Impedance-based sensing for removal of obstructions in biological lumens

Abstract

Impedance-based sensing for removal of obstructions in biological lumens is provided via a retrieval means defined along a longitudinal axis, wherein the retrieval means is configured to transition between a collapsed state and an expanded state; a plurality of electrodes integrated into the retrieval means; a retrieval member affixed to the retrieval means, configured to allow a user to pull the retrieval means and an obstruction engaged by the retrieval means along a longitudinal axis of a biological lumen; and an electrical connector configured to connect the plurality of electrodes to an impedance measuring device via the retrieval means to measure an electrical impedance across one or more pairs of the plurality of electrodes.

Description

Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCTTITLEIMPEDANCE-BASED SENSING FOR REMOVAL OF OBSTRUCTIONS IN BIOLOGICAL LUMENSCROSS-REFERENCES TO RELATED DISCLOSURES

[0001] The present disclosure claims priority to U.S. Provisional Patent Application 63 / 724,751, filed on 2024-25-11, titled “IMPEDANCE-BASED SENSING FOR REMOVAL OF OBSTRUCTIONS IN BIOLOGICAL LUMENS”, which is incorporated herein in its entirety to the extent permitted by law.BACKGROUND

[0001] Removing an obstruction from a biological limen typically involves inserting a retrieval tool, such as a mesh, via a catheter into the biological lumen and allowing the retrieval tool to engage with the obstruction. This engagement can involve the obstruction growing around a mesh over a period of time such that a structure of the retrieval tool is partially or completely enveloped in a mass of the obstruction, or a practitioner piercing through the obstruction with the retrieval tool to deliver a deployable mesh or other structure to hook the obstruction for removal. In some situations, the retrieval tool and the obstruction can then be pulled through the biological lumen together via a retrieval member to an opening, either natural or artificial, in the biological lumen from which the retrieval tool and the obstruction can be extracted.SUMMARY

[0002] When removing an obstruction from a biological lumen, significant skill is currently required on the part of a practitioner conducting the operation. Existing methods primarily rely in tactile sensation felt via a retrieval device for the practitioner to determine situational characteristics such as stent engagement, obstruction size, and obstruction composition. This reliance on “feel” can result in undesirable consequences such as a stent being pulled out of an obstruction if the stent is insufficiently engaged, or fracturing the obstruction if a composition of the obstruction is significantly different from what was assumed prior to the removal operation. Additionally, inexperienced practitioners may have not yet developed a sense of “feel” to reliably indicate when a retrieval device has engaged an obstruction, and practitioners faced with a novelAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT obstruction may have an inaccurate sense of “feel” that can lead to sub-optimal outcomes during an operation.

[0003] Devices, systems, and methods of the present disclosure advantageously provide far more accurate information about obstruction composition and stent engagement by measuring electrical impedance across a plurality of electrodes integrated into the stent. By applying an alternating voltage across two or more electrodes integrated into a body of the stent, various characteristics such as obstruction size, obstruction composition, and stent engagement can be measured and supplied to a practitioner in near-realtime. Doing so can avoid complications with obstruction removal procedures which can be dangerous and costly, and reduce the overall human skill required to successfully conduct such procedures.BRIEF DESCRIPTION OF THE DRAWINGS

[0001] Figure 1 illustrates an example obstruction removal system, according to embodiments of the present disclosure.

[0002] Figure 2 illustrates an example continuous stent with integrated electrodes partially sheathed within a catheter as part of a stent-catheter assembly, according to embodiments of the present disclosure.

[0003] Figure 3A illustrates an example stent-catheter assembly which includes a segmented stent with integrated electrodes engaged with an obstruction in a biological lumen, according to embodiments of the present disclosure.

[0004] Figure 3B illustrates an example stent-catheter assembly which includes a modular stent with integrated electrodes engaged with an obstruction in a biological lumen, according to embodiments of the present disclosure.

[0005] Figure 3C illustrates an example stent-catheter assembly which includes a braided stent with integrated electrodes engaged with an obstruction in a biological lumen, according to embodiments of the present disclosure.

[0006] Figure 4 illustrates an example method for removing an obstruction from a biological lumen, according to embodiments of the present disclosure.

[0007] Figure 5 illustrates an example collection of stent meshes in collapsed and expanded configurations, according to embodiments of the present disclosure.Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT

[0008] Figure 6 illustrates an example computing system, according to embodiments of the present disclosure.DETAILED DESCRIPTION

[0009] The present disclosure provides devices, systems, and methods for detecting an engagement of a stent with an obstruction within a biological lumen. Biological lumens such as, for example, blood vessels, can become obstructed due to a variety of phenomena (e.g., clotting, plaque formation, entry of foreign bodies, and scar tissue formation in the case of blood vessels). An obstruction in such a biological lumen can impair one or more biological functions associated with that biological lumen, and thus these obstructions are often removed once discovered.

