Multi-degree-of-freedom medical brush

Abstract

A cytological brush includes a shaft including a fluid lumen configured for passage of a fluid; the brush body comprises a fixed part and a brush body; the movable part is provided with a radial outward surface and a plurality of bristles, and the bristles protrude outwards from the radial outward surface. The movable part is configured to receive fluid through the fluid cavity channel so as to expand from an unexpanded state to an expanded state; when the movable part is in an unexpanded state, the bristles are in a retracted state; and when the movable part is in the expanded state, the bristles are in an expanded state.

Description

Cross-references to related applications

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 517,001, filed August 1, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure generally relates to multi-degree-of-freedom medical brushes and related methods, and more specifically, to cytological brushes having multi-degree-of-freedom brushes and related methods for using such cytological brushes. Background Technology

[0003] Cell sample analysis is a practical tool in disease diagnosis and treatment. Unexplained pain, abnormal symptoms, abnormal samples, or other factors may require further investigation, often using advanced medical equipment. Medical devices such as cytology brushes or other suitable instruments are used in a variety of diagnostic and surgical procedures. Many of these procedures utilize suture-guided catheters to deliver the cytology brush to narrowed areas inside the body (such as biliary strictures). Diagnostic procedures frequently require collecting mucosal tissue samples from the surface of the bile duct lumen to remove portions of suspected cancerous tissue. Diagnosing biliary strictures using cytology brushes is challenging due to the low sensitivity of cancer detection and the high likelihood of false negatives during ERCP. The low sensitivity is often caused by insufficient tissue sample collection, a limiting factor in the detection of potential malignancies.

[0004] Diagnostic procedures may include removing suspected cancerous tissue by collecting a mucosal tissue sample from the surface of the bile duct lumen. While existing cytology brushes possess a certain degree of freedom of movement (i.e., they can be guided distally into or proximally out of the patient's body along a guidewire), they may be unable to access or pass through narrow sites. For example, the tip or distal end of the brush may include radially outward-extending bristles that can change direction or otherwise impede the brush's delivery or movement (e.g., when entering a narrow site). For example, the tip or distal end of the brush may include radially outward-extending bristles that may redirect or impede the brush's delivery or movement (e.g., when entering a narrow site). In some cases, the brush's movement may terminate at a dilatation or sac anterior to the narrow site. Brushes with additional degrees of freedom of movement (such as expandable / contractable brushes) can achieve greater functionality in areas such as passing through narrow sites or collecting samples.

[0005] The apparatus and method disclosed herein can improve one or more of the aforementioned defects or solve other problems in the art. However, it should be noted that the scope of protection of this application is defined by the features described in the claims, and not by the elimination of a specific defect. Summary of the Invention

[0006] Each aspect disclosed in this disclosure may include one or more features described in combination with other disclosures.

[0007] Various aspects of this disclosure relate, in particular, to systems, apparatus, and methods for obtaining samples from a subject. Various aspects of this disclosure relate, in particular, to medical brushes having multiple degrees of freedom and related methods.

[0008] In some aspects, a cytological brush includes a shaft that may include a fluid cavity configured for fluid passage; and a brush body. The brush body may include a fixed member; and a movable member having a radially outward surface and a plurality of bristles. The bristles may project outward from the radially outward surface. The movable member may be configured to receive fluid through the fluid cavity, thereby expanding from a non-expanded state to an expanded state. In the non-expanded state of the movable member, the bristles may be in a retracted state; when the movable member is in an expanded state, the bristles may be in an extended state.

[0009] The cytology brush may include one or more of the following features: The movable component may be a balloon, which is divided into multiple balloon segments, each balloon segment including one or more bristles disposed on its outer surface. The movable component may include three balloon segments: a distal balloon segment, a middle balloon segment, and a proximal balloon segment. The bristle stiffness of the middle balloon segment may be the lowest. The distance from the central axis of the cytology brush to the bristles of the middle balloon segment may be the farthest. The balloon may be divided into three balloon segments: a proximal balloon segment, a middle balloon segment, and a distal balloon segment, each balloon segment including a distal sidewall and a proximal sidewall. The outer wall stiffness of one or more of the balloon segments may differ from the outer wall stiffness of the other balloon segments.

