container or may include a vacuum pump. The vacuum source 6 is connected to the aspiration lumen 18 of the aspiration catheter 4 via an extension tube 10 and a valve 8. In some embodiments, the vacuum source 6 may be directly connected to the aspiration lumen 18 of the aspiration catheter 4. A male luer connector 36 and a female luer connector 38 are shown in FIG. 1. As shown, the valve 8 can be a standard two-way stopcock.

[0098]

[0098] The pressure transducer 12 of the suction monitoring system 48 is configured to be fluidly connected between the vacuum source 6 and the suction catheter 4. In FIG. 2A, the suction monitoring system 48 is shown as a first embodiment of a self-contained device. The pressure transducer 12 includes a housing 40 having a cavity 42 extending between a first port 44 and a second port 46. In some embodiments, the first port 44 includes a female luer and the second port 46 includes a male luer. In some embodiments, the first port 44 includes a female luer lock and the second port 46 includes a male luer lock, each of which is detachable to a corresponding luer lock of the opposite gender. The first port 44 is configured to be connected to the vacuum source 6, either directly or with a valve 8 and / or extension tube 10 connected therebetween. The second port 46 is configured to be connected to the suction lumen 18 of the suction catheter 4, for example, by connecting the second port 46 directly or indirectly to the hub 20 of the suction catheter 4. When the aspiration system 2 is used to aspirate bodily fluids and / or substances, e.g., blood and / or blood clots, the bodily fluids and / or substances are aspirated from the beveled opening 24 at the distal end 16 to the female Luer connector 22 at the proximal end 14 through the aspiration lumen 18 of the aspiration catheter, then through the second port 46 of the pressure transducer 12, through the cavity 42, and then through the first port 44. Depending on the amount of vacuum or negative pressure applied by the vacuum source 6 and the amount of flow resistance and the resulting pressure drop along the aspiration system 2, the pressure in the cavity 42 will vary. For example, a highly viscous fluid such as blood or a fluid having solid, semi-solid, or gel-like particles or portions will generate a higher flow resistance through the relatively small aspiration lumen 18 of the aspiration catheter 4 than will water or saline. Thus, the pressure in the cavity 42 of the pressure transducer 12 will be lower (higher negative pressure gradient) as the flow resistance in the aspiration lumen 18 becomes higher.

[0099] For purposes of definition, when speaking of "vacuum," for example, a pressure of -15,000 Pascals (-2.18 pounds per square inch, or psi) is a "greater vacuum" than -10,000 Pascals (-1.45 psi). In reality, a true vacuum in which there are no molecules in the volume is extremely difficult. Furthermore, -15,000 Pascals is a "lower pressure" than -10,000 Pascals. Also, since the absolute value of -15,000 is greater than the absolute value of -10,000, -15,000 Pascals has a greater "absolute vacuum pressure" than -10,000 Pascals. In FIG. 2A, the vacuum sensor 50 is disposed within the cavity 42 of the housing 40 and is in fluid communication with the fluid passing through the cavity 42. The vacuum sensor 50 can be a standard pressure sensor or transducer, including pressure sensors designed primarily to measure positive pressures. It may use any type of pressure sensing technology known in the art, including MEMS technology. In some embodiments, the vacuum sensor 50 is configured for highest precision and / or accuracy within a pressure range of about 0 Pascals to about -101325 Pascals (-14.70 psi), or about -45000 Pascals (-6.53 psi) to about -90000 Pascals (-13.05 psi), or about -83737 Pascals (-12 psi) to about -96527 Pascals (-14 psi). In some embodiments, the power requirements for the vacuum sensor can range from 2.5 Volts DC to 10 Volts DC. In some embodiments, the vacuum sensor 50 can be an analog gauge of the output voltage. In the self-contained embodiment of FIG. 2A, the vacuum sensor 50 is powered by one or more batteries 52. Based on the power requirements of the vacuum sensor 50 described herein and the power requirements of the other components of the suction monitoring system 48, in some embodiments, the one or more batteries 52 can range from 1.5 Volts to 9 Volts. In some embodiments, a measurement device 54, which may include a microprocessor, is also included within the housing. A measurement device 54 is connected to the vacuum sensor 50 and receives a signal from the vacuum sensor 50 indicative of the real-time measured pressure.In some embodiments, the measurement device 54 includes a memory module 56 in which information is stored that may be used by the measurement device 54, for example, in calculations. The information may include, for example, an array of one or more pressure values. In some embodiments, the array of one or more pressure values ​​may be correlated with one or more different corresponding system models or catheter models. The vacuum sensor 50 may be used, in some cases, to detect only the presence or magnitude of a vacuum or negative pressure, for the purpose of monitoring whether the vacuum source 6 (e.g., a syringe) is sufficiently filled and therefore needs to be changed. The vacuum sensor 50 may be used, in some cases, to detect whether there is no vacuum or negative pressure in the system. For example, to detect whether a vacuum or negative pressure has been applied (e.g., whether the vacuum source has been turned on or off).

[0100]

[0100] One or more communication devices 58a, 58b, 58c are included within the aspiration monitoring system 48 and are connected to the measurement device 54. Each of the one or more communication devices 58a-58c is configured to generate a type of alert, including an alert signal 60a-60c, in response to at least a portion of the operation and output of the measurement device 54. In some embodiments, the communication device 58a may include one or more LEDs (light emitting diodes) configured to generate a visual alert via a visual alert signal 60a, such as a light that is illuminated continuously or in a blinking pattern. In some embodiments, the LEDs may be oriented on multiple sides of the communication device 58a so that they can be easily viewed from a variety of different positions. In some embodiments, lights other than LEDs may be used. Light pipes or other illumination conduits may also be incorporated into the embodiments to further position the visual indicator in multiple positions and / or orientations. In some embodiments, the communication device 58b may include one or more vibration generators configured to generate a tactile alert via a tactile alert signal 60b, which may include, but is not limited to, vibration or heat. In some embodiments, the vibration device may resemble a video game controller. In some embodiments, the vibration generator may include a piezoelectric element configured to vibrate when a voltage is applied to it. In some embodiments, the communication device 58c may include one or more sound generating devices configured to generate an audible alert via an audible alert signal 60c, such as a continuous or repeating noise. In some embodiments, the communication device 58c may include a speaker for generating any of a variety of sounds at any of a variety of frequencies (Hz) or sound pressures (dB) within the range of human hearing and / or human tolerance. The communication device 58c may be configured to generate sounds outside the range of human hearing in embodiments where the signal is intended to be sensed as a vibration or other tactile sensation instead of an audible sensation. In some embodiments, the sound generating device may include a buzzer configured to emit one or more audible pitches when a voltage is applied to it.In some embodiments, a piezoelectric element such as that described in connection with communication device 58b can also function as a sound generating device such as that included in communication device 58c. Alert signals 60a-60c can function as a "wake up" warning to the user if the user becomes too focused on other factors during the procedure.

[0101]

[0101] A user of the aspiration system 2 may wish to be notified of a number of conditions that may occur during use of the aspiration system 2. These potential conditions include, but are not limited to, a loss of vacuum or negative pressure due to blockage, loading of the vacuum source 6 and / or a break, crack, or puncture within the aspiration system 2, and the involvement or aspiration of a non-liquid, solid, or semi-solid material, such as a blood clot. The aspiration monitoring system 48 of FIG. 2A is configured to alert a user of the aspiration system 2 about the real-time status of the aspiration system 2, including operational status, such as: whether or not a vacuum or negative pressure is applied; flow status, including whether or not a blood clot is involved, whether or not a blood clot is being actively aspirated, whether or not the system is leaking air, whether or not the system is clogged, whether the vacuum source 6 is full and / or needs to be changed; or other potential configuration issues. The real-time feedback provided relieves the user or operator from the need for excessive personal monitoring of the vacuum source 6, the extension tube 10, or other parts of the aspiration system 2 for improper or undesirable flow or operating conditions, and therefore allows the user to be more focused on the patient receiving treatment. The user knows if a clot is being aspirated or has already been aspirated, or if there is a blockage. Additionally, the user knows if too much blood is being drawn from the patient, or if there is a fault condition such as a leak or tubing kinks in the system. A tubing kink distal to the vacuum sensor 50 can be identified (e.g., by an increase in the measured negative pressure) and a tubing kink proximal to the vacuum sensor 50 can be identified (e.g., by a drop or decrease in the negative pressure gradient). In some cases, the user can attempt to operate the catheter with a vacuum source 6 that is already full (and therefore does not have a significant negative pressure gradient). In some cases, the user may forget to open valve 8 to start suction, but the suction monitoring system 48 will identify that the system is still not functioning and can also communicate a list of potential errors or specific errors (for the particular pressure waveform measured).Real-time awareness of the many factors related to operating conditions may result in safer procedures, shorter procedure times, and reduced blood loss.

[0102]

[0102] The pressure transducer 12 of the aspiration monitoring system 48 is configured to continuously measure and monitor absolute pressure amplitudes within the closed system of the aspiration system 2, and also to measure and monitor relative pressures over time to detect notable flow changes within the flow circuit of the aspiration system 2. Some changes can be identified by absolute pressure measurements, while more subtle pressure variations can be compared to a library stored in memory. Notable conditions can be notified to the user in a timely manner. In some embodiments, the unfiltered signal may be amplified by an amplifier and filtered by a filter, for example, to increase the signal-to-noise ratio. An example of (background) noise 57 in the unfiltered signal can be seen in Figures 5A-5D (labeled in Figure 5A). In some embodiments, one or more algorithms can be used to identify a particular condition of interest, as described herein.

[0103] FIG. 2B illustrates a second embodiment of an aspiration monitoring system 62 having a pressure transducer 12 with a vacuum sensor 50 disposed within the cavity 42 of the housing 40. The vacuum sensor 50 may be powered by at least one battery 52. ​​In some embodiments, the pressure transducer 12 may be reusable and configured to allow charging of the battery 52 or a capacitor (not shown) by direct charging methods or by inductive power transfer methods and devices known in the art. Unlike the aspiration monitoring system 48 of FIG. 2A, the aspiration monitoring system 62 of FIG. 2B includes a measurement device 64, a memory module 66, and a communication device 68 that are external to the pressure transducer 12. A power supply module 72 is also external and may be used to power either the measurement device 64, the memory module 66, or the communication device 68. The communication device 68 may be any of the communication devices 58a, 58b, 58c described in connection with the aspiration monitoring system 48 of FIG. 2A and is configured to generate an alert via an alert signal 70. The communication device 68 may be portable so that it can be located near the user.

[0104] In some embodiments, the communication device 68 may be user wearable. FIG. 3 shows the aspiration monitoring system 78 including an antenna 80 connected to a measurement device 76. The measurement device 76 is similar to the measurement device 54 of the previous embodiment, except that the measurement device 76 wirelessly transmits a communication signal 84 via the antenna 80 to a corresponding antenna 82 of the communication device 74. In some embodiments, the communication device 74 includes a wristband worn by the user, which may include a vibration or heat generator. In some embodiments, the communication device 74 includes an audio speaker that may be attached to the device or even to the patient or user. In some embodiments, the communication device 74 includes an audio speaker with an earpiece or earphone that may be worn by the user. In some embodiments, Bluetooth® communication technology may be used. The real-time feedback provided by the aspiration monitoring system 62 may reduce the time that the aspiration system 2 is actively aspirating without engaging a clot, minimizing the amount of non-thrombotic blood lost through aspiration. This may be particularly beneficial in larger bore catheters, for example, catheters having a diameter of 7 French or greater. Real-time feedback can also minimize the total time the catheter is tracked back and forth through the vessel, minimizing potential damage to the vessel intima, vessel dissection, or distal embolization. By lowering the risk of the aspiration catheter tip being trapped (by suction) against the vessel wall, the distal end of the aspiration lumen can be more aggressively designed for optimal aspiration characteristics. Furthermore, techniques using aspiration catheters can be further performed in a more sophisticated manner with intermittent or continuous knowledge of the aspiration state or sufficiency of the negative pressure gradient. For example, a thrombus fragment may be aspirated, followed by a blood aspiration "chaser," followed by another thrombus fragment, and so on.

[0105]

[0105] Figure 4A shows the distal end 16 of the aspiration catheter 4 in a blood vessel 86 having at least one thrombus 88. The aspiration catheter 4 is advanced in a forward direction F, but the distal end 16 of the aspiration catheter 4 has not yet reached the proximal end 94 of the thrombus 88. The vacuum source 6 (Figure 1) is connected to the aspiration lumen 18 of the aspiration catheter 4 and is activated (i.e., valve 8 opens) to draw blood 96 into the aspiration lumen 18 (arrow A). Referring to Figure 5A, a corresponding curve 98 is depicted for a vacuum or negative pressure of a normal fluid (e.g., blood) over time relative to the conditions of Figure 4A. The curve 98 represents the vacuum or negative pressure sensed by the vacuum sensor 50 of any embodiment presented over time. With no leaks and no thrombus expelled, the curve 98 includes a downward slope 99 as the vacuum source 6 reduces the pressure in the cavity 42 of the pressure transducer 12 to a relatively steady state. A stable pressure curve 97 continues while blood 96 is being aspirated. When the vacuum source 6 is removed from the aspiration lumen 18, for example, by closing valve 8 or by removing any two ports (e.g., Luer), or when the vacuum source 6 is completely filled with blood 96, then an upslope 95 is measured.

[0106]

[0106] The measuring device 54, 64 is configured to compare the curve 97 with information stored in the memory module 56, 66 to identify this condition. In some embodiments, the measuring device 54, 64 uses an algorithm to make the comparison. In some embodiments, the measuring device 54, 64 then sends a signal to the communication device 58a-58c, 74, which generates an appropriate alert. The communication device 58a, for example a particular color LED, may be illuminated, or the LED may flash in a particular pattern or number of flashes. The communication device 58b may create a distinctive sound or generate an audio message in several languages. For example, the audio message may state "thrombus encountered" or "thrombus not encountered." Different types of sounds may be used for each of the multiple "modes" of "thrombus encountered," "active flow," and "vacuum not present." For example, a buzz sound may be used for "thrombus encountered," a beep sound may be used for "vacuum not present," etc. Characteristics of the sounds that may be varied include, but are not limited to, timbre, quality, spectrum, envelope, duration, phase, pitch (frequency), number of sounds (repetitions), etc. The communication device 58c may be vibrated or heated in a characteristic pattern, for example, for a particular number of repetitions or at a particular frequency between repetitions. The user may determine that additional fluoroscopic images (e.g., angiography) or other imaging modalities may be required to better identify the location of the thrombus 88.

[0107]

[0107] Figure 4B shows the distal end 16 of the aspiration catheter 4 advanced to a position where the distal end 16 of the aspiration catheter 4 contacts the proximal end 94 of the thrombus 88. The corresponding curve 93 in Figure 5B represents the vacuum or negative pressure sensed over time by the vacuum sensor 50 of any embodiment presented. As shown in Figure 4B and graphed in Figure 5B, the curve 93 initially has a downward slope 99 following a stable pressure curve 97, but then a clogged condition occurs if the suction causes a portion of the thrombus 88 (e.g., a large or relatively hard portion) to enter and become trapped in the aspiration lumen 18 when the distal end 16 of the aspiration catheter 4 contacts the proximal end 94 of the thrombus 88. If the distal end 16 of the aspiration catheter 4 is stuck to the thrombus 88 by the suction effect, a similar condition occurs where virtually nothing is flowing through the aspiration lumen 18. In either condition, the curve 93 includes a deviation (or blockage) in the fluid pressure 91. If the blockage (or stuck condition) continues, a flat, reduced pressure 89 is measured.

[0108]

[0108] The measuring device 54, 64 is configured to compare the curve 93 with information stored in the memory module 56, 66 to identify this condition. In some embodiments, the measuring device 54, 64 uses an algorithm to make the comparison. In some embodiments, a preset pressure difference ΔP1 can be stored in the memory module 56, 66 as a threshold, whereby measuring a pressure difference 81 below this threshold results in the measuring device 54, 64 not instructing the communication device 58a-58c, 74 to send an alert signal 60a-60c, 70. In some embodiments, if the pressure difference 81 exceeds (or is greater than or equal to) the preset pressure difference ΔP1, then the measuring device 54, 64 sends a signal to the communication device 58a-58c, 74, which generates an appropriate alert. The communication device 58a, for example a particular color LED, may be illuminated, or the LED may flash in a particular pattern or number of flashes. The communication device 58b may create a characteristic sound or generate an audio message in several languages. For example, the audio message may state "Clogged condition." The communication device 58c may vibrate or heat in a characteristic pattern, for example, for a specific number of repetitions or at a specific frequency between repetitions. Once the user recognizes that a clogged condition exists, the user may pull and retract the aspiration catheter 4 in an attempt to contact a portion of the thrombus 88 that may be aspirated. If a portion of the thrombus becomes lodged in the aspiration lumen 18 and repositioning of the aspiration catheter 4 does not produce a successful result, the aspiration catheter 4 may be removed and the aspiration system 2 may be re-purged, for example, by positive pressurization.

[0109]

[0109] Figure 4C illustrates the distal end 16 of the aspiration catheter 4 in a typical situation when a break occurs in the aspiration system 2. For example, a crack, leak, puncture, pinhole, looseness, or break may draw air into the aspiration lumen 18 of the aspiration catheter 4, the cavity 42 of the pressure transducer 12, the interior of the dilation tube 10, the valve 8, or the vacuum source 6. As graphed in curve 85 of Figure 5C, a downward slope 99 followed by a stable pressure curve 97 is measured, but at the time of break 87, an upward slope 83 begins.

[0110]

[0110] The measuring device 54, 64 is configured to compare the curve 85 with information stored in the memory module 56, 66 to identify this condition. In some embodiments, the measuring device 54, 64 uses an algorithm to make the comparison. In some embodiments, the measuring device 54, 64 then sends a signal to the communication device 58a-58c, 74, which generates an appropriate alert. The communication device 58a, for example a specific color LED, may be illuminated, and the LED may flash in a specific pattern or number of flashes. The communication device 58b may create a characteristic sound or generate an audio message in several languages. For example, the audio message may state "SYSTEM LEAK". The communication device 58c may vibrate or heat in a characteristic pattern, for example, at a specific frequency for a specific number of repetitions or repetitions. Upon receiving the alert, the user is to check the components of the aspiration system 2 and repair the damage or replace one or more of the components of the aspiration system 2. For example, in some cases, when the measurement device 54, 64 identifies a decrease in the applied vacuum or negative pressure, the communication devices 58a-58c, 74 can alert the user so that the user can change or recharge the depleted vacuum source 6 (e.g., by filling it with blood and / or blood clots).

[0111] 4D shows the distal end 16 of the aspiration catheter 4 upon successful aspiration of a piece or portion 90 of a thrombus 88. In some cases, the piece or portion 90 may follow a tortuous path 92 due to obstructions or collisions with the inner wall of the aspiration lumen 18 while being pulled through the aspiration lumen 18. In some cases, the piece or portion 90 may catch on or slip within the inner wall of the aspiration lumen 18 due to, for example, variations in the inner diameter of the aspiration lumen 18 along its length. Any of these situations may cause a series of corresponding increases and decreases in pressure detected by the pressure transducer 12 while the piece or portion 90 is moving through the aspiration lumen 18. As graphed by curve 79 in FIG. 5D, a downward slope 99 followed by a stable pressure curve 97 is measured, but as the piece or portion 90 of the thrombus 88 moves down the aspiration lumen 18 of the aspiration catheter 4, a deviation 77 in fluid pressure including one or more increases or decreases in pressure (increases or decreases in vacuum or negative pressure) is measured. Once the piece or portion 90 of the thrombus 88 exits the proximal end of the aspiration lumen 18 of the aspiration catheter 4, a second stable pressure curve 75 is measured. The duration 67 of the deviation 77 is the transit time of the particular significant piece or portion 90 of the thrombus 88. The duration 67 can range considerably, but in some cases may be less than one second and up to about 30 seconds. A single thrombus being aspirated may cause a single pressure drop (blip) that is identified by the measurement devices 54, 64. This occurrence may then be communicated to the user by the communication devices 58a-58c, 74. Repeatedly, as additional pieces or portions 90 of the clot 88 are aspirated and move down the aspiration lumen 18 of the aspiration catheter 4, another deviation 73 in fluid pressure is measured, including one or more increases or decreases in pressure (increases or decreases in vacuum or negative pressure). At the end of the curve 79, the vacuum source 6 is shown to be completely filled with blood 96 and pieces or portions 90 of the clot 88, and an upward slope 95 is measured.

[0112]

[0112] To distinguish when the pieces or portions 90 of the thrombus 88 are being actively aspirated, as in deviations 77 and 73, and when the pieces or portions of the thrombus 88 are not being actively aspirated or are not substantially aspirated, as in stable pressure curve 97, stable pressure curve 75, and stable pressure curve 71, the measurement device 54, 64 is configured to compare the curve 79 with information stored in the memory module 56, 66. In some embodiments, the measurement device 54, 64 uses an algorithm to make the comparison. In some embodiments, a pre-set pressure difference ΔP2 can be stored in the memory module 56, 66 as a threshold value, whereby measuring a pressure difference 69 below this threshold results in the measurement device 54, 64 not instructing the communication device 58a-58c, 74 to transmit a first type of alert via the alert signal 60a-60c, 70. In some embodiments, if the pressure difference 69 exceeds (or is greater than or equal to) the pre-set pressure difference ΔP2, then the measurement device 54, 64 sends a signal to the communication device 58a-58c, 74, which generates an appropriate alert. The communication device 58a may be illuminated, for example a particular color LED, and the LED may flash in a particular pattern or number of flashes. In some embodiments, the communication device 58a may include a light, and the intensity of the light increases proportionally to the pressure. The communication device 58b may create a distinctive sound or generate an audio message in several languages. For example, the audio message may state that "thrombus is being aspirated." In some embodiments, the communication device 58b may include one or more noises or beeps. In some embodiments, the communication device 58b may include a particular sequence of beeps, each corresponding to a different condition. For example, three short beeps may correspond to the thrombus not being aspirated, while five long, loud beeps may correspond to a system leak. In some embodiments, several different tones (pitches) may be used to alert the user about different conditions.As an example, a low pitched tone can be used for a first condition (e.g., clot not being aspirated) and a second, higher pitched tone can be used for a second condition (e.g., system leak). In some embodiments, a different number of tones can be used to alert the user to a first condition and a second number of tones (e.g., in a different combination or with additional tones) can be used to alert the user to a second condition. The communication device 58c can vibrate or heat in a characteristic pattern, for example, for a specific number of repetitions or at a specific frequency between repetitions. Once the user recognizes that the clot is being aspirated, the user can choose to advance (or retract) the aspiration catheter 4 along the length of the clot 88 in an attempt to continue aspirating the clot 88, for example, by fluoroscopic visualization. In some cases, the user can choose to stop advancing or retracting the aspiration catheter 4 a certain amount of time after the alert is generated to allow a piece or portion 90 of the clot 88 to completely exit the aspiration lumen 18. When the measurement device 54, 64 identifies a stable pressure curve 75, 71 following the deviation 77, 73, the measurement device 54, 64, in some embodiments, transmits a signal that causes the communication device 58a-58c, 74 to generate a second type of alert via the alert signal 60a-60c, 70. For example, in some embodiments, the communication device 58b can transmit a voice message stating "no more clots will be aspirated." Once the user realizes that no more clots will be aspirated, the user can advance or retract the aspiration catheter in an attempt to contact another portion of the clot 88 that can be aspirated. In some embodiments, the deviation 77 can be reliably identified as a true deviation indicating that the clot is being actively aspirated and the pressure differential 69 is between about 700 Pascals and about 1700 Pascals. In some embodiments, the deviation 77 can be reliably identified as a true deviation indicating that the clot is being actively aspirated and the pressure differential 69 is between about 1000 Pascals and about 1300 Pascals.In some embodiments, deviation 77 can be reliably identified as a true deviation indicating that a clot is being actively aspirated, and pressure differential 69 is approximately 1138 Pascals. Pressure differential 69 can be measured by determining baseline pressure 63 and peak pressure 61 and determining the difference in absolute values.

[0113]

[0113] For example: Absolute Value Difference (AVD) = |(-89631 Pascals) - (-90769 Pascals)| = 1138 Pascals Or, for example: Absolute Value Difference (AVD) = |(-43710 Pascals) - (-45102 Pascals)| = 1281 Pascals

[0114]

[0114] The pressure differential 81 (FIG. 5B) may also represent a deviation that the communication devices 58a-58c, 74 may then identify in a similar manner after which they may generate an appropriate alert, such as a "clogging condition."

[0115]

[0115] Because the vacuum or negative pressure has a nominal value less than zero, the peak pressure 61 is actually a lower value than the baseline pressure 63, as shown in FIG. 5D. In some embodiments, the measurement device 54, 64 may be configured to make a comparison between the stored difference time t1 and the duration 65 of only one of the one or more increases or decreases in pressure of the deviation 77, for example, by using an algorithm. For example, in some embodiments, if the duration is between about 0.001 seconds and about 0.50 seconds, the deviation may be positively identified as a true deviation indicating that the clot is being actively aspirated. In some embodiments, if the duration is between about 0.005 seconds and about 0.10 seconds, the deviation may be positively identified as a true deviation indicating that the clot is being actively aspirated. In some embodiments, if the duration is between about 0.05 seconds and about 0.20 seconds, the deviation may be positively identified as a true deviation indicating that the clot is being actively aspirated. In some embodiments, the measurement device 54, 64 is configured to recognize the deviation 77 after measuring two or more increases or decreases in pressure. In some embodiments, the measurement device 54, 64 is configured to recognize the deviation 77 after measuring five or more increases or decreases in pressure. In some embodiments, the measurement device 54, 64 is configured to recognize the deviation 77 after measuring ten or more increases or decreases in pressure.

[0116]

[0116] The reference pressure 63 may be predetermined and stored in the memory module 56, 66 in some embodiments. In some embodiments, the reference pressure 63 may be stored in the memory module 56, 66 during manufacture of the aspiration monitoring system 48, 62, 78, but the reference pressure 63 may be input by a user before or during a particular procedure. In some embodiments, the reference pressure 63 may be determined or otherwise defined by the measurement device 54, 64, 76 based on averaging a certain number of samples of the measured pressure. The reference pressure 63 may be configured as a moving average, such as a running or rolling average. Several types of moving averages may be used, including simple moving averages, cumulative moving averages, weighted moving averages, or exponential moving averages. In any of these cases, a threshold value may be determined by the measurement device 54, 64, 76 based on the determined reference pressure 63 and a known pressure difference ΔP. In some cases, the pressure difference ΔP may also be calculated by the measurement device 54, 64, 76 based on the determined reference pressure 63 and a known threshold value.

