Interventional medical devices and related methods that are beneficial in the performance of treatment under magnetic resonance imaging.

Abstract

To provide interventional medical devices useful in performing treatment under magnetic resonance imaging, and methods related thereto.SOLUTION: Example interventional medical devices useful in performing treatment under magnetic resonance imaging and methods related thereto are described. A method of making a medical device useful in procedures performed under magnetic resonance imaging includes selecting a first material, selecting a second material that is different from the first material, incorporating the second material into a portion of the first material, and forming the first and second materials into a desired structure to form the interventional medical device. The second material can be melted and disposed in a void formed in the first material, and work-hardened to increase magnetic susceptibility.SELECTED DRAWING: None

Description

Technical Field

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 135,918, filed on January 11, 2021. The entire content of this related application is hereby incorporated by reference into this application.

[0002] The present disclosure generally relates to the field of medical devices. More particularly, the present disclosure relates to interventional medical devices, imaging methods, methods of performing interventional therapy under MRI, and methods of manufacturing medical devices that are useful in the performance of therapy under magnetic resonance imaging (MRI).

Background Art

[0003] Interventional procedures performed under MRI have several advantages over X-ray-guided interventions. For example, the patient is not exposed to ionizing radiation. Also, MRI enables the characterization of tissue and fluid flow during the interventional procedure. For at least these reasons, the use of interventional MRI is becoming increasingly widely accepted, and the number of procedures that can be performed under MRI is also increasing overall.

[0004] However, in the current art, the number of interventional medical devices suitable for use under MRI is limited, and this continues to be a factor hindering the increased utilization of interventional MRI procedures. As a result, patients do not yet fully benefit from interventional MRI technology, and in fact, often have only less convenient and perhaps less effective options for a particular treatment.

[0005] For example, without interventional MRI, addressing several diseases would require the use of multiple imaging modalities in the clinical pathway from initial examination to treatment. In practice, the use of multiple imaging modalities can mean patients have to visit the healthcare facility multiple times. The conventional approach to treating prostate cancer is a good example, where visualization, biopsy, and treatment require the patient to visit the healthcare facility three times on different days. The first time, a magnetic resonance imaging (MRN) scanner is used to scan the prostate and, if any, generate images showing abnormalities. The patient then returns home for further examination of the images. If abnormalities are found, the patient returns to the healthcare facility to complete a biopsy of the tissue sample. Software is used to combine the MRN images with procedural ultrasound, providing guidance for the biopsy. This fusion reduces the value of the diagnostic MRN images. The patient then returns home again to await further examination of the biopsy sample and a determination of whether further treatment is necessary (e.g., if the examination confirms a positive prostate cancer diagnosis). If further treatment is required, the patient must visit the healthcare facility a third time for treatment. Such three patient visits often take months to complete, preventing patients from receiving prompt treatment and increasing the overall cost of treatment for both patients and healthcare providers. Furthermore, combining images from multiple imaging modalities, such as magnetic resonance imaging and ultrasound, using software presents drawbacks such as image overlay and alignment issues, as well as tissue displacement due to compression. Ultimately, these shortcomings of current treatment methods limit the overall effectiveness of the treatment. Interventional MRI has the potential to overcome these shortcomings by enabling [specific feature / method]. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] U.S. Patent Application No. 16 / 454,905 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, there is a need for novel and improved interventional medical devices, imaging methods, methods for performing interventional treatments under MRI, and methods for manufacturing medical devices that are beneficial in the implementation of MRI-guided treatment. [Means for solving the problem]

[0008] A brief overview of the selected example This specification describes various examples of interventional medical devices, imaging methods, methods for performing interventional treatments under MRI, and methods for manufacturing medical devices that are beneficial in the administration of treatment under MRI.

[0009] Examples of interventional medical devices beneficial in the administration of treatment under MRI include a body having a longitudinal central axis, a proximal end, a distal end, and an axial length. The body is formed of a first MRI-compatible material. Markers are positioned parallel to the longitudinal axis along the entire axial length of the body. The markers are formed of a second MRI-compatible material different from the first material.

[0010] Another example of an interventional medical device useful in performing treatment under MRI includes a long tubular member and multiple markers. The long tubular member has a body which has a longitudinal central axis, a proximal end, a distal end, and an axial length, defining a proximal opening, a distal opening, and a lumen extending from the proximal opening to the distal opening. Multiple markers are arranged parallel to the longitudinal axis along a portion of the axial length of the body. Each marker of the multiple markers is attached to the body. The long tubular member is formed of a first material, and each marker of the multiple markers is formed of a second material which is different from the first material and incorporated into the first material.

[0011] Other examples of interventional medical devices useful in performing treatment under MRI include a tubular member and a marker attached to the tubular member. The tubular member has a first body and a second body. The first body has a longitudinal central axis, a proximal end, and a distal end, defining a proximal opening, a distal opening, and a lumen extending from the proximal opening to the distal opening. The second body has a longitudinal central axis, a proximal end, and a distal end, defining a proximal opening, a distal opening, and a lumen extending from the proximal opening of the second body to the distal opening of the second body. The marker is positioned along a portion of the axial length of the first body, parallel to the longitudinal central axis of the first body. The marker is attached to the outer surface of the first body and is made of gadolinium. The second body is coupled to the outer surface of the first body, thereby positioning the marker completely between the first and second bodies.

[0012] Other examples of interventional medical devices useful in performing treatment under MRI include elongated tubular members and markers attached to the elongated tubular members. The elongated tubular member has a body, which has a longitudinal central axis, a proximal end, a distal end, and defines a proximal opening, a distal opening, and a lumen extending from the proximal opening to the distal opening. The body is formed of 304 stainless steel. The marker is positioned along a portion of the axial length of the body, parallel to the longitudinal central axis of the body. The marker includes a portion of the body, which includes a dimpled or peened portion, thereby hardening individual areas of the body.

