Medical devices and related methods

Abstract

The present disclosure provides medical devices, methods for making medical devices, and related systems using such medical devices. In one embodiment, a medical device may be formed by providing a core wire and then thermoforming a flex circuit over an outer surface (or at least a portion of an outer surface) of the core wire. For example, the flex circuit may be pressed upon the outer surface of the core wire and maintained in that position and orientation while subjected to heat. In one embodiment, the flex circuit may be subjected to a temperature of approximately 360°F for approximately one minute. The flex may be cooled to room temperature while still being pressed against the surface of the core wire. Electrical components may be coupled with the flex circuit to provide power and data communications between a proximal end and a distal end of the core wire.

Description

MEDICAL DEVICES AND RELATED METHODSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims benefit to U.S. Provisional Patent Application No. 63 / 712,175, filed on Oct. 25, 2024, entitled MEDICAL DEVICES AND RELATED METHODS, the disclosure of which is incorporated by reference herein in its entirety.BACKGROUND

[0002] The present disclosure relates generally to medical devices incorporating sensors, as well as systems and methods which may incorporate such devices. Additionally, the present disclosure relates to devices and systems for providing information to a healthcare practitioner who may be utilizing such devices, systems or practicing associated methods.

[0003] In one, non-limiting example, such medical devices may include intraluminal devices, such as guidewires, having one or more sensors for measuring of one or more physiological parameters and / or for imaging.

[0004] Guidewire devices are often used to lead or to guide catheters or other interventional devices to a targeted anatomical location within a patient’s body. For example, guidewires may be passed into and through a patient’s vasculature in order to reach the target location, which may be, for example, at or near the patient’s heart or brain. Radiographic imaging is conventionally utilized to assist in navigating a guidewire to the targeted location. Guidewires are available with various outer diameter sizes. Widely utilized sizes include 0.010, 0.014, 0.016, 0.018, 0.024, and 0.035 inches in diameter, for example, though they may also be smaller or larger in diameter.

[0005] In some instances, a guidewire may be used to gather physiological information from within a patient. For example, so-called “pressure wires” conventionally incorporate a single pressure sensor to detect the blood pressure within a blood vessel of a patient.

[0006] In many instances, a guidewire is placed within the body during the interventional procedure so that it can be used to guide one or more catheters or other interventional devices to the targeted anatomical location. For example, a catheter can be guided to a targeted location and, once in place, be used to image the targeting location, to aspirate clots or other occlusions, or to deliver drugs, stents, embolic devices, radiopaque dyes, replacement valves, or other devices or substances for treating the patient.

[0007] These types of interventional devices can include sensors located at the distal end in order to provide added functionality to the device. For example, intravascular ultrasound (IVUS) is an imaging technique that utilizes a catheter with an ultrasound imaging sensor attached to the distal end. Ultrasound may be utilized to image within targeted vasculature (typically the coronary arteries).

[0008] There are several challenges associated with using sensors with intraluminal devices. For example, such interventional devices have very limited space to work in, given the stringent dimensional constraints involved. As such, integrating the sensors or other electronic or optical components into the interventional device with such constraints, in a way that maintains effective functionality of all of the components, can be challenging.

[0009] The use of conventional interventional devices can also be challenging due to the need to manage several long lengths of wires and other components, including guidewires, power cables, data wires, and the like. Care must be taken with respect to what is allowed in thesterile field and when certain devices or components can be removed. Additional staff is often required simply to manage such wires, cables, and components.

[0010] As such, there is an ongoing need for improved medical devices that effectively integrate sensors and can help provide data in a more efficient manner and / or provide data previously unobtainable in a practical manner.SUMMARY

[0001] Various embodiments described herein are directed toward the incorporation of electronic components and devices (e.g., sensors and transducers) into medical devices, systems incorporating such medical devices, and related methods.

[0002] In accordance with one embodiment of the present disclosure, a medical device is provided which comprises: a core wire having a proximal section and a distal section; at least one sensor disposed at the distal section; a plurality of contact pads disposed at the proximal section; and a flex circuit electrically coupled with the plurality of contact pads and the at least one sensor.

[0003] In one embodiment, the flex circuit is a continuous body extending from the proximal section to the distal section.

[0004] In one embodiment, the flex circuit includes two or more discrete sections in electrical communication with each other.

[0005] In one embodiment, flex circuit includes a plurality of conductive traces disposed between an upper material layer and a lower material layer.

[0006] In one embodiment, the flex circuit exhibits a thickness of approximately 60 micrometers or less.

[0007] In one embodiment, an opening is formed in the upper and lower material layers a location adjacent the at least one sensor.

[0008] In one embodiment, the upper material layer and the lower material layer comprise polyimide.

[0009] In one embodiment, the plurality of traces comprise copper.

[0010] In one embodiment, each of the upper material layer and the lower material layer exhibit a thickness of approximately 25 micrometers or less.

[0011] In one embodiment, the conductive traces exhibit a thickness of approximately 10 micrometers or less.

