Medical devices

Abstract

According to one aspect, the medical device includes an elongated member with sidewalls. The sidewalls define a lumen. The lumen has a non-circular cross-sectional shape.

Description

[0001] This application is a divisional application of the invention application filed on April 6, 2018, with application number 201880014556.2 and entitled "Entry Device and Method of Using the Entry Device".

[0002] Cross-reference to related applications

[0003] This application is a continuation-into-priority of U.S. non-provisional patent application No. 15 / 946,389, filed April 5, 2018, entitled “ACCESS DEVICE METHODS OF USING THESAME,” which claims priority to U.S. provisional patent application No. 62 / 482,337, filed April 6, 2017, entitled “Modeling of Scope Irrigation and Related Systems and Methods,” and U.S. provisional patent application No. 62 / 552,819, filed August 31, 2017, entitled “Access Device and Methods of Using the Same,” the disclosure of each of which is incorporated herein by reference in its entirety.

[0004] This application also claims priority to U.S. Provisional Patent Application No. 62 / 482,337, filed April 6, 2017, entitled “Modeling of Scope Irrigation and Related Systems and Methods,” the disclosure of which is incorporated herein by reference in its entirety.

[0005] This application also claims priority to U.S. Provisional Patent Application No. 62 / 552,819, filed August 31, 2017, entitled “Access Device and Methods of Using the Same,” the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0006] This disclosure generally relates to medical devices, and more specifically to medical devices incorporating improved hydrodynamics, such as access devices or sheaths. This disclosure also generally relates to modeling and related systems and methods. More specifically, this disclosure relates to modeling of endoscope irrigation and related systems and methods. Background Technology

[0007] Various medical procedures are performed using access devices or access sleeves. For example, access devices or access sleeves can be used in procedures such as kidney stone treatment (nephrolithiasis).

[0008] In some procedures using access devices or access sheaths, physicians may need, or benefit from, visualizing or observing the procedure. Improved visibility can aid the physician in performing the procedure or make it easier. In some procedures, visibility can be improved by increasing the amount (volume) and pressure (flow rate) of fluid. However, in some cases, high intrarenal pressure can lead to adverse side effects. For example, high intrarenal pressure may increase the risk of post-treatment complications such as pyelonephritis and subsequent sepsis.

[0009] Accordingly, it may be desirable to provide a device that allows for visibility during medical procedures, such as an access device or access sheath. It may also be desirable to provide a device that improves visibility and / or optimizes fluid flow and limits or reduces internal pressures (such as intrarenal pressure), such as an access device or access sheath. Summary of the Invention

[0010] According to one aspect, the medical device includes an elongated member having sidewalls. The sidewalls define a lumen. The lumen has a non-circular cross-sectional shape. In some embodiments, the medical device may be an endoscope, such as one used during a ureteroscopy.

[0011] In some embodiments, the lumen has a first diameter with a first dimension and a second diameter with a second dimension, the first dimension being different from the second dimension, and the first diameter being disposed substantially perpendicular to the second diameter.

[0012] In some embodiments, the lumen has a first diameter with a first dimension and a second diameter with a second dimension, the first dimension being different from the second dimension, the first diameter being disposed substantially perpendicular to the second diameter and intersecting the second diameter.

[0013] In some embodiments, the sidewall includes an inner surface and an outer surface, the inner surface defining a lumen, and the outer surface being disposed opposite to the inner surface.

[0014] In some embodiments, the sidewall includes an inner surface and an outer surface, the inner surface defining a lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall.

[0015] In some embodiments, the sidewall includes an inner surface and an outer surface, the inner surface defining a lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall, the positioning member extending along the inner surface of the sidewall parallel to the longitudinal axis of the elongated member.

[0016] In some embodiments, the sidewall includes an inner surface and an outer surface, the inner surface defining a lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall extending along the inner surface of the sidewall from a first end portion of the sidewall to a second end portion of the sidewall.

[0017] In some embodiments, the sidewall includes an inner surface and an outer surface, the inner surface defining a lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall, the positioning member being configured to help retain the medical device within the lumen.

[0018] In some embodiments, the sidewall includes an inner surface and an outer surface, the inner surface defining a lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall, the positioning member being configured to help hold the medical device along a first side portion of the lumen.

[0019] In some embodiments, the sidewall includes a first positioning member and a second positioning member, the first positioning member being disposed within a cavity defined by the sidewall, the second positioning member being disposed within the cavity, and the second positioning member being spaced apart from and disposed away from the first positioning member.

[0020] In some embodiments, the sidewall includes a first positioning member and a second positioning member, the first positioning member being disposed within a cavity defined by the sidewall, the second positioning member being disposed within the cavity, and the second positioning member being spaced apart from and adjacent to the first positioning member.

[0021] In some embodiments, the device includes a side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the sidewall.

[0022] In some embodiments, the device includes: a side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the sidewall, the side port including a valve disposed within the lumen defined by the side port, the valve being configured to regulate the flow of material within the lumen defined by the side port.

[0023] In some embodiments, the device includes: a side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the sidewall; and a collection member coupled to the side port, the collection member being configured to collect material passing through the lumen defined by the side port.

[0024] In some embodiments, the device includes a handle member coupled to an elongated member.

[0025] According to another aspect, the medical device includes: an elongated member having sidewalls defining a lumen having a non-circular cross-sectional shape, the sidewalls including an inner surface and an outer surface, the inner surface defining the lumen and the outer surface disposed opposite to the inner surface; a positioning member disposed on the inner surface of the sidewalls, the positioning member being configured to assist in holding the medical device within the lumen; a side port defining the lumen, the lumen of the side port being in fluid communication with the lumen defined by the sidewalls, the side port including a valve disposed within the lumen defined by the side port, the valve being configured to regulate the flow of material within the lumen defined by the side port; and a collection member coupled to the side port, the collection member being configured to collect material passing through the lumen defined by the side port.

[0026] In some embodiments, the device includes a handle member coupled to an elongated member.

[0027] According to another aspect, a method of using a medical device includes: inserting the medical device into a patient's body, the medical device including an elongated member having a lumen having a non-circular cross-section; and inserting a medical instrument into the lumen defined by the medical device.

[0028] In some embodiments, inserting a medical device includes inserting the medical device into or through a lumen defined by the medical device, such that the medical device is positioned along one side of the lumen.

[0029] In some embodiments, the medical device includes a positioning member disposed within a lumen defined by the medical device, and inserting the medical device includes inserting the medical device into the lumen defined by the medical device such that at least a portion of the medical device is disposed between the inner surface of the sidewall and the positioning member. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a medical device according to one embodiment.

[0031] Figure 2 This is a top view of a medical device according to one embodiment.

[0032] Figure 3-5 yes Figure 2A cross-sectional view of a medical device.

[0033] Figure 6 This is a cross-sectional view of a medical device according to one embodiment.

[0034] Figure 7 This is a top view of a medical device according to one embodiment.

[0035] Figure 8 This is a top view of a medical device according to one embodiment.

[0036] Figure 9 This is a flowchart of a method according to one embodiment.

[0037] Figure 10 The flow rate through the mirror is shown.

[0038] Figure 11 The flow rate through the curved mirror is shown.

[0039] Figure 12 The flow rates for different cross-sectional shapes of the mirror body and tool are shown.

[0040] Figure 13 A graphical user interface is shown.

[0041] Figure 14 A graph depicting the change in volumetric flow rate as the size of the working tool increases is shown.

[0042] Figure 15 The geometry we aim to solve for (6) is shown.

[0043] Figure 16 This is a schematic diagram showing the transformation of a smaller circle within a larger circle, both centered on the x-axis in Cartesian coordinates, which is then converted to bipolar coordinates.

[0044] Figure 17 This is a schematic diagram of the discretization of the domain.

[0045] Figure 18 The velocity distribution is shown with r1=0.03, r2=0.06, and φ varying from 0.01 to 0.99. The domain is shifted so that the outer circle is centered at (0, 0).

[0046] Figure 19A and 19B The volumetric flow rate results from the offset model are shown.

[0047] Figure 20 This is a diagram illustrating the geometry we want to solve for in Cartesian coordinates. The eccentricities of the inner and outer ellipses are the same, therefore... .

[0048] Figure 21 This is a diagram of the transformed geometry. Here... (The distance between the x-coordinates of the centers of the ellipse), and The angle by which the inner ellipse (after its transformation into a circle) must be rotated so that its center lies on the ~x-axis is given.