[0013] An example of an imaging method includes the steps of selecting an interventional medical device having a main body with a proximal end and a distal end, and a marker attached to the main body; advancing the distal end of the interventional medical device to a first position in the patient's body passage until the marker is positioned at a second position in the body passage; scanning a portion of the body passage, including the first and second positions, using a magnetic resonance scanner; acquiring a magnetic resonance image of that portion of the body passage such that the image includes artifacts indicating the presence of the marker in that portion of the body passage; and removing the interventional medical device from the body passage.

[0014] An example of a method for performing an interventional treatment includes the steps of: selecting an interventional medical device having a main body with a proximal end and a distal end, and a marker attached to the main body; advancing the distal end of the interventional medical device to a first position in the patient's body passage until the marker is positioned at a second position in the body passage; scanning a portion of the body passage, including the second position, using a magnetic resonance scanner; obtaining a magnetic resonance image of that portion of the body passage such that the image includes artifacts indicating the presence of the marker in that portion of the body passage; viewing the artifacts in the image generated by the presence of the marker; manipulating the interventional medical device based on the location of the artifacts in the body passage; and removing the interventional medical device from the body passage.

[0015] An example of a method for manufacturing a medical device includes the steps of: selecting a first material to form an interventional medical device; selecting a second material to form a marker to be included as part of the interventional medical device; incorporating the second material into part of the first material; and forming the first and second materials into a desired structure to form an interventional medical device.

[0016] Another example of a method for manufacturing a medical device includes the steps of selecting an interventional medical device precursor having a body with proximal and distal ends, and attaching a marker to the body.

[0017] Examples of methods of performing interventional therapy include selecting an interventional medical device having a body with proximal and distal ends and a marker attached to the body, advancing the distal end of the interventional medical device into a first position within a patient's body passage until the marker is placed in a second position within the body passage, scanning a portion of the body passage including the second position within the body passage using a magnetic resonance scanner, obtaining a magnetic resonance image of that portion of the body passage such that the image includes an artifact indicating the presence of the marker within that portion of the body passage, viewing the artifact within the image generated by the presence of the marker, manipulating the interventional medical device based on the position of the artifact with respect to the body passage, and removing the interventional medical device from the body passage.

[0018] These examples of interventional medical devices, imaging methods, methods of performing interventional therapy under MRI, and methods of manufacturing medical devices can be better understood by viewing the detailed description of the selected examples below and the accompanying drawings.

Brief Description of the Drawings

[0019] [Figure 1] It is a perspective view of a first exemplary interventional medical device. [Figure 2] It is a perspective view of a second exemplary interventional medical device. [Figure 3] It is a perspective view of a third exemplary interventional medical device. [Figure 4] It is a perspective view of a fourth exemplary interventional medical device. [Figure 5] It is a schematic diagram of an exemplary method of manufacturing a medical device. [Figure 6] It is a schematic diagram of another exemplary method of manufacturing a medical device. [Figure 7] It is a partial perspective view of an exemplary system useful for incorporating a marker into the body of an interventional medical device. [Figure 8] It is a partial perspective view of an exemplary marker attached to an exemplary body of an interventional medical device. [Figure 9]A partial perspective view of another exemplary interventional medical device. [Figure 10] A schematic diagram of an exemplary imaging method. [Figure 11] A schematic diagram of an exemplary method of performing interventional treatment.

Best Mode for Carrying Out the Invention

[0020] The following detailed description and the accompanying drawings illustrate and explain various exemplary interventional medical devices, imaging methods, methods of performing interventional treatment under MRI, and methods of manufacturing medical devices. The illustrations of these examples are provided to enable those skilled in the art to manufacture, use, and perform imaging methods, methods of performing interventional treatment under MRI, and methods of manufacturing interventional medical devices. These do not limit the present invention or its scope of protection in any way. The present invention can be practiced or carried out in various ways, and the examples described and illustrated herein are not considered exhaustive.

[0021] As used herein, the term "attached" refers to one member being fixed to another member such that the members are not completely separated from each other during use as per the intended use of the product in which they are included in the attached form.

[0022] As used herein, the term "circumference" refers to the outer surrounding boundary of a body, element, or feature, without imparting any structural configuration to the body, element, or feature.

[0023] To the extent used herein, the term “marker” means discrete deposits of the first material on the second material such that the first material is visible under MRI and distinguishable from the second material under MRI; portions of an interventional device in which the first material is incorporated into the second material such that the combination of the first and second materials is visible under MRI and distinguishable from the second material under MRI; and portions of an interventional device in which the material forming part of the interventional device is manipulated such that it is visible under MRI and distinguishable from the rest of the interventional device under MRI.

[0024] As used herein, the term “passive” with respect to a marker refers to a marker that is not energized or is energized only by the electromagnetic field of a magnetic resonance scanner.

[0025] As used herein, the term “treatment” means a medical procedure performed on or within a part of a patient’s body. Examples of treatment include the delivery of a drug to a site within a blood vessel, the alteration of the local environment of a blood vessel by heating or cooling, etc., and the removal of tissue or a portion of tissue from a site within a patient’s body (i.e., biopsy).

[0026] Figure 1 shows a first exemplary interventional medical device 10. In this example, the interventional medical device 10 is a guidewire 12.

[0027] The guidewire 12 has a body 14, which has a longitudinal central axis 15, a proximal end 16, a distal end 18, and an axial length 19. The axial length 19 extends from the proximal end 16 to the distal end 18. The guidewire 12 is a flexible member and can include any suitable structure and be formed from any suitable material. In the embodiment shown in the figure, the guidewire is made of polymer and is a long tubular member defining an internal lumen. Other components such as coils can be conventionally included in the guidewire 12.