[0012] In one embodiment, the medical device further comprises at least one thermalcompression connection between at least one trace of the flex circuit and the at least one sensor.

[0013] In one embodiment, the medical device further comprises a control unit selectively coupled with the proximal section of the guidewire.

[0014] In one embodiment, the control unit is in electrical communication with the sensor, via the flex circuit, when coupled with the proximal section of the guidewire.

[0015] In one embodiment, the control unit is configured for wireless communication with at least one external unit.

[0016] In one embodiment, the flex circuit is thermoformed to exhibit a shape that is conformal to an outer surface of the core wire.

[0017] In accordance with another embodiment of the present disclosure, a method of manufacturing a medical device is provided. The method comprises: providing a core wire; thermoforming a flex circuit to exhibit a conformal shape of an outer surface of the core wire;and electrically coupling at least one electrical contact at a proximal end of the core wire with at least one sensor at a distal end of the core wire by way of the flex circuit.

[0018] In one embodiment, thermoforming the flex circuit includes pressing the flex circuit against the outer surface of the core wire and subjecting the flex circuit to a temperature of approximately 360°F.

[0019] In one embodiment, subjecting the flex circuit to a temperature of approximately 360°F includes subjecting the flex circuit to temperature of approximately 360°F for approximately one minute.

[0020] In one embodiment, the method further includes cooling the flex circuit to room temperature.

[0021] In one embodiment, thermoforming a flex circuit includes placing the flex circuit on the core wire, placing a tube of material around at least a portion of the flex circuit and an underlying portion of the core wire and heat shrinking the tube of material.

[0022] In one embodiment, the method further comprises removing the tube of material from the flex circuit and the core wire.

[0023] In one embodiment, the method further comprises placing a second tube of material over the thermoformed flex circuit and the underlying portion of the core wire and heat shrinking the second tube of material.

[0024] In one embodiment, the second tube of material comprises polyimide.

[0025] Features, elements, or components of one embodiment may be combined with features, elements, or components of other embodiments without limitation.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The foregoing and other advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which:

[0027] FIG. 1 illustrates a medical device system according to an embodiment of the present disclosure;

[0028] FIG. 2 is an enlarged detail-view of a distal end of a guidewire in accordance with an embodiment of the present disclosure;

[0029] FIG. 3 is a partial cross-sectional view of a sensor mounted in a portion of a guidewire in accordance with an embodiment of the present disclosure;

[0030] FIG. 4 depicts a distal portion of a guidewire disposed within a patient’s heart in accordance with an embodiment of the present disclosure;

[0031] FIG. 5 is an enlarged detail-view of a proximal end of a guidewire in accordance with another embodiment of the present disclosure;

[0032] FIG. 6 is a plan view of a controller removably coupled with the proximal portion of the guidewire in accordance with an embodiment of the present disclosure;

[0033] FIG. 7 depicts a plan view of a component of a guidewire according to an embodiment of the present disclosure;

[0034] FIGSs. 8A and 8B are cross-sectional views of embodiments of the component shown in FIG. 7 as taken along section line 8A / B-8A / B shown in FIG. 10B;

[0035] FIG. 9 is a cross-sectional view of the guidewire taken along section line 9-9 shown in FIG. 2;

[0036] FIGs. 10A and 10B are enlarged detail views of the component shown in FIG. 7;

[0037] FIG. 11 A and 1 IB show side views of a component according to additional embodiments of the present disclosure;

[0038] FIG. 12 is a flow diagram showing a method according to an embodiment of the present disclosure; and

[0039] FIG. 13 is an enlarged detail-view of a distal end of a guidewire in accordance with another embodiment of the present disclosure.DETAILED DESCRIPTION

[0040] Various embodiments described herein are directed toward the incorporation of electronic components and devices (e.g., sensors and transducers) into medical devices, systems incorporating such medical devices, and related methods.

[0041] In some embodiments, devices associated with cardiovascular, neurovascular, and endovascular procedures are provided having sensors integrated therewith. For example, guidewires or catheters may include sensors, transducers or other electronic or optical components integrated into the structure for detecting, imaging or measuring physiological data (e.g., pressure, flow rate, etc.), providing imaging data (e.g., ultrasound images), and providing that data to a healthcare provider in real time during an associated procedure.

[0042] In some embodiments, other sensors or electronic elements are associated with the device. For example, sensors configured to detect the presence of biological components may be incorporated into or otherwise associated with the device. In some embodiments, a transceiver unit having an antenna structure may be associated with the device for providing wireless transmission of data.

[0043] Referring to FIG. 1, a guidewire system 100 is illustrated according to an embodiment of the present disclosure. As shown, the guidewire system 100 includes aguidewire 102, a proximal device which, in some embodiments, may include a control unit 104 for providing power to, and communication with, sensors or other electronic or optical components associated with the guidewire 102. The system 100 further includes a plurality of sensors 106 (see, e.g., FIGS. 2 and 3 - also shown as 106A and 106B) associated with a distal end of the guidewire 102. The control unit 104 may include, for example, a power source (e.g., a battery), a data signal processor, a memory device, and a transmitter / receiver (referred to herein as a transceiver). In some embodiments, such components may be disposed, entirely or partially, within a body or housing of the control unit 104.