[0010] One existing technique for removing obstructions from biological lumens involves inserting a stent into the biological lumen, often via a catheter, such that the stent overlaps or perforates the obstruction within the biological lumen. The stent can be left in the biological lumen for a predetermined length of time, during which the obstruction can grow to envelop the stent in whole or in part. In some embodiments, the stent can simply be expanded within the biological lumen at an obstructed point to “grip” the obstruction from within. For the purposes of the present disclosure, a stent or member which is sufficiently attached to an obstruction to pull at least a part of the obstruction along the biological lumen is considered to be at least partially “engaged” with the obstruction.

[0011] Once the stent is engaged with the obstruction, a highly-trained medical practitioner can pull the stent (and thus at least some of the obstruction) along and out of the biological lumen. The process for extracting an engaged stent can be difficult and time-consuming, with a high incidence of obstruction loss or breakup. Worse still, even highly-trained practitioners can have difficulties in discerning when a stent or member becomes partially or wholly disengaged from an obstruction. Because of the difficulties associated with successfully removing obstructions with this method, obstruction removal is generally only performed by personnel with a high level of skill and experience. The present disclosure therefore implements a device which can assist in the obstruction removal process, thereby reducing the skill level necessary to successfully remove an obstruction, improving the success rate of such operations, reducing the time necessary to complete such operations, and other benefits that will become apparent on a detailed reading of the present disclosure.Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT

[0012] Devices, systems, and apparatuses of the present disclosure advantageously provide information about an obstruction during removal of the obstruction by providing two or more electrodes attached to or integrated within a removal stent. By measuring an impedance across the two or more electrodes and changes therein, characteristics of an obstruction such as size and composition as well as an engagement status of the obstruction with the stent can be determined quickly. Such information can greatly assist an individual performing obstruction removal and provide several benefits to the practitioner and to the patient.

[0013] Figure 1 illustrates an example obstruction removal system 100, according to embodiments of the present disclosure. In an example scenario, a catheter 130 is inserted into a biological lumen 140 containing an obstruction 142. The biological lumen 140 can, for example, be a blood vessel and the obstruction 142 can, for example, be a clot, which may have formed in the blood vessel or traveled to the blood vessel before becoming lodged therein. A retrieval member 120 is inserted into the catheter 130 and is affixed to a retrieval means, for example a stent 110, which is illustrated as being engaged with the obstruction 142. As illustrated, the stent 110 includes a plurality of electrodes 112a-l 12i (generally or collectively, electrodes 112) which are be electrically connected to a monitoring device 150. A retrieval device 160 is configured to allow a user to manipulate a position of the retrieval member 120 within the catheter 130 and, in some embodiments, permits or controls fluid flow through or from the catheter 130.

[0014] In an example operation, a practitioner inserts the catheter 130 containing the stent 110 into the biological lumen 140. The practitioner uses the retrieval device 160 to push the stent 110 via the retrieval member 120 out of the catheter 130 until the stent 110 is engaged wholly or partially with the obstruction 142. The stent 110 can have an expanded state (illustrated herein) for engaging with the obstruction 142 and a collapsed state (not illustrated) for insertion into the obstruction 142. The practitioner, as part of the operation, may transition the stent 110 between the expanded and collapsed states to better engage with the obstruction 142.

[0015] In some embodiments, the monitoring device 150, is an impedance measuring device that can applies an alternating electrical current across (via current or voltage source) any two or more of the electrodes 112 via the retrieval member 120, and measures an impedance across the two or more electrodes 112. This alternating electrical current can be sinusoidal or any other waveform at any frequency or frequencies, and can be accompanied by a direct current for measuring resistance. When the stent 110 engages with the obstruction 142, the measuredAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT impedance changes as the electrodes 112 contact a material of the obstruction 142. This change can be a lowering of the impedance in cases where the obstruction 142 is composed of material which is more conductive than a fluid contained within the biological lumen 140 or a wall material of the biological lumen 140, or the change can be an increase in impedance when the reverse is true. The monitoring device 150 can be configured to display impedance values in near-realtime to the practitioner, and can be configured to alert the practitioner (e.g., via an auditory or visual signal such as a beep or flashing light) when a change in measured impedance above a predetermined threshold occurs.

[0016] In some embodiments, the predetermined threshold for impedance changes at which alerts are to be generated can be specified by the practitioner. In some embodiments, the predetermined threshold can be included in an “obstruction profile” for an expected composition of the obstruction 142, which is selected from a library of obstruction profiles corresponding to various types of obstructions 142 within varying types of biological lumens 140. The monitoring device 150 can also measure an impedance one or more times before the stent 110 is engaged with the obstruction 142, and one or more times after the stent 110 is engaged with the obstruction 142 to automatically determine a threshold change for generating an alert. Such an automatic determination can be made by, for example, generating average impedance values for the unengaged and engaged states, then setting the threshold at an impedance value halfway between the two averages or X percent of a difference between the two average.