[0028] In this example, the marker 50 is positioned parallel to the longitudinal axis 15 along the entire axial length 19 of the body 14. The marker 50 comprises a magnetically sensitive material and is deposited on the outer surface of the body 14 and attached thereto. In some embodiments, the marker 50 is incorporated into the material forming the body 14. For example, during manufacturing, a ferromagnetic or paramagnetic compound can be incorporated into the material forming the body 14 at a desired location on the body 14. Examples of materials considered suitable for incorporation into the material forming the body 14 include ferromagnetic and paramagnetic compounds, e.g., in powder form, tantalum powder, barium sulfate, bismuth oxychloride, tungsten, iron oxide nanoparticles, functional magnetite, gadolinium, stainless steel, ferritic stainless steel, ferritic stainless steel powder, 316 stainless steel, and any other materials considered suitable for a particular embodiment. Instead of incorporating the marker into the material forming the interventional medical device, alternative embodiments may include markers positioned on the surface of the body, e.g., the inner or outer surface. For example, a marker can be printed, bonded, or electroplated onto the surface, for example, the inner or outer surface, of the main body forming the intervention device. For example, in an embodiment where the intervention medical device is made of metal, a marker can be formed by printing an ink containing a magnetically sensitive material, such as an ink containing magnetic particles, an ink containing iron oxide nanoparticles, or an ink containing iron oxide nanoparticles bound to phospholipids, onto the outer or inner surface of the main body. Alternatively, a tape containing a magnetically sensitive material, such as a magnetic tape, can be bonded to the outer or inner surface of the main body of the intervention medical device. Alternatively, a magnetically sensitive material can be electroplated onto the surface of the main body of the intervention medical device. Alternatively, in an embodiment where the intervention medical device is made of metal, a marker can be produced by hardening the portion of the main body where it is desirable to include the marker by cold working the material to increase its magnetic sensitivity.For example, a marker may be manufactured by forming a tubular body made of metal (e.g., annealed 304 stainless steel), positioning a hardening wire within the inner diameter of the tubular member so as to contact the inner surface of the tubular member, positioning a roller on the outer surface of the tubular member so as to be aligned with the hardening wire, and rolling the roller along the length of the tubular member and along the hardening wire, using the hardening wire as a backing, thereby hardening a portion of the tubular member and producing a marker. Work hardening using a roller can also be performed, in an advantageous embodiment, on a marker printed or bonded to the surface of the body, e.g., the inner or outer surface. Alternatively, in embodiments in which the interventional medical device is formed from a tubular body of metal, portions of the body where it is desirable to include a marker may include filler material. For example, in the manufacturing method of the interventional medical device described later, the tubular body is formed by rolling a ribbon-like material in the longitudinal direction to form a C-shaped intermediate member having a longitudinal cavity positioned between opposing portions. Subsequently, a laser is used to melt filler material, such as a magnetically sensitive material, and fill the cavity between the edges of the opposing parts of the C-shaped body.

[0029] The marker 50 is described as a material incorporated into the material forming the body 14 and extending along the entire axial length 19 of the body 14, but the marker may include any suitable material in any form having any suitable configuration and may be attached to the body in any suitable manner. The selection of a suitable material for the marker, a suitable configuration for the marker, and a method or technique for attaching the marker to the body of the interventional medical device may be based on various considerations, including the type of material forming the body and / or the marker. Examples of various materials considered suitable for forming the marker, configurations considered suitable for the marker, and methods and techniques for attaching the marker to the body of the interventional medical device are described herein.

[0030] In this example, a marker extending along the entire length of the body, e.g., marker 50, can be obtained in the embodiment shown in Figure 1. Alternative lengths, e.g., less than 50 percent of the axial length of the body, about 50 percent of the axial length of the body, more than 50 percent of the axial length of the body, less than 75 percent of the axial length of the body, about 75 percent of the axial length of the body, and more than 75 percent of the axial length of the body, can also be used. Lengths greater than 50 percent of the axial length of the body are considered advantageous, at least because they provide favorable imaging characteristics. Lengths equal to the entire axial length of the body are considered advantageous, at least because they provide desired manufacturability.

[0031] Any appropriate number of markers can be included in an interventional medical device according to a particular embodiment. While the first exemplary interventional medical device includes one marker 50, an interventional medical device according to a particular embodiment may include any number of markers deemed appropriate for the intended use of that particular interventional medical device. Those skilled in the art will be able to determine an appropriate number of markers based on various considerations, including the overall size and configuration of the interventional medical device, the intended use of the interventional medical device, and any desired goals or objectives for visualizing the medical device under MRI. Examples of appropriate numbers of markers to include in an interventional medical device according to a particular embodiment include one marker, two markers, multiple markers, three markers, four markers, five markers, six markers, seven markers, eight markers, nine markers, ten markers, eleven or more markers, and any other number deemed appropriate for a particular embodiment. Furthermore, in embodiments including two or more markers, the markers can be spaced apart from each other by a desired distance. For example, in an interventional medical device having three markers, the first marker can be spaced a distance of a certain distance from the second marker, and the second marker can be spaced a distance of a certain distance from the third marker. The first and second distances can be the same or different.

[0032] Figure 2 shows a second exemplary interventional medical device 110. In this example, the interventional medical device 110 is a long tubular member 112.

[0033] The elongated tubular member 112 has a body 114, which has a longitudinal central axis 115, a proximal end 116, a distal end 118, and an axial length 119, defining a proximal opening 120, a distal opening 122, and a lumen 124 extending from the proximal opening 120 to the distal opening 122. Multiple markers 150 are arranged parallel to the longitudinal axis 115 along a portion of the axial length 119 of the body 114. Each of the multiple markers 150 is attached to the body 114. In the embodiment shown in the figure, the elongated tubular member 112 is formed of polymer, and each of the multiple markers 150 includes material incorporated into the material forming the body 114.