[0010] One or more of the balloon segments with the lowest hardness rating can expand to be furthest from the central axis of the shaft. Each balloon segment may have a distal sidewall and a proximal sidewall. When the balloon segment is in its uninflated state, some of the bristles extend proximally from the distal sidewall, and another portion of the bristles extend distally from the proximal sidewall. The fluid may be air. The air may be delivered by a syringe operatively connected to the fluid channels. The cytological brush may include four fluid channels evenly spaced circumferentially along the shaft to deliver fluid to different portions of the brush. When the bristles are in the expanded state, the central axis of each bristle may be perpendicular to the central axis of the shaft. The balloon may be biased toward a contracted state. The fixing component may include: a distal wall; a proximal wall, the distal wall being longitudinally spaced from the proximal wall and connected by a plurality of longitudinal sidewalls extending between the distal wall and the proximal wall. The balloon forms an airtight seal between each of the distal sidewall, the proximal sidewall, and the longitudinal sidewall to constitute one or more chambers. These chambers receive fluid, enabling the balloon to expand and contract between an inflated and uninflated state, thereby causing the bristles to switch between an extended and retracted state. The bristles can be arranged in four pairs along the longitudinal direction of the brush, overlapping each other in the uninflated state. The balloon can switch between the inflated and uninflated states using fluid pressure.

[0011] In another aspect, a cytology brush may include a shaft and a brush body. The shaft may include a guidewire channel for guidewire passage and a movable plunger, the movement of which can cause the brush body to switch between different configurations. The brush body may include a retaining component and a balloon. The balloon may include an outer surface comprising outwardly projecting bristles. The balloon may accommodate at least a portion of the plunger and expand from an uninflated configuration to an inflated configuration, wherein the bristles may be in an undeployed configuration when the balloon is in the uninflated configuration, and the bristles are in a deployed configuration when the balloon is in the inflated configuration.

[0012] The cytology brush may include one or more of the following features: The cytology brush may include filaments connected between a plunger and a distal end of the brush body, the filaments extending longitudinally on the balloon. The filaments may be biased toward an inflated position. The plunger may be movable to bend the filaments inward, thereby causing the balloon to switch from an inflated position to an uninflated position. The balloon is made of nylon, silicone, or a polymer material.

[0013] In another embodiment, a tissue sample collection method includes the following steps: navigating a guidewire relative to the tissue to a treatment site; advancing a cytology brush along the guidewire to the treatment site; and switching the cytology brush from a non-expanded state to an expanded state. During the switching of the cytology brush from a non-expanded state to an expanded state, the bristles of one or more segments of the cytology brush switch from a non-expanded state to an expanded state. The non-expanded state may include pairs of corresponding bristles on the segment that at least partially overlap, and the expanded state may include pairs of corresponding bristles on the segment that do not overlap. The method may also include moving the cytology brush to collect tissue on the bristles by one or more of the following methods: moving longitudinally along the guidewire, moving circumferentially around the guidewire, and moving between a non-expanded state and an expanded state; converting the cytology brush from an expanded state to a non-expanded state; and removing the cytology brush from the patient's body cavity and collecting the tissue attached to the bristles.

[0014] The method may also include one or more of the following aspects. A cytological brush may include one or more sacs. The method may also include expanding at least one of the one or more sacs to an expanded shape, thereby moving the bristles to an unfolded shape.

[0015] It should be understood that the above overview and the detailed description below are exemplary and illustrative only, and do not constitute a limitation on the scope of this disclosure. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate various exemplary aspects of this disclosure and, together with the specification, illustrate the principles of this disclosure.