[0049] Figure 22 This is a schematic diagram of a domain.

[0050] Figure 23 yes Figure 22 A schematic diagram of the discretization of the domain.

[0051] Figure 24-26 The flow velocity distribution is shown.

[0052] Figure 27 and 28 The volumetric flow rate as a function of eccentricity e is shown for two different values ​​of φ.

[0053] Figure 29 For φ=0.99, it is used as θ e The volumetric flow rate is a function of .

[0054] Figure 30A and 30B It shows that for θ e =0 is the volumetric flow rate as a function of e and φ.

[0055] Figure 31 The diagram shows how the cross-sectional area of ​​the tool increases for φ=0.99 and θ. e =0 Predicted maximum eccentricity value.

[0056] Figure 32 The velocity distribution is shown with r1=0.03, r2=0.06 and φ changing from 0.01 to 0.99.

[0057] Figure 33 It shows e=0.8, θ e An elliptic velocity distribution with φ changing from 0.01 to 0.99 and φ = 0. Detailed Implementation

[0058] This document discloses detailed embodiments. However, it should be understood that the disclosed embodiments are merely examples and can be embodied in various forms. Therefore, the details of the specific structures and functions disclosed herein should not be construed as limiting, but merely as the basis for the claims and as a representative basis for teaching those skilled in the art to use the embodiments differently with substantially any suitable detailed structure. Furthermore, the terminology and phrases used herein are not restrictive, but rather provide an understandable description of the invention.

[0059] As used herein, the terms “a” or “an” are defined as one or more. The term “another” as used herein is defined as at least a second or more. The terms “comprising” and / or “having” as used herein are defined as including (i.e., open transitions).

[0060] The term "patient" may hereby be used for a person who benefits from the medical device or method disclosed in this application. For example, a patient can be a person whose body is operated on by the medical device or method disclosed in this invention. For example, in some aspects, a patient can be a human female, a human male, or any other mammal.

[0061] The terms "proximal" and "distal" in the description of the various devices, apparatuses, and components discussed in the following text of this application refer to a reference point. As used in this specification, the reference point is the operator's viewpoint. The operator can be a surgeon, physician, nurse, doctor, technician, etc., who can perform the surgery and operate the medical device as described in this invention. The term "proximal" refers to the area or portion that is closer to or most intimate with the operator during surgical procedures. The term "distal" refers to the area or portion that is further away from or most intimate with the operator.

[0062] Figure 1 This is a schematic diagram of a medical device 100 according to an embodiment of the present invention. The medical device 100 can be used in surgical procedures. For example, in some embodiments, the medical device 100 can be placed inside a patient's body to create an inlet or port for further medical procedures. More specifically, in some embodiments, the medical device 100 can be placed inside a patient's body such that a distal end portion of the medical device 100 is disposed within the patient's body, and a proximal end portion of the medical device 100 extends from the patient's body. In some embodiments, additional or auxiliary medical devices or instruments can be inserted into the patient's body via the medical device 100 to perform additional medical procedures.

[0063] In the illustrated embodiment, the medical device 100 includes an elongated member 110. The elongated member 110 includes a first or proximal end portion 112 and a second or distal end portion 114. The elongated member defines a lumen extending from the first or proximal end portion 112 to the second or distal end portion 114. In some embodiments, the elongated member 110 includes a sidewall 120. In some such embodiments, the sidewall 120 defines the lumen.

[0064] In some embodiments, the elongated member 110 is linear or generally straight or linear. In other embodiments, the elongated member 110 is curved or flexible and may have bends or curved portions. In some embodiments, the elongated member 110 or the sidewall 120 may have a non-circular cross-sectional shape. For example, the elongated member 110 or the sidewall 120 may have an oval or elliptical cross-sectional shape. In some of these embodiments, the flow of fluid within the lumen can be increased or optimized.

[0065] In other embodiments, the elongated member 110 or sidewall 120 may have a circular or circular cross-sectional shape. In still some embodiments, the elongated member 110 or sidewall 120 may have different cross-sectional shapes, such as square, rectangular, triangular, or any other shape.

[0066] The medical device 100 also includes a positioning member 140. The positioning member 140 is configured to help hold an auxiliary medical device or another medical instrument within a lumen. For example, in some embodiments, the positioning member 140 is configured to help hold the auxiliary medical device or medical instrument in place within the lumen. Specifically, the positioning member 140 may be configured to help hold the auxiliary medical device or medical instrument along one side or along a portion of the lumen of the device 100. In some such embodiments, fluid may flow along or within a portion of the lumen not occupied by the auxiliary medical device or medical instrument.

[0067] In some embodiments, the positioning member 140 is disposed within the lumen. For example, in some embodiments, the positioning member 140 is coupled to the inner surface of the sidewall 120. In some embodiments, the positioning member 140 is coupled to the elongated member 110 or the sidewall 120 via an adhesive or other coupling mechanism. In other embodiments, the positioning member 140 is integrally formed with the elongated member 110 or the sidewall 120.

[0068] As will be described in more detail below, in some embodiments, the positioning member 140 extends along the longitudinal axis of the elongated member 110 or sidewall 120. In some embodiments, the positioning member 140 extends from a first or proximal end portion 112 to a second or distal end portion 114. In some embodiments, the medical device 100 includes more than one positioning member. For example, in some embodiments, the medical device 100 may include a first positioning member disposed at a proximal end portion of the elongated member and a second positioning member disposed at a middle or distal end portion of the elongated member. In another embodiment, the medical device 100 includes a first positioning member disposed at a proximal end portion of the elongated member and a second positioning member disposed adjacent to the first positioning member at a proximal end portion of the elongated member. In still some embodiments, the medical device 100 includes more than two positioning members.

[0069] In the illustrated embodiment, the medical device 100 includes a side port 160. The side port 160 defines a lumen. The side port 160 is coupled to an elongated member 110 or a sidewall 120 such that the lumen of the side port 160 is in fluid communication with the lumen defined by the elongated member 110 or the sidewall 120. The side port 160 is configured to deliver fluid to and receive fluid from the lumen defined by the elongated member 110 or the sidewall 120.

[0070] In the illustrated embodiment, side port 160 includes valve 162. Valve 162 is disposed within a cavity defined by side port 160. Valve 162 is configured to facilitate the regulation or control of fluid flow through the cavity defined by side port 160. In some embodiments, valve 162 is a stopcock or shut-off valve. In other embodiments, valve 162 is a different type of valve.

[0071] In the illustrated embodiment, the medical device 100 includes a collection member 180. The collection member 180 is coupled to a side port 160. The collection member 180 is configured to collect material disposed within a fluid that flows through or within the lumen of the side port 160. For example, the collection member 180 may be a filter configured to collect kidney stones or kidney stone fragments delivered from a patient's body and passing through the lumen of the side port 160.

[0072] In the illustrated embodiment, the medical device 100 includes a handle member or handle portion 190. The handle member or handle portion 190 is coupled to an elongated member 110 or a sidewall 120. The handle member or handle portion 190 is configured to be gripped by a physician or other medical practitioner to place the medical device 100 inside a patient's body during use.

[0073] In use, the medical device 100 can be inserted into a patient's body. In some embodiments, the medical device 100 can be inserted into a patient's body such that a second or distal end portion 114 of the elongated member 110 is disposed within the patient's body, and a first or proximal end portion 112 of the elongated member 110 is disposed outside (or extending from) the patient's body. For example, in some embodiments, the medical device 100 can be placed within a patient's body such that the second or distal end portion 114 is disposed within the patient's kidney or ureter. In other embodiments, the medical device 100 is placed within a patient's body such that the second or distal end portion 114 is disposed at different locations within the patient's body.

[0074] Once the medical device 100 is placed inside the patient's body, other medical devices or instruments can be inserted into the patient's body through a lumen defined by the elongated member 110. For example, in some embodiments, other medical devices or instruments can be inserted into a lumen defined by the elongated member 110 or sidewall 120 such that the other medical devices or instruments are positioned along one side of the lumen. Accordingly, once such a device is placed inside the patient's body, these other or auxiliary medical devices can be used to perform additional medical procedures. In some embodiments, the other medical device or instrument is a scope. In other embodiments, the medical device is another type of medical device.

[0075] Figure 2 This is a top view of a medical device 200 according to one embodiment. Figure 3-5 This is a cross-sectional view of medical device 200.