[0044] The system 100 may further include an external computing device 110 (also referred to as a “hub”). The external computing device 110 may include, e.g., a stationary or handheld computer, a stationary or handheld display, a tablet computer, a smart phone, or other input and / or output device. In one embodiment, as depicted in FIG. 1, the external computing device 110 may be in wireless communication with the control unit 104. Any of a variety of wireless protocols may be utilized (e.g., Bluetooth, Zigbee, Wi-Fi, etc.).

[0045] The system may further include a monitor 112, or a “boom” used by medical personnel during a procedure to review data and information relating to the procedure and the status of the patient. The monitor 112 may be in wired or wireless communication with the external computing device 110 so as to display information obtained by the sensors 106 or other electronic or optical components associated with the guidewire 102. For example, if the guidewire were being used in association with a transcatheter aortic valve implantation (or replacement) - TAVI or TAVR - procedure, the sensors 106 may detect or determine a first pressure in the left ventricle and a second pressure in the aorta. Each of the sensors 106 provides a signal representative of the obtained pressures to the control unit 104, which in turn relaysthem (either as they are or as a modified signal) to the external computing device 110. The external computing device 110 then relays the pressure data to the monitor 112 and presents in a recognizable form (e.g., as number and / or in a wave form) so that an interventional cardiologist may review the sensed pressures and determine if a valve replacement is necessary - or when measuring after the initial placement of a new valve, determine if subsequent actions need to be taken (such as reseating the valve to eliminate or reduce regurgitation). It is noted that in some embodiments, components or devices - such as the external computing device 110 and the monitor 112 - may be integrated into a common device.

[0046] The external computing device 110 is also in communication with the hospital’s (or other healthcare facility’s) computing system or network 114 for access to, for example, electronic healthcare records (EHRs) which may be relevant to the current procedure. Access to such information may be beneficial, for example, to consider a specific patient’s health history as it pertains to the instant procedure. Further, the external computing device 110 may be in communication with a global cloud 116 or database having information relating to the instant procedure. The hospital computing system 114 and the cloud 116 may each be coupled with the external computing device 110 through wireless or through wired connections.

[0047] In one example, the cloud 116 may contain information relating to similar procedures including information relating to individuals in a similar demographic as the patient undergoing an instant procedure, their response to different interventions, their pressure or flow rates during a similar procedure, and other relevant data. The global cloud 116 may include computing ability to implement machine learning (or artificial intelligence) to apply the information within the global cloud to a specific procedure in light of the data being collected during the procedure. For example, a comparison of a pressure curve associated with the aorticpressure with the pressure curve of the left ventricular pressure may yield an index that is useful in determining whether an interventional act is required. In some embodiments, the index may be based strictly on a direct comparison of such pressures. However, in some embodiments, the index may be based on a dynamic analysis of the pressure curves, the past health history of the patient (e.g., as obtained from the EHR), data associated with the diagnosis and procedure outcomes of other individuals that may satisfy certain health and / or demographic criteria (e.g., age, race, weight, other diagnosed conditions, etc.). Thus, the index can be a dynamic tool to more accurately determine actions to be taken (or actions to be avoided) during a specific procedure as the procedure is being conducted.

[0048] It is noted that the system 100 may be defined to include certain basic elements (e.g., the guidewire 102 including its sensors 106, the control unit 104, and the external computing device 110), or it may be defined to include additional elements including the hospital network 114 and / or the global cloud 116). The system 100 may additionally include other components including those conventionally found in a catheterization lab, such as the monitor 112, a patient bed 118, an imaging device 120 for providing CT, X-ray, fluoroscopy, or other imaging information during the procedure. It is noted that the monitor 112 may be coupled with the imaging device 120 and may be configured to show imaging information as well as physiological information and that such information may be displayed simultaneously or individually as selectively determined by a practitioner.

[0049] Referring briefly to FIG. 2, a distal section of the guidewire 102 is depicted. The distal section includes curved (e.g, spiraled) or coiled section 130, sometimes referred to as a “pigtail”, that is configured to engage with a portion of the patient’s anatomy, effectively anchoring the guidewire in a desired position in an atraumatic fashion. In other embodiments,the “pig tail” may not be included as the guidewire may be intended for specific procedures where it wouldn’t be desired. For example, other types of distal ends or tips may be desired in association with certain cardiovascular, endovascular, or neurovascular procedures.