[0017] Figure 1 The distal portion of an exemplary medical device according to aspects of this disclosure is shown;

[0018] Figure 2A Show Figure 1 Another view of an exemplary medical device;

[0019] Figure 2B Show Figure 1 A partial transparent view of the proximal portion of an exemplary medical device;

[0020] Figure 3 Show Figure 1 Specific aspects of the distal portion of an exemplary medical device;

[0021] Figure 4 It shows Figure 1 Additional features of exemplary medical devices;

[0022] Figure 5A The distal portion of another exemplary medical device is shown;

[0023] Figure 5B It shows Figure 5A The distal portion of an exemplary medical device;

[0024] Figure 5C It shows Figure 5A The other distal portion of an exemplary medical device;

[0025] Figure 6A A schematic diagram of the distal portion of yet another exemplary medical device of this disclosure is shown;

[0026] Figure 6B It shows Figure 6A Another view of an exemplary embodiment of a medical device;

[0027] Figure 7A The distal portion of another exemplary medical device is shown;

[0028] Figure 7B It shows Figure 7A Another view of an exemplary embodiment of a medical device;

[0029] Figure 8 It shows the use of Figure 1 Methods relating to exemplary medical devices such as medical devices. Detailed Implementation

[0030] The exemplary embodiments of this disclosure will now be described in detail with reference to the accompanying drawings, in which the same reference numerals are used as much as possible to refer to the same or similar parts.

[0031] As used herein, "proximal" and "distal" describe the relative positions of the components of the exemplary medical device. "Proximal" refers to a position relatively close to the patient's exterior or to a user such as a healthcare worker holding / operating the device; conversely, "distal" refers to a position relatively far from the user holding / operating the device, or closer to the patient's interior. The terms "comprising," "including," "having," and variations thereof, as used herein, are intended to indicate non-exclusive inclusion, meaning that a device or method that includes the listed elements may include, but is not limited to, the listed elements, and may also include other elements not expressly listed or inherently present. Unless otherwise stated, the word "exemplary" means "example" only, not "ideal state." The terms "about," "substantially," and "approximately" as used herein mean within + / - 10% of the stated values.

[0032] Figures 1 to 4 A medical device 100, which can be fitted onto a guidewire (not shown), is shown. The device includes a cytology brush 102 (hereinafter referred to as the "brush") and a shaft 104, the shaft 104 being along the central longitudinal axis 138 of the medical device 100. Figure 2A , Figure 3 ) at the first end / distal end 106 and the second end / proximal end 108 ( Figure 2AExtending between [missing information]. In some aspects, one or more portions of the shaft 104 are at least flexible, and the brush 102 has multiple bristles 122. The brush 102 can be operated with multiple degrees of freedom. For example, the brush 102 can generally be configured to deliver and unfold to a treatment site, collect tissue samples at the treatment site by moving in one or more of these multiple degrees of freedom, and then retract or remove it from the patient. In these aspects, the samples collected at the treatment site can be collected and analyzed by medical personnel to obtain test results (such as biopsy results, etc.). Furthermore, as described in detail below, the brush 102 can be manipulated to change from an unfolded or retracted form to an unfolded form to collect samples. The brush 102 can then be manipulated to switch from an unfolded form to a retracted form to preserve and / or protect the samples when removing the brush 102 and the samples from the body.

[0033] In some aspects, the shaft 104 includes a guidewire channel 110 for threading a guidewire (not shown), and the brush 102 is movable along the guidewire to a treatment site within the patient. Therefore, the guidewire can be placed at or near the treatment site within the patient before the brush 102 is inserted and positioned. In some embodiments, the shaft 104 further includes one or more fluid channels 112 (…). Figure 2B ).

[0034] The fluid cavity 112 extends longitudinally along a corresponding portion of the shaft 104. For example, the shaft 104 may include a thickness 113, which is, for example, a radial thickness if the shaft 104 has a circular transverse cross-section. The thickness 113 may be formed by an inner wall 113a and an outer wall 113b, through which the fluid cavity 112 extends between the inner wall 113a and the outer wall 113b through the shaft 104. The fluid cavity 112 allows the flow or passage of a fluid (e.g., water, brine, air, etc.) that can be used to operate the brush 102, as will be described in more detail below. For example, as... Figure 2A and Figure 2B As shown, the shaft 104 may include four fluid cavities 112, and the four fluid cavities 112 may be equally spaced around the shaft 104 (i.e., each fluid cavity 112 is equidistant from the center of the shaft 104 and equidistant from the center of the shaft 104). However, it should be noted that this disclosure is not limited thereto. For example, the shaft 104 may include one, two, three, five or more fluid cavities 112, and / or the fluid cavities 112 may be unevenly distributed around the interior of the shaft 104.