[0117]

[0117] Insertion of a pressure transducer 12 consistent with either the embodiment of FIG. 2A or the embodiment of FIG. 2B does not significantly alter the performance characteristics of the aspiration system 2 since the cavity 42 is relatively short and has a relatively large inner diameter, and is therefore not a significant source of fluid flow resistance. In some embodiments, the inner diameter may be from about 2.2 mm (0.086 inches) to about 3.2 mm (0.125 inches). In some embodiments, the measurement device 54, 64, 76 need not include a microprocessor, since predefined set points (e.g., at specific thresholds) may be included in firmware, a microcontroller, or other locations. In some embodiments, but not limited to the embodiment of FIG. 2B, the pressure transducer 12 may be an off-the-shelf blood pressure monitor system modified or extended with other components. In some embodiments, the off-the-shelf blood pressure monitor system may be used as an output for the aspiration monitoring system 48, 62, 78. In some embodiments, the aspiration catheter 4 may have a pressure transducer at the distal end 16. This pressure transducer may be used as the pressure transducer 12 for the aspiration monitoring system 48, 62, 78. In some embodiments, the pressure sensor may be located in the introducer sheath, guide catheter, or other component of the system that is in fluid communication with the Tuohy-Borst valve and aspiration lumen 18. In some embodiments, the pressure sensor can be located anywhere within the aspiration lumen of the aspiration catheter.

[0118]

[0118] In some embodiments, instead of LEDs, visual alerts can be provided by a communication device 58a with a display that displays a visual message in a particular language, for example, "thrombus encountered", "thrombus not encountered", "clogged condition", "system leak", "vacuum loss", "thrombus being aspirated", or "no more thrombus aspirated". The visual message can be combined with any of the other alert signals 60a-60c, 70 described herein. The aspiration monitoring system 48, 62, 78 described herein provides real-time awareness to a user performing an aspiration procedure, such as removal of a thrombus with the aspiration system 2. One skilled in the art will recognize that by knowing the real-time status of the aspiration system 2, a user can immediately modify the procedure to optimize results, increase safety for the patient and / or medical personnel, reduce costs (e.g., number of vacuum sources 6 required), and reduce procedure time (also cost-effectiveness). Because a user is typically performing multiple tasks during a suction procedure, the sensory assistance provided by the suction monitoring system 48, 62, 78 allows the user to focus on these tasks without trying to continually monitor a situation that is often difficult to monitor visually. The user can also modify and control the suction monitoring system 48, 62, 78 through an input 59 (FIG. 2B), which may be a data entry module, a keyboard, or a series of buttons associated with a display. The input 59 may, in some embodiments, include an auditory input that receives voice commands. Alternatively, the user may enter information and control the suction monitoring system 48, 62, 78 remotely.Some alerts that a user may select or deselect in the aspiration monitoring system 48, 62, 78 include, but are not limited to: whether the aspiration system 2 is potentially blocked or clogged or is flowing normally; whether a clot has been contacted; whether a clot has occurred; whether the vacuum source 6 is adequate or whether the vacuum source 6 is depleted and in need of replacement; whether a leak is present in the aspiration system 2; whether the configuration or connection of the components of the aspiration system 2 has been performed correctly or incorrectly; whether to advance the catheter distally; whether to advance the catheter backwards; whether to continue moving the catheter at the same speed; whether to increase or decrease the speed of catheter advancement; whether a clot is being actively aspirated; and whether to stop a clot from being actively aspirated. As a user becomes more familiar with the aspiration monitoring system 48, 62, 78, the user may also unconsciously initiate certain responses to the system. For example, a user may automatically retract the catheter upon hearing a clot warning signal (e.g., three beeps), automatically initiate catheter advancement upon hearing a free blood flow signal (e.g., two beeps), and / or initiate fluoroscopy visualization. By being "one" with the suction monitoring system 48, 62, 78 and the catheter, the user optimizes their reactions and actions. This can help improve the skill of having the catheter take a small "bite" of a clot, followed by a "bite" with some fast flowing blood "chaser" to flush / open the lumen. This also helps minimize the chance of clogging, reducing the need to maintain or correct the system (removing the catheter, flushing the lumen outside the patient, replacing the catheter). The overall user experience is improved as the user gets immediate gratification and is immediately notified of any errors or instances of concern.

[0119] In some embodiments, alternative power sources may be used, e.g., standard AC power with or without an AC / DC converter; direct connection to existing equipment (e.g., vacuum pumps, etc.); solar power. The suction monitoring system 48, 62, 78 may be packaged sterile or resterilizable by techniques known to those skilled in the art. In some embodiments, a flow meter or volume meter may be used in conjunction with or in place of the pressure gauge 12, e.g., to determine clogging or changes in the magnitude of vacuum or negative pressure. In some embodiments, the input 59, power module 72, measurement device 64, memory module 66, and communication device 68 (e.g., of FIG. 2B) may all be incorporated into a single external device that may in some cases be sold separately. In some embodiments, the external device may have other functions as well, such as providing suction and / or infusion (negative and / or positive pressure) to the catheter. In other embodiments, the external device may include some, but not all, of the input 59, power module 72, measurement device 64, memory module 66, and communication device 68. For example, in some embodiments, communication device 58 (FIG. 2A) can replace external communication device 68 and can be mounted on aspiration monitoring system 48, while input 59, power module 72, measurement device 64, memory module 66 (FIG. 2B) are incorporated into a single external device. Many combinations are possible, as described in more detail herein.

[0120] Although aspiration of thrombi has been described in detail, the aspiration monitoring system 48, 62, 78 has utility in any aspiration application where a heterogeneous medium is being aspirated. This may include aspiration of emboli (not including thrombotic emboli) from ducts, vessels, or cavities of the body, or from solid or semi-solid parts of the body, including, but not limited to, fat, breast, and cancerous tissue portions.

[0121]

[0121] In some embodiments, the aspiration system 2 will be provided to the user as a kit having all or some of the described components, while in other embodiments, only the aspiration monitoring system 48 is provided. Although the discussion herein includes embodiments for aspirating clots and blood, the definition of the term "fluid" should be understood throughout to include liquids and gases.

[0122] In some embodiments, additional or alternative sensors may be used to monitor flow conditions for notification to the user, including, but not limited to, a Doppler sensor, an infrared sensor, or a laser flow detector. In some embodiments, an external Doppler sensor may be used. In some embodiments, an infrared sensor or a laser flow detector may be used around the dilation tube 10.

[0123]

[0123] Further embodiments allow real-time communication of a particular value of fluid pressure (e.g., vacuum level or negative pressure level) measured by the sensor 50. For example, as the negative pressure gradient increases, the audible sound may increase in proportion to the sound intensity or sound pressure level (dB). Alternatively, the pitch (frequency) of the audible sound may be increased as the negative pressure gradient increases and decreased in pitch as the negative pressure gradient decreases (similar to a siren). By controlling either the signal amplitude or the signal frequency in proportion to the fluid pressure, the system can give the user a real-time sense of whether the negative pressure gradient is increasing, decreasing, or remaining at that, as well as whether the pressure is close to zero or quite different from zero. When an audible sound is used as a signal, the user's eyes can remain focused on the procedure by looking at a fluoroscopic image monitor, the patient, or another piece of equipment.

[0124] FIG. 6 illustrates a graph 800 of time (x-axis) and multiple variables (y-axis). A pressure curve 802 illustrates a vacuum or negative pressure being applied with a pressure drop 808, followed by a vacuum maintenance 810a with a vacuum or negative pressure decrease 812 and a vacuum or negative pressure increase 814. A vacuum or negative pressure removal 816 is illustrated at the end of the pressure curve 802. In some cases, the vacuum or negative pressure decrease 812 may be caused by a temporary or permanent leak or detachment in the system or by the loading of a vacuum source (e.g., a syringe). In FIG. 6, a vacuum or negative pressure decrease 812 is illustrated temporarily, followed by a vacuum maintenance 810b. The vacuum or negative pressure increase 814 may in some cases be caused by a clot being aspirated through the system, may occur over a short or long period of time, and may be steady or intermittent. The amount of reduced pressure applied to the pressure curve 802 varies, but in some embodiments, it may be desirable to generally indicate to the user only whether or not a vacuum or negative pressure is being applied. The measurement device 54, 64, 76 may be configured to apply an algorithm to the signal from the vacuum sensor 50 (pressure sensor) that calculates the inverse value represented by dashed curve 804. The measurement device 54, 64, 76 may further apply an algorithm to increase, amplify, or otherwise enhance the signal to facilitate discrimination, for example, within the range of human audible discrimination (hearing). For example, a modified signal curve 806 may be created that has the following general mathematical relationship with the signal from the vacuum sensor 50 represented by pressure curve 802:

[0125]

[0125] Sound pressure level (dB) = A + B × (1 / fluid pressure) where A is the first constant, B is the second constant.

[0126]

[0126] In one particular example, a modified signal curve 806 can be created that has the following mathematical relationship with the signal from the vacuum sensor 50 represented by the pressure curve 802:

[0127]

[0127] Sound pressure level (dB) = 70 + 20 × (1 / fluid pressure (kPa)) where dB is the unit of decibels, kPa is the unit of kilopascal.

[0128]

[0128] The modified signal curve 806 can be algorithmically configured so that the sound pressure level drops below the audible level of human hearing at relatively small magnitudes of vacuum or negative pressure, giving the user an "on / off" perception of the applied vacuum or negative pressure.

[0129] FIG. 7 shows a graph 820 of time (x-axis) and multiple variables (y-axis). A pressure curve 822 shows a vacuum or negative pressure applied at a pressure drop 828 and a maintenance of vacuum or negative pressure 830a with a decrease in vacuum or negative pressure 832 and an increase in vacuum or negative pressure 834. A removal of vacuum or negative pressure 836 is shown at the end of the pressure curve 822. In some cases, the decrease in vacuum or negative pressure 832 may be caused by a temporary or permanent leak or peeling in the system or by the loading of a vacuum source (e.g., a syringe). In FIG. 7, the decrease in vacuum or negative pressure 832 is shown temporarily, followed by a maintenance of vacuum or negative pressure 830b. The increase in vacuum or negative pressure 834 may in some cases be caused by a clot being drawn through the system and may occur over a short or long period of time and may be steady or intermittent. In some cases or configurations, it may be desirable for a user to have very specific real-time or approximate real-time characteristics of the magnitude or level of the applied vacuum (generally negative pressure gradient). The measurement device 54, 64, 76 may be configured to apply an algorithm to the signal from the vacuum sensor 50 (pressure sensor) that calculates an absolute value represented by dashed curve 824. The measurement device 54, 64, 76 may further apply an algorithm to increase, amplify, or otherwise enhance the signal to facilitate discrimination, for example, within the human audible discrimination (hearing) range. For example, a modified signal curve 826 may be created that has the following general mathematical relationship with the signal from the vacuum sensor 50 represented by pressure curve 822:

[0130]

[0130] Sound pressure level (dB) = A + B × |(fluid pressure)| where A is the first constant, B is the second constant.

[0131]

[0131] In one particular example, a modified signal curve 826 can be created that has the following mathematical relationship with the signal from the vacuum sensor 50 represented by the pressure curve 822:

[0132]

[0132] Sound pressure level (dB) = 2 × |(fluid pressure (kPa))| where dB is the unit of decibels, kPa is the unit of kilopascal.

[0133]

[0133] The modified signal curve 826 may be configured with an algorithm such that the sound pressure level follows the amount of vacuum or negative pressure being applied and therefore appears to a user to be louder as the vacuum or negative pressure increases.

[0134] FIG. 8 shows a graph 840 of time (x-axis) and multiple variables (y-axis). A pressure curve 842 shows a vacuum or negative pressure applied at a pressure drop 848 and a maintenance of vacuum or negative pressure 850a with a decrease in vacuum or negative pressure 852 and an increase in vacuum or negative pressure 854. A removal of vacuum or negative pressure 856 is shown at the end of the pressure curve 842. In some cases, the decrease in vacuum or negative pressure 852 may be caused by a temporary or permanent leak or peel in the system or by the loading of a vacuum source (e.g., a syringe). In FIG. 8, the decrease in vacuum or negative pressure 852 is shown temporarily, followed by a maintenance of vacuum or negative pressure 850b. The increase in vacuum or negative pressure 854 may in some cases be caused by a clot being drawn through the system and may occur over a short or long period of time and may be steady or intermittent. As mentioned above, in some cases or configurations, it may be desirable for a user to have very specific real-time or approximate real-time characteristics of the magnitude or level of the applied vacuum (generally negative pressure gradient). The measurement device 54, 64, 76 may be configured to apply an algorithm to the signal from the vacuum sensor 50 (pressure sensor) that calculates an absolute value represented by the dashed curve 844. The measurement device 54, 64, 76 may further apply an algorithm that determines the frequency (or pitch) of an audible sound that varies within the human audible frequency range, for example, within the human audible discrimination (hearing) range. For example, a modified signal curve 846 may be created that has the following general mathematical relationship with the signal from the vacuum sensor 50 represented by the pressure curve 842:

[0135]

[0135] Sound frequency (Hz) = A + B × |(fluid pressure)| where A is the first constant, B is the second constant.

[0136]

[0136] In one particular example, a modified signal curve 846 can be created that has the following mathematical relationship to the signal from the vacuum sensor 50 represented by the pressure curve 842:

[0137]

[0137] Sound frequency (Hz) = 50 × |(fluid pressure (kPa))| where Hz is hertz (1 / second) kPa is the unit of kilopascal.

[0138]

[0138] The modified signal curve 846 may be configured with an algorithm such that the sound frequency appears to the user to follow the amount of vacuum or negative pressure being applied. In this embodiment, the pitch of the sound is "higher" when the vacuum or negative pressure increases (fluid pressure decreases) and "lower" when the vacuum or negative pressure decreases. Alternatively, the opposite may be chosen such that the pitch of the sound is lower when the vacuum or negative pressure increases.

[0139] FIG. 9 shows a graph 860 of time (x-axis) and multiple variables (y-axis). The pressure curve 862 shows a vacuum or negative pressure applied with a pressure drop 868 and a vacuum or negative pressure maintenance 870 with one or more pressure decreases and increases 872. These one or more pressure decreases and increases 872 (or vacuum or negative pressure increases and decreases) can represent, in some cases, a clot being aspirated through the aspiration lumen of the aspiration catheter. In some cases, a single decrease 873 of pressure (increase in vacuum or negative pressure) may occur. As with any one or more pressure decreases and increases 872, the single decrease in pressure 873 can, in some cases, be extended in duration as shown in FIG. 9. In some cases or configurations, it may be desirable for the user to have very specific real-time characteristics or approximate real-time characteristics as these small disruptions occur, which may correspond to the catheter finding and aspirating a portion of the clot. The measurement devices 54, 64, 76 are configured to apply an algorithm that determines the frequency (or pitch) of audible sounds that vary within the human audible frequency range, e.g., within the range of human audible discrimination (hearing). For example, a modified signal curve 866 can be created that has the following general mathematical relationship with the signal from the vacuum sensor 50 represented by the pressure curve 862:

[0140]

[0140] Sound frequency (Hz) = A + B × (fluid pressure) where A is the first constant, B is the second constant.

[0141]

[0141] In one particular example, a modified signal curve 866 can be created that has the following mathematical relationship to the signal from the vacuum sensor 50 represented by the pressure curve 862:

[0142] Sound frequency (Hz) = 40 × (fluid pressure (kPa)) where Hz is hertz (1 / second) kPa is the unit of kilopascal.

[0143]

[0143] Note that in this formula, absolute values ​​are not used, but the actual values ​​of the fluid pressure are used, or in some cases absolute values ​​(or negative values) may be used.

[0144]

[0144] The modified signal curve 866 may be configured with an algorithm such that the sound maintains a steady pitch until the clot is aspirated through the catheter, at which time the pitch changes slightly, but noticeably, from the steady pitch. For example, in some embodiments, the pitch may change from about 20 Hz to about 2000 Hz, corresponding to a pressure change of about 1 kPa to about 2 kPa, or about 40 Hz to about 80 Hz.

[0145] In any example, the modification of the signal may include any type of signal conditioning or modification, including, but not limited to, filtering, amplification, or isolation. The modified signal curve 806, 826, 846, 866 is used to determine the output signal generated by the communication device 58, 68, 74. As described above, if the output signal of the communication device 58, 68, 74 is configured to be an audible sound, the sound pressure level may be changed or the sound frequency may be changed. In some embodiments, the output signal of the communication device 58, 68, 74 may change both its sound pressure level and sound frequency. In one embodiment, the sound frequency changes continuously in proportion to the fluid pressure, but at one or more particular thresholds of the fluid pressure, the sound pressure level may change very suddenly and noticeably. Thus, communication is made in two parts: a continuous real-time status indicator and an intermittent alert indicator (fault, danger, etc.). In some cases, the continuous real-time status indicator may represent a first continuous signal and the alert indicator may represent a second alert signal. In other cases, continuous real-time status indicators and alert indicators may be combined and integrated into the same signal. In some embodiments, other psychoacoustic characteristics may be altered using a variable sound generator. In some embodiments, the spectral envelope may be altered. In some embodiments, the timbre may be altered to vary levels between bright and dark, warm and harsh, or different noise "colors" (pink, white, blue, black, etc.).

[0146]

[0146] Although an audible output from the communication devices 58, 68, 74 has been described in the examples of Figures 6-9, other communication signals including visual or tactile signals can also be used. Tactile signals can also include vibration devices or heat generating devices, either of which can be varied (as described) in relation to the measured fluid pressure. The amplitude of either frequency can be similarly varied in communication signals including signals other than audible signals already described. For example, the intensity of the light can be varied or the frequency (e.g., color) of the light can be varied. The amplitude of the displacement of the vibration device can be varied (or other techniques to vary the vibration intensity) or the frequency of the vibration can be varied.

[0147]

[0147] In some cases, a pseudo-continuous analog can be used in place of a true variable output. For example, instead of a single light with a continuously varying intensity, an array of lights can be used, for example an array containing multiple LEDs, where an increasing level of vacuum or negative pressure causes more LEDs to light up, and a decreasing level of vacuum or negative pressure causes fewer LEDs to light up. The same can be done with an array containing multiple vibrating elements, where more elements begin to vibrate with an increase or decrease in fluid pressure depending on the application.

[0148]

[0148] In any of the embodiments described in relation to Figures 6 to 9, the formula for the sound pressure level or sound frequency depending on the fluid pressure as a variable can depend on the actual measured fluid pressure or the absolute value of the actual measured fluid pressure, but it is also possible to use the measured fluid pressure in an alternative manner. For example, a reference pressure 63 that is preset, pre-determined or determined or calculated by any other method (such as averaging) can be used, and the difference between the measured pressure and the reference pressure 63 can be used as a variable, which is based on a certain dependency (e.g. a proportional relationship).

[0149]

[0149] Thus, the basic mathematical relationships used in conjunction with the proportional relationships described with respect to the embodiment of Figure 6 can be expressed as follows:

[0150]

[0150] Sound pressure level (dB) = A + B × (1 / ΔP) where A is the first constant, B is a second constant, ΔP is the difference between the reference pressure and the measured fluid pressure.

[0151] Similarly, the basic mathematical relationships used in conjunction with the proportional relationships described with respect to the embodiment of FIG.

[0152]

[0152] Sound pressure level (dB) = A + B × |(ΔP)| where A is the first constant, B is a second constant, ΔP is the difference between the reference pressure and the measured fluid pressure.

[0153] Similarly, the basic mathematical relationships used in the proportionality described with respect to the embodiment of FIG.

[0154]

[0154] Sound frequency (Hz)=A+B×|(ΔP)| where A is the first constant, B is a second constant, ΔP is the difference between the reference pressure and the measured fluid pressure.

[0155] Similarly, the basic mathematical relationships used in the proportionality described with respect to the embodiment of FIG.

[0156]

[0156] Sound frequency (Hz)=A+B×(ΔP) where A is the first constant, B is a second constant, ΔP is the difference between the reference pressure and the measured fluid pressure.

[0157]

[0157] A pressure transducer 912 of an aspiration monitoring system 900 for connecting to an aspiration system including a suction catheter 4 is shown in FIG. 10. The pressure transducer 912 includes a housing 40, a first port 44, a second port 46, and a cable 902 for transmitting a signal. The cable 902 includes an interface 904 or plug configured to connect to a port 906 of a console 908 of the aspiration monitoring system 900. The housing 40 of the pressure transducer 912 includes a cavity 42 extending between the first port 44 and the second port 46. The console 908 is powered by a power module 972 connected to the console 908 and may include an AC or DC power source. The console 908 may include a measurement device 964, a memory module 966, and a communication device 968, which may be connected to each other as described in the previous embodiment and configured such that the communication device 968 can generate a signal 970, which may be an alert signal, a continuous signal, a composite signal, or other type of signal. The console 908 may also include wired or wireless connections to other interfaces or displays found at the healthcare site, such as a monitor 931. In some embodiments, the monitor 931 may be a monitor that also displays fluoroscopic or angiographic images, or may also display electrocardiogram or blood pressure graphics or other information. The monitor 931 may have a portion that maintains the status of aspiration. For example, it may read "thrombus being aspirated" or "thrombus not detected." The pressure transducer 912 (housing 40, ports 44, 46, cable 902, interface 904) may be sold sterile and may be configured to output a signal that is received by the console 908, such as the measurement device 964 of the console 908. The pressure transducer 912 may have its own internal power source (e.g., battery 52 in FIG. 2A) or may be powered by a connection to the console 908 or by a connection to the aspiration catheter 4 or dilation tube 10. In some embodiments, the console 908 may be configured to identify and / or recognize the pressure transducer 912, for example, to recognize a particular model of the pressure transducer 912.In some embodiments, the console 908 may be configured to measure the resistance between two electrical contacts in the pressure transducer 912 to identify the type (e.g., model) of the pressure transducer. In some embodiments, the console 908 may be configured to read an RFID chip on the pressure transducer 912. The console 908 may also be configured to connect to two or more different models of pressure transducers. The ports 906 may comprise at least one port, which may include two or more ports, and each port may be configured to allow connection of a different model of pressure transducer.

[0158] 11 includes an aspiration console 1001 having a connector 1002 or hub (e.g., male luer) for connecting to an aspiration catheter 4, for example to a connector 22 (e.g., female luer) of the aspiration catheter 4. The aspiration console 1001 is powered by a power module 972 connected to the aspiration console 1001 and may include an AC or DC power source. The aspiration console 1001 may include a canister 1006 for collecting aspirated material and may include a vacuum pump 1004 for generating a vacuum for generating suction. A tube 1008 may be connected between the canister 1006 and the connector 1002. In some embodiments, the canister 1006 is removable or replaceable. The aspiration monitoring system 900 includes a pressure sensor 1010 (e.g., vacuum sensor) in fluid communication with the tube 1008. The tube 1008 may alternatively include a lumen formed inside a manufactured part. The aspiration monitoring system 900 is shown in more detail in FIG. 12 and can include some or all of the features described in connection with FIG. 10. The aspiration console 1001 can also include wired or wireless connections to other interfaces or displays found at the healthcare site, such as a monitor 931. In some embodiments, the monitor 931 can be a monitor that also displays fluoroscopic or angiographic images, or that also displays electrocardiogram or blood pressure graphics or other information. Combining all communications related to the procedure on a single monitor or at a single monitor location allows the user to achieve uninterrupted focus, freeing the user to focus solely on the safe advancement and placement of the aspiration catheter near the clot.

[0159] 13 includes an aspiration / infusion console 1101 having a first connector 1016 or hub (e.g., male luer) for connecting to an infusion lumen 1020 of a forced aspiration catheter 1013 and a second connector 1012 or hub (e.g., male luer) for connecting to an aspiration lumen 1018 of the forced aspiration catheter 1013. The first connector 1016 at the proximal end 14 of the forced aspiration catheter 1013 is configured to connect to a connector 1024 (e.g., female luer) of a y-connector 1022, and the second connector 1012 is configured to connect to a connector 1026 of the y-connector 1022. The aspiration / infusion console 1101 is powered by a power module 972 connected to the aspiration console 1101 and which may include an AC or DC power source. The aspiration console 1101 may include a canister 1106 for collecting aspirated material and may include a vacuum pump 1104 for generating a vacuum or negative pressure for generating suction. A tube 1108 may be connected between the canister 1106 and the connector 1012. The positive pressure pump 1014 is connected to a fluid source 1032 (e.g., a saline bag) and configured to infuse the infusion fluid at high pressure through the connector 1016. The aspiration monitoring system 900 includes a pressure sensor 1110 (e.g., a vacuum sensor) in fluid communication with the tube 1108. Alternatively, the tube 1108 may include a lumen formed inside the manufactured part. The aspiration monitoring system 900 is shown in more detail in FIG. 14 and may include some or all of the features described in connection with FIG. 10. At the distal end 16 of the forced aspiration catheter 1013, the infusion lumen 1020 terminates in an orifice 1028 and is configured to generate a jet 1030 formed from the high pressure infusate exiting the orifice 1028. The jet 1030 creates a suction force at the distal end 16 of the forced aspiration catheter 1013 that enters the aspiration lumen 1018 and pushes material (e.g., blood clots) into the aspiration lumen 1018 and into the canister 1106. The aspiration / infusion console 1101 can also include wired or wireless connections to other interfaces or displays found at the healthcare site, such as a monitor 931.In some embodiments, monitor 931 may be a monitor that also displays fluoroscopic or angiographic images, or may also display electrocardiogram or blood pressure graphics or other information.

[0160]

[0160] In another embodiment, the forced suction catheter 1013 of the suction catheter 4 may have an additional lumen or guide channel for placement of an additional device or tool. In some embodiments, the guidewire lumen 26 can be used as this additional lumen and can extend the entire length or most of the length of the catheter so that the lumen is accessible from the proximal end 14. The additional device or tool can include a laser fiber, a machine screw, a vibrating wire, or various other modalities to disrupt thrombus or other material.

[0161]

[0161] In any of the presented embodiments, the system may be configured such that most or all of the components are supplied together, such as a catheter and a suction monitoring system that are permanently attached to one another. In some embodiments, the suction catheter and / or the suction monitoring system may include configurations that are intentionally difficult to reprocess (e.g., clean or resterilize), thereby preventing uses that may not be recommended or warranted, which may risk patient infection and / or device malfunction. For example, the sensor or parts adjacent to the sensor may be intentionally difficult to access or clean. Or, one or more batteries may not be accessible or alterable.

[0162]

[0162] In some embodiments, it may be desirable to have other descriptive alerts that can be tied to the pressure measurement or to the pressure measurement in combination with another measured characteristic. For example, if a sensor in the aspiration catheter (accelerometer or temperature sensor) is used to detect catheter movement, changes in this sensor can be tied to the pressure sensor. In this way, a catheter that engages a clot at its tip and is moved (e.g., begins to be pulled out of the patient) may trigger an alert: "Warning: Do not move the catheter. Risk of thromboembolism."

