US-12622644-B2 - Occlusion detection via fluid dilution

US12622644B2US 12622644 B2US12622644 B2US 12622644B2US-12622644-B2

Abstract

A method of occlusion detection is disclosed. The method comprises the steps of positioning a medical tool coupled to a distal portion of a distal end of a delivery catheter at a target cavity within a patient. The medical tool includes an expandable balloon, and at least one sensor. The expandable balloon is expanded when positioned at the target cavity. The expandable balloon includes a membrane formed of a plurality of irrigation pores. Fluid is introduced into the target cavity either by injection or through the pores, or both. Using a sensor, a characteristic of blood is detected with the target cavity. The characteristic of blood is processed to determine the presence or absence of an occlusion within the cavity.

Inventors

Eid Adawi
Shmuel Auerbach
Nakdimon Nissim Levy
Eliyahu Ravuna
Iyar Rom
Shiran Eliyahu

Assignees

BIOSENSE WEBSTER (ISRAEL) LTD.

Dates

Publication Date: 20260512
Application Date: 20191219

Claims (12)

1 . A method of occlusion detection comprising: (a) determining, via a processor, an original value of at least one characteristic of blood of a patient; (b) positioning a medical tool coupled to a distal portion of a distal end of a delivery catheter at a target cavity within the patient, the medical tool comprising an expandable balloon, and at least one sensor; (c) expanding the expandable balloon when the balloon is positioned at the target cavity to thereby establish an occluded area and a leakage area of the target cavity, the expandable balloon having a distal end and a proximal end defining a longitudinal axis, and a membrane formed of a plurality of irrigation pores; (d) introducing a fluid into the target cavity; (e) detecting, via a first sensor of the at least one sensor, a first updated value of the at least one characteristic of blood in the occluded area; (f) detecting, via a second sensor of the at least one sensor, a second updated value of the at least one characteristic of blood in the leakage area, the second sensor being positioned on an outer surface of the expandable balloon to thereby contact the blood; (g) processing, via a processor, the first and second updated values of the at least one characteristic of blood; and (h) determining, via the processor, a time from when the fluid is introduced into the target cavity to when the first and second updated values of the at least one characteristic of blood return to the original value taken prior to the step of positioning the medical tool in the target cavity, and a presence or absence of an occlusion being determined by the updated values of the at least one characteristic of blood from each of the first and second sensor, the original value, and a baseline of the at least one characteristic of blood that has no occlusion.
2 . The method of claim 1 , said step of introducing the fluid into the target cavity further comprising introducing the fluid through the plurality of irrigation pores of said expandable balloon.
3 . The method of claim 1 , said step of introducing the fluid into the target cavity further comprising introducing the fluid through an inner lumen of the delivery catheter.
4 . The method of claim 1 , the target cavity comprising one of a pulmonary vein of a heart or a left atrium of the heart.
5 . The method of claim 1 , the fluid comprising a coolant.
6 . The method as in claim 1 , further comprising determining the baseline of the at least one characteristic of blood by: positioning the medical tool at a second target cavity within the patient such that there will be no occlusion; expanding the expandable balloon when the expandable balloon is positioned at the second target cavity; introducing a fluid into the second target cavity; and detecting, via the at least one sensor, at least one characteristic of blood in the second target cavity, and processing, via the processor, data of the at least one characteristic of blood and establishing the data as a baseline measurement, the at least one characteristic of blood being compared to the baseline measurement.
7 . The method of claim 6 , within the determining of the baseline, said step of introducing a fluid into the second target cavity further comprising introducing the fluid through the plurality of irrigation pores of the expandable balloon.
8 . The method of claim 6 , within the determining of the baseline, said step of introducing a fluid into the second target cavity further comprising injecting the fluid through an inner lumen of the delivery catheter.
9 . The method as in claim 6 , further comprising determining, via the processor, whether the occlusion is present in the target cavity by comparing the baseline measurement and the at least one blood measurement detected by the at least one sensor over time.
10 . The method as in claim 1 , further comprising executing, via the processor, an algorithm based on the at least one blood characteristic to determine the presence or absence of an occlusion, or a number indicating an extent of the occlusion.
11 . The method of claim 1 , the at least one sensor comprising a chemical composition sensor and the at least one characteristic of blood being a chemical composition.