[0050] The portion proximal of the coiled section 130 further includes two or more sensors 106 that are longitudinal spaced along a length of the guidewire 102. In one embodiment, the sensors 106 may be configured as pressure sensors (e.g., piezoelectric or capacitive-type pressure sensors). In one embodiment, the distal most sensor 106 A may be positioned at a location a distance Di taken from a tangent line of the proximal most portion of the coiled section 130 and which extends perpendicular to the length of the guidewire 102 as indicated in FIG. 2. In one embodiment, the distance Di may be between approximately 1 cm and approximately 3.5 cm. In one particular embodiment, the distance Di may be between approximately 2 cm and approximately 2.5 cm. Such measurements referred to above being measured from the tangent line 132 (which runs tangent to the curve of the coil 130 at the proximal-most location of the coil, and extends perpendicular to the proximally-extending longitudinal portion of the guide wire) to the center of the distal -most sensor 106A as depicted in FIG. 2.

[0051] The sensors are spaced apart a distance “D2” so that one may be positioned in a patient’s left ventricle while the other is positioned within the patient’s aorta during a diagnostic and / or an interventional procedure. In one embodiment, distance D2 may be approximately 9 centimeters (cm) apart. In one embodiment, distance D2 may be approximately 10 cm apart. In one embodiment, distance D2 may be approximately 11 cm apart. In another embodiment, distance D2 may be between approximately 8 cm and approximately 11 cm apart. In another embodiment, distance D2 may be between approximately 7 cm and approximately 12cm apart. Such measurements referred to above being measured from the center of one sensor to the center of the adjacent sensor as depicted in FIG. 2.

[0052] In one embodiment, the distance Di may be approximately 2.5 cm while the distance D2may be approximately 10 cm. In another embodiment, the distance Di may be approximately 2 cm while the distance D2 may be approximately 10 cm. Other distances may be utilized depending on, for example, intended use of the guidewire 102, expected anatomical configurations, and other relevant considerations.

[0053] Referring now to FIG. 3, a cross-sectional view of a sensor 106 mounted in the guidewire 102 is provided. The guidewire 102 includes a core wire 140 which may be formed of a metallic material such as, for example, stainless steel, titanium, or other alloys with appropriate structural and / or electrical properties. The core wire 104 has a portion removed to form a pocket 142 or a void. The pocket 142 may be formed by machining, laser ablation, or other appropriate manufacturing techniques. Next to the pocket 142, a shelf or a stepped region 144 is formed within the core wire 140. A first portion of the sensor 106 is attached to the stepped region 144 (e.g., such as by adhesive) such that another portion of the sensor 106 is cantilevered into the pocket 142, leaving a gap or a space between the underside of the cantilevered sensor portion and the bottom of the pocket 142 formed in the core wire 140.

[0054] A housing 146 is positioned over the core wire 104, the sensor 106 and the pocket 142. The housing 146 may be formed of a metallic material such as, for example, stainless steel or titanium. In one embodiment, the housing exhibits a longitudinal length “L” of approximately 0.5 cm. In other embodiments, the length L may be between approximately 1.0 cm and 0.25 cm. The housing 146 may help maintain the position of the sensor 106 or otherwise secure the sensor 106 to the core wire 104. The housing 146 additionally providessupport to the core wire 104 in the region where the pocket 142 and stepped region have been formed such that the core wire 140 may withstand bending forces applied in that region of the core wire 140 when the guidewire 102 is being navigated through a tortuous path of a patient’s anatomy. At least one opening 147 is formed in the housing 146 to provide fluid communication between the pocket 142 and the external environment in which the guidewire 102 is placed. Thus, for example, if the guidewire is positioned such that the sensor 106 is located within a patient’s aorta, the pocket is in fluid communication with the blood that is flowing within the aorta, enabling the sensor 106 to determine the blood pressure at that location.

[0055] Another material layer 148 may be positioned about the core wire 140 in locations adjacent to the housings 146 to provide a common diameter and provide a smooth outer surface for the guidewire 102 and eliminate any abrupt transitions that might otherwise occur (e.g., a stepped transition that might occur along the length of the core wire 140 and the housings 146). The material layer 148 may include, for example, a polymer material such as polyimide. In one embodiment, the material layer 148 may include a tube of Pebax ® that is heat-shrunk onto the underlying components of the guidewire 102. Pebax ® polymers are available from Arkema of Puteaux - La Defense, France. In some embodiments, the material layer 148 may extend over the housings 146, while still leaving an opening (e.g., corresponding with opening 147) for fluid communication into the pocket 142.

[0056] A flex circuit 149 may be positioned on the core wire 140 and have a portion that overlays the sensor 106. In some embodiments, as shown in FIG. 3, the flex circuit 149 is positioned on top of the sensor 106. In other embodiments, the sensor 106 is positioned atop the flex circuit 149. The flex circuit 149 includes electrical traces (as will be discussed below) thatare connected to electrical pads of the sensor 106. In some embodiments, the sensor 106 may include solder bumps formed on electrical pads and, when aligned with associated pads or contacts of the flex circuit 149 (which pads or contacts are electrically connected to traces through a top or bottom material layer), the sensor(s) 106 and flex circuit 149 can be physically and electrically coupled be an appropriate joining technique, such as a thermal-compression soldering technique. Of course, other joining techniques may be used to form a satisfactory electrical connection between the two components.