[0017] When retrieving the engaged stent 110 and the obstruction 142, the practitioner retracts the stent 110 and the obstruction 142 along a longitudinal axis of the lumen 140 into the catheter 130 using the retrieval device 160. However, as the stent 110 moves back into the catheter 130, the stent 110 can slip off of or out of the obstruction 142. Accordingly, the monitoring device 150 can be configured to measure distinct impedances across varying groups of the electrodes 112 independently of one another to detect localized changes in impedance. For example, the monitoring device 150 can be configured to produce a first impedance value between a first group including the first electrode 112a and the second electrode 112b, a second impedance value between a second group including the second electrode 112b and the third electrode 112c, a third impedance value between a third group including the third electrode 112c and the fourth electrode 112d, etc. This localized detection in specific groups of electrodes 112 enables the monitoring device 150 to detect when the stent 110 slips relative to the obstruction 142. By enabling theAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT monitoring device 150 to detect when an elevated or depressed impedance shifts occurs along subsets of the electrodes 112, the monitoring device 150 can detect more and different events than a device that solely relied on an overall impedance value for the entire stent 110.

[0018] This localized detection capability also allows for the detection of a precise location and nature of any fragmentation of the obstruction 142. For example, a split of the obstruction 142 near an end thereof might cause a sudden change of impedance across electrodes 112a, 112b, and 112c without a significant change across the other electrodes 112d-i. The monitoring device 150 can detect this change and determine that a segment of the obstruction 142 has broken off of the obstruction 142 at a point between a first grouping of the electrodes 112a- 112c and a second grouping of the electrodes 112d-l 12f The monitoring device 150 can provides the practitioner with this information or an estimate of a size of the segment of the obstruction 142 that has broken off, which can in turn be used in decision-making surrounding mitigating effects of the split.

[0019] The monitoring device 150 can also provide a practitioner with a general status of the stent 110 with respect to the obstruction 142. For example, statuses can include but are not limited to whether the stent 110 is immersed in fluid, in contact with a wall of the biological lumen 140, in contact with the obstruction 142, or engaged with the obstruction 142.

[0020] In various embodiments, the stent 110 can be can be constructed by various construction techniques such as, but is not limited to: being woven, molded, extruded, braided, monolithically constructed, welded, soldered, glued or otherwise adhered, stitched, stapled or otherwise bound together, cut, or any other construction technique which can produce a stent 110 which can expand to engage with the obstruction 142. Possible stent 110 geometries can include, but are not limited to the continuous stent 110 illustrated in Figure 1, stents 110 which include one or more distinct segments (see Figure 3A), stents 110 which include modular or detachable segments (see Figure 3B), or any other geometry capable of expanding to engage with the obstruction 142. The stent 110 can be made out of any material, including but not limited to, plastics, silicones, metals, plant-derived materials, rubbers, and composites thereof.

[0021] In some embodiments, the retrieval device 160 can include, but is not limited to, a handle or member which is gripped by the practitioner to manually manipulate the stent 110. In some embodiments, the retrieval device 160 optionally includes additional elements such as motors, sensors, and user interface controls to manipulate the stent 110 without direct contact between the retrieval member 120 and a practi oner’s hand. In some such embodiments, removalAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT of the obstruction 142 can be partially or wholly automated by interfacing the monitoring device 150 with one or more controllers (such as a computer), which can then direct the retrieval device 160 to manipulate a position of the stent 110 in response to measured impedance values reported by the monitoring device 150. In some embodiments, the monitoring device 150 includes such a controller or the controller may be a separate computing device from the monitoring device 150.

[0022] The monitoring device 150 can vary a frequency or a voltage of signal(s) applied to the electrodes 112 to determine impedance values at a variety of voltages and frequencies. Because differing materials possess differing impedance values at differing voltages and frequencies, sweeping through a range of voltages or frequencies can enable the monitoring device 150 to determine an approximate composition of the obstruction 142. This information can be provided as an overall composition, hardness, density, or other parameter, which can be mapped out as a 2- D or 3-D model of the obstruction 142 with different probable compositions, hardnesses, densities, and other parameters displayed relative to one another (derived from differing impedance measurements among differing pairs of electrodes 112). The 2-D or 3-D model can be displayed to the practitioner, allowing the practitioner to determine whether fragmentation of the obstruction 142 is likely to occur. Additionally or alternatively, the controller can be provided with the composition data and to automatically determine whether fragmentation of the obstruction 142 is likely to occur. When the controller determines that a fragmentation is likely, the controller can send an alert to the practitioner indicative of a likely fragmentation, and appropriate precautions can be taken to reduce the risk of fragmentation or to reduce the effects of such fragmentation. For example, a practitioner may pull out an engaged stent 110 more slowly when the obstruction 142 is at an elevated risk of fragmentation than when the obstruction 142 is at a lower risk of fragmentation, or may apply negative pressure (e.g., suction) to the biological lumen 140 to aspirate any fragments of the obstruction 142.

[0023] Figure 2 illustrates an example continuous stent 110 with integrated electrodes 112a- 1121 (generally or collectively, the electrodes 112) partially sheathed within a catheter 130 as part of a stent-catheter assembly 200, according to embodiments of the present disclosure. The stentcatheter assembly 200 is similar to that illustrated in Figure 1, with a continuous stent 110 that includes a plurality of integrated electrodes 112 and 212. The addition of electrodes 112j-l illustrates how a number of electrodes 112 can be expanded to any desired quantity as needed. The stent 110 can be of any length, but is preferably be longer than any obstruction 142 which the stentAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT110 will encounter. Although the electrodes 112 are illustrated as being at or near several wide points of the stent 110, the present disclosure contemplates that the electrodes 112can be located anywhere on a body of the stent 110, including, but not limited to, one or more narrow or constricted points. For example, the electrodes 112 can be disposed in groupings of three, which are placed at regular intervals along a longitudinal axis 220 of the stent 110, and each grouping of three can be disposed with substantially radially symmetry around the longitudinal axis 220 of the stent 110.