[0034] In the embodiment shown in the figure, the plurality of markers 150 includes a first marker 152, a second marker 154, and a third marker 156. The first marker 152 is spaced a first distance 153 from the second marker 154, and the second marker 154 is spaced a second distance 155 from the third marker 156. The first distance 153 is longer than and different from the second distance 155. Each marker of the plurality of markers 150 is parallel to the longitudinal axis 115 of the body 114. The first marker 152 and the third marker 156 are positioned along a first axis 157 which is parallel to the longitudinal axis 115, and the second marker 152 is positioned along a second axis 159 which is parallel to the longitudinal axis 115. The first and second axes 157 and 159 are offset from each other on the body 114 with respect to the longitudinal axis 115.

[0035] Markers 152, 154, and 156 of the plurality of markers 150 can be identical to one another in terms of physical properties, characteristics, and magnetic sensitivity. However, alternatively, markers 152, 154, and 156 of the plurality of markers 150 can differ from each other, or at least every other marker, in one or more of their physical properties, characteristics, and magnetic sensitivity. For example, each of markers 152, 154, and 156 of the plurality of markers 150 can have the same physical dimensions, including length, width, and thickness, and as a result have the same volume. Alternatively, markers 152, 154, and 156 of the plurality of markers 150 can differ from each other, or at least every other marker, in one or more of their physical properties, characteristics, and magnetic sensitivity. For example, in one embodiment, discrete markers having different physical dimensions can be used among the plurality of markers. Furthermore, in one embodiment, discrete markers having different geometric shapes can be used among multiple markers. Also, in one embodiment, discrete markers having different magnetic sensitivity can be used among multiple markers. For example, markers among multiple markers can be subjected to different degrees of work hardening to provide them with different magnetic sensitivity. This is considered advantageous because it makes it possible to distinguish between markers among multiple markers in an interventional medical device, at least when used under MRI.

[0036] Figure 3 shows a third exemplary interventional medical device 210. In this example, the interventional medical device 210 is a long tubular member 212.

[0037] The elongated tubular member 212 has a first body 214 and a second body 230. The first body 214 has a longitudinal central axis 215, a proximal end 216, and a distal end 218, defining a proximal opening 220, a distal opening 222, and a lumen 224 extending from the proximal opening 220 to the distal opening 222. The second body 230 has a longitudinal central axis 232, a proximal end 234, and a distal end 236, defining a proximal opening 238, a distal opening 240, and a lumen 242 extending from the proximal opening 238 to the distal opening 240. The marker 250 is positioned along a portion of the axial length of the first body 214, parallel to the longitudinal central axis 215 of the first body 214. The marker 250 is attached to the outer surface of the first body 214. In the embodiment shown in the figure, the marker 250 is made of gadolinium. In this embodiment, the marker 250 also includes a long strip of the material, the axial length of which is longer than half the axial length of the first body 214. The axial length of the marker 250 is longer than three-quarters of the axial length of the first body 214. The second body 230 is bonded to the outer surface of the first body 214, thereby shielding the marker 250 from contact with blood or body passages during use.

[0038] Figure 4 shows a fourth exemplary interventional medical device 310. In this example, the interventional medical device 310 is a long tubular member 312.

[0039] The elongated tubular member 312 has a body 314, which has a longitudinal central axis 315, a proximal end 316, a distal end 318, and defines a proximal opening 320, a distal opening 322, and a lumen 324 extending from the proximal opening 320 to the distal opening 322. In the illustrated embodiment, the body 314 is formed of 304 stainless steel. The marker 350 is positioned along a portion of the axial length of the body 314, parallel to the longitudinal central axis 315 of the body 314. In the illustrated embodiment, the marker 350 includes a portion of the body 314 that has been work-hardened by dimple formation or peening, resulting in the marker 350 as a whole. Local portions of the body 314 can be work-hardened by axial cold working of the body, for example, using a rotary swaging machine. In an alternative embodiment, the elongated tubular member may include first and second tubular members. A first tubular member formed of a first material (e.g., Inconel) is placed inside a second tubular member formed of a second different material (e.g., 304 stainless steel). The second tubular member may include dimpled or peened areas as described herein, providing discrete regions with increased hardness and improved magnetic sensitivity.

[0040] The exemplary interventional medical devices described herein are considered advantageous because they provide passive traceability of the device under MRI, at least during treatment. For example, in embodiments where the interventional medical device has markers positioned along its entire axial length, the entire length of the device is visible under MRI during use. In procedures where several devices are used simultaneously during treatment, the interventional medical devices described herein allow for differentiation of the interventional medical device from the others. Furthermore, by including markers along part or all of the axial length of the interventional medical device as described herein, visibility along the length of the device is provided without interfering with the visualization of anatomical features during use. Moreover, because the markers described herein are passive, they eliminate the need to include long conductive structures that are complex electrical components required for the function of active MR visualization devices and must be connected to accessory coil ports on the MR scanner.

[0041] The body of an interventional medical device can be formed from any suitable material, and the selection of a suitable material for forming the body of an interventional medical device can be made based on various considerations, including the intended use of the interventional medical device. Examples of MRI-compatible materials considered suitable for forming the body of an interventional medical device include biocompatible materials, biocompatible materials, metals, electrically insulating materials, non-conductive materials, non-magnetic materials, shape memory alloys including nickel-titanium alloys such as Nitinol, austenitic stainless steel, iron-containing stainless steel, austenitic nickel-chromium alloys (e.g., Inconel, a registered trademark of Special Metals Corporation), stainless steel including 304 stainless steel and 316 stainless steel, cobalt-chromium, cobalt-chromium alloys, titanium, thermoplastics, polymers, PEEK, carbon-filled PEEK, ceramics, magnetized recording wires, polymers, materials described herein, combinations described herein, and any other materials considered suitable for a particular embodiment.