[0076] The medical device 200 can be used in surgical procedures. For example, in some embodiments, the medical device 200 can be placed inside a patient's body to create an inlet or port for further medical procedures. More specifically, in some embodiments, the medical device 200 can be placed inside a patient's body such that a distal end portion of the medical device 200 is disposed within the patient's body, and a proximal end portion of the medical device 200 extends from the patient's body. In some embodiments, additional or auxiliary medical devices or instruments can be inserted into the patient's body via the medical device 200 to perform additional medical procedures.

[0077] In the illustrated embodiment, the medical device 200 includes an elongated member 210. The elongated member 210 includes a first or proximal end portion 212 and a second or distal end portion 214. The elongated member defines a lumen 216 extending from the first or proximal end portion 212 to the second or distal end portion 214.

[0078] In the illustrated embodiment, the elongated member 210 includes a sidewall 220. The sidewall 220 includes an inner surface 222 and an outer surface 224. The inner surface 222 is disposed opposite to the outer surface 224. The inner surface 222 defines a lumen 216.

[0079] In some embodiments, the elongated member 210 is linear or generally straight or linear. In other embodiments, the elongated member 210 is curved or flexible and may have a curved portion or bend.

[0080] In the illustrated embodiment, the elongated member 210 or sidewall 220 may have a non-circular cross-sectional shape. The elongated member 210 or sidewall 220 may have an oval or elliptical cross-sectional shape. Specifically, as... Figure 3As best illustrated, the elongated member 210 or sidewall 220 has inner diameters of different dimensions. Diameter D1 is a first dimension, and diameter D2 is a second dimension different from the first dimension. In the illustrated embodiment, diameter D1 is disposed perpendicular to or substantially perpendicular to diameter D2. In other embodiments, the diameters are not disposed perpendicular to each other. In the illustrated embodiment, fluid flow within the lumen 216 can be increased or optimized. In some embodiments, the dimensional difference between D1 and D2 is about 0.33 mm. For example, in some embodiments, the dimensional difference between D1 and D2 is between 0.25 mm and 0.08 mm. In other embodiments, the dimensional difference between D1 and D2 is less than 0.25 mm. In still some embodiments, the dimensional difference between D1 and D2 is greater than 0.5 mm. In some embodiments, the vertical diameter is about 0.34 cm, and the horizontal diameter is about 0.39 cm. In other embodiments, the vertical diameter is between 0.30 cm and 0.40 cm, and the horizontal diameter is between 0.35 cm and 0.45 cm.

[0081] In other embodiments, the elongated member or sidewall may have a circular or circular cross-sectional shape. In still other embodiments, the elongated member or sidewall may have different cross-sectional shapes, such as square, rectangular, triangular, or any other shape.

[0082] The medical device 200 also includes a positioning member 240. The positioning member 240 is configured to assist in holding an auxiliary medical device or another medical instrument within a lumen. For example, in some embodiments, the positioning member 240 is configured to assist in holding the auxiliary medical device or medical instrument in place within the lumen. In the illustrated embodiment, the medical device also includes a second positioning member 241. The second positioning member 241 is structurally and functionally similar to the positioning member 240. Accordingly, only the positioning member 240 will be discussed in detail.

[0083] like Figure 4 As best shown, the positioning member 240 is configured to help hold the auxiliary medical device or medical instrument MI along one side S1 or along a portion of the lumen 216. In some such embodiments, fluid may flow along or within a second side S2, which is the portion of the lumen 216 not occupied by the auxiliary medical device or medical instrument MI. Specifically, when the auxiliary medical device MI is disposed within the lumen 216, the auxiliary medical device MI and the medical device 200 are not arranged coaxially. In other words, the longitudinal axis LA2 of the auxiliary medical device MI is offset from the longitudinal axis LA1 of the elongated member 210 or the sidewall 220.

[0084] In the illustrated embodiment, the positioning member 240 is disposed within the lumen 216. For example, the positioning member 240 may be coupled to the inner surface 222 of the sidewall 220. In some embodiments, the positioning member 240 is coupled to the elongated member 210 or the sidewall 220 via an adhesive or other coupling mechanism. In other embodiments, the positioning member 240 is integrally formed with the elongated member 210 or the sidewall 220.

[0085] like Figure 5 As best shown in the illustrated embodiment, the positioning member 240 extends along the longitudinal axis LA1 of the elongated member 210 or sidewall 220. The positioning member 240 extends from a first or proximal end portion 212 to a second or distal end portion 214.

[0086] like Figure 6 As shown, in another embodiment, positioning members 1240A, 1240B, and 1240C are disposed at different locations along the elongated member or sidewall. In the illustrated embodiment, a pair of positioning members 1240A are disposed on or near the proximal end portion of the sidewall or elongated member. These positioning members 1240A are disposed adjacent to each other. Specifically, these positioning members 1240A are disposed at the same longitudinal location along the longitudinal axis of the sidewall or elongated member, but are circumferentially spaced apart from each other.

[0087] Positioning member 1240B is disposed at the middle portion of the side wall or the slender member. Positioning member 1240C is disposed at the distal end portion of the side wall or the slender member.

[0088] In the illustrated embodiment, the medical device 200 includes a side port 260. The side port 260 defines a lumen 264. The side port 260 is coupled to an elongated member 210 or a sidewall 220 such that the lumen 264 of the side port 260 is in fluid communication with a lumen 216 defined by the elongated member 210 or the sidewall 220. The side port 260 is configured to deliver fluid to and receive fluid from the lumen 216 defined by the elongated member 210 or the sidewall 220.

[0089] In some embodiments, a fluid source or fluid vacuum may be coupled to the side port 260 to facilitate the delivery of fluid into and from the lumen 216.

[0090] In the illustrated embodiment, side port 260 includes valve 262. Valve 262 is disposed within a cavity 264 defined by side port 260. Valve 262 is configured to facilitate the regulation or control of fluid flow through the cavity 264 defined by side port 260. In the illustrated embodiment, valve 262 is a stopcock or shut-off valve. In other embodiments, valve 262 is a different type of valve.

[0091] In the illustrated embodiment, the medical device 200 includes a collection member 280. The collection member 280 is coupled to a side port 260. The collection member 280 is configured to collect material disposed within a fluid flowing through or within a lumen 264 of the side port 260. For example, the collection member 280 may be a filter configured to collect kidney stones or kidney stone fragments delivered from a patient's body and passing through the lumen 264 of the side port 260.

[0092] In the illustrated embodiment, the medical device 200 includes a handle member or handle portion 290. The handle member or handle portion 290 is coupled to an elongated member 210 or a sidewall 220. The handle member or handle portion 290 is configured to be gripped by a physician or other medical practitioner to place the medical device 200 inside a patient's body during use.

[0093] In use, the medical device 200 can be inserted into a patient's body. In some embodiments, the medical device 200 can be inserted into a patient's body such that a second or distal end portion 214 of the elongated member 210 is disposed within the patient's body, and a first or proximal end portion 212 of the elongated member 210 is disposed outside (or extending from) the patient's body. For example, in some embodiments, the medical device 200 can be placed within a patient's body such that the second or distal end portion 214 is disposed within the patient's kidney or ureter. In other embodiments, the medical device 200 is placed within a patient's body such that the second or distal end portion 214 is disposed at different locations within the patient's body.

[0094] Once the medical device 200 is placed inside the patient's body, other medical devices or instruments can be inserted into the patient's body through a lumen defined by the elongated member 210. For example, in some embodiments, other medical devices or instruments can be inserted into a lumen defined by the elongated member 210 or sidewall 220 such that the other medical devices or instruments are positioned along one side of the lumen. Accordingly, once such a device is placed inside the patient's body, these other or auxiliary medical devices can be used to perform additional medical procedures. In some embodiments, the other medical device or instrument is a scope. In other embodiments, the medical device is another type of medical device.

[0095] Figure 7 This is a top view of a portion of a medical device 300 according to another embodiment. In this embodiment, a side port 360 is coupled to the elongated member 310 or the side wall 320 at or near the proximal end portion of the side wall 320 or the elongated member 310.

[0096] Figure 8This is a top view of a medical device 400 according to another embodiment. Similar to the embodiments described above, the medical device 400 includes a sidewall 420 or an elongated member 410 having a non-circular cross-section. The medical device 400 also includes one or more positioning members disposed within a lumen defined by the elongated member 410 or the sidewall 420.