[0024] As illustrated, the stent 110 includes a tip 210 with a narrower profile than a maximum width W or radius R (measured from and, normal to the longitudinal axis 220) of the stent 110. Those of skill in the art will appreciate that a narrowed profile tip 210 can ease the insertion of the stent 110 into an obstruction 142. Further, the stent 110 can be designed such that a longitudinal force 230 applied to the tip 210 can causes a width of the stent 110 to decrease, whereas a similar force 240applied in the opposite direction along the stent 110 can cause the width of the stent 110 to increase. Those of skill in the art will recognize that such a design can ease an insertion through and engagement with an obstruction 142 by the stent 110.

[0025] Figure 3A illustrates an example stent-catheter assembly 300a that includes a segmented stent 110 with integrated electrodes 112 engaged with an obstruction 142 in a biological lumen 140, according to embodiments of the present disclosure. In this example, a segmented stent 110 connected to a retrieval member 120 includes a first segment 320, a second segment 322, a third segment 324, a fourth segment 326, and a fifth segment 328 (generally or collectively, the segments 320-328).

[0026] In some embodiments, the stent 110 can include a plurality of distinct mesh segments 320-328 connected by one or more central members 330a-c (generally or collectively, central members 330) disposed between each pair of mesh segments 320-328 of the plurality of distinct mesh segments 320-328.

[0027] As illustrated, the first segment 320 and the fifth segment 328 are not engaged with the obstruction 142, whereas the second segment 322, the third segment 324, and the fourth segment 326 are engaged with the obstruction 142. The segments 320-328 are connected to each other and to the retrieval member 120, which can be used to insert and retrieve the stent 110.

[0028] Although one set of three electrodes 112is illustrated for each of the segments 320-328, the present disclosure contemplates that any number of electrodes 112can be provided for eachAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT segment. It will also be appreciated that increasing a number of electrodes 112 can increase an accuracy or granularity of measurements and thereby provide more useful data to a practitioner or a controller.

[0029] A monitoring device 150 can be configured to monitor which of the segments 320-328 are engaged with the obstruction 142, and can be configured to provide the practitioner with an engagement status of each of the segments 320-328 relative to an obstruction 142. The monitoring device 150 can also be configured to alert the user when a number of engaged segments 320-328 decreases or falls below a predetermined value which can be chosen by the user.

[0030] Figure 3B illustrates an example stent-catheter assembly 300b that includes a modular stent 110 with integrated electrodes 112 = engaged with an obstruction 142 in a biological lumen 140, according to embodiments of the present disclosure. In this example embodiment, each of a plurality of segments 320-328 of the stent 110 are connected by one of a plurality of connectors 340a-c (generally or collectively, connectors 340) disposed between neighboring segments 320.

[0031] The present disclosure contemplates that that modularizing the stent 110 in this way adds significantly to applications in which the stent 110 can be deployed. For example, when a size of an obstruction 142 is determined before insertion of the stent 110, the stent 110 can be customized by adding or removing segments 320-328 to match a length of the obstruction 142.

[0032] The connectors 340 can be manual connectors that are connected and detached manually by a practitioner interacting with the connectors directly or via a tool to customize the length of the stent 110, or can be automatic connectors which can, for example, be connected and detached electronically responsive to an instruction from a practitioner or controller. The connectors 340 can be mechanical connectors, magnetic connectors, adhesives, friction fittings, interference fittings, any other connecting means, and combinations thereof.

[0033] In some example scenarios, one or more segments 320-328 can be configured to detach from the stent 110 in an event where a fragmentation of the obstruction 142 is detected. Such a capability can be desirable where removal of a portion of the obstruction 142 is acceptable while leaving the one or more segments 320-328 engaged with a detached fragment of the obstruction 142 can allow the one or more segments 320-328 to further engage with the fragment of the obstruction 142. In such an example scenario, the detached one or more segments 320-328 can allow the obstruction 142 to grow and harden around those segments, and the detached segmentsAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT may automatically reconnect when contact is made between a connector 340 on the detached one or more segments 320-328 and a connector 340 on the retrieval member 120.

[0034] Figure 3C illustrates an example stent-catheter assembly 300c which includes a braided stent 110 with integrated electrodes 112 engaged with an obstruction 142 in a biological lumen 140, according to embodiments of the present disclosure. In this example scenario, the stent 110 includes a plurality of braided members 350 that form a structure capable of engaging with the obstruction 142. The electrodes 112 can be positioned as illustrated, but can be positioned anywhere else on the stent 110. Any braiding pattern can be used, including but not limited to any number of strands, flat braids, fishtail braids, cobra braids, twill braids, circular braids, and combinations and derivatives thereof. Further, individual members of a stent 110, braided or otherwise, can themselves be braided, with conductors electrically connected to the electrodes 112 forming, in whole or in part, strands of the members.