[0163] FIG. 15 is a schematic diagram showing an auxiliary aspiration system 510. The aspiration system 510 includes a remote handpiece 512 with a fluid pump 526 and an operator control interface 506. In one possible embodiment, the system 510 is a single-use disposable unit. The aspiration system 510 can also include an extension tube 514 with a fluid irrigation lumen 502 and an aspiration lumen 504, allowing independent operation of the catheter 516 without the need for repositioning the handpiece 512 during a procedure performed with the aspiration system 510. The extension tube 514 can also function as a pressure accumulator. The high pressure fluid flow from the pump 526, which can include a positive displacement pump, generates pulses with each stroke of the pump 526, generating a sinusoidal pressure map with distinct variations between the peaks and valleys of each sinusoid. The extension tube 514, in coordination with the pump 526, expands and contracts in unison with each pump pulse, reducing the pressure changes caused by the pump pulse to generate a smoother or smoother fluid flow at the tip of the catheter 516. Any tubing having suitable compliance characteristics may be used. The extension tube 514 may be permanently attached to the pump 526 or may be attached to the pump 526 by a connector 544. The connector 544 is configured to ensure that the extension tube 514 cannot be accidentally attached to the pump 526.

[0164]

[0164] An interface connector 518 couples the dilation tube 514 and the catheter 516 together. In one possible embodiment, the interface connector 518 can include a filter assembly 508 between the high pressure fluid infusion lumen 502 of the dilation tube 514 and the high pressure infusion lumen 536 of the catheter 516 (FIG. 17). The catheter 516 and the dilation tube 514 can be permanently coupled by the interface connector 518. Alternatively, the interface connector 518 can include a standardized connection so that a selected catheter 516 can be attached to the dilation tube 514. In some embodiments, the filter assembly 508 can be removably connected to the dilation tube 514 by a quick disconnect connection. The pressure transducer of the embodiments of the aspiration monitoring system presented herein can be placed at a point along the aspiration lumen 504 or at any extension of the aspiration lumen 504.

[0165]

[0165] Attached to the handpiece 512 are a fluid source 520 and a vacuum source 522. A standard hospital saline bag can be used as the fluid source 520, such a bag being readily available to the physician and providing the amount required to perform the procedure. A vacuum bottle may provide the vacuum source 522, which may be provided by a syringe, a vacuum pump, or other suitable vacuum source. The filter assembly 508 serves to filter particulates from the fluid source 520 to avoid clogging of the high pressure infusion lumen 536 and the orifice 542 (FIG. 17). As described herein, the distal section of the high pressure infusion lumen 536 can be configured with a small inner diameter, and the filter assembly 508 serves to protect its continued function. By incorporating one of the various catheters 516 into the auxiliary aspiration system 510, for example, with various lumen configurations (inner diameter, length, etc.), various aspiration qualities (aspiration speed, jet speed, jet pressure) can be applied to one or more patients. These suction qualities can be further achieved by adjustment of pump 526 to change pump characteristics (flow rate, pump pressure). In some embodiments, catheter 516 may be used manually, for example without pump 526, and controlled by manual injection. Manual use of catheter 516 may be appropriate for certain patient conditions and help reduce the cost of the procedure.

[0166]

[0166] In one possible embodiment, the catheter 516 can have a varying stiffness, being stronger at the proximal end and more flexible at the distal end. The varying stiffness of the catheter 516 can be achieved by a single tube with no radial bond between two adjacent pieces of tube. For example, the shaft of the catheter 516 can be made from a single length of metal tubing with the length of the tube cut in a helical fashion to provide flexibility to the shaft. The varying stiffness can be created by varying the pitch of the helical cut along different lengths of the metal tube. For example, the pitch of the helical cut can be smaller (the turns of the helical cut can be closer together) at the distal end of the device to provide greater flexibility. Conversely, the pitch of the helical cut can be larger (the turns of the helical cut can be farther apart) at the proximal end to increase stiffness. A single jacket covers the length of the metal tube to provide a vacuum-tight (airtight from the inside to the outside) catheter shaft. Other features of the catheter 516 are described below with reference to FIG. 17.

[0167]

[0167] Figure 16 is a schematic diagram showing the proximal portion of the handpiece 512 and auxiliary catheter aspiration system 510 in more detail. The handpiece 512 includes a control box 524 in which the power and control systems are located. The pump 526 may be a motor-driven positive displacement pump with a constant output. This pump displacement relative to the catheter volume in conjunction with the position of the orifice 542 (outlet) of the catheter high pressure lumen 536 in the aspiration lumen 538 (Figure 17) ensures that no energy is transferred from the saline pump to the patient, as all pressurized fluid is evacuated by the aspiration lumen. A master button 528 is mechanically connected to the master valve 530. When preparing the device for use, it is preferable to evacuate all air from the pressurized fluid system to reduce the possibility of air embolism. By pressing the master button 528, the user connects the fluid source 520 to the vacuum source 522 via the pump 526. This forcefully draws fluid (e.g., 0.9% NaCl solution, i.e., "saline," or heparinized saline, not "normal saline") through the entire pump system, removing all air and actively priming the system for safe operation. A pressure / vacuum valve 532 is used to turn the vacuum or negative pressure on and off in sync with the fluid pressure system. One possible valve 532 is a ported one-way valve. Such a valve is preferred over manual or electronic valve systems because it acts as a tamper-resistant safety feature by mechanically and automatically combining the operation of two major systems. Having a pressure / vacuum valve 532 eliminates the possibility of turning on the vacuum or negative pressure without operating the fluid system.

[0168]

[0168] The operator control interface 506 may include an electronic control board 550 that is powered by a power system 548 (such as a battery or power line) and can be operated by a user using one or more switches 552 and one or more indicator lights 554. The control board 550 also monitors and controls several device safety functions, including overpressure and air bubble detection and vacuum or negative pressure charging. A pressure sensor 564 monitors the pressure and senses the presence of air bubbles. Alternatively, an optical device 566 can be used to sense air bubbles. In one possible embodiment, the pump pressure is proportional to the current required to generate that pressure. Thus, if the current required by the pump 526 exceeds a pre-set limit, the control board disables the pump by cutting off the power to the pump. The detection of air bubbles may also be monitored by monitoring the current required to drive the pump at a particular moment. In order for the positive displacement pump 526 to reach high fluid pressures, there should be little or no air (which is highly compressible) present in the pump 526 or the connection system (including the catheter 516 and the extension tube 514). The fluid volume is small enough that air in the system does not create pressure at the pump head. The control board monitors the pump current for a sudden downward change that may indicate air has entered the system. If the rate of decline is faster than a preset limit, the control board disconnects power to the pump rendering it inoperable until the problem is corrected. Similarly, a blockage in the high pressure lumen 536, which may be caused by tissue or fibrous thrombus intrusion or solid emboli, can be detected by monitoring the current through the pump 526. In normal use, the current flux of the pump 526 is relatively high. For example, the pump may be configured such that the current fluctuates over 200 milliamps during normal operation, and when the current flux drops below 200 milliamps, air is identified and the system is shut down. Alternatively, a current flux in the range of, for example, 50 milliamps to 75 milliamps can be used to identify that air is in the system.Additionally, an increase in current or current flux can indicate the presence of a clot or thrombus within high pressure lumen 536. For example, a current of greater than 600 milliamps can indicate a thrombus partially or completely blocking high pressure lumen 536, or aspiration lumen 538.

[0169]

[0169] The vacuum line 556 connected to the vacuum source 522 can be connected to a negative pressure sensor 558. If the vacuum or negative pressure of the vacuum source 522 is low or if a leak is detected in the vacuum line 556, the control board 550 disables the pump 526 until the problem is corrected. The negative pressure sensor 558 may be part of a safety circuit 560 that will not operate the pump 526 if no vacuum is present. Thereby, a comprehensive safety system 562 including the safety circuit 560, the pressure sensor 564 and / or the optical device 566, and the negative pressure sensor 558 requires both pump pressure and vacuum or negative pressure for the system to operate. If a problem exists (e.g., there is an unacceptably low pump pressure or no significant vacuum or negative pressure), the control board 550 will not allow the user to operate the aspiration system 510 until all problems are corrected. This prevents air from being pumped into the patient and ensures that the aspiration system 510 does not operate with incorrect parameters.

[0170] FIG. 17 is a schematic diagram of the distal end portion 568 of the auxiliary catheter aspiration system 510, showing the catheter 516 in more detail. The catheter 516 is a single operator exchange catheter and includes a short guidewire lumen 534 attached to the distal end of the device. The guidewire lumen 534 may be about 1 cm to about 30 cm in length, about 5 cm to about 25 cm in length, about 5 cm to about 20 cm in length, or about 13.5 cm in length. The aspiration lumen 538 includes a distal opening 540 that allows for a vacuum or negative pressure (e.g., from the vacuum source 522) to draw thrombus material into the aspiration lumen 538. The high pressure lumen 536 includes a distal orifice 542 set a set amount proximal to the distal opening 540. For example, the distal orifice 42 can be set proximal to the distal opening 540 by about 0.020 inches, or by 0.020 inches ± 0.003 inches, or another desired amount. The orifice 542 is configured to spray across the aspiration lumen to macerate and / or dilute the thrombus material for transport to the vacuum source 522, for example, by lowering the effective viscosity of the thrombus material. The axial placement of the fluid orifice 542 ensures that the spray pattern interaction with the opposing lumen wall creates a spray mist and not a swirl pattern that can push embolic material out of the distal opening 540. The system may be configured such that the irrigation fluid exits the pump at a pressure of about 500 psi to about 1500 psi. In some embodiments, after pressure head loss along high pressure lumen 536, irrigation fluid exits orifice 542 at a pressure of about 600 psi to about 1200 psi, or about 650 psi to about 850 psi. In some cases, it is possible (and desirable) to use auxiliary catheter aspiration system 510 without operating pump 526, thus allowing catheter 516 to be used while manually injecting saline via a syringe, for example.Alternatively, in some cases, auxiliary catheter aspiration system 510 can be used without pump 526 attached, while manually injecting saline using a syringe through high pressure lumen 536. In the event of a clog, for example, the syringe can be removed and pump 526 can be attached and started in order to unclog high pressure lumen 536.

[0171] When normal blood flow is achieved after releasing the blockage from atherosclerotic lesions and / or thrombosis, there is occasionally a risk of reperfusion injury. This may be particularly important after thrombectomy of blood vessels supplying the brain for the treatment of embolic stroke, or after thrombectomy of coronary arteries supplying the myocardium. This also includes the case of revascularization of the myocardium after coronary intervention (e.g., thrombectomy). Reperfusion injury and microangiopathy may be mechanisms that limit significant or complete recovery of the revascularized myocardium. Sudden reperfusion of a portion of the myocardium that was previously unperfused may trigger a series of physiological processes that paralyze or damage the myocardium. Small pieces of thrombus, platelets, and distal coronary emboli such as atheromas may also be involved. Controlled preconditioning of the at-risk myocardium has been proposed to limit the effects of reperfusion injury and microangiopathy. The embodiments of the thrombectomy systems 100, 300 presented herein can be combined with additional features aimed at enabling flow control to limit potential risks from reperfusion after thrombectomy.

[0172]

[0172] Figure 18 shows a multi-purpose system 1200 including a multi-purpose catheter 1202 having an injection port 1204 and an aspiration port 1206. The injection port 1204 and the aspiration port 1206 can each include a luer connector, such as a female luer lock connector. A tubing set 1208 and a pressure sensor 1210 are connected in-line with a vacuum source 1212. A cable 1214 carries a signal from the pressure sensor 1210 to a suction monitoring system 1216 (Figure 19) and connects to the suction monitoring system 1216 via an interface 1218 or plug configured to connect to a port 1220 of a console 1222 of the suction monitoring system 1216. Using the devices and methods described herein, the suction monitoring system 1216 can be used to monitor suction. In one method of use, a syringe 1224 (Figure 18) can be used to manually inject through the injection port 1204 and the injection lumen 1225 (e.g., high pressure lumen) of the multi-purpose catheter 1202. The syringe 1224 may have an injectable volume of about 5 ml or less, or in some embodiments, about 1 ml or less. The infusion lumen 1225 may be configured to inject saline at relatively high pressure or at either high or low pressure, in some embodiments. When the valve 1226 (e.g., a stopcock) is closed to prevent the vacuum source 1212 from reducing or creating a negative pressure on the aspiration lumen 1227 via the aspiration port 1206, infusion through the infusion lumen 1225 may deliver infusion fluid to a site within the blood vessel (at the distal end of the multi-purpose catheter 1202) near the distal outlet of the infusion lumen 1225. Alternatively, when the vacuum source 1212 is removed from or simply not connected to the aspiration lumen 1227, infusion through the infusion lumen 1225 delivers infusion fluid to a site within the blood vessel near the distal outlet of the infusion lumen 1225. Any of these techniques can be used to deliver drugs to the vessel wall, or to the atherosclerotic plaque, or to the thrombus. In some cases, clot-busting drugs (tissue plasminogen activator (tPA), thrombokinase, urokinase, thrombin, plasmin) are injected into the clot or thrombus and allowed to act over a period of time.One purpose is to soften the clot over time. Lytic agents, glycoprotein inhibitors (GPIs), vasodilators, and other agents may be used to dilate blood vessels or treat disease in the area. Controlled, precise, localized delivery allows for effective use of the agent, with the desired amount being delivered to the tissue being treated with minimal spillage or waste. This efficiency reduces the cost of the procedure, as many of these agents are very expensive. Due to the precise diameter of the infusion lumen 1225 and its known length, the infusion lumen 1225 contains a known volume or dead space. This further allows for a known, controlled, and precise injection of the agent. A typical infusion lumen 1225 has a length of 150 cm and an inner diameter of 0.038 cm (0.015 inches), thus a total volume of only 0.17 ml. The volume of the infusion lumen 1225 can be altered by controlling the diameter of the inner diameter of the infusion lumen 1225 and / or the length of the infusion lumen 1225. For example, the volume of the infusion lumen 1225 may be between about 0.08 ml and about 0.26 ml, or between about 0.14 ml and about 0.20 ml. Injecting through the infusion lumen 1225 with a small bore syringe (e.g., 1 ml) or a precision pump allows for precise measurement of the agent delivered. However, when the valve 1226 or stopcock is opened and a vacuum source 1212 is connected to the aspiration port 1206, reducing or creating a negative pressure on the aspiration lumen 1227, forced aspiration is initiated, as described herein. As discussed above, the infusion lumen 1225 may serve either a closed system (aspiration) or an open system (injection of infusate). At the beginning of a procedure, it is not always known what different actions will be required, so the use of the multipurpose catheter 1202 and multipurpose system 1200 may eliminate the need to use multiple catheters (e.g., microcatheters and single-function aspiration catheters).

[0173] 20-24 show a multi-purpose system 1240 with a multi-purpose catheter 1242 having an injection port 1244 and an aspiration port 1246. Chilled saline can be injected from a saline bag 1248 (FIG. 23) through a tubing set 1250 attached to the saline bag 1248 via a spike 1252. A pump 1254 (FIG. 24), which may include a positive displacement pump such as a piston pump, includes an interface 1256 for attaching a cassette 1258 (FIG. 20). In some embodiments, the pump 1254 has a moving part that connects to a moving piston 1255 in the cassette 1258 to inject a controlled amount of fluid. As described in connection with the multi-purpose system 1200 of FIG. 18, depending on whether the valve 1260 connecting the vacuum source 1262 to the aspiration port 1246 via the extension tube 1264 is open or closed, or simply whether the vacuum source 1262 is attached or not, the infusion can serve either as a closed system (aspiration) or an open system (infusion of infusate). The pressure sensor 1266 is in communication with the interior of the extension tube 1264, but may also be in communication with the interior of other parts of the flow path. A cable 1268 carries the signal from the pressure sensor 1266 to the aspiration monitoring system 1270 (FIG. 22) and connects to the aspiration monitoring system 1270 via an interface 1272 or plug configured to connect to a port 1274 of the console 1276 of the aspiration monitoring system 1270. The utility of the multi-purpose system 1200, 1240 in the multi-mode is facilitated by the sterile fluid pathways combined with precise volumetric control (either by the miniature syringe 1224 or the precision pump 1254). Additionally, the suction monitoring systems 1216, 1270 allow for real-time feedback to the user, further facilitating controlled delivery and / or suction.

[0174]

[0174] The multipurpose system 1200, 1240 optimizes interventional procedures such as percutaneous coronary intervention (PCI) for simplicity, case flow, and cost. When a drug is injected into the coronary artery, the clot is aspirated by placing a high concentration of drug directly at the site of the lesion, which may typically be more distal (e.g., more superselective) than the location accessible by the tip of the guide catheter. This allows the amount of drug used to be minimized. By limiting the amount of a particular drug, systemic complications (e.g., bleeding) can be minimized or eliminated. The drug can be applied, for example, directly to the clot itself to soften or dissociate it. Maceration of the clot with a saline jet 1278 (FIG. 21) injected through the infusion lumen 1257 of the multipurpose catheter 1242 keeps the catheter aspiration lumen 1259 patent at all times without interruption, allowing for a standardized catheter advancement technique, for example, by slowly moving the catheter from a proximal to a distal position in the vessel (with respect to the clot). Maceration also dilutes the proximally flowing aspirate for optimal aspiration efficiency. In certain circumstances, aspiration can be performed until normal blood flow is restored (at least to a significant level), after which the vacuum source 1262 can be closed via valve 1260 and chilled infusate can be infused into the vessel. The resulting selective cooling of this area helps to reduce reperfusion injury by potentially slowing ischemic cellular metabolism. The infusion of chilled infusate can be used any time after aspiration and before stent insertion without removing the aspiration device and without advancing a new infusate device. With the multi-purpose catheter 1202, 1242 already in place, this important operation can begin immediately. Having all of this functionality in one catheter can also provide cost savings to the user.

[0175] In the aspiration mode, the aspiration monitoring system 1216, 1270 can constantly monitor the proper functioning of the aspiration circuit. The user knows when an important event occurs, when an alarm is communicated, or when the system (e.g., motor) is shut down, which events require attendance. This knowledge helps the user avoid sticking the catheter too far distally and potentially causing distal embolism. In the infusion / infusate cooling mode, the pump 1254 pumps at a fixed, predefined volume or rate to deliver a constant temperature cooling infusate. Core body temperature feedback (e.g., by rectal, esophageal, ear or other temperature probe) can be used to indicate to the system that further cooling should be stopped. For example, a core body temperature below 35° C. or below 34° C. Feedback of temperature below a threshold can be used to stop the pump and / or send an alarm. A precise and direct infusate path to the catheter tip and / or ischemic area provides focused cooling and induces minimal systemic hypothermia. Bypassing the aspiration lumen (e.g., with valve 1260 closed), there is less chance of unintended emboli being refluxed into the vessel and therefore sent downstream into a risk area, thereby eliminating the need to replace the device after flow is restored.

[0176]

[0176] In some cases, in the infusion mode, the infusate is injected into the fluid infusion lumen 1225, 1257 at a relatively low pressure. In some cases, maceration is performed at a relatively high pressure. In some cases, the multi-purpose system 1240 can be used without the pump 1254 attached, while the saline injection is performed manually using a syringe attached to the injection port 1244. In the event of a clog, the syringe can be removed and the pump 1254 can be attached and started, for example, to unclog the infusion lumen 1257. In an exemplary procedure, the user places a catheter similar to the multi-purpose catheter 1202 of FIG. 18 or the multi-purpose catheter 1242 of FIGS. 20-21 into the vasculature. Initially, the user can choose not to have the pump 1254 or the syringe 1224 (FIG. 18) attached to the multi-purpose catheter 1202, 1242. The user can then begin suction through the suction lumen 1227, 1259 via the vacuum source 1212, 1262, thus utilizing the multi-purpose catheter 1202, 1242 as a simple (vacuum or negative pressure only) suction catheter. If the user determines that additional positive pressure injection of saline and / or medication is needed, for example to overcome a clog, overcome slow suction, or to enhance maceration or dilution of the clot, the user can attach the pump 1254 or syringe 1224 to the injection port 1204, 1244 and begin injecting the saline and / or medication.

[0177]

[0177] In one embodiment, the aspiration system includes an elongated catheter having a proximal end and a distal end, the catheter including an aspiration lumen having a proximal end and a distal end, a high pressure infusion lumen having a proximal end and a distal end and extending from the proximal end of the catheter to a location adjacent the distal end of the aspiration lumen, and at least one orifice at or near the distal end of the high pressure infusion lumen and configured to allow high pressure liquid infused through the high pressure infusion lumen to be released into the aspiration lumen, the proximal end of the high pressure infusion lumen configured to be repeatedly connectable and disconnectable to one or more infusion modules. In some embodiments, the one or more infusion modules include a first infusion module and a second infusion module. In some embodiments, the first infusion module includes a pump and the second infusion module includes a syringe. In some embodiments, the second infusion module includes a syringe having a volume of about 5 ml or less. In some embodiments, the second infusion module includes a syringe having a volume of about 1 ml or less. In some embodiments, the second infusion module includes a syringe containing a medicament.

[0178] 25-33 show several different embodiments of a device having a pressure sensor 1300 configured to function as a component in an aspiration monitoring system that shares some or all of the functionality of any one of the aspiration monitoring systems 48, 62, 78, 900, 1216, 1270 presented herein. FIG. 25 shows an aspiration catheter 1302 having a distal end 1304 and a proximal end 1306, the proximal end 1306 including a female luer connector 1308. The pressure sensor 1300 is in fluid communication (e.g., fluidly connected) with the lumen of the aspiration catheter 1302. FIG. 26 shows a tubing set 1310 having a male luer 1312 and a female luer 1314, an extension tube 1316, and a stopcock 1318. The pressure sensor 1300 is in fluid communication with the lumen of the extension tube 1316. FIG. 27 shows a stopcock 1320 having a male luer 1322, a female luer 1324, and a valve 1326, which is disposed proximal to a pressure sensor 1300. The pressure sensor 1300 is in fluid communication with the interior cavity of the stopcock 1320. FIG. 28 shows a stopcock 1328 having a male luer 1330, a female luer 1332, and a valve 1334, which is disposed distal to the pressure sensor 1300. The pressure sensor 1300 is in fluid communication with the interior cavity of the stopcock 1328. FIG. 29 shows a syringe 1336 having a male luer 1342, a barrel 1338, and a plunger 1340. The syringe 1336, such as a VacLok® syringe, can include a locking mechanism 1344 that allows the plunger 1340 to be locked relative to the barrel 1338. The pressure sensor 1300 is disposed distal to the barrel 1338 and is in fluid communication with the interior cavity of the barrel 1338 .

[0179] FIG. 30 shows a syringe 1346 having a male luer 1352 (i.e., luer connector, luer lock), a barrel 1348, and a plunger 1350. The syringe 1346 may include a locking mechanism 1344. The pressure sensor 1300 is in fluid communication with the interior cavity of the barrel 1348 and may be directly connected to either the barrel 1348 or the male luer 1352, or directly connected to a hollow transition 1351 between them. FIG. 31 shows an aspiration system 1354 with a syringe 1356 having a male luer 1357, a barrel 1358, and a plunger 1360. The syringe 1356 may include a locking mechanism 1344. The aspiration system 1354 also includes a connector assembly 1361 including a male luer 1362, a valve 1364, and a female luer 1365 (connected below the male luer 1357 in FIG. 31). The pressure sensor 1300 is in fluid communication with the internal lumen or cavity between the barrel 1358 of the syringe 1356 and the male luer 1362 of the connector assembly 1361. FIG. 32 shows an aspiration system 1366 with a syringe 1368 having a male luer 1369, a barrel 1370, and a plunger 1372. The syringe 1368 may include a locking mechanism 1344. The aspiration system 1366 also includes a connector assembly 1373 including a male luer 1374, a valve 1376, and a female luer 1377 (connected below the male luer 1369 in FIG. 32). The pressure sensor 1300 is in fluid communication with the internal lumen or cavity between the barrel 1370 of the syringe 1368 and the male luer 1374 of the connector assembly 1373. 33 illustrates an aspiration system 1378 with a syringe 1380 having a male luer 1382, a barrel 1384, and a plunger 1386. The syringe 1380 may include a locking mechanism 1344. The aspiration system 1378 further includes a tubing set 1388 having a male luer 1390 and a female luer 1392. A valve 1394 is disposed either proximal or distal to the pressure sensor 1300. An extension tube 1396 may be utilized to connect one or more components of the tubing set 1388, although in some cases the components may be directly connected.The pressure sensor 1300 is in fluid communication with the internal lumen of the tubing set 1388. The stopcock or valve in any of these embodiments may be a one-way stopcock or a three-way stopcock or a one-way valve or a three-way valve. There may be other embodiments that combine one or more elements of each of the embodiments presented herein. These embodiments are also included within the scope of this disclosure. In any of the embodiments in which a male luer is used, it may be replaced with a female luer or another liquid-tight connector. In any of the embodiments in which a female luer is used, it may be replaced with a male luer or another liquid-tight connector. In this way, any of the connector assemblies 1361, 1373 may be connected to the syringes 1356, 1368 in a reverse manner, i.e., the distal end may become the proximal end and thus connected to the syringes 1356, 1368, and the proximal end may become the distal end.

[0180]

[0180] Figure 34 illustrates a thrombectomy system 300 incorporating high pressure injection of a liquid, such as sterile saline, to macerate and aspirate the thrombus 104. The guide catheter 108 has an inner lumen 110 extending between a proximal end 144 and a distal end 120. As described with respect to the previous embodiment, a y-connector 148 connected to the proximal end 144 of the guide catheter 108 includes a proximal seal 150 and a side port 152 and is configured to connect the inner lumen 110 of the guide catheter 108 to a vacuum source 146. As described with respect to the previous embodiment, the thrombectomy catheter 306 comprises a distal tube 314 having a distal end 316 and a proximal end 318, the proximal end 318 incorporating one or more sealing members 324 for sealing an annulus 342 between the guide catheter 108 and the distal tube 314. The distal tube 314 has an aspiration lumen 330. A support / supply tube 368 having a lumen 370 is connected to the distal tube 314. The support / supply tube 368 functions as a support member for pushing and pulling the thrombectomy catheter 306, but is also a conduit (via lumen 370) for high pressure saline that is pumped from a proximal end 372 to a distal end 374. The saline is supplied from a saline source 376 (e.g., a saline bag, bottle), pressurized by a pump 378, and passed through a supply tube 380 and through a luer connector 382 that is connected to a luer hub 384 that is connected to the support / supply tube 368. In some embodiments, the support / supply tube 368 comprises a hypotube. In some embodiments, the support / supply tube 368 comprises stainless steel or nitinol. The distal end 316 of the distal tube 314 can include a skive 358 that aids in the trackability of the distal tube 314 through the patient's vasculature. In some embodiments, the inner diameter of the aspiration lumen 330 of the distal tube 314 may be about one French size smaller than the inner diameter of the inner lumen 110 of the guide catheter 108. In some embodiments, the thrombectomy catheter 306 includes a support tube or support shaft to replace the support / feed tube, which does not include a lumen 370.Thus, aspiration is controlled solely by suction of the inner lumen 110 of the guide catheter 108 in combination with the aspiration lumen 330 of the distal tube 314, and no injection of high pressure liquid is required. Other embodiments of the thrombectomy catheter 306 are described in U.S. Patent No. 9,433,427, entitled "Systems and Methods for Management of Thrombosis," issued September 6, 2016.