[0035] Combination Figure 1 , Figure 3 and Figure 4The brush 102 generally includes a fixed structure 116 and a flexible structure 118, the flexible structure 118 being a movable component that may include an expandable outward surface that can expand and contract between an unexpanded and an expanded state (similar to the expansion and contraction of a balloon, for example). Switching between the unexpanded and expanded states of the flexible structure 118 allows the bristles 122 of the brush 102 to move from a relaxed state (or “undeployed state”) to an deployed state, and vice versa based on this expansion. The bristles 122 project outward from the radially outward surface 117 of the flexible structure 118. When the bristles 122 are in the deployed state, their direction of extension is generally perpendicular to the central longitudinal axis 138 of the shaft 104. In some embodiments, the bristles 122 are in pairs, for example, parallel to each other in the deployed state, and at least partially overlapping when in the undeployed state.

[0036] In some embodiments, the flexible structure 118 is biased toward a contracted shape. Additionally or alternatively, the flexible structure 118 may be divided into one or more segments (e.g., Figure 3 As shown, it is divided into three segments: distal segment 124, intermediate segment 128, and proximal segment 126. Figure 4 As shown, each segment 124, 126, 128 may generally have a distal sidewall 132 and a proximal sidewall 134. Bristles 122 may protrude distally or proximally from either or both of the distal sidewall 132 and the proximal sidewall 134. Partial bristles 122 of adjacent walls or adjacent portions may intersect or overlap to form a capturing structure 136 to assist in capturing or retaining tissue 114. Figure 4 In these respects, the arrangement of the bristles helps to increase the amount of tissue 114 collected and retained by brush 102.

[0037] One or more segments 124, 126, 128 of brush 102 may have different characteristics, such as different material properties of each segment, which causes them to work differently, thereby facilitating sample collection and / or retention, as detailed below. For example, different material properties and / or the fluid supplied to brush 102 may cause at least one segment to expand and / or contract in a different manner than the other segments.

[0038] Figure 3 and Figure 4 The expanded and contracted forms of brush 102 are shown respectively. Figure 3In the specific exemplary embodiment shown, the material used to manufacture the balloon portion 128 of the middle segment has lower hardness and / or higher flexibility compared to the materials used to manufacture the balloon portions 124 of the distal segment and 126 of the proximal segment. In some embodiments, this material may be nylon, silicone, or a polymer-based material. The segments may be made of the same material or different materials. In some embodiments, segments that expand with higher flexibility may be made of a material with thinner walls and / or better flexibility; segments that expand with lower flexibility may be made of a material with thicker walls and / or poorer flexibility. In this exemplary embodiment, the middle segment 128 has the lowest hardness rating. Therefore, as Figure 3 As shown, the outer wall of the middle segment 128 is furthest from the central longitudinal axis 138. In some embodiments, the distance between the bristles 122 of the middle segment 128 and the central longitudinal axis 138 of the brush 102 is also greater than that of the bristles 122 of the distal segment 124 and / or the proximal segment 126. In these respects, the bristles 122 of the middle segment 128 can collect samples or patient tissues at locations further from the central longitudinal axis 138 of the brush 102. In some embodiments, the bristles 122 and / or the segments may have substantially the same characteristics, allowing the diameter of the brush 102 to remain consistent. Furthermore, the smaller size of the distal segment 124 and the proximal segment 126 facilitates the gradual entry and / or withdrawal of the brush 102 into and / or from small tissue areas of the body (such as narrow areas).