[0035] When inside of a lumen of a catheterl40, the stent 110 can have a first diameter DI, and when exposed from the lumen of the catheter the stent 110 can have a second diameter D2, where the second diameter D2 is larger than the first diameter DI. The electrodes 112 can be regularly spaced along the stent 110 or spaced apart at variable distances. The stent 110 can have an electrical connector 340 between a main portion of the stent 110 and a retrieval member.

[0036] Figure 4 illustrates an example method 400 for removing an obstruction from a biological lumen, according to embodiments of the present disclosure.

[0037] At block 410, a practitioner inserts a catheter 130 into a biological lumen 140. For example, a doctor can insert a butterfly catheter into a blood vessel of a patient via a trocar.

[0038] At block 420, the practitioner deploys a stent 100 with integrated electrodes 112 into an obstruction 142. For example, the blood vessel can contain a clot (e.g., the obstruction 142), which can be perforated by a stainless steel coronary stent 110 with integrated electrodes 112 and which was previously contained in the butterfly catheter. It will be appreciated that a stainless steel stent 110 construction can necessitate some form of insulation between portions of the stent 110 body and one or more conductors associated with the electrodes 112, which can include portions of the stent 110 body.

[0039] At block 430, a monitoring device 150 measures an impedance across at least one pair of electrodes 112. For example, an impedance analyzer (e.g., the monitoring device 150) can test each possible pairing of the electrodes 112 with an alternating current (and possibly also a variousAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT voltages and frequencies) to determine impedance values between at least one pair of electrodes 112. This process can be repeated many times in rapid succession such that a continuous or near- continuous monitoring of impedance values is provided. In various embodiments, the measuring process may select any possible pairings of the electrodes 112 to measure impedance across, or may confine measurements to pairs of electrodes in a given segments of the stent 110 or a given distance away from one another along a length of the stent 110.

[0040] At block 440, the monitoring device 150 determines characteristics of the obstruction 142 and a status of the stent 110. For example, the impedance analyzer (the monitoring device 150) can determine that the clot (the obstruction 142) is approximately 5 millimeters (mm) long and is mostly comprised of lipids in a uniform distribution along a longitudinal axis of the stent 110. In another example, The impedance analyzer (the monitoring device 150) can also determine that the stent 110 is partially engaged with the clot (the obstruction 142) along three-quarters of the stent’s 110 longitudinal axis.

[0041] At block 450, the practitioner removes the obstruction 142 based on the determined characteristic and status. For example, the practitioner can monitor the composition of the clot (the obstruction 142) as being mostly comprised of lipids and determine that a relatively slow extraction speed is desirable to avoid fragmentation of the clot, in contrast to a clot composed mostly of platelets that a faster extraction speed would be desirable for. The practitioner can also determine that additional time should be allowed to pass before attempting to remove the clot if the stent 110 is only partially engaged. The practitioner can wait until the impedance analyzer indicates that the stent 110 is fully engaged with the clot, and then begin pulling the clot along a longitudinal axis of the blood vessel (the biological lumen 140) until the clot is within the catheter 130, from which the clot can be extracted.

[0042] Figure 5 illustrates an example collection 500 of stent meshes in collapsed and expanded configurations, according to embodiments of the present disclosure. In a first example, a collapsed continuous stent 510 is depicted with three electrodes 112 labeled. Although only three electrodes 112 are labeled, it will be appreciated that any number of electrodes 112 can be included in the collapsed continuous stent 510. As can be seen, the collapsed continuous stent 510 is of a first diameter DI. This is in contrast to an expanded continuous stent 520, which can be a same stent 110 as the collapsed continuous stent 510 in an expanded state. As can be seen, the expanded continuous stent 520 is of a second diameter which is larger than the first diameter, with theAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT electrodes 112 placed in same positions along a body of the expanded continuous stent 520 as along a body of the collapsed continuous stent 510, but at a greater distance in from one another in the expanded continuous stent 520 as opposed to the collapsed continuous stent 510 by virtue of an increased diameter.

[0043] Similarly, a second example provides a collapsed segmented stent 530 and an expanded segmented stent 540, each comprising a plurality of segments 320-328 and with electrodes 112. Just as with the collapsed continuous stent 510 and the expanded continuous stent 520, the collapsed segmented stent 530 has a first diameter which is smaller than a second diameter of the expanded segmented stent 540. Of note is that the expanded segmented stent 540 has not expanded to a same degree across an entire longitudinal axis of the expanded segmented stent 540 relative to the collapsed segmented stent 530. This can be due to being partially still within a lumen of a catheter, being in contact with or engaged with an obstruction, or a result of an inconsistent diameter of a biological lumen containing the expanded segmented stent 540. It will be appreciated that this varying increase in diameter is also possible in the case of the expanded continuous stent 520.