[0181] FIG. 35 shows the proximal end of a guide catheter 108 used with an aspiration catheter, such as the thrombectomy catheter 306 of FIG. 34. A hemostatic valve 389 in a y-connector 390 seals off both the support / supply tube 391 and the guidewire 28. The hemostatic valve 389 (e.g., Touhy-Borst, longitudinally spring-loaded seal, etc.) must be adjusted to allow movement (translation, rotation) of the catheter and / or guidewire 28, but not allow air to be drawn into the lumen during aspiration. Due to the constant adjustments often required for the hemostatic valve 389, e.g., to aid in catheter and / or guidewire movement, the hemostatic valve 389 can create a large variability in the amount of air that may leak. Leaks (e.g., at location 393) can be fast and may not be known to the user. The pressure sensor 394 used in conjunction with any of the aspiration monitoring systems described herein allows a user to immediately know if the seal of the hemostasis valve 389 of the y-connector 390 is not sealed properly. Additionally, leaks between the distal luer 388 of the y-connector 390 and the luer hub 386 of the guide catheter 108 can be detected by the aspiration monitoring system. Additionally, leaks between the luer 392 of the pressure sensor 394 and the side port 395 of the y-connector 390, or between the luer connector 396 of the extension tube 387 and the luer fitting 397 of the pressure sensor 394 can be detected by the aspiration monitoring system. The aspiration monitoring system may be integral with or configured to be attachable to any component of the aspiration circuit (e.g., aspiration catheter, syringe / vacuum source), or may be connected in series (at any point) between these components. In some embodiments, the aspiration monitoring system may comprise a flow sensor or pressure sensor or detector configured to be in series or parallel with the component or to be placed in series or parallel with the component. In any of these configurations, a number of different leak locations can be assessed by the suction monitoring system of the embodiments disclosed herein.The suction monitoring system may be configured to detect changes, relative changes, absolute changes, thresholds, absolute values, the presence or lack of pressure and / or flow. The suction monitoring system may be configured to determine the operational status of a system including a catheter having an aspiration lumen. In some cases, the suction monitoring system may be configured to provide information regarding the operation of the system that is not discernible from typical cues such as angiograms, sounds, sensations, or other visual, auditory, tactile, or other feedback from the system itself.

[0182]

[0182] Figure 36 shows an aspiration system 1400 comprising an aspiration catheter 1402 with an elongated shaft 1401 including an aspiration lumen 1404 having an open distal end 1405 and a proximal end 1406 configured to connect to a peristaltic pump 1408. The peristaltic pump 1408 can be a roller pump having a base 1426, a pressure shoe 1428 carried by the base 1426, and a rotatable head 1430 rotatably connected to the base 1426 and carrying two or more rollers 1432a-1432d. The rollers 1432a-1432d are arranged around a circumference 1434 of the rotatable head 1430. The rotatable head 1430 is configured to be rotatable in at least a first rotational direction 1436 with respect to a rotation axis 1499. The rotatable head 1430 can be rotated by a motor 1497, either directly or together with a gear train 1495. The peristaltic pump 1408 may be battery powered, and the battery may be rechargeable by wire or wirelessly. The peristaltic pump 1408 may alternatively or additionally be powered by a power cord 1493 configured to connect to a power source. An extension tube 1438 having a distal end 1440 and a proximal end 1442 and having a lumen 1444 extending therethrough is hydraulically connected to the proximal end 1406 of the aspiration lumen 1404 via a connector 1424. The extension tube 1438 may be supplied (e.g., sterile) with the aspiration catheter 1402 or may be supplied separately packaged. A Touhy-Borst seal 1446 mounted on the connector 1424 is configured to be loosened / opened to allow for insertion of a guidewire 1448 through the connector 1424 and the aspiration lumen 1404. Thus, the aspiration lumen 1404 can be used to track the aspiration catheter 1402 over a guidewire 1448 through the subject's vasculature. The Touhy-Borst 1446 can be tightened to seal off the guidewire 1448 and maintain hemostasis. Other types of seals can be incorporated in place of the Touhy-Borst 1446, including spring-loaded, longitudinally compressible and actuatable seals.The extension tube 1438 includes a male luer 1450 at its distal end 1440 for connecting to a female luer 1452 of the connector 1424. The male luer 1450 may include a stopcock 1454 configured to rotate to select between an open position (as shown) or a closed position. The extension tube 1438 and its components may be supplied sterile as a single unit. Alternatively, the extension tube 1438 may be integral with the suction lumen 1404 or may be permanently attached to the connector 1424. In use, the compressible portion 1437 of the extension tube 1438 is positioned within the pressure shoe 1428 of the peristaltic pump 1408 such that, as the rotatable head 1430 is rotated in the rotational direction 1436, one at a time, fluid is forced through the lumen 1444 of the extension tube 1438 from the distal end 1440 to the proximal end 1442 via compression of the compressible portion 1437 by the rollers 1432. The single insertion step for connecting the compressible portion 1437 to the peristaltic pump 1408 is simple, fast, reliable, and does not require any connections (e.g., luers, etc.) that must be sealed. Also, compared to a vacuum pump or a vacuum syringe, it is easy to visualize whether a peristaltic pump is working properly. This may be because under relatively high vacuum or negative pressure conditions, blood tends to cavitate and therefore fill the space of the container (e.g., canister or syringe) at an accelerated rate due to the excess gas volume. Air bubbles can also make it more difficult to see inside and visually inspect conditions. Optionally, an interface 1456 on the peristaltic pump 1408 is configured to allow a user to input information or commands to the peristaltic pump 1408 or other components of the system 1400. Otherwise, the hardware or firmware may be pre-programmed with specific running parameters (motor speed, rotation speed, etc.). In some embodiments, there are only two rollers 1432. In other embodiments, there are three rollers 1432. In yet other embodiments, there are four rollers 1432, as shown.In an alternative embodiment, instead of rollers, smooth, rounded ridges of rigid material slide over the compressible portion 1437 and compress it. In this alternative embodiment, the compressible portion 1437 and / or the ridges may be treated with a lubricious material or constructed from a significantly lubricious material to favor sliding friction between the compressible portion 1437 and the ridges. Returning to the embodiment of FIG. 36, the compressible portion 1437 may comprise silicone tubing, polyurethane tubing, polyvinyl chloride tubing, or other compressible tubing. The compressible section 1437 may be a relatively short section that is attachable and detachable to the peripheral end of the extension tube 1438, or in other embodiments, may comprise the entire extension tube 1438 between the distal end 1440 and the proximal end 1442. The proximal end 1442 of the extension tube 1438 can be connected to a hub 1457 of a canister 1458 having an interior 1460 to allow fluid 1459 passing through the extension tube 1438 to pass to the interior 1460. An additional hub 1462 in the canister 1458 can be left open (as shown) to allow the uncharged interior 1460 to match atmospheric pressure. Alternatively, the canister 1458 can be replaced with another type of receptacle, such as a bag, or more specifically, an empty infusion bag configured to collect aspirant therein.

[0183]

[0183] The suction catheter 1402 further has a high pressure infusion lumen 1410 for infusing saline from a fluid source 1479, for example, via a high pressure pump 1412. The tubing set 1464 may include a pump cartridge 1466 having a piston, or bellows, or other moving element that the pump 1412 can operate using an internal motor 1491, thus pressurizing saline (or other fluid) from the fluid source 1479 at a significantly high pressure so that the saline is forced through the infusion lumen 1410 of the suction catheter 1402. The tubing set 1464 includes a proximal end 1468 having a spike 1489 or other connecting element for hydraulically connecting the tubing set 1464 to the fluid source 1479. The tubing set 1464 further has a distal end 1470 that may include a male luer and is configured to hydraulically connect the tubing set 1464 to the infusion lumen 1410 via a female luer 1472. The tubing set 1464 may be supplied sterile as a single unit or may be permanently attached to the suction catheter 1402. In use, infused saline is forced by the pump 1412 through the infusion lumen 1410 and exits an orifice 1474 at the distal end 1476 of the infusion lumen 1410. The infusion lumen 1410 may extend into a separate tube 1478 (infusion tube) that is substantially or completely within the shaft 1401. In some embodiments, the tube 1478 is attached to the inner wall of the shaft 1401 only at the distal end portion 1403. Thus, the free-floating nature of the remaining portion of the tube 1478 within the suction lumen 1404 increases the flexibility and trackability of the shaft 1401. Also, the likelihood of the tube 1478 kinking due to bending of the shaft 1401 is reduced because bending of the shaft 1401 is not directly applied to the tube 1478. High pressure saline is forced out of orifice 1474 through infusion tube 1478, creating a jet 1487. Jet 1487 is within aspiration lumen 1404 just proximal to open distal end 1405, which can create a Venturi effect to push blood or clots externally adjacent open distal end 1405 into aspiration lumen 1404.Operation of the peristaltic pump 1408, with the rotatable head 1430 rotating in a first rotational direction 1436, continuously and forcibly moves the fluid column within the lumen 1444 of the expansion tube 1438, thereby pulling the fluid column within the suction lumen 1404, thereby moving fluid and clots from the open distal end 1405 of the suction lumen 1404 to the proximal end 1442 of the expansion tube 1438. The combination of the action of the peristaltic pump 1408 and the jet 1487 generated by the high pressure saline causes maceration of the thrombus and movement / flow of material (saline / blood / macerated thrombus / thrombus fragments) through the suction lumen 1404 from the open distal end 1405 to the proximal end 1406, through the interior 1485 of the connector 1424, through the lumen 1444 of the extension tube 1438 from the distal end 1440 to the proximal end 1442, and finally into the interior 1460 of the canister 1458. Thus, thrombus within a subject's blood vessels can be macerated and removed by using the system 1400. The blood vessels may include peripheral blood vessels, coronary blood vessels, or blood vessels within the subject's head or neck, including the carotid or cerebral arteries.

[0184]

[0184] The suction monitoring system 1414 including the pressure transducer 1416 may be connected, for example, between the distal end 1440 of the extension tube 1438 and the connector 1424 and / or between the proximal end 1406 of the suction lumen 1404 of the suction catheter 1402. The suction monitoring system 1414 may include any of the features described in connection with the other suction monitoring systems 48, 62, 78, 900, 1216, 1270 disclosed herein. A signal from the pressure transducer 1416 is carried over an electrical cable 1480 to an input 1482 of the pump 1412. A controller 1484 within the pump 1412 is configured to control the operation of the pump 1412 including the motor 1491, although the controller 1484 may also be configured to control the operation of the peristaltic pump 1408 via a cable 1486 or wirelessly. The controller 1484 may comprise a microcontroller. Alternatively, the controller 1484 may be located within the peristaltic pump 1408 or may be located elsewhere. Control using the signal of the measured pressure from the pressure transducer 1416 adds an additional element of safety to the system 1400. Furthermore, non-functioning system 1400 or specific components of the system 1400 may be quickly identified. For example, leaks, faulty connections, incomplete priming of one of the lumens, rupture, or breakage may cause a change in the signal from the pressure transducer 1416 and thus allow their identification. Unacceptably high pressures may also be quickly identified and the controller 1484 may be configured to automatically shut down the pump 1412, thus protecting the motor 1491 of the pump 1412 from burning or overheating, as well as any associated failures or hazards. The peristaltic pump 1408 may also be shut down by the controller 1484. In some embodiments, the peristaltic pump 1408 is configured to be shut down by the controller 1484 after the pump 1412 is shut down (e.g., after a finite delay). The delay can be between about 0.01 seconds and about 1.00 seconds, or between about 0.10 seconds and about 0.25 seconds. The integrity of the tube 1478 is also protected, for example, avoiding unnaturally high pressures that could lead to rupture.In some embodiments, the peristaltic pump 1408 may be battery powered and the controller 1484 may be located within the peristaltic pump 1408, thus providing a self-contained peristaltic pump 1408 that may be easily moved from one location to another. In some embodiments, the peristaltic pump 1408 may even be easily cleanable and sterilizable so that it may be located within a sterile field, such as a sterile field near a patient. In some embodiments, the pump 1412 is configured to remain in a non-sterile field and the peristaltic pump 1408 is configured for sterile use. The push button 1411 may be mounted on the peristaltic pump 1408 and configured for activation by a user, e.g., a user who is scrubbed for contact with sterile articles only. The push button 1411 may be configured to start or stop operation of the peristaltic pump 1408. Additionally, the push button may be configured to start or stop operation of the pump 1412 (e.g., via cable 1486). In some embodiments, the peristaltic pump 1408 and the pump 1412 are combined into a single console, which allows for a smaller size that can be attached to a standard IV pole.

[0185]

[0185] In some embodiments, activation of the push button 1411 by a user's finger initiates operation of the peristaltic pump 1408, which then initiates operation of the pump 1412 after a short delay after the peristaltic pump 1408 has been initiated. The delay is useful to ensure that some suction or a significant amount of suction has been applied to the aspiration lumen 1404 before injecting pressurized fluid (e.g., saline) through the infusion lumen 1410. Thus, blood vessels or other vasculature near the open distal end 1405 are spared injection of fluid from the high pressure jet, since they are instead aspirated through the aspiration lumen 1404, along with aspirated clots or blood. Additionally, in some embodiments, activation of the push button 1411 by a user's finger while the pump 1412 and peristaltic pump 1408 are operating simultaneously stops operation of the pump 1412 and operation of the peristaltic pump 1408. In other embodiments, a delay can be implemented, for example, such that the pump 1412 is stopped and then the peristaltic pump 1408 is stopped after a short delay. The length of the described delay can be between about 0.01 seconds and about 1.00 seconds, or between about 0.10 seconds and about 0.25 seconds. In some embodiments, the controller 1484 is configured to change the rotational speed of the rotatable head 1430 of the peristaltic pump 1408, e.g., to speed up or slow down. In some embodiments, the controller 1484 is configured to change the flow rate (infusion rate) of the pump 1412, e.g., to increase the infusion rate or decrease the infusion rate. In some embodiments, the controller 1484 is configured to change the flow rate / flow rate of both pumps 1408, 1412 simultaneously. In some embodiments, the controller 1484 is configured to change the flow rate / flow rate of one of the pumps 1408, 1412 and then change the other flow rate / flow rate of the pumps 1408, 1412 after a certain delay. Any of these commands from the controller 1484 may be responsive to a change in the signal received from the pressure transducer 1416 .The peristaltic pump 1408 at its peak pulse (e.g., sine wave peak amplitude) provides a significant negative pressure gradient such that the difference between the pressure transducer 1416 reading in a clogged state and the pressure transducer 1416 reading in a free-flow state is amplified. Thus, more potential thromboembolic events, such as a clot being released from the open distal end 1405 of the aspiration lumen 1404 of the aspiration catheter 1402, are avoided. The pressure fluctuations of the pressure transducer 1416 tend to be significantly larger when using the peristaltic pump 1408 than when using a vacuum pump or other vacuum source (e.g., vacuum syringe). One important advantage is that the user can be clearly made aware when a clot / thrombus is not being aspirated, and therefore when the aspiration is free-flowing and causing blood loss without removing the clot 1402. It is much easier to recognize the state of the open distal end 1405 of the aspiration catheter. Current vacuum pumps do not have a similar clear way of indicating active and dormant states. Thus, the user is notified and the pumps 1408, 1412 are stopped to minimize blood loss and allow for repositioning of the clot. Peristaltic pumps 1408 also tend to be less noisy than vacuum pumps and less likely to disrupt communication or increase stress for medical personnel during the procedure.

[0186]

[0186] When the peristaltic pump 1408 is stopped, at least one roller 1432 remains in a position compressing the compressible portion 1437 of the dilation tube 1438. Therefore, no on-off valve, pinch valve, stopcock, or other valve is required. The fact that the rotatable head 1430 is already moving means that when the peristaltic pump 1408 is stopped, the roller 1432 moves rapidly to an occlusion position without significant inertia requirements. This therefore allows for faster activation than a standard electrically activated pinch valve, which is initially stationary and must be moved before it can be pinched. The motor 1497 may comprise a stepper motor that is oriented (e.g., by the controller 1484) such that the rotatable head directs one of the rollers 1432 to occlude the lumen 1444 of the dilation tube 1438 with the compressible portion 1437. In FIG. 36, the roller 1432c is in a position to occlude the lumen 1444 (when the motor 1497 is stopped). Thus, the peristaltic pump 1408 itself can inherently minimize the possibility of distal embolism, since immediate or near-instant stopping of the pump would cause stagnation. Alternatively, a non-stepping motor, such as a brushless DC motor, can be utilized in place of a stepping motor, along with an encoder (e.g., an optical encoder) or another type of position sensor. Additionally, unmacerated clots can thus be stopped from entering the aspiration lumen 1404. As described, in other embodiments, the rollers 1432 can be replaced by non-rotating ridges or protrusions that slide over the compressible portion 1437 of the extension tube 1438 instead of rolling over. In some embodiments, the ridges / protrusions and / or the outer surface of the compressible portion 1437 can be coated with silicone, hydrophilic, or other lubricious materials to reduce friction.

[0187]

[0187] The controller 1484 may be configured to control the operation of the pump 1412 to cause the pump 1412 to inject pressurized fluid in a pulsatile manner. The high pressure jet is applied in a pulsatile manner to optimize the cutting ability of the jet at a portion of the thrombus. For example, a portion of the thrombus aspirated into the open distal end 1405 of the suction lumen 1404 of the suction catheter 1402 may be more easily cut by the pulsating jet, similar to a reciprocating saw. The controller 1484 may also be configured to operate the pump 1412 to pressurize fluid through the infusion lumen to cause one or more jets to pulsate. The controller 1484 may also be configured to operate the peristaltic pump 1408 to further assist that pressurized fluid injected through the infusion lumen to pulsate one or more jets. For example, the controller 1484 may send a signal to cause a sinusoidal variation in the speed of the motor 1491. The degree of pulsatility (pulse rate, peak pulse, pulse waveform, rise time, on time, off time) may be regulated and controllably applied by the controller 1484 on the pump 1412 and / or peristaltic pump 1408.

[0188]

[0188] The use of the peristaltic pump 1408 ensures that the interior of the suction lumen 1404 and lumen 1444 of the extension tube 1438, as well as its contents, are not contacted, thus further ensuring the maintenance of sterility. The use of the peristaltic pump 1408 also minimizes or substantially does not cause cavitation to the blood being removed. If there was cavitation during aspiration, proximal to the peristaltic pump 1408, after the blood and aspirate passes through the rollers 1432, the blood is exposed to atmospheric pressure and the cavitation disappears. It is therefore easier to determine the amount of blood that has been or is being collected in the canister 1458, because the indicated amount of collected blood is clearly visible and not obscured by air bubbles or foam so that it can be reliably measured. In addition, it is easier to quickly reuse the blood, for example, if it is to be reinfused into a subject. It is also safer and more reliable to inject blood that is free of large air bubbles. The use of a vacuum source, such as a thermos or vacuum syringe, may tend to cause greater cavitation. Thus, the peristaltic pump 1408 may be used to achieve an efficient treatment and to maximize the amount of blood that may be reinfused. The tubing set 1464 separates the extension of the infusion lumen 1410 from the aspiration lumen 1404 at the male luer 1410 of the connector 1424, and thus only the compressible portion 1437 of the extension tube 1438 needs to be compressed by the rollers 1432. Thus, other portions of the aspiration catheter 1402 are not compressed by the rollers 1432 and therefore are not in danger of being crushed or otherwise damaged. The distal end 1483 of the aspiration catheter 1402 may, in some embodiments, resemble the distal end of the catheter 516 of FIG. 17. The suction catheter 1402 may, in some embodiments, be replaced by a thrombectomy catheter 306 as described in the thrombectomy system 300 of FIG. 34 or in U.S. Patent No. 9,433,427, issued Sep. 6, 2016 and entitled “Systems and Methods for Management of Thrombosis.” The use of a peristaltic pump 1408 has additional advantages over a vacuum pump.The peristaltic pump 1408 can be configured to be controlled by the controller 1484 to only operate when the pump 1412 is injecting. Thus, noise is reduced compared to systems that use a vacuum pump, since the vacuum pump is always on (operating).

[0189]

[0189] FIG. 37 shows a subject 1500 on a hospital bed 1502 or table being infused with blood in three different modalities. During a thrombectomy procedure, a thrombus / clot is removed from the subject's 1500 blood vessel. In some cases, the patient's blood volume becomes abnormally low and fluids and blood need to be reinfused into the patient. In the first modality, the peristaltic pump 1408 of the system 1400 of FIG. 36 is shown. An aspiration catheter 1402 is inserted into the subject 1500 and an aspiration (thrombectomy) procedure is performed. Instead of a canister 1458, an extension tube 1438 at its distal end 1442 is connected to an intravascular (IV) line 1504 that is inserted into the subject's 1500 vein. The blood is driven by rollers 1432 of the peristaltic pump 1408 through a blood filter 1506, which removes any residual thrombus or particles before the blood is infused into the subject's vein. Heparin or other additives may also be added to the blood as it is infused into the subject 1500 at port 1481 in communication with the intravascular (IV) line 1504. Because the blood only flows through a single sterile composite conduit, an efficient and clean reinfusion method is realized. The blood may be purified, for example, to remove red blood cells or portions of red blood cells that have undergone hemolysis. One such reinfusion device is the Haemonetics Cell Saver® Elite+Autotransfusion System. The peristaltic pump 1408 is believed to cause less damage to the blood cells and therefore may require less, if any, cleaning. Thus, due to the advantages of the peristaltic pump 1408, a higher blood yield is possible after using the Cell Saver. Also, the blood may be easily transferred in a contactless manner to the Cell Saver directly from the extension tube 1438, which is not possible with transfer from a collection container used with a vacuum source. When sent directly to the Cell Saver, the blood may even be kept sterile. In some embodiments, the dilation tube 1438 may be significantly translucent so that the thrombus can be evaluated during aspiration. A video camera or a magnifying element (such as a low power microscope) can be focused on the dilation tube 1438 to better identify the condition (amount, amount of maceration) of the thrombus being aspirated.There can be near real-time feedback on the status of the thrombus being dislodged from within the patient's vasculature.

[0190]

[0190] In the second modality, blood is collected in a canister 1458 from a previous treatment (Fig. 36). The blood can then be filtered or spun in a centrifuge to obtain certain components. Heparin or other additives can also be added to the blood. The blood is then placed in a blood bag 1508 (or blood bottle) and infused into the veins of the subject 1500 using passive drip via an IV line 1510 (e.g., by gravity alone). In other cases, a pressurizable bag 1512 can be used around the blood bag 1508 to increase compression of the blood bag 1508 and therefore increase the flow rate into the veins. In some cases, the blood can even be infused directly into the arterial system, for example, via an a-line. The blood can be further purified as described above.

[0191]

[0191] In the third modality, blood is collected in a canister 1458 from a previous treatment (Fig. 36). The blood can then be filtered or spun in a centrifuge to obtain certain components. Heparin or other additives can also be added to the blood. The blood is then placed in a blood bag 1514 and pumped into the vein of the subject 1500 using an infusion pump 1516. Insertion points 1518a, 1518b, 1518c are shown for the first, second, and third modalities, respectively. The blood can be further purified as described above.

[0192] 38 shows an alternative suction system 1400' comprising an suction catheter 1402' comprising an elongate shaft 1401' including an suction lumen 1404' having an open distal end 1405' and a proximal end 1406' configured to connect to a peristaltic pump 1408. The peristaltic pump 1408 may be a roller pump having a base 1426, a pressure shoe 1428 carried by the base 1426, and a rotatable head 1430 rotatably connected to the base 1426 and carrying two or more rollers 1432a-d. The rollers 1432a-d are arranged around a circumference 1434 of the rotatable head 1430. The rotatable head 1430 is configured to be rotatable in at least a first rotational direction 1436 relative to a rotation axis 1499. The rotatable head 1430 may be rotated by a motor 1497, either directly or with a gear train 1495. The peristaltic pump 1408 may be battery powered, and the battery may be rechargeable by wire or wirelessly. The peristaltic pump 1408 may alternatively or additionally be powered by a power cord 1493 configured to connect to a power source. An extension tube 1438 having a distal end 1440 and a proximal end 1442, and having a lumen 1444 extending therethrough, is hydraulically connected to the proximal end 1406' of the aspiration lumen 1404' via a connector 1424'. The extension tube 1438 may be supplied (e.g., sterile) with the aspiration catheter 1402' or may be supplied separately packaged. The Touhy-Borst seal 1446' is connectable and detachable to the connector 1424' (e.g., via Luer connections 1750, 1752) and is configured to be loosened / opened to allow insertion of a guidewire 1448 through the connector 1424' and aspiration lumen 1404'. Thus, the aspiration lumen 1404' can be used to track the aspiration catheter 1402' over the guidewire 1448 through the subject's vasculature. The Touhy-Borst 1446' can be tightened to seal off the guidewire 1448 and maintain hemostasis.Other types of seals may be incorporated in place of the Touhy-Borst 1446', including a spring-loaded, longitudinally compressible and actuatable seal. The distal end 1440 of the dilation tube 1438 slides over a first barb fitting 1754 of the y-connector 1756. The second dilation tube 1760 has a distal end 1761 that slides over a second barb fitting 1758 of the y-connector 1756. The third dilation tube 1762 has a proximal end 1763 that slides over a third barb fitting 1764 of the y-connector 1756. The second dilation tube 1760 and the third dilation tube 1762 are configured to operate under negative pressure without collapsing and may include standard suction tubing. The distal end 1765 of the third extension tube 1762 is connected to the female luer 1452' side port of the connector 1424' by molding, or by adhesive or welding, or by an attachable and detachable connection such as a luer 1766. The length of each of the second extension tube 1760 and the third extension tube 1762 can vary. In some embodiments, the third extension tube 1762 is relatively short and the y-connector 1756 is configured to be placed in a sterile area near the patient. In other embodiments, the third extension tube 1762 is configured to be relatively long and the y-connector 1756 is configured to be placed in a non-sterile area away from the patient. The second extension tube 1760 is optional and the third extension tube 1762 can have a much longer length and the pressure transducer 1416 / suction monitoring system 1414 can be attached directly to the y-connector 1756 at the barb fitting 1758. This connection may be a direct connection, which is why the barb fitting 1758 is also optional. If a longer third extension tube 1762 is used, the y-connector 1756 and the suction monitoring system 1414 may both be near the pump 1412 and both may be in a non-sterile area.