[0039] Furthermore, bristles 122 in different segments or within the same segment may also have different characteristics. In some aspects, all bristles 122 of brush 102 are of similar length (as shown in the figure), but this disclosure is not limited thereto. The length, cross-sectional dimensions, spacing, etc., of the bristles 122 may vary, and their stiffness (e.g., measured by a hardness tester), durability, or other material properties may also differ. In some embodiments, the arrangement of the bristles 122 may be similar to... Figures 1 to 4 As shown, for example, a section of the brush may have two or more rows of bristles (such as short bristle rows and long bristle rows) on a single wall, which helps to increase the amount of sample collected.

[0040] Still with Figures 1 to 4 The illustrated embodiment is for reference only. The brush 102 can switch between an expanded and contracted state by delivering and / or withdrawing working fluid. For example, a user can inject fluid (such as water, saline, air, etc.) into the fluid channel 112 using a syringe or other device operatively connected to the shaft 104. Applying positive relative pressure forces the fluid to flow through the fluid channel 112 and into the brush 102. The injection of fluid causes the expandable portion of the brush 102 to expand, causing the bristles 122 to switch to an expanded state. Applying negative relative pressure to the working fluid (such as water, saline, air, etc.) reduces the pressure inside the brush 102, causing the expandable portion to relax. In some embodiments, if the number of fluid channels 112 is... Figure 2A and Figure 2BUnlike the previous method, the working fluid can be delivered to the distal side through the fluid channel 112, and then enter the common chamber or fluid distribution ring inside the distal side of the fixed structure 116 (where each fluid channel 112 can be fluidly connected), and then enter the balloon or other operating sections, so that the fluid enters each part of the expandable brush at basically the same pressure.

[0041] In addition, brush 102 can rotate around the central longitudinal axis 138 ( Figure 2A , Figure 3 The brush 102 rotates to collect tissue samples. The user can control the rotation of the brush 102 using one or more tools / devices outside the patient's body (such as the handle at the distal end of the medical device 100). The user can rotate the brush 102 about its central longitudinal axis 138, increasing the contact between the bristles and the patient's tissue, thereby increasing the sample collection volume of the bristles 122. Additionally, by using pushing and pulling forces, the brush 102 can be advanced distally or retracted proximally (e.g., along a guidewire), moving the brush through the patient to the treatment site. Furthermore, the brush can also expand and contract as described above. Therefore, the brush 102 can perform tissue / sample collection through at least six degrees of freedom of movement.

[0042] See Figures 5A to 5C Another embodiment of a medical device for collecting tissue samples is shown. Figure 5A A cytological brush 140 (hereinafter referred to as "brush") is shown, comprising a fixed structure 142 and a flexible structure 144, the outer surface 148 of which includes bristles 122. For example... Figure 5C As shown, the flexible structure 144 is a spherical structure or a flexible sleeve, positioned in... Figure 5B The outer side of the fixing structure 142 is shown. The fixing structure 142 includes a longitudinal sidewall 156, a distal wall 152, and a proximal wall 154. Figure 5C One of the longitudinal sidewalls 156 is shown as a protrusion. The longitudinal sidewall 156, distal wall 152, and proximal wall 154 can form a chamber 158. The chambers 158 are radially spaced, and each wall, along with the flexible structure 144, can help form an airtight seal around each chamber 158. As described above, fluid passage 112 ( Figure 5B One or more fluids are delivered or extracted into the chamber 158, causing the flexible structure 144 and bristles 122 to switch from a relaxed state to an expanded state.

[0043] After the flexible structure 144 is substantially in place and surrounds the fixed structure 142, the expansion and contraction of the flexible structure can be achieved by supplying or extracting fluid into the chamber 158, thereby causing the bristles 122 on it to unfold or retract. When the bristles 122 switch from an unfolded state to a relaxed state, two or more bristles 122 will at least partially overlap, which helps to capture and / or retain tissue. The captured and / or retained tissue can be removed from the patient's body along with the brush for sample analysis, as detailed above. In some embodiments, the flexible structure 144 that can be adapted to be installed on the outside of the fixed structure 142 can be of various types (such as an adapted sleeve), and different types of flexible structures can give the brush 140 different working characteristics (such as the number of bristles, the hardness, etc.).

[0044] like Figure 5C As shown, the bristles 122 can be arranged in parallel rows (such as two rows of parallel bristles) and have basically the same length, but this disclosure is not limited to this. The bristles 122 can be arranged in any way on the outer surface 148 of the flexible structure.