[0097] In the illustrated embodiment, the medical device 400 further includes a hub 492. The hub 492 is configured to engage an auxiliary medical device or medical instrument inserted into a lumen defined by an elongated member 410 or sidewall 420. The hub 492 may be configured to engage the auxiliary medical device or medical instrument such that the auxiliary medical device or medical instrument is removably coupled to the hub 492. In some embodiments, the hub 492 may include a latch or latching system configured to engage the auxiliary medical device or medical instrument to removably couple the auxiliary medical device or medical instrument to the hub 492.

[0098] In the illustrated embodiments, the elongated member 410 or sidewall 420 may be configured to resist kinking. For example, in some embodiments, the elongated member 410 or sidewall 420 may include a sheath reinforced by a coil (such as a stainless steel coil). Furthermore, in some embodiments, the outer surface of the sidewall or elongated member 410 may include a coating, such as a hydrophilic coating. The coating may be configured to facilitate insertion or placement of the device within a patient's body.

[0099] In the illustrated embodiment, the medical device 400 includes a radiopaque marker 494. The radiopaque marker 494 can be observed by fluorescence examination to confirm the placement of the device 400 within the patient's body.

[0100] In the illustrated embodiment, the medical device 400 includes a tapered end portion 496. In some embodiments, the tapered end portion 496 may be stiffer or more rigid than other portions of the elongated member 410. For example, the tapered end portion 496 may be formed of a material with a different hardness than the material forming the rest of the elongated member 410. In some embodiments, the tapered end is configured to facilitate placement of the device 400 into a patient's body. Furthermore, the tapered end may reduce trauma to the patient during insertion of the device into the patient's body.

[0101] In some embodiments, the tampon 499 may be used to assist in the placement or insertion of a device into a patient's body. For example, in some embodiments, the tampon 499 is a tubular member that can be inserted into the lumen of the device 400 and used to provide support for the device during placement of the device 400. Once the device 400 is placed in the body, the tampon 499 can be removed from the device 400 and the patient's body. In some embodiments, the tampon 499 has a circular cross-section. In other embodiments, the tampon 499 has a cross-section of different shapes.

[0102] Figure 9 This is a flowchart of method 500 according to an embodiment of the present invention. At 510, a medical device is inserted into the patient's body. In some embodiments, the medical device is inserted into the patient's body such that a distal end portion of the device is disposed within the body and a proximal end portion of the device is disposed outside the patient's body. For example, in some embodiments, the device may be placed within the patient's body such that a distal end portion is disposed within the patient's kidney or ureter.

[0103] At point 520, an auxiliary medical device or medical instrument is inserted into the patient's body via a lumen defined by the medical device. In some embodiments, the auxiliary medical device or medical instrument is inserted into the lumen such that it is positioned at or along a portion of one side of the lumen. In some embodiments, the auxiliary medical device or medical instrument is a scope. In other embodiments, it is a device for another type of medical procedure.

[0104] In some embodiments, ureteroscopy can be performed to diagnose and treat urethral diseases and ureteral strictures. In some procedures, ureteroscopy is a surgical procedure used to remove kidney stones. In some ureteroscopic procedures, irrigation or continuous irrigation is used to clear the operator's view and open the ureter. Accordingly, optimizing irrigation for visualization can be beneficial. Some challenges include: irrigation loss when instruments are inserted into the patient, high renal pressure, stone retraction, and the difficulty of controlling and maintaining flow.

[0105] In some cases, mathematical modeling can be used to determine the impact of parameters (such as mirror size and shape, tool size and shape, and flushing settings) on flushing flow, to validate the mathematical model experimentally, and to use the model to optimize flushing. Modeling can be used to analyze the flow effects (such as the influence of position and cross-sectional shape) of straight or linear mirrors, deflected mirrors, and mirrors using working tools or auxiliary tools.

[0106] Medical devices such as ureteroscopes described herein can be inserted retrogradely through the urethra, enabling the diagnosis and treatment of urethral abnormalities. As described herein, exemplary medical devices or ureteroscopes may have handles coupled to an axis.

[0107] The handle can have any shape suitable for gripping and controlling the ureteroscope. The proximal end of the shaft is coupled to the distal end of the handle. The ureteroscope may include a steering mechanism for deflecting the distal end of the shaft along one or more planes. The shaft includes at least one working channel extending between its proximal and distal ends. In some examples, the shaft may include one or more electronic components, such as a camera or other imaging device, a light source, and / or other sensors. Additionally or alternatively, the shaft may include a lumen for light transmission and / or steering control components.

[0108] The handle may also include an umbilical hub or connector to facilitate electrical connections and functions, such as data transmission and / or power supply for a light source. Additionally, the handle may include at least one port (e.g., a T-shaped or Y-shaped Luer port connection). The port may be fluidly coupled to one or more sources of flushing and / or aspiration fluid. Accordingly, flushing fluid may be delivered (e.g., pumped) via the port through the working channel and exit from the distal end of the shaft to aid in visualization and / or opening of the ureter. The port may also receive an insertion portion (e.g., the shaft) of an assistive medical device to allow the assistive medical device into the working channel of the shaft. The distal end of the medical device may extend out of the shaft and retract into the distal end of the shaft. The distal end of the medical device may include, for example, biopsy forceps, graspers, baskets, snares, probes, scissors, retrieval devices, lasers, and / or any other suitable tools for, for example, removing kidney stones.

[0109] The foregoing and the following description cover various aspects of exemplary ureteroscopes and exemplary medical devices. As noted above, some of the figures, among others, illustrate mathematical modeling of ureteroscopic flushing. This mathematical modeling is also described in detail below. In some embodiments, the modeling provides data that can be used to precisely and accurately control ureteroscopic flushing. For example, the modeling may provide data about ureteroscope design that can help a user design, select, and / or operate the ureteroscope (such data includes, for example, the cross-sectional area of ​​the working channel, the cross-sectional shape of the working channel, the curvature of the shaft, the material properties of the shaft, the surface properties of the working channel, and / or any other aspects that may affect the flow of flushing fluid through the working channel) and / or data about medical device design that can help a user design, select, and / or operate the medical device for use with the ureteroscope (such data includes, for example, the cross-sectional area of ​​the insertion portion of the medical device, the cross-sectional shape of the insertion portion, the material properties of the insertion portion, the external surface properties of the insertion portion, the position / or orientation of the insertion portion in the working channel, and / or any other aspects that may affect the flow of flushing fluid through the working channel). Additionally or alternatively, modeling can provide data that helps the user determine how much flushing fluid flows through the working channel to ensure that the required level of flushing fluid flow (e.g., optimal flow rate, flow volume, or one within a desired range) is delivered to the target area. Based on the data, the user and / or control system can set / adjust operating parameters of the pump or other fluid source, modify aspects of the working channel, and / or modify aspects of the medical device to achieve the desired level of flushing fluid flow. Other types of devices can replace the ureteroscope, including, for example, hysteroscopes, endoscopes, bronchoscopes, cystoscopes, endoscopes, colonoscopes, and similar devices.

[0110] Figure 10 The flow rate or fluid flow rate through the mirror is shown. The higher the head, the greater the deviation. Figure 11 The flow rate, or fluid flow rate, through the curved mirror is shown. The flow rate decreases slightly with curvature. Figure 12 The flow rates for different cross-sectional shapes of the mirror body and tool are shown.

[0111] Modeling can be performed by any suitable computing system, including, for example, a desktop computer, laptop, smartphone, etc. The computing system can be operationally connected to the fluid supply to set / adjust operating parameters of the fluid supply based on the modeling. It is also conceivable that the computing system may include one or more input devices for automatically identifying the ureteroscope and / or medical device (e.g., via RFID, barcode scanning, etc.) or otherwise, and can perform modeling based on the received inputs and take other actions (e.g., set / adjust fluid flow, send alarms, or perform any other suitable task). Additionally or alternatively, such as... Figure 10The graphical user interface (GUI) shown can be used to receive data for modeling and / or to communicate data to the user.