[0193]

[0193] In use, the compressible portion 1437 of the dilation tube 1438 is positioned within the pressure shoe 1428 of the peristaltic pump 1408 such that, upon rotation of the rotatable head 1430 in the rotational direction 1436, fluid is forced through the lumen 1444 of the dilation tube 1438 from the distal end 1440 to the proximal end 1442, one at a time, via compression of the compressible portion 1437 by the rollers 1432. Optionally, the interface 1456 on the peristaltic pump 1408 is configured to allow a user to input information or commands to the peristaltic pump 1408 or other components of the system 1400'. Otherwise, the hardware or firmware may be pre-programmed with specific execution parameters (motor speed, rotation speed, etc.). In some embodiments, there are only two rollers 1432. In other embodiments, there are three rollers 1432. In yet other embodiments, there are four rollers 1432, as shown. As described, the rollers 1432 can be replaced by ridges or protrusions. The compressible portion 1437 can include silicone tubing, polyurethane tubing, polyvinyl chloride tubing, or other compressible tubing. The compressible section 1437 can be a relatively short section that is attachable and detachable to the peripheral end of the extension tube 1438, or in other embodiments, can include the entire extension tube 1438 between the distal end 1440 and the proximal end 1442. The proximal end 1442 of the extension tube 1438 can be connected to a hub 1457 of a canister 1458 having an interior 1460 to allow fluid 1459 passing through the extension tube 1438 to pass to the interior 1460. An additional hub 1462 in the canister 1458 can be left open (as shown) to allow the uncharged interior 1460 to match atmospheric pressure. Alternatively, the canister 1458 can be replaced with a bag, such as an empty infusion bag, configured to collect aspirate therein.

[0194]

[0194] The suction catheter 1402' further has a high pressure infusion lumen 1410' for infusing saline from a fluid source 1479, for example, via a high pressure pump 1412. The tubing set 1464 may include a pump cartridge 1466 having a piston or bellows, or other moving element that the pump 1412 can operate using an internal motor 1491, thus pressurizing saline (or other fluid) from the fluid source 1479 at a significantly high pressure so that the saline is forced through the infusion lumen 1410' of the suction catheter 1402'. The tubing set 1464 includes a proximal end 1468 having a spike 1489, or other connecting element, for hydraulically connecting the tubing set 1464 to the fluid source 1479. The tubing set 1464 further has a distal end 1470 (which may include a male luer) configured to hydraulically connect to the infusion lumen 1410' via a female luer 1472'. In use, infused saline is forced by pump 1412 through infusion lumen 1410' and exits through orifice 1474' at distal end 1476' of infusion lumen 1410'. Infusion lumen 1410' can extend into a separate tube 1478' (infusion tube) that is substantially entirely within shaft 1401'. In some embodiments, tube 1478' is attached to the inner wall of shaft 1401' only at distal end portion 1403'. Thus, the free-floating nature of the remaining portion of tube 1478' within aspiration lumen 1404' enhances the flexibility and trackability of shaft 1401'. High pressure saline is forced through infusion tube 1478' and out orifice 1474', causing a jet (similar to jet 1487 in FIG. 36). The jet is directed into the aspiration lumen 1404' just proximal to the open distal end 1405', which can create a Venturi effect and push blood or clots externally adjacent the open distal end 1405' into the aspiration lumen 1404'.The action of the peristaltic pump 1408 in combination with the jets generated by the high pressure saline causes maceration of the thrombus and movement / flow of material (saline / blood / macerated thrombus / thrombus fragments) through the suction lumen 1404' from the open distal end 1405' to the proximal end 1406', through the female luer 1452' of the connector 1424', through the lumen 1444 of the extension tube 1438 from the distal end 1440 to the proximal end 1442, and finally into the interior 1460 of the canister 1458. Thus, thrombus within a subject's blood vessels can be macerated and removed by using the system 1400'. The blood vessels may include peripheral blood vessels, coronary blood vessels, or blood vessels within the subject's head or neck, including the carotid or cerebral arteries.

[0195]

[0195] The suction monitoring system 1414 with pressure transducer 1416 may be connected, for example, proximal to the connector 1424' and / or proximal to the proximal end 1406' of the suction lumen 1404' of the suction catheter 1402' such that the pressure transducer 1416 is hydraulically connected to the suction lumen 1404'. In the suction system 1400' of FIG. 38, the suction monitoring system 1414 is spaced apart from the y-connector 1756 by a relatively long second extension tube 1760 (or, as in the case of the suction system 2100 of FIG. 74, by a relatively long third extension tube 1762) such that the suction monitoring system 1414 resides in a non-sterile field. Thus, the suction monitoring system 1414 may be set up, prepared, calibrated, and operated by a technician, sales representative, nurse, or other medical personnel who are not "scrubbed" and therefore do not need to maintain sterility. For example, the suction monitoring system 1414 may be located near the pump 1412 or on the same table as the pump 1412. The suction monitoring system 1414 may include any of the features described in connection with the other suction monitoring systems 48, 62, 78, 900, 1216, 1270 disclosed herein. A signal from the pressure transducer 1416 is carried over an electrical cable 1480 to an input 1482 of the pump 1412. A controller 1484 within the pump 1412 is configured to control the operation of the pump 1412, including the motor 1491, but the controller 1484 may also be configured to control the operation of the peristaltic pump 1408 via a cable 1486 or wirelessly. The controller 1484 may comprise a microcontroller. Alternatively, the controller 1484 may be located within the peristaltic pump 1408 or may be located elsewhere. The control using a signal of the measured pressure from the pressure transducer 1416 adds an additional element of safety to the system 1400'. Additionally, non-functioning equipment (due to leaks, faulty connections, imperfect priming, ruptures, blockages) can be quickly identified. Unacceptably high pressures can also be quickly identified, protecting the motor 1491 of the pump 1412 from the risk of burning out or overheating. The integrity of the tube 1478' is also protected, avoiding unnaturally high pressures that could lead to, for example, rupture.

[0196]

[0196] The suction catheter 1402' is similar to the suction catheter 1402 of Fig. 36, except that the female luer 1452' is located distal to the connector 1424' from the female luer 1472'. Thus, the aspirated blood / thrombus / saline enters the female luer 1452' without having to contact internal irregularities 1425' (in geometry, shape) within the connector 1424' that might otherwise cause flow resistance or trap clots (e.g., between the tube 1478' and the interior of the connector 1424').

[0197]

[0197] The foot pedal 1451 has a base 1453 and a pedal 1455 connected to the base 1453 and movable or actuable by application of a user's foot. The pedal 1455 may be spring loaded, depressed by application of a moment or compressive force, or may instead comprise a membrane switch. When activated, the pedal 1455 may switch on and off in some embodiments, and in other embodiments may be actuable when a force, pressure, or moment is applied and deactivated when no force, pressure, or moment is applied. A first cable 1461 carries a signal from the foot pedal 1451 to the pump 1412 via a plug 1465 connected to an input jack 1467. In some embodiments, activation of the pedal 1455 by the user's foot causes a signal via the first cable 1461 to be received by the controller 1484 commanding the pump 1412 to start and via the cable 1486 commanding the peristaltic pump 1408 to start, thus initiating operation of the pump 1412 and simultaneously initiating operation of the peristaltic pump 1408. In some embodiments, activation of the pedal 1455 by the user's foot initiates operation of the peristaltic pump 1408, which then initiates operation of the pump 1412 with a short delay after the peristaltic pump 1408 is initiated. The delay is useful to ensure that some suction or a significant amount of suction has been applied to the aspiration lumen 1404' before injecting pressurized fluid (e.g., saline) through the infusion lumen 1410'. Thus, blood vessels or other vasculature near the open distal end 1405' are spared injection of fluid from the high pressure jet, as they are instead aspirated through the aspiration lumen 1404' along with clots or blood. In some embodiments, the plug 1465 of the foot pedal 1451 may include a resistor 1759, and the pump 1412 may include an identification circuit 1757 configured to read the resistance of the resistor 1759. For example, the resistor 1759 may complete a partial Wheatstone bridge that is mounted on the identification circuit 1757 such that the pump 1412 can recognize the foot pedal 1451 and act accordingly.Alternatively, the resistor 1759 may be present in the foot pedal 1451 itself, instead of in the plug 1465. The cable 1461 may provide an electrical connection to the resistor 1759 in that particular case. Alternatively, the resistor 1759 may be replaced by an RFID chip configured to be powered and read by the identification circuit 1757.

[0198]

[0198] Additionally, in some embodiments, activation of the pedal 1455 by the user's foot during operation of the pump 1412 and the peristaltic pump 1408 simultaneously stops operation of the pump 1412 and the peristaltic pump 1408. In other embodiments, a delay can be implemented, for example, such that the pump 1412 is stopped and then the peristaltic pump 1408 is stopped after a short delay. The length of the described delay can be between about 0.01 seconds and about 1.00 seconds, or between about 0.10 seconds and about 0.25 seconds. Activation (on / off) of the pump 1412 and / or the peristaltic pump 1408 via the foot pedal 1451 allows for hands-free activation, allowing a single user to operate the suction catheter 1402' and the guidewire 1448 with both hands. The location of the foot pedal 1451 can be tactilely located with the user's foot while the user maintains visual contact with the patient and / or any monitors or other medical personnel. Alternatively, a second cable 1463 carries a signal directly from the foot pedal 1451 to the peristaltic pump 1408 via a plug 1469 connected to an input jack 1471. Thus, operation of the foot pedal 1451 can be configured to control operation of the peristaltic pump 1408, for example, in an embodiment where there is no cable 1486. ​​However, in the embodiment of FIG. 38 which includes cable 1486, cable 1463 is not required.

[0199]

[0199] In other embodiments, the foot pedal 1451 may be replaced with another type of switch, including but not limited to a toggle on / off push button or hand switch, a voice activated switch (voice activated, clap activated, click activated), a light switch (beam / light sensor for hand or foot interruption), or any other type of switch that can be activated by medical personnel. The switch may be in a remote location (e.g., a control room) or may be near the treatment area. The switch may also be a sterile switch or may be sterilizable for location on the sterile field.

[0200]

[0200] In some cases, activation and deactivation (turning on and off) of the suction flow applied by peristaltic pump 1408 to suction lumen 1404' can be accomplished by leaving peristaltic pump 1408 running while a user opens and closes stopcock 1454. In some embodiments, controller 1484 controls the initiation of both peristaltic pump 1408 and pump 1412 substantially simultaneously. In some embodiments, controller 1484 controls the initiation of peristaltic pump 1408 and, following a particular delay, controls the initiation of pump 1412. The delay can be within the ranges discussed above.

[0201]

[0201] The controller 1484 also monitors and controls several device safety features, including overpressure detection, air bubble detection, and vacuum or negative pressure charging. An additional pressure transducer 1415' mounted on the connector 1424' monitors the pressure (i.e., injection pressure) and senses the presence of air bubbles. Alternatively, or in combination, an optical device 1417' can be used to sense air bubbles. In one possible embodiment, the pump pressure is proportional to the current required by the pump 1412 to generate that particular pressure. Thus, if the current required by the pump 1412 exceeds a preset limit, the controller 1484 disables the pump 1412 by cutting off the power to the pump 1412. Air bubble detection can also be monitored by monitoring the current required to drive the pump 1412 at a particular moment. In order for the pump 1412 to reach high fluid pressures, there should be little or no air (which is highly compressible) in the pump 1412 or the connection system (including the suction lumen 1404' and tubing set 1464 of the suction catheter 1402'). The fluid volume is small enough that air in the system does not create pressure at the pump head. A sufficient amount of liquid is needed proximally to allow a finite amount of air to flow. The controller 1484 monitors the pump 1412 current for a sudden downward change that may indicate air has entered the system. If the rate of decline is faster than a preset limit, the controller 1484 disables the pump 1412 by cutting power to the pump 1412 until the problem is corrected.

[0202] In some embodiments, the fluid level sensor 1473 is mounted to the side of the canister 1458 and configured to sense when the canister 1458 approaches or reaches its full level. The fluid level sensor 1473 is configured to output a signal via a cable 1475 attached via an input 1477 (plug / jack) of the pump 4112. The signal from the fluid level sensor 1473 may be received by a controller 1484, which may be configured to stop the pump 1412 and the peristaltic pump 1408 via cable 1486 simultaneously or immediately with a delay therebetween, as previously described. The fluid level sensor 1473 may include an optical sensor, and the canister 1458 may have transparent walls to allow the optical sensor to measure reflective fluctuations when no fluid is adjacent or when fluid is adjacent. Alternatively, the fluid level sensor 1473 may include a piezoresistive pressure sensor within the volume 1460 of the canister 1458 at a desired height representing a "full" canister 1458. Other types of fluid sensors are also contemplated, such as floats, strain gauges, laser sensors, ultrasonic sensors, or capacitive sensors. In each of these embodiments, a signal may be transmitted wirelessly or via cable 1475 such that the peristaltic pump 1408 and / or pump 1412 may be shut down when the "full" level is reached.

[0203]

[0203] In some embodiments, the peristaltic pump 1408 and the pump 1412 are combined into a single console. This allows for a smaller size that can be attached to a standard IV pole. FIG. 74 shows an aspiration system 2100 with all the features of the aspiration system that is 1400' of FIG. 38, but the peristaltic pump feature 2108 and the infusion pump feature 2112 are both included in a single console 2102. The third extension tube 1762 is elongated, and the aspiration monitoring system 1414 is directly connected or connectable to the y-connector 1756. The aspiration monitoring system 1414 may be in a non-sterile area. Thus, the aspiration monitoring system 1414 may be set up, prepared, calibrated, and operated by a technician, sales representative, nurse, or other medical personnel who are not "scrubbed" and therefore do not need to maintain sterility. For example, the aspiration monitoring system 1414 may be located on the same table as the console 2102. Cable 1486 of system 1400' of FIG. 38 is not required since a similar connection is located inside console 2100. Cable 1463 of system 1400' of FIG. 38 is also not required since cable 1461 can transfer all signals to and from foot pedal 1451. Luer 1766 may be attachable and detachable, or in other embodiments may be permanently connected to female luer 1452' of connector 1424'.

[0204] FIG. 39 shows an alternative suction system 1400″ including the suction catheter 1402′ of FIG. 38. However, a centrifugal pump 1409 is substituted for the peristaltic pump 1408. The proximal end 1442 of the extension tube 1438 is connected to an inlet 1413 that allows aspirant to enter the chamber 1419. An impeller 1421 is rotatably held within the chamber 1419 by a first bearing 1423 and a second bearing 1427. A first seal 1429 and a second seal 1431 allow the impeller 1421 to rotate (curved arrow) without aspirant leaking. A motor 1433 is configured to rotate the impeller 1421. The aspirant is pushed from the outlet 1435 into an outlet tube 1439 that is connected to a hub 1457 of a canister 1458. The user interface 1441 can be manipulated by a user to activate the centrifugal pump 1409. In some embodiments, an Angiodynamics AngioVac centrifugal pump can be used as the centrifugal pump 1409.

[0205] The suction catheters 1402, 1402' of Figures 36, 38 and 39 are shown as having pressurized fluid infusion via the infusion lumen 1410, 1410'. However, other embodiments of the suction system 1400, 1400' in which the suction catheter 1402, 1402' is replaced by a standard suction catheter, such as the suction catheter 4 of Figure 1, do not have an infusion lumen.

[0206]

[0206] Instead of collecting the aspirated material in a blood bag, blood bottle, or canister 1458, the aspirated components (blood, clot, saline, slurry, etc.) can be placed in a reinfusion device, such as the Stryker ConstaVac (CBCII) Blood Conservation System, or the Haemonetics OrthoPAT Orthopedic Perioperative Autotransfusion System. The blood can be purified by the reinfusion device, for example, to remove red blood cells or portions of red blood cells that have undergone hemolysis. One such reinfusion device is the Haemonetics Cell Saver® Elite+ Autotransfusion System.

[0207]

[0207] In some embodiments, the blood may be cooled before being injected. In some embodiments, the blood may be heated before being injected. In some embodiments, other drugs may be added to the blood before it is inserted. In some cases, the blood may be diluted with saline to reduce viscosity or to lower the hematocrit. This may result in reduced hemolysis. In some cases, the blood collected in the canister 1458, or coming from the extension tube 1438, may even be used as donor blood for injection into another patient.

[0208] In some embodiments, additional or alternative sensors may be used to monitor flow conditions to notify the user, including, but not limited to, Doppler sensors, infrared sensors, or laser flow detection devices. In some embodiments, an externally mounted (non-contact) Doppler sensor may be used. In some embodiments, an infrared sensor or laser flow detection device may be used around the extension tube 1438. Alternative sensors (e.g., flow sensors, etc.) may be placed at several different locations along the aspiration path, including on or in the extension tube 1438, distal to the impeller 1421 of the centrifugal pump 1409, or on or in the outlet tube 1439 proximal to the impeller 1421 of the centrifugal pump 1409. Or, in embodiments using a peristaltic pump 1408, an alternative sensor may be placed on or in the extension tube 1438 distal or proximal to the rotatable head 1430 of the peristaltic pump 1408.

[0209]

[0209] A suction system 1600 utilizing an ultrasonic sensor 1602 is shown in Figs. 40-42. The suction system 1600 is similar to the suction system 1400' of Fig. 38, except for the addition of the ultrasonic sensor 1602 and other related components. Alternate embodiments may utilize the teachings of other suction system embodiments disclosed herein. The ultrasonic sensor may be configured for analog output (e.g., with a variable voltage output), for example, ranging from 0 volts DC to 1 volt DC, or 0 volts DC to 5 volts DC, or 0 volts DC to 10 volts DC. Referring to Fig. 41, the ultrasonic sensor 1602 is inserted into a side port 1606 of a y-connector 1604. The y-connector 1604 has a distal connector 1608 attached to the proximal end 1603 of a tube 1610. The tube 1610 slides over a barb 1605 that constitutes the distal connector 1608. The distal end 1607 of the tube 1610 is connected to the proximal end 1406' of the suction lumen 1404' of the suction catheter 1402' via a connector 1609 and an aspiration monitoring system 1414 attached to a female luer 1452' of the connector 1424'. The proximal connector 1612 of the y-connector 1604 is connected to a friction fitting 1616 of an extension tube 1614. The proximal connector 1612 also includes a barb. The extension tube 1614 is connectable to a peristaltic pump 1608, but may alternatively be connected to a centrifugal pump 1409, or one of the vacuum sources described herein. The ultrasonic sensor 1602 is positioned such that its distal end 1618 is adjacent the aspiration flow (straight arrow). A fitting 1620 at the proximal end of the ultrasonic sensor 1602 is configured to secure the ultrasonic sensor 1602 to the side port 1606 at its desired position. This may be a friction fit, screw mount, snap and adhesive connection, thermal connection, or other fastening means. The output (e.g., voltage) of the ultrasonic sensor is transmitted through a cable 1622. A strain relief 1601 connected to the cable 1622 and fitting 1620 serves to protect a first end 1611 of the cable 1622 from damage due to bending, tension, or compression.

[0210] In one embodiment, the ultrasonic sensor 1602 has an analog channel that outputs a signal referenced to ground that varies between 0 and 5 volts DC. At very low flow rates, the signal is often sinusoidal, but at high flow rates, typically occurring during aspiration of clots / thrombi / blood, the flow rate is large enough that the channel saturates and appears as a variable digital pulse stream roughly proportional to the flow. The pulse frequency of this channel is relatively high, meaning that a pseudo digital on / off occurs when the flow rate exceeds a certain value. This specific value can be adjusted by connecting appropriate electronics. Along with the pseudo digital nature of the channel, a dedicated digital I / O pin is utilized that feeds a high priority interrupt handler. This allows for very efficient counting of rising signal transitions of this pulse stream at fixed time intervals. The pulse count above / below one or more pre-determined thresholds ultimately determines whether the overall system is in a free-flow or clot removal state, and to what extent.

[0211] FIG. 42 shows a console 1624 having an input jack 1626 to which a plug 1628 at the second end 1613 of the cable 1622 is attached. The console 1624 includes an internal measurement device 1630 configured to count the number of times N during a predetermined time period P that the signal being output by the ultrasonic sensor 1602 exceeds a predetermined threshold amplitude A. The measurement device 1630 is further configured to determine whether the number of times N is (a) greater than (or equal to or greater than) a predetermined value V or (b) less than (or equal to or less than) a predetermined value V. For example, in one embodiment, the predetermined time period P is input to the measurement device 1630 (e.g., via a user interface 1632) as 0.33 seconds. An algorithm within the measurement device 1630 counts the number of threshold crossings output by the ultrasonic sensor 1602 during this predetermined time period P. The measurement device 1630 then applies a particular logic scheme. In some embodiments, this logic scheme can simply be "flow" or "no flow." For example, if there are 0 to 150 counts within the period P, a "no flow" condition is identified, and if there are 151 or more counts within the period P, a "flow" condition is identified. The measurement device 1630 may include a microprocessor. A communication device 1634 mounted on the console 1624 may be controlled by the measurement device 1630 or by a separate controller to identify a first communication mode of a "no flow" condition and a second communication mode of a "flow" condition. In some embodiments, the first communication mode may include the absence of a signal from the communication device 1634 (e.g., no light is illuminated, no sound is generated, no vibration or heat is generated), and the second communication mode may include a light being illuminated, or a message being displayed (e.g., the word "flow"), or an audio message being played (a sound indicating "aspiration is occurring"), or an audio alert (e.g., a "beep"), or a mechanical alert (e.g., a vibration). The amplitude of the communication (e.g. dB of sound, light intensity, etc.) can be increased by pressing the increase button 1615 or decreased by pressing the decrease button 1617. The current level of amplitude is shown on the display 1619.The display may comprise a series of LEDs 1621 configured to light up, with higher amplitude corresponding to more LEDs being lit.

[0212]

[0212] In other embodiments, the first and second communication modes may each include several perceptible signals (auditory, visual, tactile), each different from the other. In other embodiments, more complex logic schemes may be used. For example, for a given period P of 0.33 seconds, if there are 0 to 150 counts within the period P, a "no flow" state is identified; if there are 151 to 225 counts within the period P, a "low flow" state is identified; if there are 226 to 350 counts within the period P, a "medium flow" state is identified; and if there are 351 or more counts, a "high flow" state is identified. The "no flow" state may correspond to the first communication mode, the "low flow" state may correspond to the second communication mode, the "medium flow" state may correspond to the third communication mode, and the "high flow" state may correspond to the fourth communication mode. The first communication mode may be processed by the communication device 1634, which remains silent and / or non-visual / non-vibrational / non-heating, etc. The second communication mode may be handled by the communication device beeping (through an audio speaker) or flashing (through a guided or other light) at a frequency of 2 Hz. The third communication mode may be handled by the communication device beeping (through an audio speaker) or flashing (through a guided or other light) at a frequency of 4 Hz. The fourth communication mode may be handled by the communication device beeping (through an audio speaker) or flashing (through a guided or other light) at a frequency of 10 Hz. In another embodiment, the second communication mode may be handled by the communication device beeping (through an audio speaker) or flashing (through a guided or other light) at a frequency of 0.5 Hz. The third communication mode may be handled by the communication device beeping (through an audio speaker) or flashing (through a guided or other light) at a frequency of 1 Hz. The fourth communication mode may be handled by the communication device beeping (through an audio speaker) or flashing (through a guided or other light) at a frequency of 2 Hz. Additionally or alternatively, the strength of the signal may increase from the second communication mode to the fourth communication mode, for example by 10 dB from the second to the third, and another 10 dB from the third to the fourth.Or an increase of 5 dB each time.

[0213]

[0213] In an alternative embodiment, the ultrasonic sensor 1602 may have an analog to digital module and may only output a digital signal characteristic of 1 (flow above a certain threshold flow rate) or 0 (flow below a certain threshold flow rate).

[0214]

[0214] The predetermined period of time P may be between about 0.01 seconds and about 1.00 seconds, or between about 0.10 seconds and about 0.50 seconds, or between about 0.20 seconds and about 0.40 seconds. The predetermined period of time P may be adjustable by a user, for example, via the user interface 1632.

[0215]

[0215] In certain aspiration procedures, if the clot is not adequately aspirated but aspiration continues, an unacceptably large amount of blood may be aspirated from the patient. This can lead to dehydration, a drop in blood pressure, and even blood loss in the patient, all potentially serious events that could jeopardize the success of the procedure and put the patient at risk. The ability to constantly recognize if blood is being aspirated at an unacceptable rate is a key factor in achieving a high degree of safety and efficiency.

[0216]

[0216] Disclosed herein is a system for catheter aspiration configured to communicate flow status and / or flow rate information to a user, as determined by metering fluid, blood, clots, or other material aspirated from a patient over a period of time.

[0217]

[0217] Figure 43 shows an aspiration system 200 comprising an aspiration catheter 202 with an elongated shaft 201 including an aspiration lumen 204 having an open distal end 205 and a proximal end 206 configured to connect to a peristaltic pump 208. The peristaltic pump 208 may be a roller pump having a base 226, a pressure shoe 228 carried by the base 226, and a rotatable head 230 rotatably connected to the base 226 and carrying two or more rollers 232a-d. The rollers 232a-d are arranged around a circumference 234 of the rotatable head 230. The rotatable head 230 is configured to be rotatable in at least a first rotational direction 236 (e.g., by a motor, directly, or with a gear train, as shown in Figure 36). The peristaltic pump 208 may be battery powered, and the battery may be rechargeable by wire or wirelessly. The peristaltic pump 208 may alternatively or additionally be powered by a power cord configured to connect to a power source. An extension tube 238 having a distal end 240 and a proximal end 242 and having a lumen 244 extending therethrough is hydraulically connected to the proximal end 206 of the aspiration lumen 204 of the aspiration catheter 202 via a connector 224. The extension tube 238 may be supplied (e.g., sterile) with the aspiration catheter 202 or may be supplied separately packaged. A Touhy-Borst seal 246 mounted on the connector 224 is configured to be loosened / opened to allow insertion of a guidewire 248 through the connector 224 and the aspiration lumen 204, which may be used to track the aspiration catheter 202 through the subject's vasculature. The Touhy-Borst 246 may be tightened to seal the guidewire 248 and maintain hemostasis. Other types of seals may be incorporated in place of the Touhy-Borst 246, including spring-loaded, longitudinally compressible and actuatable seals. The extension tube 238 includes a male luer 250 at its distal end 240 for connecting to a female luer 252 of the connector 224. Alternatively, as shown, the suction monitoring system 214 may be attached therebetween.The male luer 250 may include a stopcock 254 configured to rotate to select an open position (as shown) or a closed position. Alternatively, the extension tube 238 may be integral with the suction lumen 204 or may be permanently attached to the connector 224. In use, the compressible portion 237 of the extension tube 238 is disposed within the pressure shoe 228 of the peristaltic pump 208 such that, upon rotation of the rotatable head 230 in a rotational direction 236 (e.g., via input to the interface 256 by a user), fluid is forced from the distal end 240 to the proximal end 242 through the lumen 244 of the extension tube 238, one at a time, via compression of the compressible portion 237 by the rollers 232. In some embodiments, there are only two rollers 232. In other embodiments, there are three rollers 232. In yet other embodiments, there are four rollers 232, as shown. As described, the rollers 232 may be replaced by ridges or protrusions. The compressible portion 237 may include silicone, polyurethane, polyvinyl chloride, or other compressible tubing. The compressible portion 237 may be a relatively short section that is attachable and detachable to a peripheral end of the extension tube 238, or in other embodiments, may include the entire extension tube 238 between the distal end 240 and the proximal end 242. The proximal end 242 of the extension tube 238 may be connected to a hub 257 formed on the cap 213 of the canister 258, the canister 258 having an interior 260, which may allow fluid 259 passing through the extension tube 238 to enter the interior 260. An additional hub 262 may be provided within the canister 258, and may be left open (as shown) to allow the unfilled interior 260 to equalize to atmospheric pressure.