[0057] The configuration of the cantilevered sensor 106 within the pocket enables the sensor 106 to avoid or minimize inaccurate pressure readings that might otherwise be induced by the bending of the core wire 140. In other words, the bending of the core wire 140 at the location of the sensor 106 does not subject the sensor to a false reading because the cantilevered portion is “free” from the bending and does not register such bending forces as it would if the entire sensor were adhered or otherwise attached to the core wire 140.

[0058] The resulting guidewire 102 may have a size such that the outer diameter (e.g., after application of other outer members and / or coatings) is about 0.008 inches to about 0.040 inches, though larger or smaller sizes may also be utilized depending on particular application needs. For example, particular embodiments may have outer diameter sizes corresponding to standard guidewire sizes such as approximately 0.010 inches, 0.014 inches, 0.016 inches, 0.018 inches, 0.024 inches, 0.035 inches, 0.038 inches, or other such sizes common to guidewire devices. As previously noted, the wire 102 may be formed from materials comprising stainless steel or other metal or alloy having similar appropriate properties.

[0059] While the guidewire 102 has been primarily described as including pressure sensors, it is noted that other sensors may be used in addition to such pressure sensors or in the alternative of such pressure sensors. For example, the sensors may additionally, or alternatively, be configured to determine flow rate or to sense the presence of biological components or measure physiological parameters in the targeted anatomical location (e.g., in the blood). Example biological components that may be detected / measured include sugar levels, pH levels, CO2 levels (CO2 partial pressure, bicarbonate levels), oxygen levels (oxygen partial pressure, oxygen saturation), temperature, and other such substrates and physiological parameters. The one or more sensors may be configured to sense the presence, absence, or levels of biological components such as, for example, immune system-related molecules (e.g., macrophages, lymphocytes, T cells, natural killer cells, monocytes, other white blood cells, etc.), inflammatory markers (e.g., C-reactive protein, procalcitonin, amyloid A, cytokines, alpha- 1 -acid glycoprotein, ceruloplasmin, hepcidin, haptoglobin, etc.), platelets, hemoglobin, ammonia, creatinine, bilimbin, homocysteine, albumin, lactate, pyruvate, ketone bodies, ion and / or nutrient levels (e.g., glucose, urea, chloride, sodium, potassium, calcium, iron / ferritin, copper, zinc, magnesium, vitamins, etc.), hormones (e.g., estradiol, follicle-stimulating hormone, aldosterone, progesterone, luteinizing hormone, testosterone, thyroxine, thyrotropin, parathyroid hormone, insulin, glucagon, cortisol, prolactin, etc.), enzymes (e.g., amylase, lactate dehydrogenase, lipase, creatine kinase), lipids (e.g., triglycerides, HDL cholesterol, LDL cholesterol), tumor markers (e.g., alpha fetoprotein, beta human chorionic gonadotrophin, carcinoembryonic antigen, prostate specific antigen, calcitonin), and / or toxins (e.g., lead, ethanol).

[0060] Referring briefly to FIG. 4, the distal section of the guidewire 102 is shown to be positioned within a patient’s anatomy such that a first sensor 106 A is located within the patient’s left ventricle 150 and a second sensor is positioned within the patient’s aorta 152. As noted above, this enables pressure readings to be taken simultaneously at both locations to determine, for example, the level of regurgitation that a patient is experiencing across the aortic valve. The pressure readings may be displayed on a monitor 112 (FIG. 1) for a practitioner to review and determine what, if any, action should be taken. The guidewire 102, thus, may be used in diagnosis of a patient’s condition, but also used after the diagnosis to guide a catheter delivering a replacement valve to the target location if needed or desired. Subsequent the delivery and placement of a new valve 154 (shown in dashed lines), the guidewire 102 may be again used to measure pressures in the left ventricle and the aorta to determine if the valve implantation / replacement was successful, or if repositioning of the valve may be desirable. Thus, the guidewire 102 may be used throughout the valve replacement procedure without removal or displacement of the guidewire 102 until the practitioner is satisfied with the placement and securement of the new valve.

[0061] Referring now to FIGs. 5 and 6, a proximal end of the guidewire 102 and a control unit 104 for attachment to the proximal end of the guidewire 102, respectively, are shown. As shown in FIG. 5, a proximal end of the guidewire 102 may include a plurality of electrodes or electrical contacts 160A-160E. The contacts 160A-160E are configured to make electrical connection with corresponding contacts or electrodes (not shown) in the control unit 104. In the embodiment shown, each of the contacts 160A-160E may be electrically coupled with conductors or traces of one or more flex circuits that, individually or collectively, extend alength of the guidewire 102, providing an electrical path between the electrical contacts 160A-160E and the sensors 106 in the distal section of the guidewire 102.

[0062] The guidewire 102 may additionally include a keyed or locking feature 162 in its proximal section. The locking feature 162 may include a shoulder or reduced diameter section configured for engagement with a locking structure or mechanism 164 located within a housing 166 of the control unit 104 (see FIG. 6). The locking feature 162 and locking mechanism 164 work together to retain the guidewire 102 in a desired longitudinal position relative to the control unit 104 during use of the guidewire.