[0045] Figure 6A and Figure 6B An embodiment of a cytology brush 164 (hereinafter referred to as "brush") is shown, wherein its flexible component 168 and fixed component 170 are... Figures 5A to 5C The flexible structure 144 and the fixed structure 142 are similar in structure. That is, the flexible component 168 is a flexible sleeve, positioned on the fixed component 170, covering one or more chambers (not shown) on the fixed component 170, so that a part of the flexible component 168 can be folded into the chamber.

[0046] The brush 164 also includes a plunger 162 and a spring 160 (which may be made of, for example, flat wire). Figure 6A As shown, plunger 162 is in the first position, and spring 160 is in the relaxed position. Figure 6B As shown, plunger 162 is pushed distally to a second position and inserted into chamber 166 of fixation member 170. Insertion of plunger 162 causes spring 160 to bend or flex inward (i.e., the middle portion of filament 160 bends radially inward toward longitudinal axis 161). Since both distal end 160a and proximal end 160b of spring 160 are fixed to fixation member 170 on outer surface 172 of flexible member 168, spring 160 bends inward as plunger 162 compresses it longitudinally. As spring 160 bends inward, it exerts force inward toward flexible member 168. As flexible member 168 moves inward, at least a portion of bristles 122 on its outer surface 172 moves to a retracted position and at least partially overlaps, facilitating the capture or retention of one or more tissue samples during removal of brush 164 from the patient.

[0047] In some embodiments, spring 160 may be coupled to flexible member 168. When plunger 162 moves proximally, making room for spring 160 to move to a first position, spring 160 may pull flexible member 168 back to an expanded state, causing bristles 122 to extend (for sample collection). In other embodiments, flexible member 168 may be biased toward an expanded state, and may or may not be coupled to spring 160; therefore, as long as spring 160 does not move flexible member 168 toward a retracted state, flexible member 168 will default to an expanded state.

[0048] Figure 7A and Figure 7B Another embodiment of the medical device 180 is shown, which includes a cytological brush 182 (hereinafter referred to as the "brush"), the brush 182 including an expandable member 184 and a retaining member 186. A filament 199 is connected to the retaining member 186. The filament 199 may be attached to a longitudinal sidewall 195 of the retaining member 186. The outer surface of the expandable member 184 includes bristles 122. The expandable element 188 expands as it is pushed outward or otherwise pushed outward by a plunger 190 moving distally. When the plunger 190 extends distally, the plunger 190 may be configured to fit between the expandable member 184 and the retaining member 186. When the plunger 190 is between the expandable member 184 and the retaining member 186, the plunger 190 at least partially forces the expandable member 184 radially outward, for example, causing the expandable member 184 and its bristles from a retracted position. Figure 7A Switch to expanded form ( Figure 7B It should be noted that the fixed component 186 may be movable (e.g., along the longitudinal direction), but its size and shape will not expand or otherwise change during the operation of the medical device 180.

[0049] In some embodiments, the plunger 190 may be divided into a distal section 192 and a proximal section 194. The distal section 192 may be tapered or partially tapered (e.g., partially tapered or truncated tapered). The cross-sectional shape of the proximal section 194 remains consistent along its length. The distal section 192 may have notches 193 that adapt to the longitudinal sidewalls 195 of the retaining member 186 when the plunger 190 is advanced distally and / or the retaining member 186 is retracted proximally, with each notch 193 separating a protrusion 197 in the distal section 192.

[0050] In an embodiment, one or more of the plunger 190 and brush 182 may be movable relative to the other of the plunger 190 and brush 182. This relative movement may cause the distal segment 192 of the plunger to be located radially inward or rearward relative to the outer surface of the expandable member 184. For example, in one aspect, the plunger 190 may be advanced distally relative to the brush 182, such that at least a portion of the distal segment 192 is located radially inward or rearward relative to at least a portion of the expandable member 184. In another aspect, the brush 182 may be retracted proximally relative to the plunger 190. In this aspect, one or more filaments 199 may be retracted proximally, causing the brush 182 to retract relative to the plunger 190. Based on this longitudinal relative movement, the expandable member 184 may expand outward, causing the bristles 122 to expand outward, for example, to collect a sample. In some embodiments, the distal segment 192 may extend toward the front (i.e., distal) of the distal segment 196 of the retaining member 186 until the proximal segment 194 is located radially inside all or part of the expandable member 188, such that the bristles 122 near the distal end 196 of the brush 182 extend to the same extent as the bristles at the other end.