[0218]

[0218] In use, the distal section of the aspiration catheter 202 is inserted into the subject's vasculature such that the open distal end 205 is adjacent to or within the thrombus. Fluid containing the thrombus is then aspirated into the aspiration lumen 204 by action of the peristaltic pump 208 and removed using the aspiration system 200. The blood vessels being treated may include peripheral blood vessels, pulmonary blood vessels such as the pulmonary artery, coronary blood vessels, or blood vessels in the subject's head or neck, including the carotid or cerebral arteries.

[0219]

[0219] The suction system 200 further comprises a suction monitoring system 1800 configured to provide information to a user regarding the status of the suction. The suction monitoring system 1800 functions by measuring the fluid 259 accumulated at the bottom of the interior 260 of the canister 258 at multiple points in time and thus estimating the (volumetric) flow rate of the fluid 259 exiting the lumen 244 of the extension tube 238. The suction monitoring system 1800 comprises a scale 1802 (or balance) having a base 1804. A weighing platform 1806 is connected to the base 1804 and is movable relative to the base 1804 (e.g., along a vertical axis V) such that the weight of the fluid 259 accumulated at the bottom of the canister 258 outputs a signal 1808 indicative of the weight. The scale may be configured to output the signal 1808 indicative of the weight, or in some embodiments, a particular altitude (above sea level) at which the scale 1802 is located may be input into the scale 1802 so that a value of mass can be output. A standard setting may assume the procedure is performed at sea level and calculate the mass accordingly. In some embodiments, the scale 1802 may even include an altimeter or other sensor to automatically determine the altitude so that the mass can be output. Regardless, even if weight is output, the change in weight of the fluid 259 over time is proportional to the change in mass of the fluid 259 over time at any particular altitude. Thus, the signal 1808 may indicate mass or indicate weight while remaining within a range that allows for the change in mass of the fluid 259 over time to be demonstrated. Thus, the system 200 may predict blood loss from the patient by evaluation of the total cumulative weight / mass of blood captured in the canister 258. The measured weight / mass of blood may be converted to the volume (ml) of blood lost by the system 200.

[0220]

[0220] The signal 1808 is sent to a processor 1810. See also FIG. 44. The processor 1810, which may comprise a microprocessor, includes a clock that allows for the combination of time data with weight or mass values ​​from the signal. In some embodiments, the scale 1802 may include a tare button or control so that the tare weight of the canister 258 can be subtracted from the amount weighed by the scale 1802. Thus, the scale 1802 is "zeroed" and only the weight or mass of the fluid 259 in the canister 258 is weighed at each point in time. The sample rate at which the values ​​of the signal 1808 are taken along with the time stamps may range from about 0.01 Hz to about 10 kHz, or from about 0.02 Hz to about 1 kHz, or from about 1 Hz to about 100 Hz. The processed signal 1812 is output to a graphic display 1814 for viewing by a user. In some embodiments, the graphic display 1814 can display an xy graph 1816, where the x-axis represents time and the y-axis represents the weight or mass of the fluid 259 in the canister 258. In other embodiments, the graphic display 1814 can display an xy graph 1816, where the x-axis represents time and the y-axis represents the flow rate. The flow rate (FR) can be calculated from the following formula:

[0221]

[0221] FR = (W c -W p ) / (T c -T p ), where W c is the current value of the weight of fluid 259 W p is the previous value of the weight of fluid 259 T c is the current timestamp value T p is the previous timestamp value.

[0222]

[0222] In another embodiment, the flow rate (FR) can be calculated from the following formula:

[0223]

[0223] FR = (W c-W pn ) / (T c -T pn ), where W c is the current value of the weight of fluid 259 W pn is the nth previous value of the weight of fluid 259 T c is the current timestamp value T pn is the nth previous timestamp value.

[0224]

[0224] In other embodiments, the flow rate may be constructed as a moving average, such as a running or rolling average. Several types of moving averages may be used, including a simple moving average, a cumulative moving average, a weighted moving average, or an exponential moving average.

[0225]

[0225] Instead of an xy graph, a visual display with one or more LED lights may be used. For example, higher flow rates may be indicated by a range of shades of green, while lower flow rates may be indicated by a range of shades of red. Alternatively, the intensity of the light may vary with the change in flow rate, or the change in weight or mass. For example, the intensity of the light may be proportional to the measured / calculated flow rate. A loudspeaker may present the change in weight / mass over time, or the change in flow rate over time, as a continuous or continuous sound with a pitch that varies proportionally to the change in value. For example, a higher pitch means a higher flow rate. Alternatively, the intensity of the sound may vary (higher flow rate = higher dB).

[0226]

[0226] The change in flow rate may indicate the number of occurrences of an operation in the aspiration system 200. For example, a flow rate that suddenly decreases a significant amount may indicate a clot is lodged in the aspiration lumen 204 or the lumen 244 of the extension tube 238. In some cases, a decrease in flow rate of 90% or more may indicate a blockage. When a blockage occurs, the amount of fluid that can be aspirated and delivered to the canister 258 may be severely limited. The loudspeaker 1818 is also configured to generate an audible alarm when a threshold flow rate is crossed. The threshold flow rate may be entered into the memory 1822 of the scale 1802 using the user interface 1820. When the flow rate decreases to a value lower than the threshold flow rate, the loudspeaker 1818 is caused to sound an alarm. In some embodiments, the controller 215 in the peristaltic pump 208 may be connected (wired or wirelessly) to the processor 1810 and configured to activate an alarm on the loudspeaker 1818. If the flow rate increases above a threshold flow rate, the loudspeaker 1818 may be deactivated so that no alarm sounds. Alternatively, the loudspeaker 1818 may be replaced or augmented by a visual and / or tactile alarm. A visual alarm may include one or more lights, including one or more LEDs. A tactile alarm may include a vibrating device, such as a piezoelectric, or a weight-offset rotating device.

[0227]

[0227] A change in flow rate may also indicate other changes in condition, such as a rupture of one of the walls of the tubular member, or a break in one of the connections. In one of these leak conditions, the flow rate may be significantly reduced, and thus identified by a change in flow rate measured by the aspiration monitoring system 1800. The system 200 may be configured to activate an alarm (e.g., via the loudspeaker 1818) when free flow of blood is detected. In other words, when the system is apparently aspirating only blood and not clots. Thus, a measured flow rate crossing above a certain threshold stored in memory 1822 indicative of free flowing blood may cause the controller 215 to activate an alarm.

[0228]

[0228] The secondary suction monitoring system 214 including the pressure transducer 216 may be connected, for example, between the distal end 240 of the extension tube 238 and the connector 224 and / or the proximal end 206 of the suction lumen 204 of the suction catheter 202. The signal from the pressure transducer 216 may be conveyed wirelessly or by a cable (not shown) to the controller 215. The controller 215 may comprise a microcontroller. The controller 215 may be located within the peristaltic pump 208 or may be located in another component or location. Using the measured pressure for control adds an additional element of safety to the system 200. Furthermore, non-functioning devices (due to leaks, faulty connections, faulty priming, ruptures, blockages) can be quickly identified. Unacceptably high or low pressures can also be quickly identified, protecting the motor of the peristaltic pump 208 from the risk of burning out or overheating. Data from the pressure transducer 216 and the scale 1802 can be used together to optimize or create a more accurate signal indicating aspiration flow or indicating the presence of a clot / thrombus, the presence of a blockage, the presence of a rupture, or a disconnected fluid circuit.

[0229]

[0229] A foot pedal 251 is shown having a base 253 and a pedal 255 connected to the base 253 and movable or actuable by application of a user's foot. The pedal 255 may be spring loaded, depressed by application of a moment or compressive force, or may instead comprise a membrane switch. When activated, the pedal 255 may switch on and off in some embodiments, and in other embodiments may be actuable when a force, pressure, or moment is applied and deactivated when no force, pressure, or moment is applied. A cable 263 carries a signal from the foot pedal 251 to the peristaltic pump 208 via a plug 269 connected to an input jack 271. The pedal 255 may be activated by the user's foot to start or stop operation of the peristaltic pump 208.

[0230]

[0230] In other embodiments, the foot pedal 251 may be replaced with another type of switch, including but not limited to a toggle on / off push button or hand switch, a voice activated switch (voice activated, clap activated, click activated), a light switch (beam / light sensor for hand or foot interruption), or any other type of switch that can be activated by medical personnel. The switch may be in a remote location (e.g., a control room) or may be near the treatment area. The switch may also be a sterile switch or may be sterilizable for location on the sterile field.

[0231]

[0231] In some cases, activation and deactivation (turning on and off) of the suction flow applied to the suction lumen 204 by the peristaltic pump 208 can be done by leaving the peristaltic pump 208 running while a user opens and closes the stopcock 254. Alternatively, a pinch valve (not shown) connected to the extension tube 238 can be used to open and close the lumen 244, thus starting and stopping suction. The pinch valve can be actuated by a foot pedal (similar to foot pedal 251) or by another control device (e.g., on interface 256 of the peristaltic pump 208).

[0232]

[0232] After the aspirated material is collected in a blood bag, blood bottle, or canister 258, the aspirated components (blood, clot, saline, slurry, etc.) can be placed into a reinfusion device such as the Stryker ConstaVac (CBCII) Blood Conservation System or the Haemonetics OrthoPAT Orthopedic Perioperative Autotransfusion System.

[0233]

[0233] In some embodiments, the blood may be cooled before being injected. In some embodiments, the blood may be heated before being injected. In some embodiments, other drugs may be added to the blood before it is inserted. In some cases, the blood may be diluted with saline to reduce viscosity or to lower the hematocrit. This may result in reduced hemolysis. In some cases, the blood collected in the canister 258, or coming from the extension tube 238, may even be used as donor blood for injection into another patient.

[0234] In some embodiments, additional or alternative sensors may be used to monitor flow conditions to notify the user, including, but not limited to, Doppler sensors, infrared sensors, or laser flow detection devices. In some embodiments, an externally mounted (non-contact) Doppler sensor may be used. In some embodiments, an infrared sensor or laser flow detection device may be used around the extension tube 238. Alternative sensors (e.g., flow sensors, etc.) may be placed at several different locations along the aspiration path, including on or within the extension tube 238, either proximal or distal to the rotatable head 230 of the peristaltic pump 208.

[0235]

[0235] Figure 45 shows a forced suction system 400 comprising an suction catheter 402 with an elongated shaft 401 including an suction lumen 404 having an open distal end 405 and a proximal end 406 configured to connect to a peristaltic pump 408. The peristaltic pump 408 may be a roller pump having a base 426, a pressure shoe 428 carried by the base 426, and a rotatable head 430 rotatably connected to the base 426 and carrying two or more rollers 432a-432d. The rollers 432a-432d are arranged around a circumference 434 of the rotatable head 430. The rotatable head 430 is configured to be rotatable in at least a first rotational direction 436 (e.g., by a motor, directly, or with a gear train, as shown in Figure 36). The peristaltic pump 408 may be battery powered, and the battery may be rechargeable by wire or wirelessly. The peristaltic pump 408 may alternatively or additionally be powered by a power cord configured to connect to a power source. An extension tube 438 having a distal end 440 and a proximal end 442 and having a lumen 444 extending therethrough is hydraulically connected to the proximal end 406 of the aspiration lumen 404 of the aspiration catheter 402 via a connector 424. The extension tube 438 may be supplied (e.g., sterile) with the aspiration catheter 202 or may be supplied separately packaged. A Touhy-Borst seal 446 mounted on the connector 424 is configured to be loosened / opened to allow insertion of a guidewire 448 through the connector 424 and the aspiration lumen 404, which may be used to track the aspiration catheter 402 through the subject's vasculature. The Touhy-Borst 446 may be tightened to seal the guidewire 448 and maintain hemostasis. Other types of seals may be incorporated in place of the Touhy-Borst 246, including spring-loaded, longitudinally compressible and actuatable seals. The extension tube 438 includes a male luer 450 at its distal end 440 for connecting to a female luer 452 of the connector 424. Alternatively, as shown, the suction monitoring system 414 may be attached therebetween.The male luer 450 may include a stopcock 454 configured to rotate to select an open position (as shown) or a closed position. Alternatively, the extension tube 438 may be integral with the suction lumen 404 or may be permanently attached to the connector 424. In use, the compressible portion 437 of the extension tube 438 is disposed within the pressure shoe 428 of the peristaltic pump 408 such that, upon rotation of the rotatable head 430 in a rotational direction 436 (e.g., via input to the interface 456 by a user), fluid is forced from the distal end 440 to the proximal end 442 through the lumen 444 of the extension tube 438, one at a time, via compression of the compressible portion 437 by the rollers 432. In some embodiments, there are only two rollers 432. In other embodiments, there are three rollers 432. In yet other embodiments, there are four rollers 432, as shown. As described, the rollers 432 may be replaced by ridges or protrusions. The compressible portion 437 may include silicone, polyurethane, polyvinyl chloride, or other compressible tubing. The compressible portion 437 may be a relatively short section that is attachable and detachable to the peripheral end of the extension tube 438, or in other embodiments, may include the entire extension tube 438 between the distal end 440 and the proximal end 442. The proximal end 442 of the extension tube 438 may be connected to a hub 457 of a canister 458 having an interior 460 to allow fluid 459 passing through the extension tube 438 to pass to the interior 460. An additional hub 462 in the canister 458 may be left open (as shown) to allow the uncharged interior 460 to match atmospheric pressure. A filter 443 (optional) is placed in line between the extension tube 438 and the canister 458 to capture blood clots aspirated from the patient. The filter 443 may have a transparent sidewall to allow a physician or other medical staff to visually assess the clot, such as the size of each piece, the number of pieces, the total amount of clot (e.g., in terms of volume), or the condition of the clot or remaining clot (organized / fibrous, or soft), etc.The accumulation of thrombus in the filter 443, or the lack thereof, can be used as a cue to move the open distal end 405 of the suction catheter 402 to a different position, or to temporarily or permanently stop treatment, or to increase or decrease the pump speed.

[0236]

[0236] The suction catheter 402 further has a high pressure infusion lumen 410 for infusing saline from a fluid source 499, for example, via a high pressure pump 412. The tubing set 464 may include a pump cartridge 466 having a piston or bellows, or other movable element that the pump 412 may operate using an internal motor (not shown), which applies high pressure to the saline from the fluid source 499 such that the saline is forced through the infusion lumen 410 of the suction catheter 402. The tubing set 464 includes a proximal end 468 having a spike 497 or other element for hydraulically connecting it to the fluid source 499. The tubing set 464 further has a distal end 470 (which may include a male luer) configured to hydraulically connect to the infusion lumen 410 via a female luer 472. The infused saline is forced by the pump 412 through the infusion lumen 410 and exits an orifice 474 at the distal end 476 of the infusion lumen 410. The infusion lumen 410 may be within a tube 478 that is substantially or completely within the shaft 401. In some embodiments, the tube 478 is attached to the inner wall of the shaft 401 only at the distal end portion 403. Thus, the free-floating nature of the remaining portion of the tube 478 within the aspiration lumen 404 increases the flexibility and trackability of the shaft 401. High pressure saline is forced through the orifice 474, causing a jet. The jet is directed into the aspiration lumen 404 just proximal to the open distal end 405, which may create a Venturi effect to push blood or clots externally adjacent the open distal end 405 into the aspiration lumen 404. The action of the peristaltic pump 408 in combination with the jets generated by the high pressure saline causes maceration of the thrombus and movement / flow of material (saline / blood / macerated thrombus / thrombus fragments) through the suction lumen 404 from the open distal end 405 to the proximal end 406, through the connector 424, through the lumen 444 of the extension tube 438 from the distal end 440 to the proximal end 442, and finally into the interior 460 of the canister 458. Thus, thrombus within a subject's blood vessels can be macerated and removed by using the system 400.The blood vessels to be treated may include peripheral blood vessels, pulmonary blood vessels, such as the pulmonary artery, coronary blood vessels, or blood vessels within the subject's head or neck, including the carotid or cerebral arteries.

[0237]

[0237] The forced suction system 400 further comprises a suction monitoring system 1800 configured to provide information to a user regarding the status of the suction. The suction monitoring system 1800 functions by measuring the fluid 459 accumulated at the bottom of the interior 460 of the canister 458 at multiple points in time and thus estimating the flow rate of the fluid 459 exiting the lumen 444 of the extension tube 438. The suction monitoring system 1800 comprises a scale 1802 (or balance) having a base 1804. A weighing platform 1806 is connected to the base 1804 and is movable relative to the base 1804 (e.g., along a vertical axis V) such that the weight of the fluid 459 accumulated at the bottom of the canister 458 outputs a signal 1808 indicative of the weight. The scale may be configured to output the signal 1808 indicative of the weight, or in some embodiments, a particular altitude (above sea level) at which the scale 1802 is located may be input into the scale 1802 so that a value of mass can be output. In some embodiments, the scale 1802 may even include an altimeter or other sensor to automatically determine altitude so that mass can be output. Regardless, even if weight is output, the change in weight of the fluid 459 over time is proportional to the change in mass of the fluid 459 over time at any particular altitude. Thus, the signal 1808 may indicate mass or indicate weight while remaining within a range that allows for the change in mass of the fluid 459 over time to be demonstrated. Thus, the system 400 may predict blood loss from the patient by assessment of the total cumulative weight / mass of blood captured in the canister 458. The measured weight / mass of blood may be converted to the volume (ml) of blood lost by the system 400.

[0238]

[0238] The signal 1808 is sent to a processor 1810. See also FIG. 44. The processor 1810, which may comprise a microprocessor, includes a clock that allows for the combination of time data with weight or mass values ​​from the signal. In some embodiments, the scale 1802 may include a tare button or control so that the tare weight of the canister 458 can be subtracted from the amount being weighed by the scale 1802. Thus, the scale 1802 is "zeroed" and only the weight or mass of the fluid 459 in the canister 458 is weighed at each point in time. The sample rate at which the values ​​of the signal 1808 are taken along with the time stamps may range from about 0.01 Hz to about 10 kHz, or from about 0.02 Hz to about 1 kHz, or from about 1 Hz to about 100 Hz. The processed signal 1812 is output to a graphic display 1814 for viewing by a user. In some embodiments, the graphic display 1814 can display an xy graph 1816, where the x-axis represents time and the y-axis represents the weight or mass of the fluid 459 in the canister 458. In other embodiments, the graphic display 1814 can display an xy graph 1816, where the x-axis represents time and the y-axis represents the flow rate. The flow rate (FR) can be calculated from the following formula:

[0239]

[0239] FR = (W c -W p ) / (T c -T p ), where W c is the current value of the weight of fluid 459 W p is the previous value of the weight of fluid 459 T c is the current timestamp value T p is the previous timestamp value.

[0240]

[0240] In another embodiment, the flow rate (FR) can be calculated from the following formula:

[0241]

[0241] FR = (W c-W pn ) / (T c -T pn ), where W c is the current value of the weight of fluid 459 W pn is the nth previous value of the weight of fluid 459 T c is the current timestamp value T pn is the nth previous timestamp value.

[0242]

[0242] In other embodiments, the flow rate may be constructed as a moving average, such as a running or rolling average. Several types of moving averages may be used, including a simple moving average, a cumulative moving average, a weighted moving average, or an exponential moving average.

[0243]

[0243] Instead of an xy graph, a visual display with one or more LED lights may be used. For example, higher flow rates may be indicated by a range of shades of green, while lower flow rates may be indicated by a range of shades of red. Alternatively, the intensity of the light may vary with the change in flow rate or the change in weight or mass. For example, the intensity of the light may be proportional to the measured / calculated flow rate. A loudspeaker may present the change in weight / mass over time, or the change in flow rate over time, as a continuous or continuous sound with a pitch that varies proportionally to the change in value. For example, a higher pitch means a higher flow rate. Alternatively, the intensity of the sound may vary (higher flow rate = higher dB).

[0244]

[0244] The change in flow rate may indicate the number of occurrences of operations in the forced aspiration system 400. For example, a flow rate that suddenly decreases a significant amount may indicate a clot is lodged in the aspiration lumen 404 or the lumen 444 of the extension tube 438. In some cases, a decrease in flow rate of 90% or more may indicate a blockage. When a blockage occurs, the amount of fluid that can be aspirated and delivered to the canister 458 may be severely limited. The loudspeaker 1818 is also configured to generate an audible alarm when a threshold flow rate is crossed. The threshold flow rate may be entered into the memory 1822 of the scale 1802 using the user interface 1820. When the flow rate decreases to a value lower than the threshold flow rate, the loudspeaker 1818 is made to sound an alarm. In some embodiments, the controller 484 on the pump 412, or a different controller on one of the other components, may be connected (wired or wirelessly) to the processor 1810 and configured to activate an alarm on the loudspeaker 1818. If the flow rate increases above a threshold flow rate, the loudspeaker 1818 may be deactivated so that no alarm sounds. Alternatively, the loudspeaker 1818 may be replaced or augmented by a visual and / or tactile alarm. A visual alarm may include one or more lights, including one or more LEDs. A tactile alarm may include a vibrating device, such as a piezoelectric, or a weight-offset rotating device.

[0245]

[0245] A change in flow rate may also indicate other changes in condition, such as a rupture of one of the walls of the tubular member, or a break in one of the connections. In one of these leak conditions, the flow rate may be significantly reduced, and thus identified by a change in flow rate measured by the aspiration monitoring system 1800. The system 400 may be configured to activate an alarm (e.g., via the loudspeaker 1818) when free flow of blood is detected. In other words, when the system is apparently aspirating only blood and not clots. Thus, a measured flow rate crossing above a certain threshold stored in memory 1822 indicative of free flowing blood may cause the controller 484 to activate an alarm.

[0246]

[0246] A secondary suction monitoring system 414 including a pressure transducer 416 may be connected, for example, between the distal end 440 of the extension tube 438 and the connector 424 and / or the proximal end 406 of the suction lumen 404 of the suction catheter 402. A signal from the pressure transducer 416 is carried on an electrical cable 480 to an input 482 of the pump 412. A controller 484 in the pump 412 is configured to control the operation of the pump 412, but may also be configured to control the operation of the peristaltic pump 408 via a cable 486 or wirelessly. The controller 484 may comprise a microcontroller. Alternatively, the controller 484 may be located in the peristaltic pump 408 or may be located in another component or location. Control using measured pressure adds an additional safety element to the system 400. Additionally, non-functioning devices (due to leaks, faulty connections, faulty priming, ruptures, blockages) can be quickly identified. Unacceptably high pressures can also be quickly identified, protecting the motor of the pump 412 from the risk of burning out or overheating. The integrity of the tubing 478 is also protected, avoiding unnaturally high pressures that could lead to, for example, rupturing the tubing 478. Data from the pressure transducer 416 and the scale 1802 can be used together to optimize or create a more accurate signal indicating aspiration flow or indicating the presence of a clot / thrombus, the presence of a blockage, the presence of a rupture, or a disconnected fluid circuit.

[0247]

[0247] Female luer 452 is located distally on connector 424 from female luer 472. Thus, aspirated blood / thrombus / saline enters female luer 452 without having to contact internal irregularities 425 (in geometry, shape) within connector 424 that might otherwise cause flow resistance or trap thrombus (e.g., between tubing 478 and the interior of connector 424.

[0248] A foot pedal 451 is shown having a base 453 and a pedal 455 connected to the base 453 and movable or actuable by application of a user's foot. The pedal 455 may be spring loaded, depressed by application of a moment or compression force, or may instead comprise a membrane switch. When activated, the pedal 455 may switch on and off in some embodiments, and in other embodiments may be actuable when a force, pressure, or moment is applied and deactivated when no force, pressure, or moment is applied. A first cable 461 carries a signal from the foot pedal 451 to the pump 412 via a plug 465 connected to an input jack 467. A second cable 463 carries a signal from the foot pedal 451 to the peristaltic pump 408 via a plug 469 connected to an input jack 471. In some embodiments, activation of the pedal 455 by the user's foot initiates operation of the pump 412 and simultaneously initiates operation of the peristaltic pump 408. In some embodiments, activation of pedal 455 by the user's foot initiates operation of peristaltic pump 408, which then initiates operation of pump 412 a short delay after peristaltic pump 408 is initiated. Controller 484 is programmed or programmable to provide the delay or lack of delay. The delay is useful to ensure that some suction, or a significant amount of suction, has been applied to aspiration lumen 404 before injecting pressurized fluid (e.g., saline) through infusion lumen 410. All may be controlled by controller 484 of pump 412 in response to a signal via cable 463 from foot pedal 451. Thus, blood vessels or other vasculature near open distal end 405 are spared infusion of fluid from the high pressure jet, as it is instead aspirated through aspiration lumen 404.

[0249]

[0249] Additionally, in some embodiments, activation of pedal 455 by the user's foot while pump 412 and peristaltic pump 408 are operating simultaneously stops operation of pump 412 and peristaltic pump 408. In other embodiments, a delay can be implemented (e.g., by controller 484) such that pump 412 is stopped and then peristaltic pump 408 is stopped after a short delay. The length of the described delay can be between about 0.01 seconds and about 1.00 seconds, or between about 0.10 seconds and about 0.25 seconds. Activation (on / off) of pump 412 and / or peristaltic pump 408 via foot pedal 451 allows for hands-free activation, allowing a single user to operate aspiration catheter 402 and guidewire 448 with both hands.

[0250]

[0250] In other embodiments, the foot pedal 451 may be replaced with another type of switch, including but not limited to a toggle on / off push button or hand switch, a voice activated switch (voice activated, clap activated, click activated), a light switch (beam / light sensor for hand or foot interruption), or any other type of switch that can be activated by medical personnel. The switch may be in a remote location (e.g., a control room) or may be near the treatment area. The switch may also be a sterile switch or may be sterilizable for location on the sterile field.

[0251]

[0251] In some cases, activation and deactivation (turning on and off) of the suction flow provided by peristaltic pump 408 to suction lumen 404 can be done by leaving peristaltic pump 408 running while a user opens and closes stopcock 454. Alternatively, a pinch valve (not shown) connected to extension tube 438 can be used to open and close lumen 444, thus starting and stopping suction. The pinch valve can be actuated by a foot pedal (similar to foot pedal 451) or by another control device (e.g., on interface 456 of peristaltic pump 408 or interface of pump 412).