[0044] Figure 6 illustrates an example computing system 600, according to embodiments of the present disclosure. In the example computing system 600, a processor 610 executes an operating system 622 and one or more programs 624 held in a memory 620 (which can include but is not limited to volatile memory and non-volatile storage). A communication interface 630 can be employed to communicate with peripherals, such as a monitoring device 150 as well as a user interface and one or more other computing systems 600. In a context of the present disclosure, the one or more programs 624 can include but are not limited to applications that analyze inputs received from a monitoring device 150 via the communication interface 630 and which alert a practitioner when a predetermined criterion or criteria are met. These criteria can be held in the memory 620, and can be modified by the practitioner as desired. The one or more programs 624 can also automatically manage and manipulate a stent retrieval device 100 as desired in embodiments where full or near-full automation is implemented.

[0045] The present disclosure may also be understood with reference to the following numbered clauses.

[0046] Clause 1 : A system, comprising: a retrieval means defined along a longitudinal axis, wherein the retrieval means is configured to transition between a collapsed state and an expandedAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT state; a plurality of electrodes integrated into the retrieval means; a retrieval member affixed to the retrieval means, configured to allow a user to pull the retrieval means and an obstruction engaged by the retrieval means along a longitudinal axis of a biological lumen; and an electrical connector configured to connect the plurality of electrodes to an impedance measuring device via the retrieval means to measure an electrical impedance across one or more pairs of the plurality of electrodes.

[0047] Clause 2: The system of any of clauses 1-10, wherein the electrodes receive a sinusoidal electrical signal and a direct current from the impedance measuring device.

[0048] Clause 3: The system of any of clauses 1-10, wherein the impedance measuring device determines, based at least partially upon the electrical impedance, a state of the retrieval means at least one of: immersed in fluid, in contact with a wall of the biological lumen, in contact with the obstruction, and engaged with the obstruction.

[0049] Clause 4: The system of any of clauses 1-10, wherein the impedance measuring device determines, based at least partially upon the electrical impedance, that the retrieval means is no longer in contact with the obstruction and alerts a user based upon the determination.

[0050] Clause 5: The system of any of clauses 1-10,, wherein the retrieval means comprises a plurality of distinct mesh segments connected by one or more central members disposed between each pair of mesh segments of the plurality of distinct mesh segments.

[0051] Clause 6: The system of any of clauses 1-10, wherein electrodes of the plurality of electrodes are disposed in groupings of three placed at regular intervals along a longitudinal axis of the retrieval means, and wherein each grouping of three is disposed with substantially radially symmetry around the longitudinal axis of the retrieval means.

[0052] Clause 7: The system of any of clauses 1-10, wherein the plurality of electrodes are divided into at least a first group and a second group, and wherein the impedance measuring device is configured to measure a first group impedance across the first group and a second group impedance across the second group independently of one another.

[0053] Clause 8: The system of any of clauses 1-10, wherein the impedance measuring device employs a difference in the first group impedance and the second group impedance to determine at least one of a size of the obstruction, a makeup of the obstruction, a hardness of the obstruction, and a density of the obstruction.

[0054] Clause 9: The system of any of clauses 1-10, wherein the impedance measuring device is configured to alert a user in response to determining that the electrical impedance has changed.Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT

[0055] Clause 10: The system of any of clauses 1-10, wherein the retrieval means comprises a braided structure.

[0056] Clause 11 : A method, comprising: inserting a retrieval means into a biological lumen; applying an electrical current across at least two electrodes integrated into the retrieval means; measuring an impedance across the at least two electrodes; determining, based at least partially upon the measured impedance, that the retrieval means is engaged with an obstruction within the biological lumen; and alerting a user that the retrieval means is engaged with the obstruction.

[0057] Clause 12: The method of any of clauses 11-17, further comprising pulling the retrieval means along a longitudinal axis of the biological lumen via a retrieval member with the obstruction retained by the retrieval means.

[0058] Clause 13: The method of any of clauses 11-17, further comprising: determining, at least partially based upon the measured impedance, that the retrieval means has at least partially become disengaged from the obstruction; and alerting the user that the retrieval means has at least partially become disengaged from the obstruction.

[0059] Clause 14: The method of any of clauses 11-17, further comprising: determining, based at least partially upon the measured impedance, that the retrieval means is in contact with a wall of the biological lumen; and alerting the user that the retrieval means is in contact with the wall of the biological lumen.

[0060] Clause 15: The method of any of clauses 11-17,, further comprising: determining, based at least partially upon the measured impedance, that the retrieval means is immersed in a fluid; and alerting the user that the retrieval means is immersed in the fluid.

[0061] Clause 16: The method of any of clauses 11-17, further comprising: determining, based at least partially upon the measured impedance, a cross-sectional size of the biological lumen where the retrieval means is deployed; and alerting the user of the cross-sectional size of the biological lumen where the retrieval means is deployed.

[0062] Clause 17: The method of any of clauses 11-17, further comprising: determining, based at least partially upon the measured impedance and locations of the electrodes along a length of the retrieval means, a length of the obstruction; and alerting the user of the length of the obstruction.

[0063] Clause 18: A tool, comprising: a catheter; a stent retriever, comprising: a plurality of electrodes disposed at regular intervals along a longitudinal length of the stent retriever between aAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT first end and a second end of a deployable section of the stent retriever; and an electrical connector disposed at the second end of the deployable section; wherein the deployable section, when disposed within a lumen of the catheter, has a first configuration with a first diameter, and when exposed from the lumen of the catheter has a second configuration with a second diameter that is greater than the first diameter.