[0112] 1. Modeling

[0113] Consider the flow during irrigation through a ureteroscope with a working tool located within the channel. The modeling of this setup assumes the tool is concentrically positioned within the working channel, which facilitates a simple annular Poiseuille flow model driven by the hydrostatic head generated by the height of the bag through which the irrigation fluid passes. This model takes the following form:

[0114] (1)

[0115] Here, Q is the volumetric flow rate, and r o It is the radius of the working channel, r i Let be the radius of the working tool, h and L be the height of the saline bag and the length of the microscope body, respectively, and p and μ be the density and viscosity of the rinsing fluid, respectively. When comparing the predictions obtained from this mathematical model with wet laboratory data, discrepancies may exist between the two curves, as exemplified in... Figure 11 As shown in the image. Figure 11 A graph depicting the change in volumetric flow rate as the size of the working tool increases is shown.

[0116] In some cases, the mathematical model of equation (1) underestimates the measured flow rate. This underestimation of the measured data may be due to the assumption that the working tool is concentrically located within the working channel. Here, we reconsider the initial assumptions by allowing the working tool to be non-centrally located within the channel to understand the effect of this offset.

[0117] 2. Governing equations

[0118] To derive the simple formula given by equation (1), we consider steady unidirectional flow in the ring. Here, we review its brief derivation.

[0119] 2.1. Navel-Stokes

[0120] The Navel-Stokes equations for incompressible fluids are:

[0121] (2)

[0122] (3)

[0123] where u = (u x , u y , u z ) describes the flow in the x, y, and z directions, and ρ and μ are the density and viscosity of the flushing fluid.

[0124] 2.2. Steady-state unidirectional flow

[0125] Some systems are steady-state systems. In these systems, the flow is independent of time; therefore, we can neglect the time derivative in equation (3). We also assume that the flow is unidirectional along the mirror in the axial direction, i.e., u z And therefore u x =u y =0. Therefore, the Navel-Stokes equations become:

[0126] (4)

[0127] (5)

[0128] And accompanied by Write (5) in the following form:

[0129] (6)

[0130] We see that the LHS is independent of x and y, and the RHS is independent of z (because the relevant partial derivatives are zero). Therefore, the pressure gradient dp / dz must be a constant. For simplicity, we will henceforth denote u := u z .

[0131] 2.3. Boundary Conditions

[0132] We begin by modeling the cross-sections of the tool and the work channel as a pair of non-concentric circles, both centered on the x-axis. We denote the radius of the tool as r. i (Inner), and the radius of the working channel is expressed as r. o (External), where we note r i <r o We set the center coordinates of the tools and channels to (w) respectively. i , 0) and (w o Without loss of generality, we will assume w = 0. i <w o Therefore, the center of the inner circle shifts to the left of the center of the outer circle. Thus, by applying no-slip conditions to both the outer surface of the tool and the inner surface of the working channel, we obtain the following boundary conditions:

[0133]

[0134]

[0135] We then review (x - w) 2 + y 2= r 2 It is the equation of a circle with radius r at a fixed center (w, 0).

[0136] 3. Transform to bipolar coordinates

[0137] Previously, when solving (6) to obtain the solution (1) of the toroidal flow, we used a polar coordinate system facilitated by the rotational symmetry of the geometry, which is caused by the concentricity of the inner and outer circles.

[0138] Figure 15 The geometry we aim to solve for (6) is shown. Here, the domain Ω represents the space between the inner circle and the outer circle (the tool channel and the working channel, respectively).

[0139] We now aim to solve (6) over the field Ω, as Figure 15 As shown in the diagram. Therefore, we adopt a bipolar coordinate system (η, ξ) associated with Cartesian coordinates:

[0140] (9)

[0141] (10)

[0142] Here, we will show that the line representing the constant η is an offset circle centered on the x-axis in Cartesian coordinates, while the line representing the constant ξ corresponds to an offset circle centered on the y-axis. We assume that the inner and outer circles in our domain are centered on the x-axis, and therefore will correspond to the values ​​of the constant η. The coordinates of ξ vary from 0 to 2π and behave similarly to angular coordinates in polar coordinates.

[0143] 3.1. Transition Domain

[0144] To describe a circular boundary in bipolar coordinates, for example Figure 15 For those mentioned, we first consider the general formula for a circle with radius r centered at (w,0), which in Cartesian coordinates is:

[0145] (x - w) 2 + y 2 = r 2 (11)

[0146] Or equivalently:

[0147] x 2 + y 2 + w 2 -r 2 = 2xw (12)

[0148] To manipulate the expressions related to Cartesian and bipolar coordinates to a form similar to this, we first solve for cosξ (9) to obtain:

[0149] (13)

[0150] Dividing (9) by (10) we get:

[0151]

[0152] And in order to solve for sinξ, we obtain:

[0153] (14)

[0154] Now, in the identity sin 2 ξ+cos 2 Using expressions (13) and (14) in ξ=1, we find that:

[0155] x 2 + y 2 + c 2 = 2xc coth η. (15)

[0156] Therefore, comparing (15) and (12), we immediately see that the coordinates of the center of the circle are given by the following equation:

[0157] w = c coth η. (16)

[0158] Connecting (15) and (12) again, we also obtain w 2 -r 2 =c 2 Therefore, using (16), we can rearrange to obtain:

[0159] (17)

[0160] Therefore, the line with constant η represents a circle in Cartesian coordinates, with radius c / sinh η and centered at (c coth η, 0). For the inner and outer circles in our domain, we introduce values ​​of constant η, i.e., n i and η i , making

[0161] r i = ,w i = c coth η i (18)

[0162] r o = w o = c coth η o (19)

[0163] Figure 16 This is a schematic diagram showing the transformation of a smaller circle within a larger circle, both centered on the x-axis in Cartesian coordinates, which is then converted to bipolar coordinates.

[0164] Here we note that, from (17), we see that a circle with a larger radius corresponds to a smaller value of η, therefore η o <η i From definitions (18) and (19), we can draw the following conclusions.

[0165] c = r i | sinh η i | = r o | sinh η o | (20)

[0166] Therefore, our domain Ω corresponds to η. o ≤η≤η i And 0 ≤ ξ ≤ 2π, and the transformation of the domain from Cartesian coordinates to bipolar coordinates is... Figure 16 This is depicted graphically. We now consider the distance between the two centers, which we represent as d = w. o -w i (exist Figure 15 (as marked in the text). Limit value η i, η o > 0, therefore sinhη i , sinhη o >0, we get using (16):

[0167] d = r o cosh η o -r i cosh η i . (twenty one)

[0168] Using (20) and (21), and the identity cosh 2 ηo - sinh 2 With ηo = 1, we obtain:

[0169] cosh η i = (twenty two)

[0170] Similarly, using the identity cosh 2 η i -sinh 2 η i =1, we get:

[0171] cosh ηo = (twenty three)

[0172] Define dimensionless parameters

[0173] (twenty four)

[0174] (25)

[0175] We can represent (22) and (23) as:

[0176] (26)

[0177] (27)

[0178] Based on the geometric properties of a circle, we can obtain η. i and η o The expression.

[0179] 4. Circular geometric shapes

[0180] We will now analyze the effect of offsetting the tool in the work channel using bipolar coordinates. Here, we treat the cross-sections of the work tool and the channel as circles; in the next section, we will extend this analysis to elliptical geometry.

[0181] 4.1. Transformation Equation

[0182] We will now represent the equations (6) for the steady unidirectional flow in bipolar coordinates. To do this, we first consider the position of any point in the (x, y) space, which can be characterized by (η, ξ) as follows:

[0183] (28)

[0184] To represent the Laplace operator of a scalar field in curvilinear coordinates (such as bipolar coordinates), we define a scaling factor. ,and Use formula

[0185] (29)

[0186] It is derived from (1). For the bipolar coordinate system, we calculate the scale factor as

[0187] (30)

[0188] Therefore, applying the operator transformation formula given in (29), the governing equation (6) becomes

[0189] (31)

[0190] Here we recall that dp / dz is a constant pressure gradient.

[0191] 4.2. Boundary Conditions

[0192] Now, the no-slip boundary conditions are given in bipolar coordinates:

[0193] u(η, ξ) = 0 on η = n i , η o (32)

[0194] We now need two additional boundary conditions with respect to ξ, and due to the line of symmetry along the x-axis, we can reduce the size of the domain to 0 ≤ ξ ≤ π, where the condition is:

[0195] (33)

[0196] This allows for the desired symmetrical velocity distribution.