[0252]

[0252] The controller 484 also monitors and controls several device safety features, including overpressure detection, air bubble detection, and vacuum or negative pressure charging. An additional pressure transducer 415 monitors the pressure (i.e., injection pressure) and senses the presence of air bubbles. Alternatively, or in combination, an optical device 417 can be used to sense air bubbles. In one possible embodiment, the pump pressure is proportional to the current required to generate that pressure. Thus, if the current required by the pump 412 exceeds a pre-set limit, the controller 484 disables the pump 412 by disconnecting the power to the pump 412. Air bubble detection can also be monitored by monitoring the current required to drive the pump 412 at a particular moment. In order for the pump 412 to reach high fluid pressures, there should be little or no air (which is highly compressible) in the pump 412 or the connection system (including the aspiration lumen 404 and tubing set 464 of the aspiration catheter 402). The fluid volume is small enough that air in the system does not create pressure at the pump head. A sufficient amount of liquid is required proximally to flush a finite amount of air. The controller 484 monitors the pump 412 current for a sudden downward change that may indicate air has entered the system. If the rate of drop is faster than a preset limit, the controller 484 disables the pump 412 by cutting power to the pump until the problem is corrected.

[0253]

[0253] After the aspirated material is collected in a blood bag, blood bottle, or canister 458, the aspirated components (blood, clot, saline, slurry, etc.) can be placed into a reinfusion device such as the Stryker ConstaVac (CBCII) Blood Conservation System or the Haemonetics OrthoPAT Orthopedic Perioperative Autotransfusion System.

[0254]

[0254] In some embodiments, the blood may be cooled before being injected. In some embodiments, the blood may be heated before being injected. In some embodiments, other drugs may be added to the blood before it is inserted. In some cases, the blood may be diluted with saline to reduce viscosity or to lower the hematocrit. This may result in reduced hemolysis. In some cases, the blood collected in the canister 458, or coming from the extension tube 438, may even be used as donor blood for injection into another patient.

[0255] In some embodiments, additional or alternative sensors may be used to monitor flow conditions for notification to the user, including, but not limited to, Doppler sensors, infrared sensors, or laser flow detection devices. In some embodiments, an externally mounted (non-contact) Doppler sensor may be used. In some embodiments, an infrared sensor or laser flow detection device may be used around the extension tube 438. Alternative sensors (e.g., flow sensors, etc.) may be placed at several different locations along the aspiration path, including on or within the extension tube 438, either proximal or distal to the rotatable head 430 of the peristaltic pump 408.

[0256]

[0256] Figure 46 illustrates an alternative suction monitoring system 1900 that shares features with the suction monitoring system 1800 of Figure 44, but is configured to weigh a fluid 259, 459 contained in a canister 258, 458 by suspending the canister 258, 458 from hooks 1902, 1904 extending from a frame 1906 supported on a weighing platform 1806. The frame 1906 comprises two vertical legs 1910, 1912 and a crossbar 1908 connected to each of the vertical legs 1910, 1912. The crossbar 1908 is configured to support the hooks 1902, 1904 and the canister 258, 458 (when suspended). The canister 258, 458 may include hooks, recesses, or loops configured to engage and interface with one or both of the hooks 1902, 1904.

[0257]

[0257] Although the above describes embodiments of the present disclosure, other and further embodiments may be devised without departing from the basic scope of the invention. Alternatively, instead of using an extension tube 238, 438 configured for use with a peristaltic pump 208, 408, the extension tube 238, 438 may include a luer connector (or other sealing connector) at its proximal end and may be configured to be attached to an evacuable syringe (e.g., 20 ml or 30 ml). The syringe may be hung from a hook 1902, 1904 (or equivalent) and the weight of the syringe and extension tube 238, 438 may be tared from the scale 1802. Thus, as the syringe is filled, the increase in weight / mass of aspirate collecting in the syringe is measured over time in the same manner that the contents of the canister 258, 458 are weighed. The evacuable syringe may also be replaced by a bell jar connected to a vacuum pump, and the bell jar and connecting tubes are tared from the measured weight / mass. FIG. 47 shows an aspiration system 1928 similar to the aspiration system 200 of FIG. 43, except that the peristaltic pump 208 and canister 258 are replaced by a vacuum pump 1930 and a vacuum chamber 1934, or a bell jar having a base 1936 and a lid 1938 sealably disposed thereon. The vacuum pump 1930 may be actuated by a control device 1999 mounted on its exterior surface 1997, or may be controllable (on / off) by a foot pedal 251. A vacuum tube 1932 connects the vacuum pump 1930 to an interior 1940 of the vacuum chamber 1934. A control valve 1948 is adjustable to control an aperture between the vacuum tube 1932 and the interior 1940 of the vacuum chamber 1934. The interior 1940 communicates with the lumen 244 of the dilation tube 238 via a proximal end 242 that is connected to a port 1942 of the vacuum chamber 1934. An adjustable valve 1946 controls an aperture between the interior 1940 of the vacuum chamber 1934 and the lumen 244 of the dilation tube 238. The vacuum pump 1930 is separately supported on a table, cart, or other support.The weight of the vacuum tube 1932 and the extension tube 238 can be tared from the readout of the scale 1802 so that only the weight of the fluid / clot etc. drawn into the interior 1940 of the vacuum chamber 1934 is measured over time.

[0258] Thrombosis (thrombus, blood clots) within the vascular system, including blood vessels such as arteries and veins, is a significant risk factor that can be debilitating and even fatal. Aspiration systems, including aspiration catheters, include aspiration-only devices as well as forced aspiration devices configured to inject pressurized fluid, such as heparinized saline, into the distal portion of the aspiration lumen to create a greater aspiration pressure gradient, allowing for the maceration and removal of significant clots. While many of these aspiration systems are used in peripheral or coronary arteries, thromboembolic stroke involving the arteries of the neck and head is also a concern. Many of the arteries of the neck and head, including the cerebral arteries, basilar artery, and other nearby communicating arteries, are located quite far from traditional insertion / puncture sites, such as the femoral and radial arteries. The pathways to these arteries can be very tortuous, and the vessels are often small caliber, so long, small diameter catheters with great flexibility at the distal end are utilized. Many of these design criteria confound other physical requirements of aspiration catheters, such as a large diameter aspiration lumen to increase aspiration flow, or multiple lumens in forced aspiration catheters that must fit into a small diameter overall catheter shaft.

[0259]

[0259] Clogging of the aspiration catheter, for example by a large clot, is a common concern for users. Techniques to avoid clogging / occlusion of material in the catheter often involve quickly and aggressively advancing the aspiration catheter or gently picking at the end of the clot to ensure that only a small piece or portion is introduced at a time, which is small enough not to clog or occlude the aspiration lumen. If the device becomes clogged during use, there is an increased chance of accidental dislodgement of the clot downstream; this is called peripheral embolization. Because this type of aspiration procedure is often used in highly technical emergency settings, early detection of clogging of the aspiration catheter for users during aspiration can contribute to the success of the procedure and clinical outcomes. Several sources report that up to 50% of used aspiration catheters become clogged during use.

[0260]

[0260] A user may have difficulty determining whether there is a vacuum or negative pressure gradient in the system. For example, a user may have difficulty determining whether a vacuum or negative pressure is being applied (e.g., a vacuum source or negative pressure supply pump is turned on or off). Additionally, a user may have difficulty determining whether there has been a vacuum or negative pressure drop in the system, for example, because the syringe (or other vacuum source or negative pressure supply pump) is filled with fluid or due to a leak in the system. Blood is relatively opaque and can coat the walls of the syringe, making it difficult to determine when the syringe is filled. This makes it difficult to determine whether sufficient vacuum or negative pressure is being applied to the aspiration catheter. The vacuum or negative pressure level may change to an unacceptable level even before the syringe is filled. An extension tube or other tube may also cause a drop in the vacuum or negative pressure gradient in the system. Kinks in certain tubes may be difficult for a user to see or identify. It is also difficult to determine whether there is an air leak in the system, which can be another cause for a vacuum or negative pressure drop, even before the syringe is filled with the aspiration fluid.

[0261]

[0261] Figure 48 shows an aspiration system 600 comprising an aspiration catheter 602 with an elongated shaft 601 including an aspiration lumen 604 having an open distal end 605 and a proximal end 606 configured to connect to a peristaltic pump 608. The peristaltic pump 608 may be a roller pump having a base 626, a pressure shoe 628 carried by the base 626, and a rotatable head 630 rotatably connected to the base 626 and carrying two or more rollers 632a-632d. The rollers 632a-632d are arranged around a circumference 634 of the rotatable head 630. The rotatable head 630 is configured to be rotatable in at least a first rotational direction 636 (e.g., by a motor, directly, or with a gear train, not shown). The peristaltic pump 608 may be battery powered, and the battery may be rechargeable by wire or wirelessly. The peristaltic pump 608 may alternatively or additionally be powered by a power cord (not shown) configured to connect to a power source. An extension tube 638 having a distal end 640 and a proximal end 642 and having a lumen 644 extending therethrough is hydraulically connected to the proximal end 606 of the aspiration lumen 604 via a connector 624. A Touhy-Borst seal 646 allows for the insertion of a guidewire 648 through the connector 624 and the aspiration lumen 604, which may be used to track the aspiration catheter 602 through the subject's vasculature, as described herein. The Touhy-Borst 646 may be tightened to seal the guidewire 648 and maintain hemostasis. The extension tube 638 may include a male luer 650 at its distal end 640 for connection to a female luer 652 of the connector 624. The male luer 650 may include a stopcock 654 configured to rotate between an open position (as shown) or a closed position. Alternatively, the extension tube 638 may be integral with the suction lumen 604 or may be permanently attached to the connector 624.In use, the compressible portion 637 of the dilation tube 638 is positioned within the pressure shoe 628 of the peristaltic pump 608 such that, upon rotation of the rotatable head 630 in a rotational direction 636 (e.g., via input by a user to the interface 656), fluid is forced through the lumen 644 of the dilation tube 638 from the distal end 640 to the proximal end 642, one at a time, via compression of the compressible portion 637 by the rollers 632. In some embodiments, there are only two rollers 632. In other embodiments, there are three rollers 632. In yet other embodiments, as shown, there are four rollers 632. As discussed, the rollers 632 can be replaced by ridges or protrusions. The compressible portion 637 or any compressible portion described herein can include silicone tubing, polyurethane tubing, polyvinyl chloride tubing, thermoplastic elastomer (TPE), such as Bioprene®, a registered trademark of Watson-Marlowe, Inc., Wilmington, Massachusetts, USA, or other compressible tubing. The compressible section 637 may be a relatively short section that is attachable and detachable to the peripheral end of the dilation tube 638, or in other embodiments, may include the entire dilation tube 638 between the distal end 640 and the proximal end 642. The proximal end 642 of the dilation tube 638 may be connected to a canister 658 having an interior 660 to allow fluid 659 passing through the dilation tube 638 to pass to the interior 660. The proximal end 642 of the dilation tube 638 is connected to the canister 658 by a tube clamp 657 that holds the dilation tube 638 longitudinally without compromising the patency of the lumen 644. In addition to the end hole 621, there are also multiple side holes 623, similar to a sump tube, to minimize fluid resistance at the proximal end 642 of the dilation tube. In other embodiments, the end hole 621 may be blocked with outflow only venting from the multiple side holes 623. The side holes 623 ensure that the minimum area of ​​flow resistance within the extension tube 638 is not at the proximal end 642. The side holes 623 help prevent spillage into the canister 658.The spurting of blood is a negative element, applying shear stress to the blood, causing hemolysis or platelet activation, thus damaging or altering the blood that may have been desired for reinfusion into the patient. An additional hub 662 in the canister 658 can be left open (as shown) to allow the uncharged interior 660 to match atmospheric pressure.

[0262]

[0262] Because the suction catheter 602 is configured to be inserted into an artery that may supply vital organs (heart, brain, etc.), tight control of flow through the catheter allows for a higher level of safety. A recognition system is provided to ensure that the suction catheter 602 is used only with the peristaltic pump 608 and the infusion pump 612, and not with alternative devices that do not have the same level of control over suction and infusion. The identification circuit 619 in the peristaltic pump 608 is connected to the controller 684 (e.g., via cable 686) and also electrically connects to the first port 611 and the second port 613. The extension tube 638 may include a first tether 690 having a first identification module 607 configured to be plugged into or otherwise secured in close proximity to the first port 611. Additionally or alternatively, the suction catheter 602 may comprise a second tether 688 having a second identification module 609 configured to plug into or otherwise be secured in close proximity to the second port 613. The controller 684 is configured to allow operation of the infusion pump 612 and / or the peristaltic pump 608 to occur only if one or both of the identification modules 607, 609 are identified by the identification circuit 619 as being the correct components (correct model, correct size, correct clinical application, etc.). Thus, the pumps 612, 608 are enabled or disabled by the controller 684 depending on the information provided by the identification modules 607, 609. In some embodiments, one or both of the identification modules 607, 609 comprise an RFID (radio frequency identification) chip and an identification circuit 619 configured to provide power to the RFID chip to receive and read data. In some embodiments, the identification circuit 619 may be further configured to write to the RFID chip. In other embodiments, one or both of the identification modules 607, 609 include a resistor and an identification circuit 619 configured to read the resistance of the resistor. For example, the resistor may complete a partial Wheatstone bridge mounted to the identification circuit 619.

[0263]

[0263] The suction catheter 602 further has a high pressure infusion lumen 610 for infusing saline from a fluid source 679, for example, via a high pressure pump 612. The tubing set 664 may include a pump cartridge 666 having a piston or bellows or other moving element that the pump 612 can operate using an internal motor 691, thus pressurizing saline or other fluid from the fluid source 679 at a significantly high pressure so that the saline is forced through the infusion lumen 610 of the suction catheter 602. The tubing set 664 includes a proximal end 668 having a spike 689 or other element for hydraulically connecting it to the fluid source 679. The tubing set 1464 further has a distal end 670 (which may include a male luer) configured to hydraulically connect to the infusion lumen 610 via a female luer 672. Infused saline is forced by pump 612 through infusion lumen 610 and exits orifice 674 in hollow end portion 675 connected to distal end 676 of infusion tube 678 containing infusion lumen 610. Tube 678 may be substantially or completely within shaft 601. In some embodiments, tube 678 is attached to the inner wall of shaft 601 only at distal end portion 603. Thus, the free-floating nature of the remaining portion of tube 678 within aspiration lumen 604 enhances the flexibility and trackability of shaft 601. High pressure saline is forced through orifice 674, causing a jet, i.e., one or more jets. The jet is directed into aspiration lumen 604 just proximal to open distal end 605, which may create a Venturi effect to push blood or clots externally adjacent to open distal end 605 into aspiration lumen 640. The action of the peristaltic pump 608 in combination with the jets generated by the high pressure saline causes maceration of the thrombus and movement / flow of material (saline / blood / macerated thrombus / thrombus fragments) through the suction lumen 604 from the open distal end 605 to the proximal end 606, through the connector 624, through the lumen 644 of the extension tube 638 from the distal end 640 to the proximal end 642, and finally into the interior 660 of the canister 658.Thus, blood clots in the subject's blood vessels can be macerated and removed by using the system 600. The blood vessels can include peripheral blood vessels, coronary blood vessels, or blood vessels in the subject's head or neck, including the carotid, cerebral, basilar, and communicating arteries. The aspiration monitoring system 614, including the pressure transducer 616, can be connected, for example, between the distal end 640 of the extension tube 638 and the connector 624 and / or the proximal end 606 of the aspiration lumen 604 of the aspiration catheter 602. The aspiration monitoring system 614 or any of the others described herein can include any of the features described in connection with the aspiration monitoring system described in U.S. Patent Application No. 2017 / 0056032 to Look et al., filed August 23, 2016, and published March 2, 2017. The signal from the pressure transducer 616 is carried on an electrical cable 680 to an input 682 of the pump 612. A controller 684 within the pump 612 is configured to control the operation of the pump 612, including the motor 691, but the controller 684 may also be configured to control the operation of the peristaltic pump 608 via a cable 686 or wirelessly. The controller 684 may comprise a microcontroller. Alternatively, the controller 684 may be located within the peristaltic pump 608 or may be located elsewhere. The control using the measured pressure signal from the pressure transducer 616 adds an additional element of safety to the system 600. Furthermore, non-functioning devices (due to leaks, faulty connections, faulty priming, ruptures, blockages) can be quickly identified. Unacceptably high pressures can also be quickly identified, protecting the motor 691 of the pump 612 from the risk of burning out or overheating. The integrity of the tube 678 is also protected, avoiding unnaturally high pressures that could lead to, for example, ruptures.

[0264]

[0264] The female luer 652 of the aspiration catheter 602 is located distally on the connector 624 from the female luer 672. Thus, the aspirated blood / thrombus / saline enters the female luer 652 without having to contact internal irregularities 625 (in geometry, shape) within the connector 624 that might otherwise cause flow resistance or trap thrombus (e.g., between the tube 678 and the interior of the connector 624.

[0265]

[0265] The foot pedal 651 has a base 653 and a pedal 655 connected to the base 653 and movable or actuable by application of a user's foot. The pedal 655 may be spring loaded, depressed by application of a moment or compressive force, or may instead comprise a membrane switch. When activated, the pedal 655 may switch on and off in some embodiments, and in other embodiments may be actuable when a force, pressure, or moment is applied and deactivated when no force, pressure, or moment is applied. A first cable 661 carries a signal from the foot pedal 651 to the pump 612 via a plug 665 connected to an input jack 667. A second cable 663 carries a signal from the foot pedal 651 to the peristaltic pump 608 via a plug 669 connected to an input jack 671. In some embodiments, activation of the pedal 655 by the user's foot initiates operation of the pump 612 and simultaneously initiates operation of the peristaltic pump 608. In some embodiments, activation of pedal 655 by the user's foot initiates operation of peristaltic pump 608, which then initiates operation of pump 612 a short delay after peristaltic pump 608 is initiated. The delay is useful to ensure that some suction or a significant amount of suction has been applied to aspiration lumen 604 before injecting pressurized fluid (e.g., saline) through infusion lumen 610. Thus, blood vessels or other vasculature near open distal end 605 are spared the infusion of fluid from the high pressure jet, as it is instead aspirated through aspiration lumen 604.

[0266]

[0266] Additionally, in some embodiments, activation of the pedal 655 by the user's foot during operation of the pump 612 and the peristaltic pump 608 simultaneously stops operation of the pump 612 and the peristaltic pump 608. In other embodiments, a delay can be implemented, for example, such that the pump 612 is stopped and then the peristaltic pump 608 is stopped after a short delay. The length of the described delay can be between about 0.01 seconds and about 1.00 seconds, or between about 0.10 seconds and about 0.25 seconds. Activation (on / off) of the pump 612 and / or the peristaltic pump 608 via the foot pedal 651 allows for hands-free activation, allowing a single user to operate the suction catheter 602 and the guidewire 648 with both hands. The location of the foot pedal 651 can be tactilely located with the user's foot while the user maintains visual contact with the patient and / or any monitors or other medical personnel.

[0267]

[0267] In other embodiments, the foot pedal 651 may be replaced with another type of switch, including but not limited to a toggle on / off push button or hand switch, a voice activated switch (voice activated, clap activated, click activated), a light switch (beam / light sensor for hand or foot interruption), or any other type of switch that can be activated by medical personnel. The switch may be in a remote location (e.g., a control room) or may be near the treatment area. The switch may also be a sterile switch or may be sterilizable for location on the sterile field.

[0268]

[0268] In some cases, activation and deactivation (turning on and off) of the suction flow applied by peristaltic pump 608 to suction lumen 604 can be accomplished by leaving peristaltic pump 608 running while a user opens and closes stopcock 654. In other embodiments, the stopcock can be replaced by a pinch valve (not shown) to open or compress extension tube 638. The pinch valve can be operated by a foot switch or push button (on / off).

[0269]

[0269] The controller 684 also monitors and controls several device safety features, including overpressure detection, air bubble detection, and vacuum or negative pressure charging. An additional pressure transducer 615 mounted on the connector 624 monitors the pressure (i.e., injection pressure) and senses the presence of air bubbles. Alternatively, or in combination, an optical device 617 can be used to sense air bubbles. In one possible embodiment, the pump pressure is proportional to the current required by the pump 612 to generate that particular pressure. Thus, if the current required by the pump 612 exceeds a pre-set limit, the controller 684 disables the pump 612 by cutting off the power to the pump 612. Air bubble detection can also be monitored by monitoring the current required to drive the pump 612 at a particular moment. In order for the pump 612 to reach high fluid pressures, there should be little or no air (which is highly compressible) in the pump 612 or the connection system (including the aspiration lumen 604 and the tubing set 664 of the aspiration catheter 604). The fluid volume is small enough that air in the system does not create pressure at the pump head. A sufficient amount of liquid is required proximally to allow a finite amount of air to flow. The controller 684 monitors the pump 612 current for a sudden downward change that may indicate air has entered the system. If the rate of decline is faster than a preset limit, the controller 684 disables the pump 612 by cutting power to the pump until the problem is corrected.

[0270]

[0270] The suction catheter 602 of Figure 48 is shown as having pressurized fluid infusion via the infusion lumen 610. However, in other embodiments of the aspiration system 600, the suction catheter 602 is replaced by a standard suction catheter that does not have an infusion lumen.

[0271]

[0271] Instead of collecting the aspirated material in a blood bag, blood bottle, or canister 658, the aspirated components (blood, clot, saline, slurry, etc.) can be placed in a reinfusion device, such as the Stryker ConstaVac (CBCII) Blood Conservation System, or the Haemonetics OrthoPAT Orthopedic Perioperative Autotransfusion System. In some embodiments, the canister 658 itself may comprise a reinfusion device. Returning at least a portion of the aspirated blood to the patient by reinfusion helps reduce blood loss, which is one of the drawbacks inherent to aspiration.

[0272]

[0272] In some embodiments, the blood may be cooled before being injected. In some embodiments, the blood may be heated before being injected. In some embodiments, other drugs may be added to the blood before it is inserted. In some cases, the blood may be diluted with saline to reduce viscosity or to lower the hematocrit. This may result in reduced hemolysis. In some cases, the blood collected in the canister 658, or coming from the extension tube 638, may even be used as donor blood for injection into another patient.

[0273] In some embodiments, additional or alternative sensors may be used to monitor flow conditions to notify the user, including, but not limited to, Doppler sensors, infrared sensors, or laser flow detection devices. In some embodiments, an externally mounted (non-contact) Doppler sensor may be used. In some embodiments, an infrared sensor or laser flow detection device may be used around the extension tube 638. Alternative sensors (e.g., flow sensors, etc.) may be placed at several different locations along the aspiration path, including on or within the extension tube 638, either proximal or distal to the rotatable head 630 of the peristaltic pump 608.

[0274] 49 illustrates an aspiration catheter 700 having an elongated shaft 702 with a radiopaque marker band 704 attached to a distal end 706 of the shaft 702. The shaft 702 defines an aspiration lumen 708 having an open distal end 710. An infusion tube 712 having a distal end 714 is capped off with a micromachined cap 716. The micromachined cap 716 has an inner cylindrical cavity 718 configured for placement over the distal end 714 of the infusion tube 712. An outer cylindrical surface 720 of the distal end 714 of the infusion tube 712 is sealingly connected to the micromachined cap 716 at the inner cylindrical cavity 718 such that the infusion lumen 722 of the infusion tube 712 is closed, sealed, and resistant to high pressures at the distal end 714. The outer cylindrical surface 720 may be connected to the micromachined cap 716 at the inner cylindrical cavity 718 by at least one of an adhesive, an epoxy, a weld (e.g., ultrasonic welding or fusing of other materials), or a solvent. Alternatively, a circumferential seal (a thin elastomeric ring) may be inserted between the outer cylindrical surface 720 and the micromachined cap 716 at the inner cylindrical cavity 718 to create a seal and friction fit. The micromachined cap 716 may comprise a number of different materials including a polymer or a metal. The micromachined cap 716 may be constructed by a number of different processes including micromachining, microinjection molding, three-dimensional printing, photolithography, shadow masking, etching, or microforming. These processes include additive and subtractive processes. The orifice 730 is formed in the wall 732 of the inlet tube 712 and has a similar function to the orifice 674 of FIG. 48. Because the distal end 714 of the infusion tube 712 is sealed, high pressure fluid is forced out of the orifice 730 into the aspiration lumen 708 (arrow).

[0275]

[0275] The outer surface 724 of the infusion tube 712 is connected to the inner surface 726 of the aspiration lumen 708 with adhesive 728 (or epoxy, or other bonding means). The infusion tube 712 is connected in a specific rotational orientation relative to the aspiration lumen 708 such that the orifice 730 is directed to the opposite surface 734 within the aspiration lumen 708. The unconnected section 736 extends a significant portion of the length of the aspiration catheter 700 in the proximal direction, thus allowing for improved flexibility and trackability. The center of the orifice 730 may be located a distance d2, for example, between about 0.05 mm and about 10.00 mm, from the proximal end of the micromachined cap 716 such that the jet emanating from the orifice 730 passes through the micromachined cap 716. The center of the orifice 730 is located a distance d1 from the open distal end 710 of the aspiration lumen 708 such that the distal end of the micromachined cap 716 does not extend from the aspiration lumen 708. However, in some embodiments, the micro-fabricated cap may be configured to extend from the suction lumen 708 so long as it does not have sharp leading features.

[0276] 50 illustrates an aspiration catheter 740 having an elongated shaft 742 with a radiopaque marker band 744 attached to a distal end 746 of the shaft 742. The shaft 742 defines an aspiration lumen 748 having an open distal end 750. An infusion tube 752 having a distal end 754 is capped off with a micromachined cap 756. The micromachined cap 756 has an inner cylindrical cavity 758 configured for placement over the distal end 754 of the infusion tube 752. An outer cylindrical surface 760 of the distal end 754 of the infusion tube 752 is sealingly connected to the micromachined cap 756 at the inner cylindrical cavity 758 such that the infusion lumen 762 of the infusion tube 752 is closed, sealed, and resistant to high pressures at the distal end 754. A reinforcing ring 795 is attached to the infusion lumen 762 of the infusion tube 752 at the distal end 754 to reinforce the distal end 754 and enable a higher strength seal. The reinforcing ring 795 may also be configured to enable a friction fit seal. The reinforcing ring may comprise a high strength metallic material, such as stainless steel, or a hard polymer. The outer cylindrical surface 760 may be connected and / or sealed to the micromachined cap 756 at the inner cylindrical cavity 758 by any of the methods or materials described in connection with the aspiration catheter 700 of FIG. 49. The micromachined cap 756 may comprise any material and may be formed by any of the processes described in connection with the micromachined cap 716 of FIG. An orifice 770 is formed in the wall 772 of the infusion tube 752 and has a similar function as the orifice 674 of FIG. 48. Because the distal end 754 of the infusion tube 752 is sealed, high pressure fluid is forced out of the orifice 770 and into the aspiration lumen 748.

[0277]

[0277] An outer surface 764 of the infusion tube 752 is connected to an inner surface 766 of the aspiration lumen 748 with adhesive 768 (or epoxy, or other bonding means). The infusion tube 752 is connected in a specific rotational orientation relative to the aspiration lumen 748 such that an orifice 770 is directed toward an opposing surface 774 within the aspiration lumen 748. The adhesive 768 connection extends proximally a significant portion of the length of the aspiration catheter 740.