[0063] As indicated in FIG. 6, the guidewire 102 may be coupled with the control unit 104 by sliding the guidewire 102 in a direction parallel to its length (as indicated at 168) through an opening 170 formed in a surface of the housing 164 (FIG. 6 depicts the guidewire inserted into the housing as indicated by dashed lines). The control unit 104 (in addition to components and features previously mentioned) may include input features 172 (e.g., buttons, sliders, touchpads, directional pads, switches, etc.) to provide control of or communication with the sensors 106, transmission of data, and / or control of external components such as the external computing device 110 or monitor 112 (see FIG. 1). Additionally, the control unit 104 may include output features 174 (e.g., lights, screens, audio speakers, etc.) to provide feedback regarding operational status of the guidewire 102 or other components of the system 100.

[0064] Referring now to FIG. 7, a plan view is shown of a flex circuit 149 in accordance with an embodiment of the present disclosure. The flex circuit 149 includes multiple traces 178 that extend between connecting pads 180A-180E (which correlate with and are in electrical communication with contacts 160A-160E - see FIG. 5) at its proximal end and the sensors 106A and 106B at the distal end of the guidewire 102 (see FIGS. 2 and 3). The traces178 may be formed of a conductive material and may include metals such as, for example, copper or gold. In the embodiment shown, the flex circuit 149 includes six individual traces -three for each sensor 106A and 106B. However, the number of traces may be different from the embodiment shown depending, for example, on the number of sensors used, the specific connection requirements of each sensor, or the use of other electrical components (e.g., integrated circuits) positioned on the guidewire 102. In one embodiment, such as shown in FIG.8A (in conjunction with FIG. 7), the traces 178 may be positioned (e.g., sandwiched) between a bottom layer of material 181 and a top layer of material 182. In one embodiment, the material may include polyimide, although other materials may be used. In one embodiment, the bottom layer of material and the top layer of material 182 may be approximately 20 to approximately 35 micrometers (pm) thick (i.e., the distance or depth extending into the plane of the drawing) while the individual traces 178 may be approximately 7 to approximately 12 pm thick. In one embodiment, the bottom layer of material and the top layer of material 182 may each be approximately 25 pm, the conductive traces 178 may be approximately 9 pm thick, making the entire flex circuit approximately 60 pm or less.

[0065] In another embodiment, such as shown in FIG. 8B in conjunction with FIG. 7, the traces 178 of the flex circuit 149 may be poisoned on top of a first material layer 181 without another material layer being positioned on top of the conductive traces 178. In other words, in such an embodiment, the top material layer is eliminated in the flex circuit 149, providing the flex circuit 149 with reduced overall thickness. Other than the elimination of such a top material layer, the other components of the flex circuit for the embodiment depicted in FIG. 8B may be similar to those described above in association with FIG. 8A. Either of the embodiments described in association with FIGS. 8 A and 8B may be pre-fabricated such that the flex circuit149 is a complete and independent circuit component fabricated independently of the core wire 140 or of other components. In some embodiments, the flex circuit 149 and the sensors 106 may be separate components and include discrete assembly acts. In other embodiments, the sensor(s) 106 may be fabricated with, or mounted to, the flex circuit 149 prior to placing the flex circuit 149 on the core wire 140 in a “chip-on-flex” design, such that the sensors 106 and flex circuit are assembled with the core wire 140 essentially simultaneously.

[0066] Referring briefly to FIG. 9 (and in conjunction with FIG. 3), the flex circuit 149 may be positioned on the core wire 140 such that its width wraps at least partially around the circumference of the core 140 as it extends longitudinally (e.g., from a distal portion toward a proximal portion) along the core wire 140. In one embodiment, the width of the flex circuit 149 may wrap around or cover approximately 40% to approximately 50% of the circumference of the core wire 140 (e.g., extending through an arc A of approximately 144 degrees to approximately 180 degrees). An additional material layer 148 (such as described with respect to FIG. 3) may be positioned over, and completely circumscribe, the core wire 140 and the flex circuit 149 while extending a substantial portion of the length of the guidewire 102, if not the majority or substantial entirety of the length of the guidewire 102. In one embodiment, a Pebax ® or other tube may be heat shrunk over the core wire 140 and flex circuit (and other components such as sensors, electrical connections, and / or other conductive wires). In the case that the flex circuit 149 doesn’t include a top material layer (e.g., such as depicted in FIG. 8B), the additional material layer 148 may serve as an insulative layer over the conductive traces 178.

[0067] Referring again to FIG. 7, the flex circuit 149 may be as long (e.g., from the proximal end with the connecting pads 180A-180E to the distal end with the sensor-connecting sites 184A and 184B) as is needed according to the length of guidewire 102. As a non-limitingexample, the flex may be 280 cm in one embodiment, and exhibit a width (i.e., as measured in the “up-down” direction when viewing FIG. 7) of approximately 0.03 inch to approximately 0.08 inch. In some embodiments, the flex circuit may be configured to only overlay a portion of the circumference of the core wire 140 (as noted above), while in other embodiments, the flex circuit (or portions thereof) may completely circumscribe the core wire 140.