[0197] 4.3. Solving the equation: Finite difference scheme

[0198] To solve numerically (31), we first discretize the rectangular (η, ξ) domain, as follows: Figure 17 As shown in the diagram. As an illustrative example, we consider η, (n...) n ) and in ξ(n ξ In this case, the number of points selected is 5. The corresponding spatial step size is h. η and h ξ Calculated as h η =(η i -η o ) / (n η -1) and h ξ = π / (n ξ - 1). Figure 17 This is a schematic diagram of the discretization of the domain.

[0199] Then, we approximate the partial derivatives in equation (31) using finite differences to construct a linear system. Using the central difference approximation, we can approximate (31) as:

[0200]

[0201] U i,j yes The numerical approximation. Discretization of the domain in... Figure 17 As shown in the image. All in... Multiplying by (34), we obtain the following equation:

[0202]

[0203] This can be represented as a linear system of the form

[0204] Au = b (36)

[0205] in We obtain the following by directly applying the no-slip boundary condition (32):

[0206] (37)

[0207] And we approximate it using the symmetric boundary condition (33):

[0208] (38)

[0209] (38) is obtained from the one-sided approximation of the first derivative. Therefore, only the solution remains. Figure 17 The interior points in, and therefore A is an N×N pentagonal matrix containing the coefficients given by the left side of (35) (where And vector b for i = 2, ..., n η -1, j = 2, ..., n ξ -1 contains the right-hand side value from (35).

[0210] 4.4. Solving the equation: Analytical solution

[0211] The analytical solution of (31) describes the fully developed flow in the eccentric ring as presented in [2]:

[0212] (39)

[0213] in

[0214]

[0215]

[0216]

[0217]

[0218] Therefore, by using an approximation of an infinite sum, we can compare it with our numerical solution to verify the results.

[0219] 4.5 Results: Velocity Distribution

[0220] After constructing the linear system described in the previous section, we solve for the velocity Au = b at discrete points. After converting the corresponding (η, ξ) values ​​back to Cartesian coordinates (x, y), we can plot the resulting velocity distribution. To display it as a continuous color map, we execute MATLAB's `griddata` function, which linearly interpolates the solution on a grid of x and y values ​​for solving the equation. Here, we consider the effect of changing the offset parameter φ on the velocity distribution formed in the domain. Figure 18 The velocity distribution is shown with r1=0.03, r2=0.06, and φ varying from 0.01 to 0.99. We have shifted the domain, so the outer circle is centered at (0, 0).

[0221] We from Figure 15 As can be seen, the maximum velocity obtained increases with increasing φ. Intuitively, this relates to the increased maximum distance between the two boundaries where the velocity is zero, thus providing a larger area for the flow to develop. The velocity distribution generated using the analytical solution (39) with 50 infinite sum terms shows good qualitative agreement with the numerical results.

[0222] 4.6. Results: Volumetric Flow Rate

[0223] The volumetric flow rate Q is calculated by integrating the velocity over the domain. Therefore, we have

[0224] (40)

[0225] We can use MATLAB's trapezoidal numerical integral (trapz) to numerically approximate this integral.

[0226] Figure 19A The effect of shifting the working tool from the center to the edge of the channel on the volumetric flow rate is shown. Here, r1 = 0.03 cm, r2 = 0.06 cm, and h = 79.5 cm.

[0227] Figure 19B Numerical and analytical solutions for the offset model are shown, illustrating the variation in volumetric flow rate as tool size increases. These are compared with experimental data and the concentric model.

[0228] like Figure 19B As shown, the increase in volumetric flow rate φ from 0.01 to 0.99 is related to... Figure 28 The increase in maximum speed shown is correlated with this. Therefore, for the parameters used, we achieved an approximately 130% increase in volumetric flow rate when the working tool shifts from the center to the edge of the working channel. The decrease in volumetric flow rate with working tool size is shown in the diagram. Figure 19AIn the diagram, the comparison between the numerical and analytical solutions of the migration model is shown as φ = 0.85. These are then compared with experimental data and the original concentricity prediction results, such as... Figure 11 As shown in the diagram. We see that this updated mathematical model, which considers the tool as an offset within the channel, gives better predictions for the experiments compared to the concentric model. An offset of φ=0.85 was chosen here because it shows a good fit to the experimental data. Figure 19B In the process, we also see good agreement between the analytical solution (39) and the numerical solution obtained by solving the finite difference scheme.

[0229] 5. Elliptical geometry

[0230] We now consider the effect of changing the cross-sectional shape of the working channel and tool to an ellipse instead of a circle. The eccentricity of an ellipse is related to its major and minor axes, thus describing how it is "flattened." Zero eccentricity represents a circle, and as this value increases, the shape tends towards an infinitely long and thin horizontal ellipse. We consider the tool and channel to be ellipses with the same eccentricity *e*, where the corresponding major and minor axes are *a*. i and b i For tools, and a o and b o Used for channels. Figure 20 The domain is represented in Cartesian coordinates. We note that since the geometry is no longer rotationally symmetric, it is no longer possible to generalize that both the tool and the channel are centered along the x-axis, and therefore we allow the center of the inner ellipse to be located anywhere within the outer channel. However, for simplicity, we maintain the orientation of the inner ellipse, i.e., the corresponding axes of the inner and outer geometries remain parallel.

[0231] Figure 20 This is a graph of the geometry we want to solve for in Cartesian coordinates. Here, the eccentricities of the inner and outer ellipses are the same, therefore... .

[0232] By using the formula for an ellipse with a given center, major axis, and minor axis, we can write a description Figure 20 The equations for the inner and outer ellipses are shown below. The inner ellipse is given by the following equation:

[0233] (41)

[0234] And the equation of the external ellipse is:

[0235] (42)

[0236] We aim to solve our governing equations (6) with finite differences in this altered domain, therefore we will transform the elliptical geometry so that it can be represented as a rectangular y-domain in bipolar coordinates (η, ξ) as before. To obtain a similar... Figure 21 For the geometry shown, we scale the axes to transform the ellipse into a circle, then rotate the new coordinate system so that the tool's center is positioned along the x-axis of the new coordinate system. Therefore, we introduce a change in the variable.

[0237] (43)

[0238] (44)

[0239] in

[0240] (45)

[0241] This is the angle by which we rotated the coordinates after scaling the y-axis. With respect to these new coordinates, the equation representing the ellipse becomes:

[0242] (46)

[0243] For external ellipse, and

[0244] (47)

[0245] Used for the inner ellipse. We can see from these equations that, in the (˜x, ˜y) coordinate system, the inner and outer ellipses are respectively defined by a radius of a. o and a i The circles represent both centered on the x-axis. The new geometry is as follows: Figure 21 As shown in the figure, we can now represent the boundary as a constant η value in bipolar coordinates.

[0246] Figure 21 It is a diagram of the transformed geometry. Here (The distance between the x-coordinates of the centers of the ellipse), and The angle by which the inner ellipse (after its transformation into a circle) must be rotated so that its center lies on the ~x-axis is given.

[0247] 5.1. Transformation Equation

[0248] We now use the (˜x, ˜y) terms given in (43) to represent the governing equation (6) to obtain:

[0249] (48)

[0250] in Transforming (48) into bipolar coordinates defined by (9) and (10), we obtain the following elliptic partial differential equation:

[0251] (49)

[0252] Where α, β, γ, Δ1, and Δ2 are functions of η and ξ given below.

[0253] α(η, ξ) = (cosξ cosh η - 1) 2 (cos 2 θ + k 2 sin 2 θ) + sin 2 ξ(k 2 cos 2 θ +sin 2 θ) sinh 2 η

[0254] β(η, ξ) = (k 2 - 1) cos(2θ)(cos ξ cosh η - 1) sin ξ sinh η

[0255] γ(η, ξ) = (cosξ cosh η - 1) 2 (k 2 cos 2 θ + sin 2 θ) + sin 2 ξ(cos 2 θ + k 2 sin 2 θ) sinh 2 η

[0256] Δ1(η, ξ) = (k 2 - 1) cos 2 θ(cos ξ - cos(2ξ) cosh η) sinh η

[0257] Δ2(η, ξ) = (k 2 - 1) cos 2 θ sin ξ(cos ξ cosh 2 η + cos ξ sinh 2 η - coshη)

[0258] 5.2. Boundary Conditions

[0259] Now, the no-slip boundary conditions are given in bipolar coordinates:

[0260] u(η, ξ) = 0 on η = η i , η o (50)

[0261] Since we no longer have a domain symmetric across the x-axis, we must apply different boundary conditions with the ξ term, and we take these:

[0262] (51)

[0263] (52)

[0264] It ensures the periodicity of the domain with respect to ξ, where the period is 2π.