[0064] Clause 19: The tool of any of clauses 18-24, further comprising a monitoring component configured to measure an impedance across at least two electrodes of the plurality of electrodes.

[0065] Clause 20: The tool of any of clauses 18-24, wherein the monitoring component determines, based on the impedance, a state of the stent retriever as at least one of: immersed in fluid,

[0066] in contact with a wall of a biological lumen, in contact with an obstruction, and engaged with the obstruction.

[0067] Clause 21 : The tool of any of clauses 18-24, wherein the monitoring component determines, based on the impedance, that the stent retriever is no longer in contact with the obstruction and alerts a user based upon the determination.

[0068] Clause 22: The tool of any of clauses 18-24, wherein the plurality of electrodes are divided into at least a first group and a second group, and wherein the monitoring component is configured to measure a first group impedance across the first group and a second group impedance across the second group independently of one another.

[0069] Clause 23: The tool of any of clauses 18-24, wherein the monitoring component employs a difference in the first group impedance and the second group impedance to determine at least one of: a size of an obstruction, a makeup of the obstruction, a hardness of the obstruction, and a density of the obstruction.

[0070] Clause 24: The tool of any of clauses 18-24, wherein the monitoring component is configured to alert a user responsive to determining that the impedance has changed.

[0071] The description refers to Figures and drawings which are provided for exemplary purposes only. Alternative implementations of the present disclosure can combine, substitute, omit, or add to any elements contemplated herein without regard for which particular Figure or portion of the description contains an element. Some elements of the present disclosure can be implemented as hardware, software, or firmware, and absent an explicit specification or inherentAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT requirement that an element be implemented by one, it is to be understood that an element can be implemented by any of these techniques and combinations thereof.

[0072] As used herein, the term “program” is defined as stored machine-readable instructions which, when executed by a processing device, cause the processing device to perform a sequence of actions to carry out the functions of that program. Examples of processing devices include but are not limited to processors, microprocessors, controllers including programmable logic controllers (PLCs), field programmable gate arrays (FPGAs), digital signal processors (DSPs), application specific integrated circuits (ASICs), microcontrollers, system on a chip (SoC) devices, custom circuitry capable of performing logical operations, or any other device capable of carrying out machine logic.

[0073] The above description refers to one or more flowcharts of one or more example methods. It will be appreciated that the one or more example methods contains steps which can be rearranged, added to, omitted, modified, or otherwise altered without departing from a scope of this disclosure. Methods described above can be implemented in any manner, including but not limited to by computer-readable instructions stored in a non-transitory medium for execution by a processing device. These instructions can take the form of software and / or firmware, and in some cases can be reflected in a physical configuration of computer circuitry (e.g. dedicated hardware). As used herein, the terms “computer readable medium” refers to one or more instructions stored in a non-transitory storage associated with or accessible by a processing device and should not be construed as referring to a transitory propagation of a signal in any way, shape, or form.

[0074] It will be appreciated that any specific embodiments described herein are presented for exemplary purposes only and are not limiting. Accordingly, any elements of any embodiment described herein can be omitted, altered, added to, combined across exemplary embodiments, or otherwise modified to produce various additional possible embodiments not explicitly discussed herein. In cases where elements of two particular embodiments discussed herein are not expressly mutually exclusive, it is to be understood that those elements can be combined freely as desired.

[0075] The many benefits, solutions, advantages, and causes thereof extolled by the present disclosure are not to be taken as limiting or necessary, and embodiments that fail to provide some or all of said benefits, solutions, advantages, and causes thereof are to be taken as within a scope of the present disclosure. The scope of the claimed technology is to be solely defined by the following claims, amendments thereto during pendency of this application, and issued equivalentsAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT thereof. Moreover in this document, relational terms such as first and second, top and bottom, and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0076] The terms "comprises," "comprising," “has”, “having,” “includes”, “including,” “contains”, “containing” or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0077] An element proceeded by “comprises ... a”, “has . .. a”, “includes . . . a”, “contains ... a” does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises, has, includes, contains the element.

[0078] The terms “a” and “an” are defined as one or more unless explicitly stated otherwise herein.

[0079] The terms “substantially”, “essentially”, “approximately”, “about” or any other version thereof, are defined as being close to as understood by one of ordinary skill in the art, and in one non-limiting embodiment the term is defined to be within 10%, in another embodiment within 5%, in another embodiment within 1% and in another embodiment within 0.5%.

[0080] The term “coupled” as used herein is defined as connected, although not necessarily directly and not necessarily mechanically.

[0081] A device or structure that is “configured” in a certain way is configured in at least that way, but can also be configured in ways that are not listed.

[0082] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter can lie in less than all features of a single disclosed embodiment. Thus, the following claims are herebyAttorney Docket No. : 1956788.00448Client Docket No.: 2023-266-PCT incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.