[0042] Any markers included in an interventional medical device as described herein have the property of generating visual artifacts during MRI procedures in which the interventional medical device is imaged. These visual artifacts can be used to locate the interventional medical device relative to other parts of the MRI image, for example, the vascular portion into which the interventional medical device is advanced. The interventional medical device may also include any appropriate type and number of markers that allow the device to be visualized in magnetic resonance imaging and ensure the visibility of the device without obscuring the target tissue during treatment (e.g., biopsy, removal). Markers included in the body of the interventional medical device may be attached to the body using any appropriate technique and may be formed from any appropriate material. Examples of techniques considered appropriate for attaching markers to the body of the interventional medical device include pressing, welding, the use of adhesives containing the marker material in the material forming the body, and any other method or technique considered appropriate for a particular embodiment. Examples of materials considered suitable for forming markers include biocompatible materials, biocompatible materials, MRI-compatible materials, magnetically sensitive materials including paramagnetic and ferromagnetic materials, metals, electrically insulating materials, non-conductive materials, shape memory alloys including nickel-titanium alloys such as Nitinol, nickel-iron alloys such as Mu-metal, austenitic stainless steel, iron-containing stainless steel, stainless steel including Inconel, cobalt-chromium, cobalt-chromium alloys, Inconel, titanium, ferromagnetic passive materials, ferromagnetic or paramagnetic compounds, such as those in powder form, tantalum powder, barium sulfate, bismuth oxychloride, tungsten, iron oxide nanoparticles, functionalized magnetite, gadolinium, inks, inks containing magnetic particles, inks containing iron oxide nanoparticles, inks containing iron oxide nanoparticles bonded to phospholipids, the materials described herein, the combinations described herein, and any other materials considered suitable for a particular embodiment. Furthermore, the marker may also include any suitable structure attached to the body of an interventional medical device or any suitable treatment applied to the body of an interventional medical device.For example, markers may include strip materials, magnetic inks, sputtered magnetic marks of various shapes and / or configurations, swaging, dimple formation, and / or peening of a material forming the body of an interventional medical device (e.g., annealed 304 stainless steel), or combinations thereof. Further examples of markers considered suitable for inclusion in an interventional medical device are described in Patent Document 1, filed June 27, 2019, which is incorporated herein by reference in its entirety to illustrate markers considered suitable for inclusion in an interventional medical device. Any markers included in an interventional medical device can be recognized, translated into virtual instructions in a program, and identified by a unique pattern displayed on a screen.

[0043] This specification describes various imaging methods, methods for performing interventional treatments under MRI guidance, and methods for manufacturing interventional medical devices. Although the methods described herein are shown and described as a series of actions, it should be understood and recognized that the methods are not limited by the order of the actions, as some of these actions may be omitted, performed in the order shown in the figures or descriptions, performed in a different order, or performed simultaneously with other actions described herein.

[0044] Figure 5 is a schematic diagram of an exemplary manufacturing method 400 for a medical device.

[0045] Initially, step 402 includes selecting a first material for forming an interventional medical device. Another step 404 includes selecting a second material for forming a marker to be included as part of the interventional medical device. Another step 406 includes incorporating the second material into part of the first material. Another step 408 includes forming the first and second materials into a desired structure to form the interventional medical device.

[0046] Step 402, selecting a first material, can be achieved by identifying a material desirable for forming an interventional medical device, including a marker intended for use with an MRI. The first material may include any material considered suitable for forming an interventional medical device or a long component of an interventional medical device, such as those described herein.

[0047] Step 404, selecting a second material, can be achieved by identifying a material desirable for forming a marker to be included in the interventional medical device for use with an MRI. The second material may include any magnetically sensitive material, such as those described herein, that is considered suitable for forming a marker.

[0048] Step 406, which involves incorporating a second material into a portion of the first material, can be implemented using any suitable method or technique to incorporate the second material into the first material such that the second material provides a desirable marker for an interventional medical device as described herein. The selection of a suitable method or technique can be based on various considerations, including the properties of the first material, the second material, or both. For example, step 406 can be implemented by dispersing the second material, such as a powdered ferromagnetic compound, a powdered paramagnetic compound, iron oxide nanoparticles, or functionalized magnetite, in a first material such as a polymer. This method alters how the compound behaves in a magnetic field, influencing the spins of neighboring hydrogen atoms in the compound to ensure visibility under MRI. In an advantageous embodiment, step 406 is performed before the commencement of step 408. Performing step 406 to incorporate the second material into a portion of the first material, and then performing the final step of the method for manufacturing the interventional medical device 400, is considered advantageous because, at least by doing so, one or more marker materials, i.e., the second material, are incorporated into the first material before the final step of the medical device manufacturing process.

[0049] The second material may be incorporated into any suitable portion of the first material, and the selection of a suitable portion of the first material for incorporating the second material can be made based on various considerations, including the intended use of the interventional medical device being formed. Examples of portions of the first material that are considered suitable for incorporating the second material include portions that run along the entire axial length but only a portion of the width, portions that run along a portion of the axial length and a portion of the width, portions that run along multiple portions of the axial length, portions described herein, and any other portions that are considered suitable for a particular embodiment.

[0050] As an alternative to step 406, which involves incorporating the second material into a portion of the first material, the second material may be deposited on top of the first material, which may include attaching the second material to the first material. For these methods, any suitable method or technique may be used for depositing the material on top of another material, and, in a favorable embodiment, for attaching the first material to the second material, including bonding, printing, electroplating, and other suitable methods or techniques.