[0265] 5.3. Specifying the geometry

[0266] We can determine this by specifying three parameters. Figure 17 The elliptical geometry shown is given by the three parameters: the eccentricity e of the ellipse, the relative offset ψ, and the angle θ formed between the x-axis and the line connecting the center of the ellipse. e The eccentricity is given by the following formula:

[0267] (53)

[0268] So that for the circle e=0, therefore and = ao. The offset parameter φ is defined as:

[0269] (54)

[0270] in It is the distance between the center of the tool and the center of the channel, and and They are respectively in terms of angle θ e The radii of the inner and outer ellipses, such as Figure 22 As shown in the image.

[0271] Figure 22 This is a schematic diagram of the domain. We specify ψ, e, and θ. e And use them to determine θ.

[0272] We find that ψ (which can be interpreted as the relative distance of the ellipse shifted concentrically along the line connecting the centers of the two ellipses relative to the maximum possible displacement in that direction) is preserved through coordinate transformation, and that ψ is used in bipolar coordinates after the coordinate (43) transformation. Using e, ψ, θ e a i and a oWe can determine w y and ( Figure 20 ), which can be used to determine θ, which is the angle by which the coordinate system must rotate once the ellipse is transformed into a circle. Therefore, we have the information needed to perform the coordinate transformation, and thus solve in this geometric domain (49).

[0273] 5.4. Finite Difference Scheme

[0274] We now construct a finite difference scheme to numerically solve (49) which follows appropriate boundary conditions (51) and (52).

[0275] Figure 23 This is a schematic diagram of the discretization of the domain. Here, the change in i represents the change in η, and the increase in j changes ξ.

[0276] We use h η = (η i - η o ) / (n η - 1) the step size of η and h ξ = 2π / (n ξ - 1) The ξ-step size is used for the center difference approximation, where n η and n ξ This represents the number of discretizations of these two axes. We have obtained a finite difference scheme.

[0277]

[0278] α, β, γ, Δ1, and Δ2 are estimated at (i, j). To solve the equation at each point, we can express it as a linear system of the form Au = b, where... We ensure that the following no-slip condition is applied directly:

[0279] (55)

[0280] Furthermore, we apply the periodicity condition using the following one-sided difference approximation, where the one-sided difference approximation is:

[0281] (56)

[0282] And ensure

[0283] (57)

[0284] The complete system produces a sparse N×N matrix with nine non-zero diagonals, where .

[0285] 5.5. Results: Velocity Distribution

[0286] After constructing the linear system described in the previous section, we solve for Au = b to obtain the velocities at discrete points. After converting the corresponding (η, ξ) values ​​back to Cartesian coordinates (x, y), we can plot the resulting velocity distribution. To display this as a continuous color map, we execute MATLAB's `griddata` function, which linearly interpolates the solution on a grid of x and y values ​​from the equation. Here, we consider changing the three dimensionless parameters (i.e., φ, θ...). e The effects of (e) on the velocity distribution in the cross section.

[0287] 5.5.1. Changing φ

[0288] Here, we consider shifting the tool's position from the center of the channel to its edge. The parameter φ characterizes this offset, where φ=0 corresponds to a concentric ellipse, and φ=1 indicates that the inner ellipse contacts the circumference of the channel. Due to the definition of bipolar coordinates, we cannot set φ=0, as this would define η... i and η o This involves division by zero. We also cannot set φ=1, because this would lead to η1=η2, thus preventing us from discretizing the domain. Therefore, to avoid this difficulty, we approximate the maximum possible shift of φ=0.01 and the concentric ellipse of φ=0.99.

[0289] Figure 24 θ is shown e The velocity distributions are given by =0, e=0.8, and φ changing from 0.01 to 0.99.

[0290] exist Figure 24 In the diagram, we see that the maximum achieved velocity increases when we change φ for a fixed eccentricity and offset angle. This is intuitive because moving the tool away from the center maximizes the maximum distance between the no-slip or zero-velocity conditions applied to the boundary. These velocity distributions show good agreement with COMSOL simulations, as shown in A.2.

[0291] 5.5.2. Changing θ e

[0292] We will now fix the offset to the maximum value (φ=0.99) and explore the effect of the rotation tool's position.

[0293] Figure 25 The values ​​of φ=0.99, e=0.8, and θ are shown. e The velocity distribution varies between 0 and π / 2.

[0294] Figure 25This illustrates how we rotate the inner ellipse from one position to another (corresponding to θ increasing from 0 to π / 2). e When this occurs, the maximum speed decreases. As mentioned earlier, this corresponds to a decrease in the maximum distance between the inner and outer boundaries.

[0295] 5.5.3. Change e

[0296] If we fix φ=0.99, θ e =0, and by changing e, we can determine the effect of changing the eccentricity of the inner and outer ellipses.

[0297] Figure 26 It shows φ=0.99, θ e =0 and the velocity distribution where e changes from 0 (circular) to 0.99. Here, we constrain the cross-sectional areas of the tool and channel to π (0.03) respectively. 2 And π (0.06) 2 .

[0298] We from Figure 26 We observe the effect of increasing the eccentricity while maintaining the cross-sectional area of ​​the tool and channel. We see that the maximum speed appears to increase with increasing eccentricity. However, if we increase the eccentricity further, this value begins to decrease, indicating that there exists an optimal non-zero eccentricity value that maximizes the flow rate per tool size.

[0299] 5.6. Results: Volumetric Flow Rate

[0300] We can calculate the volumetric flow rate using the calculated velocity distribution, which is obtained by integrating the velocity over the cross-sectional domain. Therefore, the volumetric flow rate is obtained as follows:

[0301]

[0302] After explicitly calculating the Jacobian determinant of the transformation, it becomes

[0303] (58)

[0304] We can use MATLAB's trapez function to numerically approximate this integral.

[0305] Figure 27 and 28 The figure shows the eccentricity for two different φ values. e The volumetric flow rate is a function of . Figure 27 The volumetric flow rate as a function of the elliptic eccentricity is shown for the case of near concentricity. Figure 28 The volumetric flow rate as a function of the elliptic eccentricity is shown for the inner ellipse with maximum displacement.

[0306] exist Figure 27 and 28 In the diagram, we observe the effect of increasing the ellipse eccentricity on two different offset values. For nearly concentric ellipses (φ=0.01), the volumetric flow rate is maximized when the ellipse has zero eccentricity or is circular in shape. For large offsets (φ=0.99), an eccentricity value of approximately e=0.7 ensures the maximum volumetric flow rate.

[0307] Figure 29 For φ=0.99, it is used as θ e The volumetric flow rate is a function of .

[0308] exist Figure 29 In the middle, we see that when the tool is at θ e Maximum volumetric flow rate is achieved at the position θ = 0. As the angle moves away from this position, the flow rate decreases rapidly, but decreases again as the angle approaches θ. e =π / 2 or a small increase in flow rate as the tool moves toward the bottom of the working channel.

[0309] Figure 30A and 30B It shows that for θ e The volumetric flow rate is 0 as a function of e and φ. We calculated the volumetric flow rate at 100 points; 10 values ​​of e and φ. e The 10 values. Figure 30A This shows the expression θ for a fixed cross-sectional area. e The volumetric flow rate is a function of φ and e with a value of 0. The area of ​​the tool is π (0.03). 2 And the channel area is φ(0.06). 2 . Figure 30B This shows θ as a constant perimeter. e The volumetric flow rate is a function of φ and e with a value of 0. The tool circumference is 2π (0.03), and the channel circumference is 2π (0.06).

[0310] Figure 30A and 30B This shows the changes in eccentricity (e) and offset (φ) values ​​(for a fixed angle θ). e =0) on the effect on volumetric flow rate. We see that when the cross-sectional area of ​​the channel and tool (16a) or the corresponding perimeter (16b) is fixed, the maximum volumetric flow rate is achieved at the maximum offset and is used for the fixed non-zero eccentricity.

[0311] Figure 30A and 30B It shows that for θ e=0 for volumetric flow rate as a function of e and φ. We calculated the volumetric flow rate at 100 points; 10 values ​​for e and 10 values ​​for φ. Figure 30A This shows the expression θ for a fixed cross-sectional area. e The volumetric flow rate is a function of φ and e with a value of 0. The area of ​​the tool is π (0.03). 2 And the channel area is φ(0.06). 2 . Figure 30B This shows θ as a constant perimeter. e The volumetric flow rate is a function of φ and e with a value of 0. The tool circumference is 2π (0.03), and the channel circumference is 2π (0.06).