Claims

Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCTCLAIMSWhat is claimed is:

1. A system, comprising: a retrieval means defined along a longitudinal axis, wherein the retrieval means is configured to transition between a collapsed state and an expanded state; a plurality of electrodes integrated into the retrieval means; a retrieval member affixed to the retrieval means, configured to allow a user to pull the retrieval means and an obstruction engaged by the retrieval means along a longitudinal axis of a biological lumen; and an electrical connector configured to connect the plurality of electrodes to an impedance measuring device via the retrieval means to measure an electrical impedance across one or more pairs of the plurality of electrodes.

2. The system of claim 1, wherein the electrodes receive a sinusoidal electrical signal and a direct current from the impedance measuring device.

3. The system of claim 1, wherein the impedance measuring device determines, based at least partially upon the electrical impedance, a state of the retrieval means at least one of: immersed in fluid, in contact with a wall of the biological lumen, in contact with the obstruction, and engaged with the obstruction.

4. The system of claim 1, wherein the impedance measuring device determines, based at least partially upon the electrical impedance, that the retrieval means is no longer in contact with the obstruction and alerts a user based upon the determination.

5. The system of claim 1, wherein the retrieval means comprises a plurality of distinct mesh segments connected by one or more central members disposed between each pair of mesh segments of the plurality of distinct mesh segments.Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT6. The system of claim 1, wherein electrodes of the plurality of electrodes are disposed in groupings of three placed at regular intervals along a longitudinal axis of the retrieval means, and wherein each grouping of three is disposed with substantially radially symmetry around the longitudinal axis of the retrieval means.

7. The system of claim 1, wherein the plurality of electrodes are divided into at least a first group and a second group, and wherein the impedance measuring device is configured to measure a first group impedance across the first group and a second group impedance across the second group independently of one another.

8. The system of claim 7, wherein the impedance measuring device employs a difference in the first group impedance and the second group impedance to determine at least one of: a size of the obstruction, a makeup of the obstruction, a hardness of the obstruction, and a density of the obstruction.

9. The system of claim 1, wherein the impedance measuring device is configured to alert a user in response to determining that the electrical impedance has changed.

10. The system of claim 1, wherein the retrieval means comprises a braided structure.

11. A method, comprising: inserting a retrieval means into a biological lumen; applying an electrical current across at least two electrodes integrated into the retrieval means; measuring an impedance across the at least two electrodes; determining, based at least partially upon the measured impedance, that the retrieval means is engaged with an obstruction within the biological lumen; and alerting a user that the retrieval means is engaged with the obstruction.Attorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT12. The method of claim 11, further comprising pulling the retrieval means along a longitudinal axis of the biological lumen via a retrieval member with the obstruction retained by the retrieval means.

13. The method of claim 12, further comprising: determining, at least partially based upon the measured impedance, that the retrieval means has at least partially become disengaged from the obstruction; and alerting the user that the retrieval means has at least partially become disengaged from the obstruction.

14. The method of claim 11, further comprising: determining, based at least partially upon the measured impedance, that the retrieval means is in contact with a wall of the biological lumen; and alerting the user that the retrieval means is in contact with the wall of the biological lumen.

15. The method of claim 11, further comprising: determining, based at least partially upon the measured impedance, that the retrieval means is immersed in a fluid; and alerting the user that the retrieval means is immersed in the fluid.

16. The method of claim 11, further comprising: determining, based at least partially upon the measured impedance, a cross-sectional size of the biological lumen where the retrieval means is deployed; and alerting the user of the cross-sectional size of the biological lumen where the retrieval means is deployed.

17. The method of claim 11, further comprising: determining, based at least partially upon the measured impedance and locations of the electrodes along a length of the retrieval means, a length of the obstruction; andAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT alerting the user of the length of the obstruction.

18. A tool, comprising: a catheter; a stent retriever, comprising: a plurality of electrodes disposed at regular intervals along a longitudinal length of the stent retriever between a first end and a second end of a deployable section of the stent retriever; and an electrical connector disposed at the second end of the deployable section; wherein the deployable section, when disposed within a lumen of the catheter, has a first configuration with a first diameter, and when exposed from the lumen of the catheter has a second configuration with a second diameter that is greater than the first diameter.

19. The tool of claim 18, further comprising a monitoring component configured to measure an impedance across at least two electrodes of the plurality of electrodes.

20. The tool of claim 19, wherein the monitoring component determines, based on the impedance, a state of the stent retriever as at least one of: immersed in fluid, in contact with a wall of a biological lumen, in contact with an obstruction, and engaged with the obstruction.

21. The tool of claim 20, wherein the monitoring component determines, based on the impedance, that the stent retriever is no longer in contact with the obstruction and alerts a user based upon the determination.

22. The tool of claim 19, wherein the plurality of electrodes are divided into at least a first group and a second group, and wherein the monitoring component is configured to measure aAttorney Docket No.: 1956788.00448Client Docket No.: 2023-266-PCT first group impedance across the first group and a second group impedance across the second group independently of one another.

23. The tool of claim 22, wherein the monitoring component employs a difference in the first group impedance and the second group impedance to determine at least one of a size of an obstruction, a makeup of the obstruction, a hardness of the obstruction, and a density of the obstruction.

24. The tool of claim 19, wherein the monitoring component is configured to alert a user responsive to determining that the impedance has changed.

Images