[0051] Step 406, and optionally step 404 if additional selections are needed, can be repeated any number of times if it is desirable to include several markers, for example, multiple markers, in the interventional medical device. In these examples, each individual example of step 404 and / or 406 can be performed to provide several markers having the same or different physical properties, characteristics, and magnetic sensitivity, as described above. These examples can also include additional steps to produce a desired difference in one or more of the physical properties, characteristics, and magnetic sensitivity of the markers. For example, different types and / or degrees of work hardening can be applied to individual markers to provide them with different magnetic sensitivity. This is considered advantageous, at least because it allows for the distinction of markers among multiple markers in the interventional medical device when used under MRI.

[0052] Step 408, forming the first and second materials into a desired structure to form an interventional medical device, can be accomplished using any suitable method or technique for forming the first and second materials into a desired structure. The selection of a suitable method or technique can be based on various considerations, such as the properties of the first and second materials. Examples of methods and techniques considered suitable for forming an interventional medical device include casting, injection molding, extrusion, and any other methods or techniques considered suitable for a particular embodiment.

[0053] The methods described herein are useful in the manufacture of various interventional medical devices and precursors of such interventional medical devices, such as guidewires, catheters, needles, sheaths, snares, and other interventional medical devices.

[0054] Figure 6 is a schematic diagram of another exemplary manufacturing method 500 for medical devices.

[0055] Initially, step 502 includes selecting an interventional medical device precursor having a body with proximal and distal ends. Another step 504 includes selecting a marker. Another step 506 includes attaching the marker to the body.

[0056] Step 502, selecting an interventional medical device precursor, can be accomplished by identifying an interventional medical device to which it is desirable to attach a marker for use with MRI. The interventional medical device can be any suitable interventional medical device or a precursor to such an interventional medical device. Examples of suitable interventional medical devices include guidewires, catheters, needles, sheaths, snares, or any other suitable interventional medical devices. Implantable medical devices, such as stents, frames, valves, filters, occluders, and other devices, can also be selected in this step.

[0057] Step 504, selecting a marker, can be accomplished by identifying a material on which it is desirable to form a marker to be included in the interventional medical device for use with an MRI. The marker may include any material and / or structure that is considered suitable for forming a marker, such as those described herein. Alternatively, step 504 can be accomplished by selecting a method or technique for imparting marker properties to a material forming the interventional medical device precursor.

[0058] Step 506, attaching the marker to the body, can be accomplished using any suitable method or technique for attaching the marker to the body. The selection of a suitable method or technique can be based on various considerations, such as the characteristics of the interventional medical device precursor and / or marker. For example, step 506 can be accomplished by printing the marker (e.g., magnetic ink, magnetic ink containing magnetic particles) onto the surface of the body, e.g., the outer or inner surface; applying the marker (e.g., formed from gadolinium) to the surface of the body, e.g., the outer or inner surface; and / or welding the marker to the body. In embodiments in which the marker is formed using gadolinium or other materials, an optional step includes attaching a second body to the first body so that the marker is completely covered and shielded from contact with body passages and / or blood vessels during use. In some embodiments, additional steps may be included. For example, a step of rolling a ribbon-like material, e.g., Inconel, along the longitudinal axis of the ribbon to form a C-shaped intermediate may be included. These methods may include a step of using a laser to melt the material (e.g., Inconel, 304 stainless steel) on which the marker is to be formed. In an advantageous embodiment, these methods may include a step of introducing the molten material into a cavity after the step of rolling the ribbon-shaped material and after the step of melting the material to form the marker, and using the molten material to fill the cavity between the edges of a C-shaped tubular body. The melting and filling steps can be performed sequentially, but in an advantageous embodiment, they can be performed simultaneously. Figure 7 shows an exemplary system 610 that is considered suitable for incorporating a marker into a body using this method. System 610 includes a laser beam 612 focused by a focusing optical system 614, a wire 618 of a second material 620, and a wire feeder 616 that feeds the wire 618 of a first material 628, which has already been rolled from a ribbon shape into a C-shaped object with a cavity 622 between opposing surfaces 624, 626. The gas nozzle 630 delivers shielding gas to the interaction point between the laser beam 612 and the wire 618.

[0059] Figure 8 shows how a wire 618 of the second material 620 is melted into a longitudinal cavity 622 between opposing surfaces 624, 626 of the first material 628, which is rolled from a ribbon-like structure into a C-shaped object having a cavity 622 between opposing surfaces 624, 626. In this example, and in other exemplary ways in which the second material is welded or otherwise attached to the first material, the welding or attachment may use other materials that include the second material 620 or incorporate the magnetically sensitive material which is the second material during attachment to the first material.

[0060] In embodiments in which the marker is welded to a tubular body, additional steps may include: rolling a ribbon-shaped first material lengthwise to form a C-shaped intermediate member having opposing portions and a longitudinal cavity between them; melting the material forming the marker (e.g., a magnetically sensitive material such as 304 stainless steel) using, for example, a laser; filling the cavity between the opposing portions of the C-shaped intermediate member to form a tubular body; and cold working part or all of the marker material to enhance the magnetic sensitivity of the marker of the interventional medical device. The step of cold working part or all of the marker material can be achieved, for example, by placing a hardened wire in a lumen defined by the tubular body and rolling the marker material against the hardened wire. As an example, Figure 9 shows a marker 602 in which a second material 620 comprises stainless steel, which is placed in a longitudinal cavity of the C-shaped intermediate member 630 to form a tubular body 632. The stainless steel is work-hardened along the length of the marker, for example, by rolling the body 632 or by drawing the plug through its lumen 634, as described above.

[0061] In embodiments in which a method or technique for imparting marker properties to a material forming an interventional medical device precursor is used, step 506 may include a suitable work hardening method or technique for hardening a region along the length of the interventional medical device, where it is desirable to include a marker to enhance magnetic sensitivity. Examples of suitable work hardening methods or techniques include swaging, rotary swaging, and dimple formation or peening.