[0051] Figure 8 An exemplary method of using a medical device such as the medical device 100 described above is shown. Although combined with... Figures 1 to 4 The exemplary embodiments shown are for Figure 8 The method described herein is explained, but it should be understood that the working principles described herein also apply to other embodiments shown and described herein, as well as other embodiments conforming to the features of the appended claims. In step 802, a sheath or insertion device (not shown) may be inserted into the patient through an incision or natural cavity and may be navigated by a user (e.g., a physician) to a treatment site (e.g., a narrowed area). For example, an endoscope or other medical device may be inserted into the patient and navigated through a lumen within the patient's body using imaging or other navigation tools until a target area is reached distally, which may be a treatment site (e.g., a treatment site for obtaining tissue samples).

[0052] In step 804, a guidewire may be inserted into the lumen of the sheath or insertion device and advanced to the treatment site within the patient. For example, the guidewire may be pushed to the treatment site within the lumen of the sheath or insertion device. The guidewire may be guided to the treatment site by applying a thrust to its proximal portion. In some aspects, the sheath or insertion device may remain in the patient's body near the treatment site, or along a portion of the path leading to the treatment site. In other aspects, the sheath or insertion device may be withdrawn from the patient's body once the guidewire is in place and near the treatment site.

[0053] In step 806, the brush 102 can be slidably placed or positioned on the guidewire from outside the patient (e.g., positioning the proximal end of the guidewire within the guidewire lumen 110), and the brush 102 can be delivered along the length of the guidewire to the treatment site. Because the brush 102 is configured such that the guidewire is received within the guidewire lumen 110, the brush 102 can be delivered along the guidewire until the brush 102 reaches the treatment site.

[0054] Once brush 102 reaches the treatment site, it can be converted from an unexpanded state to an expanded state. For example, in some embodiments, this operation can expand the balloon, causing the bristles to push against the tissue, allowing the bristles to scrape the tissue in step 808. The balloon may be filled with a working fluid, such as air. In some embodiments, the user may use a syringe or other pump to pressurize the working fluid into the balloon through the fluid lumen 112. In other embodiments, the balloon may be in an expanded state by default, and the user may apply negative pressure (relative negative pressure) to keep brush 102 in a contracted state during delivery; once brush 102 reaches the treatment site, the negative pressure is released, causing the bristles 122 of brush 102 to expand and contact the tissue at the treatment site. That is, the expanded bristles 122 push against the tissue, allowing the bristles to scrape the tissue.

[0055] In step 810, when the brush 102 is in an expanded state at the treatment site, the user can push, pull, and / or rotate the brush 102 (i.e., rotate it circumferentially about the guidewire) to collect a tissue sample. In embodiments, the user can manipulate the distal end of the brush 102 to move it. For example, the brush 102 can be pushed, pulled, and / or rotated via a wire or other device connected to the shaft 104. In some embodiments, the shaft 104 can be extended from the treatment site to the entire path of the user of the medical device 100.

[0056] In step 812, the user can switch brush 102 from an expanded state back to an unexpanded state. For example, in embodiments with a balloon structure, the user can retract the balloon to enter a relaxed or contracted state. In some embodiments, the contracted state requires applying negative pressure to the expandable portion. For example, embodiments where the balloon is biased to the expanded state. Once the balloon is in the contracted state, the user can withdraw the balloon from the patient in step 814 to retrieve a tissue sample. In other embodiments, the user can remove the plunger or other components to contract the expandable segment. In one embodiment, brush 102 can be removed from the patient in a proximal direction relative to the guidewire, while the guidewire can remain in the patient until sufficient tissue sample is confirmed to have been collected. In other embodiments, the guidewire and brush 102 can be withdrawn simultaneously or together.