[0068] Referring to FIGs. 10A and 10B in conjunction with FIG. 7, the traces 178 near the distal end of the flex circuit 149 terminate at sensor-connection sites 184A and 184B that correspond with the locations of sensor 106A and 106B (depicted as dashed lines). The sensor-connection sites 184A and 184B may include openings 186 through the bottom 181 and top 182 material layers (or just the bottom 181 in the case of the embodiment shown in FIG. 8B) providing communication to the pocket 142 formed in the core wire 140 (see FIG. 3).

[0069] Referring briefly to FIGs. 11 A and 1 IB, additional embodiments of flex circuits are shown. For example, a flex circuit 190 is shown in FIG. 11 A having multiple longitudinal sections 192A-192C that overlay each other. In the embodiment shown, a portion of a distal section 192A overlays a first portion of a mid-section 192B at one end while a portion of a proximal section 192C overlays another portion of the mid-section 192B at another end. In some embodiments, the mid-section 192B may be a relatively short section acting as a “bridge” between the distal and proximal sections 192A and 192C. In other embodiments, the sections may each exhibit common lengths, or may each exhibit distinct lengths. Discrete physical and electrical connections 194 may be made between traces in the one section and traces an overlaying section through a variety of joining techniques including compression, thermalcompression, or through various soldering techniques. More or fewer than three sections may be used depending, for example, the length of the guidewire.

[0070] The flex circuit 200 shown in FIG. 1 IB is similar to that described with respect to FIG. 9 A, but the distal section 202 A and the proximal section 202C are position end-to-end with portions of the mid-section 202B rather than overlapping or overlaying it. Individual wires 204 or other electrically connecting structures may be used to connect the traces in adjacent sections using appropriate bonding techniques. It is noted that in some embodiments, rather than a “chip-on-flex” design, the sensors 106 may be electrically coupled to a flex circuit by individual wires (similar to wires 204). In some embodiments, the guidewire may include a length of flex circuit connected to a length of individual wires (e.g., trifilar wires) that then connect to the sensors at the distal end. In some embodiments, there may also be individual wires connecting the flex circuit to the conductors at the proximal end (e.g., conductors 160A-160E).

[0071] Referring now to FIG. 12, a method of forming a medical device is shown in accordance with an embodiment of the present disclosure. The method 250 includes providing a core wire as indicated at 252 and providing a flex circuit at 254. The flex circuit is positioned on the core wire in a desired location and orientation as indicated at 256. The flex circuit, or portions thereof, are thermoformed (or “flex-formed”) to the core wire, as indicated at 258, to cause the flex circuit to take, and retain, a form that conforms with the outer surface of the core wire (e.g., taking the shape such as indicated in FIG. 9).

[0072] The thermoforming of the flex circuit to the core wire may include applying pressure to flex circuit to hold it in a conformal position relative to the core wire (or to a separate mandrel) while heating the flex circuit to a desire temperature, for a desired period of time, and then cooling the flex circuit in such a way that it retains its core wire-conforming shape. In one embodiment, the flex circuit may be placed over a core wire and a layer of polymer materialmay be placed around the flex circuit and core wire. The assembly (e.g., core wire, flex circuit, and polymer material) may be heated. The applied heat may cause the material layer to shrink and hold the flex circuit against the surface of the core wire with an increased force. In one embodiment, the assembly may be heated to approximately 360°F for approximately one minute, and then naturally cooled to ambient temperatures. The outer material layer may then be peeled off, or otherwise removed from the assembly, with the flex circuit remaining in a conformal shape with respect to the surface of the core wire. In some embodiments, the temperature may be higher or lower than 360°F (e.g., between approximately 345°F and approximately 375°F) and the heating time may be more or less than a minute (e.g., between approximately 45 seconds and approximately 75 seconds). The material layer may comprise a peelable fluorinated ethylene propylene (FEP) heat shrink tubing that shrinks to compress the flex circuit against the core wire when heated. In one embodiment, the material layer may include a tubing having a wall thickness between approximately 0.005 inch and approximately 0.018 inch. In another embodiment, the material layer may include a tubing having a wall thickness between approximately 0.007 inch and approximately 0.010 inch.

[0073] After the flex circuit has been thermoformed, the outer material layer (e.g., the heat shrunk tubing) may be peeled off of the assembly, leaving the flex circuit in its conformal state, ready for further processing and assembly. In some embodiments, the sensors of the guidewire may be placed on and bonded with the traces of the flex circuit prior to thermoforming. In other embodiments, the sensors of the guidewire may be positioned and bonded to the flex circuit after the act of thermoforming. Once the outer material layer has been peeled or otherwise removed from the assembly, a permanent outer layer (e.g., additionalmaterial layer 148), such as Pebax ® may be placed over the assembly and heat shrunk over the core wire and flex circuit as indicated at 260.