12 . A method of occlusion detection comprising: (a) determining, via a processor and at least one sensor, an original value of at least one characteristic of blood of a patient; (b) positioning a medical tool coupled to a distal portion of a distal end of a delivery catheter at a target cavity within the patient, the medical tool comprising an expandable balloon having an electrode, and the at least one sensor; (c) after determining the original value, expanding the expandable balloon when the balloon is positioned at the target cavity, the expandable balloon having a distal end and a proximal end defining a longitudinal axis, and a membrane formed of a plurality of irrigation pores; (d) introducing a fluid into the target cavity; (e) detecting, via the at least one sensor, an updated value of the at least one characteristic of blood in the target cavity; (f) processing, via a processor, the updated value of the at least one characteristic of blood; and (g) determining, via the processor, a time from when the fluid is introduced into the target cavity to when the updated value of the at least one characteristic of blood returns to the original value taken prior to the step of positioning the medical tool in the target cavity, and determining a presence or absence of an occlusion by the updated value of the at least one characteristic of blood and a time taken for the updated value of the at least one characteristic of blood to return to the original value, the original value including a baseline of the at least one characteristic of blood that has no occlusion.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 62/786,957 filed on Dec. 31, 2018, and U.S. Provisional Application No. 62/786,997 filed on Dec. 31, 2018, the content of which are hereby incorporated by reference herein. This application incorporates herein by reference as if fully set forth the contents of a non-provisional application titled Occlusion Detection By Pressure Measurement being filed on the same day as this application. That non-provisional application claims the benefit of U.S. Provisional Application No. 62/786,982 filed on Dec. 31, 2018. This application incorporates herein by reference as if fully set forth the contents of that provisional application. BACKGROUND The present invention concerns detecting occlusion within cavities of the heart using fluid dilution systems and methods. However, it should be understood that the systems, devices and methods of the present invention are not limited to use for detecting occlusion within cardiac cavities. In addition, the present invention could be used for determining occlusions in other parts of the body, such as blood clots in the brain. The fluid dilution systems, device and methods of the present invention are disclosed in two exemplary embodiments. Under a first exemplary embodiment, the fluid dilution system, device and methods are used to detect occlusion of the pulmonary vein (“PV”) or other heart cavities during ablation of cardiac tissue. Ablation of cardiac tissue has been used to treat cardiac arrhythmias. Ablative energies are typically provided to cardiac tissue by a tip portion which can deliver ablative energy alongside the tissue to be ablated. Some of these catheters administer ablative energy from various electrodes three-dimensional structures. Ablative procedures incorporating such catheters may be visualized using fluoroscopy. Under the second exemplary embodiment, the fluid dilution system, device and methods are used to detect occlusion of the left atrial appendage, or the left atrium as part of reducing the risk imposed by atrial fibrillation. The upper chambers of the heart, the atria, have appendages attached to each of them. For example, the left atrial appendage is a feature of all human hearts. The physiologic function of such appendages is not completely understood, but they do act as a filling reservoir during the normal pumping of the heart. The appendages typically protrude from the atria and cover an external portion of the atria. Atrial appendages differ substantially from one to another. For example, one atrial appendage may be configured as a tapered protrusion while another atrial appendage may be configured as a re-entrant, sock-like hole. The inner surface of an appendage is conventionally trabeculated with cords of muscular cardiac tissue traversing its surface with one or multiple lobes. The atrial appendages appear to be inert while blood is being pumped through them during normal heart function. In other words, the appendages don't appear to have a noticeable effect on blood pumped through them during normal heart function. However, in cases of atrial fibrillation, when the atria go into arrhythmia, blood may pool and thrombose inside of the appendages. Among other things, this can pose a stroke risk when it occurs in the left appendage since the thrombus may be pumped out of the heart and into the cranial circulation once normal sinus rhythm is restored following arrhythmia events. Historically, appendages have sometimes been modified surgically to reduce the risk imposed by atrial fibrillation. In recent years devices which may be delivered percutaneously into the left atrial appendage have been introduced. The basic function of these devices is to exclude the volume within the appendage with an implant which then allows blood within the appendage to safely thrombose and then to be gradually incorporated into cardiac tissue. This process, coupled with the growth of endothelium over the face of the device, can leave a smooth, endothelialized surface where the appendage is located. In comparison to surgical procedures, devices implanted percutaneously are a less invasive means for addressing the problems associated with the left atrial appendage. In general, occlusion is detected by injecting contrast fluid into a target cavity, e.g., the pulmonary vein or the left atrium, and observing whether the contrast fluid escapes from the target cavity. However, contrast fluid has several disadvantages, such as allergic reactions. It would therefore be advantageous to provide a system, method and/or device that is capable of occlusion detection in the pulmonary vein, the left atrial appendage, the left atrium, and other cavities of the heart, as well as in other parts of the human body, without use of contrast fluid. SUMMARY Under the first exemplary embodiment, a system, a device and methods for occlusion detection within the pulmonary vein are d