[0062] All methods may include appropriate finishing steps. For example, in a method resulting in the formation of a tubular member, a plug may be passed through the inner lumen of the tubular member to flatten the area of ​​the tubular member including the joint. Including the step of passing the plug through the inner lumen of the tubular member is considered advantageous because it removes at least all inward-facing material that may result from the welding or attachment process. Furthermore, the step of passing the plug through the inner lumen of the tubular member is considered advantageous because it flattens the portion of the tubular member including the joint or attachment, which can contribute to the work hardening of this portion of the tubular member. In some exemplary methods in which a ribbon-shaped first material is rolled into a C-shaped elongated member, the surface of the ribbon that will be located inside the resulting C-shaped member may be electroplated with nickel or the like before the welding or attachment step is performed.

[0063] Figure 10 is a schematic diagram of an exemplary imaging method 700.

[0064] The initial step 702 includes selecting an interventional medical device having a main body with proximal and distal ends and a marker attached to the main body. Another step 704 includes advancing the distal end of the interventional medical device to a first position in the patient's body passage until the marker is positioned at a second position in the body passage. Another step 706 includes scanning the portion of the body passage, including the first and second positions, using a magnetic resonance scanner. Another step 708 includes acquiring a magnetic resonance image of that portion of the body passage such that the image includes artifacts indicating the presence of the marker in that portion of the body passage. With respect to this step 708, one still image can be obtained. Alternatively, this step 708 can be repeated a desired number of times to obtain multiple magnetic resonance images, which can be classified as cines to show motion, and / or step 708 can include acquiring a live image, which is performed, for example, under live real-time MRI visualization. Another step 710 includes removing the interventional medical device from the body passage.

[0065] Step 702, selecting an interventional medical device, can also be accomplished by selecting any suitable interventional medical device, such as those described herein or those formed using the methods described herein. Body passages may include any suitable part of the body, including existing body passages, body cavities, and / or body passages created through tissue layers and / or fascia using the devices described herein.

[0066] Figure 11 is a schematic diagram of an exemplary administration method 800 of the interventional drip therapy.

[0067] The initial step 802 includes selecting an interventional medical device having a main body with proximal and distal ends and a marker attached to the main body. Another step 804 includes advancing the distal end of the interventional medical device to a first location in the patient's body passage until the marker is positioned at a second location in the body passage. Another step 806 includes scanning the portion of the body passage, including the second location, using a magnetic resonance scanner. Another step 808 includes obtaining a magnetic resonance image of that portion of the body passage so that the image includes artifacts indicating the presence of the marker in that portion of the body passage. Another step 810 includes viewing the artifacts in the image generated by the presence of the marker. Another step 812 includes manipulating the interventional medical device based on the location of the artifacts in relation to the body passage. Another step 814 includes removing the interventional medical device from the body passage.

[0068] Step 812 is performed in a manner that achieves or contributes to achieving the desired clinical outcome of Method 800 for administering the interventional treatment. Therefore, the nature of Step 812 in which the interventional medical device is operated depends on the nature of the interventional medical device and the desired clinical outcome. Examples of suitable actions that can be performed for this step include, but are not limited to, advancing the interventional medical device axially within a body passage, rotating the interventional medical device within a body passage, extending the interventional medical device radially within a body passage, and pulling back a portion of the interventional medical device axially so that the other portion of the interventional medical device or a second medical device associated with the interventional medical device can be extended radially within a body passage. In an alternative embodiment, Step 812 may be omitted from Method 800 if operation of the interventional medical device is not desired.

[0069] Any of the steps performed by magnetic resonance scanning can be achieved using any suitable magnetic resonance scanner, such as conventional magnetic resonance scanners, magnetic resonance scanners utilizing magnetic fields of 0.55T, 1.5T, 3T, approximately 0.055T to 1.5T, less than 1T, and any other magnetic resonance scanner deemed suitable for a particular embodiment.

[0070] Any step performed within the body passage can be carried out using any suitable part of the patient, and the selection of a suitable part of the patient to be scanned can be made based on various considerations, including the treatment to be performed. Examples of suitable parts of the patient include the limbs (e.g., arms, legs), chest, breasts, spine, neck, head, abdomen, pelvis, prostate, periprostatic structures, around the parts described herein, and / or other parts of the patient that are considered suitable for a particular embodiment.

[0071] Those skilled in the art will see, by referring to the entire teaching of this disclosure, that various improvements and modifications can be devised to the examples described and illustrated herein, and that various elements and features of one example described and illustrated herein can be combined with various elements and features of other examples without departing from the scope of the invention. Accordingly, the particular arrangement of elements and steps disclosed herein is merely selected by the inventors to illustrate and illustrate examples of the invention and is not intended to limit the scope of the invention or its protection granted by the entire scope of the accompanying claims and any equivalent thereof. [Explanation of symbols]

[0072] 10 Interventional medical devices 12 Guidewires 14 Main unit 15. Longitudinal central axis 16 Proximal end 18 Distal end 19 Axial length 50 Markers 110 Interventional medical devices 112 Long tubular member 114 Main unit 115 Longitudinal central axis 116 Proximal end 117 Distal end 119 Axial length 120 Proximal opening 122 Distal opening 124 lumens 150, 152, 154, 156 Markers 153 First distance 155 Second distance 157 The First Axis 159 The second axis 210 Interventional medical devices 212 Long tubular member 214 The first body 215 Longitudinal central axis 216 Proximal end 218 Distal end 220 Proximal opening 222 Distal opening 224 lumens 230 Second Main Body 232 Lengthwise central axis 234 Proximal end 236 Distal end 238 Proximal opening 240 Distal opening 242 lumens 250 Markers 310 Interventional medical devices 312 Long tubular member 314 Main Unit 315 Lengthwise central axis 316 Proximal end 318 Distal end 320 Proximal opening 322 Distal opening 324 lumens 350 Markers 400 Manufacturing method 500 Manufacturing method 602 Marker 610 System for integrating markers into the main unit 612 Laser beams 614 Focusing Optical System 616 Wire feeder 618 wire 620 Second material 622 Cavity 624,626 Opposing surfaces 628 First material 630 C-shaped intermediate member 632 Tubular body 634 lumens 700 Imaging Methods 800 Enforcement method