[0074] In some embodiments, the act of thermoforming may take place along substantially the entire length of the flex circuit. In other embodiments, thermoforming may take place at selected locations along a length of the flex circuit. For example, thermoforming might take place only at locations of bonding (see bonding descriptions above association with FIGs. 11 A and 1 IB). Additionally, while the method 250 describes the acts in an example sequence, other sequences are considered. For example, the provision of a core wire 252 and a flex circuit 254 need not take place in a particular order. Additionally, the in some embodiments, the material layer provided in act 260 may be placed over the flex circuit and core wire prior to the thermoforming if, for example, heating conditions for thermoforming are conducive to simultaneously heat shrinking the permanent material layer.

[0075] Referring briefly to FIG. 13, another guidewire 210 is shown which includes multiple sensors 212 (three are shown, but more than three may be included) and having an atraumatic tip 214 for use in a different procedure that the guidewire 102 previously described. As noted before, the guidewires described herein may be configured for use in various procedures including, for example, the TAVI / TAVR procedure described above, percutaneous coronary interventions, endovascular procedures, and neurovascular procedures. The flex circuits described herein may be utilized in the guidewire 210 shown in FIG. 10 and in other embodiments configured for such procedures and may be used in association with guidewires having a variety of sizes as described herein.

[0076] In various embodiments, different numbers of and types of sensors may be used. For example, in some embodiments, ten or more pressures sensors may be used todetermine a pressure gradient within a portion of a patient’s vasculature. In some embodiments, one or more pressure sensors may be combined with one or more flow sensors to determine multiple physiological variables.

[0077] While the disclosed embodiments may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. It is noted that features, elements, or components of one embodiment may be combined with features, elements, or components of other embodiments without limitation. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.

Claims

CLAIMSWhat is claimed is:

1. A medical device comprising:a core wire having a proximal section and a distal section;at least one sensor disposed at the distal section;a plurality of contact pads disposed at the proximal section;a flex circuit electrically coupled with the plurality of contact pads and the at least one sensor.

2. The medical device of claim 1, wherein the flex circuit is a continuous body extending from the proximal section to the distal section.

3. The medical device of claim 1, wherein the flex circuit includes two or more discrete sections in electrical communication with each other.

4. The medical device of claim 1, wherein flex circuit includes a plurality of conductive traces disposed between an upper material layer and a lower material layer.

5. The medical device of claim 4, wherein the flex circuit exhibits a thickness of approximately 60 micrometers or less.

6. The medical device of claim 4, wherein an opening is formed in the upper and lower material layers a location adjacent the at least one sensor.

7. The medical device of claim 4, wherein the upper material layer and the lower material layer comprise polyimide.

8. The medical device of claim 7, wherein the plurality of traces comprise copper.

9. The medical device of claim 8, wherein each of the upper material layer and the lower material layer exhibit a thickness of approximately 25 micrometers or less.

10. The medical device of claim 9, wherein the plurality of conductive traces each exhibit a thickness of approximately 10 micrometers or less.

11. The medical device of claim 1, comprising at least one thermal-compression connection between at least one trace of the flex circuit and the at least one sensor.

12. The medical device of claim 1, further comprising a control unit selectively coupled with the proximal section of the guidewire.

13. The medical device of claim 12, wherein the control unit is in electrical communication with the sensor, via the flex circuit, when coupled with the proximal section of the guidewire.

14. The medical device of claim 13, wherein the control unit is configured for wireless communication with at least one external unit.

15. The medical device of claim 1, wherein the flex circuit is thermoformed to exhibit a shape that is conformal to an outer surface of the core wire.

16. A method of manufacturing a medical device, the method comprising: providing a core wire;thermoforming a flex circuit to exhibit a conformal shape of an outer surface of the core wire;electrically coupling at least one electrical contact at a proximal end of the core wire with at least one sensor at a distal end of the core wire by way of the flex circuit.

17. The method according to claim 16, wherein thermoforming the flex circuit includes pressing the flex circuit against the outer surface of the core wire and subjecting the flex circuit to a temperature of approximately 360°F.

18. The method according to claim 17, wherein subjecting the flex circuit to a temperature of approximately 360°F includes subjecting the flex circuit to temperature of approximately 360°F for approximately one minute.

19. The method according to claim 18, further comprising cooling the flex circuit to room temperature.

20. The method according to claim 16, wherein thermoforming a flex circuit includes placing the flex circuit on the core wire, placing a tube of material around at least a portion of the flex circuit and an underlying portion of the core wire and heat shrinking the tube of material.

21. The method according to claim 20, further comprising removing the tube of material from the flex circuit and the core wire.

22. The method according to claim 21, further comprising placing a second tube of material over the thermoformed flex circuit and the underlying portion of the core wire and heat shrinking the second tube of material.

23. The method according to claim 22, wherein the second tube of material comprises polyimide.

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