[0312] Figure 31 The diagram shows how the cross-sectional area of ​​the tool increases for φ=0.99 and θ. e =0 is the predicted maximum eccentricity value. Calculate over 10,000 points; 100 eccentricity values ​​and 100 cross-sectional areas.

[0313] exist Figure 31 In the diagram, we observed the evolution of the optimal eccentricity value as the tool size increases. It is evident that when the tool size approaches zero, the optimal eccentricity also approaches zero. This is expected, as for circular geometry, maximum flow is achieved in an unobstructed channel. As the tool size increases, both the tool and the channel must become more eccentric to maximize flow.

[0314] The following references are incorporated herein by reference: (1) KF Riley, MP Hobson and SJ Bence. Mathematical Methods for Physics and Engineering. Cambridge University Press, Cambridge, UK, 2006; and (2) William T. Snyder and Gerald A. Goldstein. An analysis of fully developed laminarflow in an eccentric annulus. AIChE Journal, 11(3): 462-467, 1965.

[0315] Verification of velocity distribution

[0316] A.1. Circular domain: Analytical solution

[0317] Figure 32The velocity distributions are shown for r1=0.03, r2=0.06, and φ varying from 0.01 to 0.99. We have shifted the domain, so the outer circle is centered at (0,0). These are obtained from the analytical solution (39) with fifty approximations for infinite sums.

[0318] A.2. Elliptic Domain: COMSOL Simulation

[0319] Figure 33 It shows e=0.8, θ e =0 and φ varies from 0.01 to 0.99 in an elliptical velocity distribution. These regions are constrained to regions of circular tools and channels with radii of 0.03 and 0.06, respectively. These are generated by solving the governing equation (6) in the desired domain on COMSOL.

[0320] While certain features of the described embodiments have been shown as described herein, many modifications, substitutions, alterations, and equivalents will now occur to those skilled in the art. Therefore, it should be understood that the appended claims are intended to cover all such modifications and variations falling within the scope of the embodiments.

Claims

1. A medical device comprising: An elongated member having sidewalls defining a lumen having a non-circular cross-sectional shape.

2. The medical device according to claim 1, wherein, The lumen has a first diameter with a first dimension and a second diameter with a second dimension, the first dimension being different from the second dimension, and the first diameter being set approximately perpendicular to the second diameter.

3. The medical device according to claim 1, wherein, The lumen has a first diameter with a first dimension and a second diameter with a second dimension, the first dimension being different from the second dimension, the first diameter being disposed approximately perpendicular to the second diameter and intersecting the second diameter.

4. The medical device according to claim 1, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, and the outer surface being disposed opposite to the inner surface.

5. The medical device according to any one of claims 1-3, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall.

6. The medical device according to any one of claims 1-3, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall, the positioning member extending along the inner surface of the sidewall parallel to the longitudinal axis of the elongated member.

7. The medical device according to any one of claims 1-3, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall extending along the inner surface of the sidewall from a first end portion of the sidewall to a second end portion of the sidewall.

8. The medical device according to any one of claims 1-3, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall, the positioning member being configured to help retain the medical device within the lumen.

9. The medical device according to any one of claims 1-3, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall, the positioning member being configured to help hold the medical device along a first side portion of the lumen.

10. The medical device according to any one of claims 1-3, wherein, The sidewall includes a first positioning member and a second positioning member. The first positioning member is disposed within the cavity defined by the sidewall, and the second positioning member is disposed within the cavity. The second positioning member is spaced apart from and away from the first positioning member.

11. The medical device according to any one of claims 1-3, wherein, The sidewall includes a first positioning member and a second positioning member. The first positioning member is disposed within the cavity defined by the sidewall, and the second positioning member is disposed within the cavity. The second positioning member is spaced apart from and adjacent to the first positioning member.

12. The medical device according to any one of claims 1-11, further comprising: A side port defining a lumen, the lumen of which is in fluid communication with a lumen defined by the side wall.

13. The medical device according to any one of claims 1-11, further comprising: A side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the side wall, the side port including a valve disposed within the lumen defined by the side port, the valve being configured to regulate the flow of material within the lumen defined by the side port.

14. The medical device according to any one of claims 1-11, further comprising: A side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the sidewall; as well as A collection member is attached to the side port, the collection member being configured to collect material passing through a lumen defined by the side port.

15. The medical device according to any one of claims 1-14, further comprising: A handle component connected to the elongated member.

16. A medical device comprising: An elongated member having sidewalls defining a lumen having a non-circular cross-sectional shape.

17. The medical device according to claim 16, wherein, The lumen has a first diameter with a first dimension and a second diameter with a second dimension, the first dimension being different from the second dimension, and the first diameter being set approximately perpendicular to the second diameter.

18. The medical device according to claim 16, wherein, The lumen has a first diameter with a first dimension and a second diameter with a second dimension, the first dimension being different from the second dimension, the first diameter being disposed approximately perpendicular to the second diameter and intersecting the second diameter.

19. The medical device according to claim 16, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, and the outer surface being disposed opposite to the inner surface.

20. The medical device according to claim 16, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall.

21. The medical device according to claim 16, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall, the positioning member extending along the inner surface of the sidewall parallel to the longitudinal axis of the elongated member.

22. The medical device according to claim 16, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member being disposed on the inner surface of the sidewall extending along the inner surface of the sidewall from a first end portion of the sidewall to a second end portion of the sidewall.

23. The medical device according to claim 16, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall, the positioning member being configured to help retain the medical device within the lumen.

24. The medical device according to claim 16, wherein, The sidewall includes an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, and a positioning member disposed on the inner surface of the sidewall, the positioning member being configured to help hold the medical device along a first side portion of the lumen.

25. The medical device according to claim 16, wherein, The sidewall includes a first positioning member and a second positioning member. The first positioning member is disposed within a cavity defined by the sidewall, and the second positioning member is disposed within the cavity. The second positioning member is spaced apart from and away from the first positioning member.

26. The medical device according to claim 16, wherein, The sidewall includes a first positioning member and a second positioning member. The first positioning member is disposed within a cavity defined by the sidewall, and the second positioning member is disposed within the cavity. The second positioning member is spaced apart from and adjacent to the first positioning member.

27. The medical device of claim 16, further comprising: A side port defining a lumen, the lumen of which is in fluid communication with a lumen defined by the side wall.

28. The medical device of claim 16, further comprising: A side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the side wall, the side port including a valve disposed within the lumen defined by the side port, the valve being configured to regulate the flow of material within the lumen defined by the side port.

29. The medical device according to claim 16, further comprising: A side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the sidewall; as well as A collection member is attached to the side port, the collection member being configured to collect material passing through a lumen defined by the side port.

30. The medical device of claim 16, further comprising: A handle component connected to the elongated member.

31. A medical device comprising: An elongated member having sidewalls defining a lumen having a non-circular cross-sectional shape, the sidewalls including an inner surface and an outer surface, the inner surface defining the lumen, the outer surface being disposed opposite to the inner surface, a positioning member disposed on the inner surface of the sidewalls, the positioning member being configured to help hold a medical device within the lumen; A side port defining a lumen, the lumen of the side port being in fluid communication with a lumen defined by the side wall, the side port including a valve disposed within the lumen defined by the side port, the valve being configured to regulate the flow of material within the lumen defined by the side port; as well as A collection member is attached to the side port, the collection member being configured to collect material passing through a lumen defined by the side port.

32. The medical device according to claim 31, further comprising: A handle component connected to the elongated member.

33. A method of using a medical device, comprising: The medical device is inserted into the patient's body, the medical device comprising an elongated member having a lumen having a non-circular cross-section; as well as The medical device is inserted into the lumen defined by the medical device.

34. The method according to claim 33, wherein, Inserting the medical device includes inserting the medical device into a lumen defined by the medical device, such that the medical device is positioned along one side of the lumen.

35. The method according to claim 33, wherein, The medical device includes a positioning member disposed within a lumen defined by the medical device, and inserting the medical device includes inserting the medical device into the lumen defined by the medical device such that at least a portion of the medical device is disposed between the inner surface of the sidewall and the positioning member.

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