Claims

1. In a method for manufacturing a medical device useful in procedures performed under magnetic resonance imaging, The steps include selecting a first material for forming an interventional medical device for use under magnetic resonance imaging, A step of selecting a second material for forming a marker to be included in part of the interventional medical device, wherein the second material includes a magnetically sensitive material different from the first material, The steps include: incorporating the second material into a part of the first material so that the combination of the first material and the second material can be visualized under magnetic resonance imaging and distinguished from the first material; The steps include: incorporating the second material into a part of the first material, then forming the first and second materials into a tubular member having an internal lumen to form the interventional medical device for use under magnetic resonance imaging; The steps include attaching an additional marker to the interventional medical device, A method that includes this.

2. The first material includes a ribbon having a longitudinal axis, The process further includes the step of rolling the ribbon along the longitudinal axis to form a C-shaped intermediate member having opposing portions and a longitudinal cavity positioned between the opposing portions, The step of incorporating the second material into a portion of the first material includes the step of placing the second material in the longitudinal cavity. The method according to claim 1.

3. The method of claim 2, wherein the second material includes a wire.

4. The method of claim 3, further comprising the step of melting the wire.

5. The method of claim 4, wherein the steps of melting the wire and incorporating the second material into a portion of the first material are performed sequentially.

6. The method of claim 5, wherein the step of melting the wire and the step of incorporating the second material into a portion of the first material are performed simultaneously.

7. The method of claim 1, further comprising the step of placing the tubular member inside a second tubular member.

8. The method of claim 1, wherein the first material includes a magnetic resonance imaging-compatible material.

9. The method of claim 8, wherein the first material includes one of a nickel-chromium alloy and a nickel-titanium alloy.

10. The method of claim 9, wherein the second material includes a paramagnetic material or a ferromagnetic material.

11. The method of claim 1, wherein the second material includes a paramagnetic material or a ferromagnetic material.

12. The method of claim 11, wherein the second material includes a powder.

13. The method of claim 1, further comprising the step of cold working the second material to enhance its magnetic sensitivity.

14. The method of claim 13, wherein the step of cold working the second material is performed before the step of forming the first and second materials into a tubular member is performed.

15. The method of claim 13, wherein the step of cold working the second material is performed after the step of forming the first and second materials into tubular members has been performed.

16. The method of claim 13, wherein the step of cold working the second material is performed while the step of forming the first and second materials into tubular members is being performed.

17. The step of incorporating the second material into a portion of the first material is repeated to form a plurality of markers. The steps include work-hardening a first marker among the plurality of markers to increase the magnetic sensitivity of the first marker by a first amount, The steps include work-hardening a second marker among the plurality of markers to increase the magnetic sensitivity of the second marker by a second amount different from the first amount, The method of claim 1, further comprising:

18. In a method for manufacturing a medical device useful in procedures performed under magnetic resonance imaging, A step of selecting a first material for forming an interventional medical device, wherein the first material includes a ribbon having a longitudinal axis, A step of selecting a second material for forming a marker to be included in part of the interventional medical device, wherein the second material includes a magnetically sensitive material different from the first material, The steps include rolling the ribbon along the longitudinal axis to form a C-shaped intermediate member having opposing portions and a longitudinal cavity positioned between the opposing portions, The process involves, during the rolling of the ribbon, melting the second material and placing the second material in the cavity to form a long tubular member having an internal lumen, The steps include cold working the second material to increase its magnetic sensitivity, A method that includes this.

19. In a method for manufacturing a medical device useful in procedures performed under magnetic resonance imaging, A step of selecting a first material for forming an interventional medical device, wherein the first material includes a ribbon having a longitudinal axis, A step of selecting a second material for forming a marker to be included in part of the interventional medical device, wherein the second material includes a wire containing a paramagnetic material different from the first material, The steps include rolling the ribbon along the longitudinal axis to form a C-shaped intermediate member having opposing portions and a longitudinal cavity positioned between the opposing portions, The steps include melting the wire to form a molten second material, The steps include: placing the molten second material into the cavity to form a long tubular member having an internal lumen; The steps include cold working the second material to increase its magnetic sensitivity, Includes, A method in which the steps of rolling the ribbon, melting the wire, and placing the second material into the longitudinal cavity are performed simultaneously.

20. The method according to claim 1, wherein the second material is barium sulfate, bismuth oxychloride, tungsten, iron oxide nanoparticles, functional magnetite, gadolinium, stainless steel, ferritic stainless steel, ferritic stainless steel, or 316 stainless steel.

21. The method according to claim 1, wherein the additional marker and the combination of the first material and the second material include discrete markers having different dimensions.

22. The method according to claim 1, wherein the additional marker and the combination of the first material and the second material include discrete markers having different geometric shapes.

23. The method according to claim 1, wherein the additional marker and the combination of the first material and the second material include discrete markers having different magnetic sensitivity.

24. The interventional medical device has an axial length, The method according to claim 1, wherein the combination of the first material and the second material provides exhibits along the axial length.

25. The interventional medical device has an axial length, The method according to claim 1, wherein the combination of the first material and the second material provides exhibits along the entire axial length.

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