[0057] The embodiments disclosed herein are applicable to a variety of different medical or non-medical procedures. Furthermore, during implementation, certain features of the above embodiments may be selectively combined or omitted without departing from the scope of this disclosure.

[0058] While the principles of this disclosure are illustrated herein with reference to exemplary aspects for specific applications, it should be understood that this disclosure is not limited to these exemplary aspects. Those skilled in the art and familiar with the teachings provided herein will recognize that other variations, applications, implementations, and equivalent substitutions fall within the scope of the implementations described herein. Therefore, this disclosure should not be construed as limited to the foregoing description.

Claims

1. A cytological brush, wherein, include: A shaft, the shaft including a fluid cavity configured for the passage of fluid; The brush body includes: Fixed components; and A movable component having a radially outward surface and a plurality of bristles, wherein the bristles project outward from the radially outward surface; wherein The movable component is configured to receive fluid through the fluid cavity, thereby expanding from an unexpanded state to an expanded state; in the unexpanded state of the movable component, the bristles are in a retracted state; when the movable component is in an expanded state, the bristles are in an extended state.

2. The cytological brush according to claim 1, wherein, The movable component is a balloon, which is divided into multiple balloon segments, each of which includes one or more bristles on its outer surface.

3. The cytological brush according to claim 1 or 2, wherein, The movable component includes three balloon segments: a distal balloon segment, a middle balloon segment, and a proximal balloon segment; the middle balloon segment has the lowest bristle stiffness.

4. The cytological brush according to any one of claims 1 to 3, wherein, The bristles of the intermediate balloon segment extend the furthest distance from the central axis of the cytological brush.

5. The cytological brush according to claim 1 or 2, wherein, The balloon is divided into three segments: a proximal balloon segment, a middle balloon segment, and a distal balloon segment; each balloon segment includes a distal lateral wall and a proximal lateral wall.

6. The cytological brush according to any one of claims 1 to 5, wherein, The outer wall hardness of one or more of the balloon segments is different from the outer wall hardness of the other balloon segments.

7. The cytological brush according to any one of claims 1 to 6, wherein, One or more of the balloon segments with the lowest hardness level expand to be furthest from the central axis of the shaft.

8. The cytological brush according to any one of claims 1 to 7, wherein, Each of the balloon segments has a distal sidewall and a proximal sidewall; and, when the balloon segment is in an uninflated state, a portion of the bristles extend from the distal sidewall toward the proximal sidewall, and another portion of the bristles extend from the proximal sidewall toward the distal sidewall.

9. The cytological brush according to any one of claims 1 to 8, wherein, The fluid is air, and the air is delivered by a syringe operatively connected to the fluid cavity.

10. The cytology brush according to any one of claims 1 to 9, comprising four fluid channels evenly spaced circumferentially along the shaft to deliver fluid to a portion of the brush, respectively.

11. The cytological brush according to any one of claims 1 to 10, wherein, When the bristles are in the unfolded state, the central axis of each bristle is perpendicular to the central axis of the shaft.

12. The cytological brush according to any one of claims 1 to 2, wherein, The balloon is biased toward a contracted shape.

13. The cytological brush according to claim 2, wherein, The fixing component also includes: distal wall; A proximal wall, the distal wall being longitudinally spaced from the proximal wall and connected by a plurality of longitudinal sidewalls extending between the distal wall and the proximal wall, wherein The balloon forms an airtight seal between each of the distal sidewall, the proximal sidewall, and the longitudinal sidewall to constitute one or more chambers; the chambers receive fluid to enable the balloon to expand and contract between an expanded and unexpanded state, thereby causing the bristles to switch between an extended and retracted state.

14. The cytological brush according to claim 13, wherein, The bristles are arranged in four pairs along the longitudinal direction of the brush and overlap each other in their unfurled state.

15. The cytological brush according to claim 13, wherein, The balloon switches between its inflated and uninflated states using fluid pressure.

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