[0278]

[0278] Figure 51 shows an aspiration catheter 701 having an elongated shaft 703 with a radiopaque marker band 705 attached to a distal end 707 of the shaft 703. The shaft 703 defines an aspiration lumen 709 having an open distal end 711. An infusion tube 713 having a distal end 715 is capped off with a micromachined cap 717. The distal end 715 is necked down from the remainder of the infusion tube 713 by a heating and / or tensile drawing process to create a smaller outer diameter of the distal end 715. The micromachined cap 717 has an inner cylindrical cavity 719 configured to be positioned over the reduced diameter distal end 715 of the infusion tube 713. An outer cylindrical surface 721 of the distal end 715 of the infusion tube 713 is sealingly connected to the micromachined cap 717 at the inner cylindrical cavity 719 such that the infusion lumen 723 of the infusion tube 713 is closed and sealed at the distal end 715 and resists high pressure. The smaller diameter of the distal end 715 and the inner cylindrical cavity 719 allows for a relatively high strength connection because it increases the hoop strength of the distal end 715. The outer cylindrical surface 721 may be connected and / or sealed to the micromachined cap 717 at the inner cylindrical cavity 719 by any of the methods or materials described in connection with the aspiration catheter 700 of FIG. 49. The micromachined cap 717 may comprise any material and may be formed by any of the processes described in connection with the micromachined cap 716 of FIG. 49. An orifice 731 is formed in the wall 733 of the infusion tube 713 and has a similar function to the orifice 674 of FIG. Because the distal end 715 of the infusion tube 713 is sealed, the high pressure fluid is forced out of the orifice 731 and into the aspiration lumen 709 .

[0279]

[0279] The outer surface 725 of the infusion tube 713 is not connected to the inner surface 727 of the aspiration lumen 709. Instead, the micromachined cap 717 is connected to the inner surface 727 with adhesive 729 (or epoxy, or other bonding means). The unconnected section 737 of the infusion tube 713 extends proximally a significant portion of the length of the aspiration catheter 701, thus allowing for increased flexibility and trackability. The micromachined cap 717 is connected such that the infusion tube 713 is held in a specific rotational orientation relative to the aspiration lumen 709, so that the orifice 731 is directed toward the opposing surface 735 within the aspiration lumen 709.

[0280] 52 illustrates an aspiration catheter 741 having an elongated shaft 743 with a radiopaque marker band 745 attached to a distal end 747 of the shaft 743. The shaft 743 defines an aspiration lumen 749 with an open distal end 751. An infusion tube 753 having a distal end 755 is capped off with a micromachined cap 757. The micromachined cap 757 has an inner cylindrical cavity 759 including a proximal portion 799 configured for placement over the distal end 755 of the infusion tube 753. An outer cylindrical surface 761 of the distal end 755 of the infusion tube 753 is sealingly connected to the micromachined cap 757 at the inner proximal portion 799 of the cylindrical cavity 759 such that the infusion lumen 763 of the infusion tube 753 is sealed and resistant to high pressure. The outer cylindrical surface 761 may be connected and / or sealed to the micromachined cap 757 at the proximal portion 799 of the inner cylindrical cavity 759 by any of the methods or materials described in connection with the suction catheter 700 of FIG. 49. The micromachined cap 757 may comprise any material and may be formed by any of the processes described in connection with the micromachined cap 716 of FIG. 49. The orifice 771 is an outlet of the distal portion 797 of the inner cylindrical cavity 759 in communication with the proximal portion 799. The inner cylindrical cavity 759 of FIG. 52 has a curved shape, but may instead form an L-shape or be at an angle of 45° to the longitudinal axis of the suction catheter 741. The angle may vary between 45° and 135°. The orifice 771 is formed in the wall 773 of the micromachined cap 757 and has a similar function to the orifice 674 of FIG. 48. The high pressure fluid is forced through the inner cylindrical cavity 759 , out the orifice 771 and into the suction lumen 749 because the distal end 755 of the infusion tube 753 is sealed.

[0281]

[0281] The outer surface 765 of the infusion tube 753 is connected to the inner surface 767 of the aspiration lumen 708 with adhesive 769 (or epoxy, or other bonding means). The infusion tube 753 is connected in a specific rotational orientation relative to the aspiration lumen 749 such that the orifice 771 is directed to the opposing surface 775 of the aspiration lumen 749. The unconnected section 777 extends a significant portion of the length of the aspiration catheter 741 proximally, thus allowing for improved flexibility and trackability. One or more of the individual features of the aspiration catheters 700, 740, 701, 741 of Figures 49-52 may be rearranged to create other new embodiments. Each of the individual features allows for the manufacture of a small diameter aspiration catheter capable of tracking distal vasculature, such as the vasculature of the head and neck, while also providing aspiration, including high pressure forced infusion.

[0282] 53-56 show an insertable infusion tube 920 and a method for using it on a patient. For simplicity, the patient is not shown and the device is shown in a straight configuration, but during use, the device will typically be tracked through bends in the patient's vasculature. In FIG. 53, a microcatheter 924 is configured to track the patient's neurovasculature, including the Circle of Willis and the cerebral arteries. The microcatheter 924 may be incorporated as a component of the aspiration system 922 (FIGS. 54-56) or may be a standard microcatheter purchased separately by the user. The microcatheter 924 comprises a shaft 926 having a proximal end 928 and a distal end 930, and a lumen 932 extending through the shaft 926. A luer hub 934 (e.g., a female luer connector) is sealingly attached to the proximal end 928 of the shaft 926. The microcatheter 924 may have a distal radiopaque marker (not shown) applied in a manner similar to the radiopaque marker bands 704, 744, 705, 745 of the aspiration catheters 700, 740, 701, 741 of FIGS. 49-52. The connector 936 may include a male luer 938 for connecting to the luer hub 934 and may include a valve 940, which may include a Touhy-Borst or equivalent. The side port 942 of the connector 936 may include a female luer for connecting to the male luer 650 of the extension tube 638 of the system 600 described in detail in connection with FIG. 48. In FIG. 53, the user tracks the microcatheter 924 over the guidewire 944 to a blood vessel that is the area of ​​interest. In some cases, the area of ​​interest may be one of the cerebral arteries or other nearby arteries where a thrombus 946 (FIG. 54) is causing a thromboembolic stroke in the patient.

[0283] In FIG. 54, the user removes the guidewire 944 and inserts the insertable infusion tube 920 through the Touhy-Borst 940, into the connector 936 and into the lumen 932 of the microcatheter 924. The insertable infusion tube 920 may include a micromachined cap 948 as described in any of the embodiments of FIGs. 49-52, or may include alternative configurations. However, the insertable infusion tube 920 at least comprises a high strength hollow tube 952, which may include stainless steel, nickel titanium alloy, polyimide, or other high strength material having sufficient column strength to be inserted through the lumen 932 of the microcatheter 924. The micromachined cap 924 includes an orifice 950 configured to provide a jet of pressurized fluid, similar to the orifice 771 of the micromachined cap 757 of FIG. 52. In FIG. 55, the user advances the insertable infusion tube 920 further through the lumen 932 of the microcatheter 924 toward the distal end 930. The stop 954 is connected to the outside of the high strength hollow tube 952 and has a front surface 956 configured to abut a proximal surface 958 of the connector 936 when the center of the orifice 950 is located at a preferred distance (e.g., d1 as in FIG. 49 ) from the distal end of the microcatheter 924. The insertable infusion tube 920 may be realized in different models, each having different lengths between the front surface 956 and the center of the orifice 950, each configured to be used with a particular length of microcatheter 924 or a particular model of microcatheter 924, or a particular microcatheter 924 model / connector 936 model combination. In some embodiments, the connector 936 may be a component of the insertable infusion tube 920 and may be permanently sealed and connected to the high strength hollow tube 952 at the proximal region, instead of the Touhy-Borst 940. Thus, the connection of the male luer 938 to the luer hub 934 realizes a longitudinal stop that controls the d1 distance.

[0284]

[0284] Due to the small diameter and tortuosity of blood vessels, it may not always be possible to track the aspiration catheter 602 with forced aspiration capability (FIG. 48) with high pressure injection into the neurovasculature. Thus, the insertable infusion tube 920 allows the microcatheter 924 to be converted into a forced aspiration catheter. Thus, forced aspiration may occur at very distal locations, and at locations distal to significant bends, where a microcatheter is usually the preferred means of access. The small diameter insertable infusion tube 920 can be inserted through the lumen 932 of the microcatheter 924 after the microcatheter 924 is inserted into the area of ​​interest. In alternative procedures and embodiments of the system, the microcatheter 924 inserted over the guidewire 944 may be replaced by a flow-directed catheter having a lumen configured for placement of the insertable infusion tube 920 inserted into the area of ​​interest without a guidewire.

[0285]

[0285] Figure 57 illustrates a particular distal configuration of the distal end 913 of the insertable infusion tube 920. With this configuration, the micromachined cap 948 and orifice 950 can be controllably and repeatedly inserted through the lumen 932 of the microcatheter 924, so that the orifice is automatically oriented and one or more jets emanating from the orifice 950 (i.e., one or more orifices 950) are directed against the opposing wall 929 within the lumen 932 of the microcatheter 924. The micromachined cap 948 has a distal taper 960, which may include a fillet or bevel, or other type of lead-in shape. The purpose of the distal taper 960 is to facilitate insertion into the connector 936, luer hub 934, or lumen 932 (Figure 54), and to facilitate advancement of the micromachined cap 948 through the lumen 932, especially when the shaft 926 is in a tortuous state. The splined loop 962 is connected to the micromachined cap 948 and may be formed from a wire such as stainless steel or cobalt-chromium-nickel-molybdenum, or may include a superelastic material such as a nickel-titanium alloy. The splined loop 962 is configured to have a diameter that is slightly smaller, equal to, or slightly larger than the diameter of the lumen 932 of the microcatheter 924. Referring to FIG. 58, a first end 921 of the splined loop 962 is connected to a circumferential groove 923 of the micromachined cap 948. There is a gap 925 between the first end 921 and the second end 927 of the splined loop 962, which allows space for the two ends 921, 927 to move closer together, and thus, stress applied to the splined loop 962 from, for example, the wall around the lumen 932 of the microcatheter 924, forces the diameter of the splined loop 962 to be smaller. The rotational orientation between the spline loop 962 and the micromachined cap 948 is fixed relative to one another (by connecting the first end 921 to the groove 923), so that the orifice 950 remains directed toward the opposite wall 929 within the lumen 932.The spline loop 962 is located at a different longitudinal position than the orifice 950 on the micromachined cap 948, so that the spline loop 962 does not block or deflect the jet emanating from the orifice 950. In this embodiment, the spline loop 962 is slightly distal to the orifice 950, but in other embodiments, it may be located proximally instead. In other alternative embodiments, the spline loop 962 (or any similar structure) may actually be used to at least somewhat deflect the jet emanating from the orifice 950, for the purpose of changing the shape or direction of the jet, such as, for example, deflecting the jet at least partially proximally longitudinally. Thus, in these alternative embodiments, it may actually be desirable to locate the spline loop 962 at approximately the same longitudinal position as the orifice 950.

[0286] In FIG. 59, the splined loop 962 is replaced by a splined ring 933 that is attached to the high strength hollow tube 952 in place of the micromachined cap 948. The splined ring 933 is formed from a flat wire (such as stainless steel or nickel titanium alloy) or a hard polymer strip (polyimide or other hard polymer), shaped like the number "6", and extends between a first end 935 and a second end 937. The first loop portion 939 is configured to extend around the high strength hollow tube 952 for connection thereon, and the second loop portion 941 serves the same purpose as the splined loop 962 of FIGS. 57-58 to guide the micromachined cap 948 and rotate and direct the orifice 950 into the lumen 932. Alternatively, other spline shapes may be used that help maintain the micromachined cap 948 against the wall on one side of the lumen 932 and / or help resist rotation between the shaft 926 of the microcatheter 924 and either the high strength hollow tube 952 or the micromachined cap 948 (either of the two includes the orifice 950). The spline loop 962 or spline ring 933, respectively, may be made of a radiopaque material or may include a radiopaque material as a base or a plating or coating. Thus, it is easier to visualize the movement of the orifice 950 down the lumen 932 of the microcatheter 924 with x-ray or fluoroscopy during the procedure. The micromachined cap 948 may also or instead include a radiopaque material or a radiopaque coating or plating. The insertable infusion tube 920 in the presented embodiment is configured to be removable from the lumen 932 of the microcatheter 924 so that the microcatheter 924 can then be used for one of its other functions (delivering an embolic coil or embolic material, a drug, exchanging the guidewire 944, or aspirating through the empty lumen 932). In an alternative embodiment, the orifice 950 in the micromachined cap 948 can be used to infuse a drug or other material into the vasculature, for example, by stopping or avoiding reduced or negative pressure on the proximal end of the lumen 932.

[0287] 60-63 show a method for treating a patient using the aspiration system 600 of FIG. 48, using the aspiration catheter 602, or any of the alternative aspiration catheters 700, 740, 701, 741. Alternatively, the method may be accomplished using the aspiration system 922, or using an insertable infusion tube 920 with a standard single lumen catheter, such as a microcatheter 924, guide catheter, or guide sheath (long sheath). All of these systems may utilize a pump 612 and a peristaltic pump 608 as described in FIG. 48. In FIG. 60, the aspiration catheter 602 is tracked (e.g., using a guidewire 648) into a blood vessel 943 and advanced such that the open distal end 605 is adjacent the proximal end 945 of a thrombus 947. In some cases, aspiration utilizing high pressure injection from pump 612 through tubing set 664 combined with distal to proximal flow impulses imparted by peristaltic pump 608 to expansion tube 638 is not sufficient to draw thrombus 947 sufficiently into open distal end 605 and aspiration lumen 604 so that it can be macerated and aspirated. Sometimes the cause of this is that the space 949 distal to thrombus 947 acts as a relative vacuum, pulling the thrombus with force (e.g., distally, away from aspiration catheter 602) making it difficult to aspirate the thrombus. Although blood vessel 943 is shown in a relatively normal state, it may have collapsed due to lack of blood pressure due to occlusion by thrombus 947. In other cases, some of the thrombus 947 may have distinct solid or semi-solid portions that impede the ability to flow in a distal to proximal direction.

[0288]

[0288] A user encounters this condition while attempting to aspiration via operation of pump 612 and peristaltic pump 608, and aspiration catheter 602 is inserted and advanced into blood vessel 943 as shown in FIG. 60. The user can then use techniques with aspiration system 600 to alleviate the substantially no flow condition. In FIG. 61, the user advances aspiration catheter 602 so that the open distal end 605 of aspiration lumen 604 is distal to thrombus 947. Advancement of the open distal end 605 of aspiration catheter 602 through thrombus 947 can be accomplished without the use of a guidewire 648, although in certain instances a guidewire 648 must be used to cannulate and then track the aspiration catheter 602 through thrombus 947.

[0289] In FIG. 62, while the peristaltic pump 608 is not activated, the user activates the pump 612 to inject fluid. Thus, pressurized fluid (e.g., heparinized saline, or saline mixed with a thrombolytic drug) is injected through the infusion lumen 610 of the tube 678, through the orifice 674, into the suction lumen 604, and then out the open distal end 605 (arrow) into the space 949 of the blood vessel 943. This occurs because, without suction through the suction lumen 604, the stopped peristaltic pump 608 acts as a closed valve, and one of the rollers 632 compresses the compressible portion 637 of the expansion tube 638. The injection of fluid increases the fluid volume of the space 949, and by so doing, can also increase its internal pressure, thus neutralizing the previous relative vacuum effect caused by the space 949. There is flowable material in space 949, so suction using peristaltic pump 608 in conjunction with pump 612 can begin to macerate and aspirate thrombus 947 (by now turning on peristaltic pump 608). The aspiration catheter 602 can also be retracted as shown in Figure 63 to make better contact with thrombus 947 and increase the percentage of thrombus 947 that is aspirated. This can continue until all, or at least a clinically significant portion, of thrombus 947 has been aspirated.

[0290] Returning to FIG. 62, in certain cases, such as thromboembolic stroke, downstream tissue may not be receiving sufficient flow due to an obstruction caused by a thrombus 947. A user may run fluid from a fluid source 679 through a cooling system, such as a heat exchanger or thermoelectric cooler 951 (FIG. 48) that the tubing set 664 may operate, thereby cooling the fluid. Additionally, an extracorporeal circuit 953 (FIG. 62) may be attached to the tubing set 664, such that blood removed from the patient (e.g., via a femoral artery, femoral vein, or jugular sheath 955) is added to the fluid from the fluid source 679, such that some oxygenated blood is infused into the space 949, some of which may potentially provide oxygen or nutrients to the downstream tissue. The cooled fluid (saline, blood, or saline and blood) may further reduce metabolic demand by actively cooling the downstream tissue. The inventors have demonstrated that using a pump 612 that utilizes a removable cartridge having a piston, hemolysis can be maintained at acceptably low values ​​during this type of injection and during mixing of the injected saline with the blood, from a mixture containing about 10% blood to a mixture containing about 80% blood.

[0291] 64-65 illustrate a method for treating a patient using the aspiration system 600 of FIG. 48, but incorporating an aspiration catheter 957 having a translatable infusion tube 959. The aspiration catheter 957 has an elongated shaft 963 having an aspiration lumen 965 with a proximal end 971 and an open distal end 961. The translatable infusion tube 959 has an infusion lumen 973 having a proximal end 975 and a distal end 977. The distal end 977 is connected to a micromachined cap 979 having an orifice 981 such that pressurized fluid infused through the infusion lumen 973 exits from the orifice 981, such as the orifice 771 of FIG. 52. At a sufficiently high infusion pressure, the fluid can be expelled from the orifice 981 in a jet. Alternatively, the distal end 977 of the infusion lumen 973 may be blocked or capped, or there may be an orifice formed in the wall of the infusion tube 959, as in Figs. 49-51. The pump 612 and peristaltic pump 608 described in Fig. 48 may be utilized. In Fig. 64, the suction catheter 957 is tracked (e.g., using a guidewire 648) into the blood vessel 943 and advanced such that the open distal end 961 is adjacent the proximal end 945 of the thrombus 947. A proximal female luer connector 983 is connected to the infusion lumen 973 and configured to connect to the male luer / distal end 670 of the tubing set 664. A filter 985 may be inserted between the female luer connector 983 and the male luer 670 to filter particles (Fig. 65). The filter has a proximal female luer 987 and a distal male luer 989. Filter 985 may be used with any of the embodiments described herein in which fluid may be injected (intentionally or unintentionally) into a patient's bloodstream.

[0292] As discussed, in some cases, suction utilizing high pressure infusion from pump 612 through tubing set 664 combined with distal to proximal flow impulses imparted by peristaltic pump 608 to expansion tube 638 is not sufficient to draw thrombus 947 sufficiently into open distal end 961 and aspiration lumen 965 so that it can be macerated and aspirated. Rigid tube 991 can be coaxially connected onto infusion tube 959 at its proximal length or infusion tube 959 itself can be made rigid in the proximal direction. Rigid tube 991 and / or female luer connector 983 and / or attached filter 985 can be grasped by the user such that the user can advance rigid tube 991 and infusion tube 959 in sequence distally, causing micromachined cap 979 and orifice 981 to be displaced distally through thrombus 947 and into space 949 distal of thrombus 947. In some cases, it may be sufficient to move distally to a distal portion of the thrombus 947. A dynamic seal 993 (O-ring, quad-ring, etc.) may be sealed onto the rigid tube 991 at all longitudinal positions of the rigid tube 991. Once the orifice 981 is located within the space 949, the pump 612 operates without operation of the peristaltic pump 608 (or with the peristaltic pump set significantly lower), which causes fluid to be infused through the infusion lumen 973 and out of the orifice 981 into the space 949.

[0293]

[0293] Injection of fluid can increase the fluid volume of the space 949 and thereby also increase its pressure, thus neutralizing the previous relative vacuum effect from the space 949. Flowable material is present in the space 949 to allow suction using the peristaltic pump 608 together with the pump 612 to begin maceration and aspiration of the thrombus 947 (by turning on the peristaltic pump 608). The shaft 963 of the catheter 957 can also be advanced and retracted during aspiration to increase the percentage of the thrombus 947 being aspirated. Additionally, the injection tube 959 can be advanced or retracted relative to the catheter. The orifice 981 can be adjusted to a suitable position inside the aspiration lumen 965 or slightly outside the aspiration lumen 965. This can be continued until all or at least a clinically significant portion of the thrombus 947 is aspirated. As discussed, in connection with certain ischemic conditions caused by clots 947, including stroke, the user can run fluid from the fluid source 679 through a cooling system, such as a heat exchanger or thermoelectric cooler 951 (FIG. 48) that the tubing set 664 can operate, thereby cooling the fluid. Additionally, an extracorporeal circuit 953 (as in FIG. 62) can be attached to the tubing set 664, such that blood removed from the patient (e.g., via a femoral artery, femoral vein, or jugular sheath 955) is added to the fluid from the fluid source 679, such that some oxygenated blood is infused into the space 949, some of which may potentially supply downstream tissues. The cooled fluid (saline, blood, or saline and blood) can further reduce the metabolic demands of downstream tissues.

[0294] 66-69 illustrate a method for treating a patient using the aspiration system 600 of FIG. 48, but incorporating an aspiration catheter 967 having a translatable infusion tube 969. The aspiration catheter 967 has an elongated shaft 995 having an aspiration lumen 997 with a proximal end 999 and an open distal end 2066. The translatable infusion tube 969 has an infusion lumen 2068 having a proximal end 2070 and a distal end 974. The distal end 974 has a distal orifice 2072 such that pressurized fluid infused through the infusion lumen 2068 exits the orifice 2072, as in FIG. 69. At a sufficiently high infusion pressure, the fluid may be expelled in a jet. The pump 612 and peristaltic pump 608 described in FIG. 48 may be utilized. 68 and 70, an occluder 976 comprising an elongated shaft 978 and a handle 980 at its proximal end 984 has an elastomeric occlusion element 982 connected to its distal end 986 by a connecting member 988. The occlusion ...

Claims

1. an aspiration catheter configured for placement within a blood vessel of a subject, the aspiration catheter comprising an elongate shaft comprising an aspiration lumen having a proximal end and an open distal end; a dilation tube having distal and proximal ends and a lumen extending therebetween, the distal end of the lumen of the dilation tube being configured to be hydraulically connected to the aspiration lumen of the aspiration catheter at or adjacent the proximal end of the aspiration lumen of the aspiration catheter; a peristaltic pump configured to drive fluid through the expansion tube, the peristaltic pump comprising a pump base having a pressure shoe and a rotatable head, the rotatable head including two or more compression elements arranged around its circumference; a compressible tubular portion disposed between the distal end and the proximal end of the dilation tube, the compressible tubular portion configured to be connected to the pressure shoe and the rotatable head of the peristaltic pump, such that operation of the peristaltic pump rotates the rotatable head such that the two or more compression elements drive fluid from the aspiration lumen of the aspiration catheter through the dilation tube from the distal end of the dilation tube to the proximal end of the dilation tube; a first sensor configured to measure pressure through at least one of the aspiration lumen or the lumen of the dilation tube; a controller configured to receive a first signal from the first sensor and configured to vary operation of the peristaltic pump based at least in part on the first signal received from the first sensor related to a change in the pressure; A system for catheter-based aspiration comprising:

2. 2. The system for catheter-based aspiration of claim 1, wherein the controller is configured to vary a rotational speed of the rotatable head of the peristaltic pump based at least in part on the first signal received from the first sensor related to the change in pressure.

3. 2. The system for catheter-based aspiration of claim 1, wherein the controller is configured to stop rotation of the rotatable head of the peristaltic pump based at least in part on the first signal received from the first sensor related to a change in the pressure.

4. 4. The system for catheter-based aspiration of claim 3, wherein the controller is configured to stop rotation of the rotatable head of the peristaltic pump to cause a first compression element of the two or more compression elements to occlude the dilation tube with the compressible tubular portion.

5. The system for catheter-based aspiration of claim 1 , wherein the two or more compression elements comprise two or more rollers.

6. The system for catheter-based aspiration of claim 1 , wherein the first sensor comprises a pressure transducer.

7. The system for catheter-based aspiration of claim 1 , further comprising a collection receptacle having an interior, the proximal end of the dilation tube configured to deliver the fluid to the interior of the collection receptacle.

8. 10. The system for catheter-based aspiration of claim 1, further comprising a return conduit hydraulically connected to the extension tube and configured to return to the vascular system of a subject's fluid that has passed through the extension tube from the distal end to the proximal end.

9. The system for catheter-based aspiration of claim 8 , further comprising a filter disposed between the extension tube and the return conduit.

10. 2. The system for catheter-based aspiration of claim 1, wherein the suction catheter further comprises an infusion lumen extending into the aspiration lumen and having a distal end and a proximal end, and an orifice at or near the distal end of the infusion lumen, the orifice configured to generate one or more jets in the aspiration lumen when pressurized fluid is infused through the infusion lumen, the system further comprising an infusion pump configured to pressurize fluid through the infusion lumen, and the controller configured to vary operation of the infusion pump.

11. The system for catheter-based aspiration of claim 10 , wherein the controller is configured to cause the infusion pump to infuse in a pulsatile manner.

12. The system for catheter-based aspiration of claim 10 , wherein the controller is configured to control a time interval between initiation of operation of the peristaltic pump and initiation of operation of the infusion pump.

13. The system for catheter-based aspiration of claim 12 , wherein the controller is configured to initiate operation of the peristaltic pump and the infusion pump substantially simultaneously.

14. The system for catheter-based aspiration of claim 10 , wherein the controller is configured to control a time interval between ceasing operation of the peristaltic pump and ceasing operation of the infusion pump.

15. The system for catheter-based aspiration of claim 14 , wherein the controller is configured to stop operation of the peristaltic pump and the infusion pump substantially simultaneously.

16. 11. The system for catheter-based aspiration of claim 10, wherein the controller is further configured to vary the operation of the infusion pump based at least in part on the first signal received from the first sensor related to the change in pressure.

17. 2. The system for catheter-based aspiration of claim 1, wherein at least one of the dilation tube or the suction catheter comprises an identification module configured to be read by the peristaltic pump to authorize use of the peristaltic pump with the dilation tube and the suction catheter.

18. The system for catheter-based aspiration of claim 1 , further comprising a foot pedal configured to send a signal to the controller to vary operation of the peristaltic pump.

19. A system for catheter-based suction as described in claim 1, further comprising an on / off hand switch configured to send a signal to the controller to change the operation of the peristaltic pump.

20. A system for catheter-based aspiration as described in claim 1, wherein the first sensor is configured to directly measure pressure in at least one of the aspiration lumen or the lumen of the expansion tube.

21. The system for catheter-based suction as described in claim 1, wherein the compressible tubular portion comprises a material selected from the list consisting of silicone, polyurethane, and polyvinyl chloride.

22. A system for catheter-based suction as described in claim 1, wherein an outer surface of the compressible tubular portion includes a coating of a lubricous material.

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