The instant disclosure relates to a temperature sensor and three-dimensional electrode.
Medical devices, catheters, and/or cardiovascular catheters, such as electrophysiology catheters can be used in a variety of diagnostic, therapeutic, mapping and/or ablative procedures to diagnose and/or correct conditions such as atrial arrhythmias, including for example, ectopic atrial tachycardia, atrial fibrillation, and/or atrial flutter. Arrhythmias can create a variety of conditions including irregular heart rates, loss of synchronous atrioventricular contractions and/or stasis of blood flow in a chamber of a heart, which can lead to a variety of symptomatic and asymptomatic ailments and even death.
A medical device can be threaded through a vasculature of a patient to a site where the diagnostic, therapeutic, mapping, and/or ablative procedure to diagnose and/or correct the condition is performed. To aid in the delivery of the medical device to the site, sensors (e.g., electrodes) can be placed on the medical device, which can receive signals that are generated proximate to the patient from a device (e.g., electromagnetic field generator). Based on the received signals, an orientation and/or position of the medical device can be computed.
Once the medical device has reached the site, one or more of the variety of diagnostic, therapeutic, mapping and/or ablative procedures to diagnose and/or correct conditions can be performed. In some of those procedures, it can be beneficial to attain a temperature at the site. Accordingly, a temperature sensor can be included on the medical device and can be configured to measure a temperature at the site.
Various embodiments of the present disclosure include a medical device that includes an elongate shaft extending along a shaft longitudinal axis and includes a shaft proximal portion and a shaft distal portion. The medical device can include an electrode disposed on the shaft distal portion. The medical device can include a first conductor lead and a second conductor lead, each of the conductor leads electrically being coupled to the electrode. A thermocouple junction formed via a thermocouple conductor can be electrically coupled to the electrode and the first conductor lead.
Various embodiments of the present disclosure include a medical device that includes an elongate shaft extending along a shaft longitudinal axis and includes a shaft proximal portion and a shaft distal portion. An electrode can be disposed on the shaft distal portion, the electrode including a three-dimensional profile portion, the three-dimensional profile portion extending upwardly from a surface. A face can extend across a top of the upwardly extending profile portion, wherein the electrode is disposed on the face.
Various embodiments of the present disclosure can include a medical device. The medical device can include an elongate shaft extending along a shaft longitudinal axis and comprising a shaft proximal portion and a shaft distal portion. An ablation tip can be connected to the shaft distal portion, wherein the ablation tip is a conductive shell disposed over an end of the shaft distal portion. A printed temperature sensor can be thermally coupled with the conductive shell, wherein the temperature sensor is a printed temperature sensor and is configured to sense a temperature of the conductive shell. A pair of leads can extend along the elongate shaft and can be electrically coupled with the temperature sensor.
Various embodiments of the present disclosure include a medical device. The medical device can include an elongate shaft extending along a shaft longitudinal axis and comprising a shaft proximal portion and a shaft distal portion. A balloon can be disposed along the shaft distal. In some embodiments, a plurality of temperature sensors can be disposed on the balloon.
Various embodiments of the present disclosure can include a medical device. The medical device can include an elongate shaft extending along a shaft longitudinal axis and comprising a proximal portion and a distal portion. The medical device can include an elevated electrode disposed on the distal portion, wherein the elevated electrode is a spherical cap. The spherical cap includes a core formed from a first conductive material. An exterior of the core can be coated with a second conductive material.
Electrodes and/or temperature sensors can be used to perform therapeutic and/or diagnostic functions in regards to the body. Electrodes and temperature sensors can be formed as separate elements on a medical device, which can be used to contact tissue associated with the body. Embodiments of the present disclosure can provide an electrode and temperature sensor that is incorporated into one element, thus allowing for the temperature sensor to measure a temperature at the site where the electrode is contacting the tissue. This can improve accuracy and can also decrease a cost of goods associated with the manufacture of the temperature sensor and electrode, by combining both the temperature sensor and electrode into one element. Additionally, embodiments of the present disclosure can provide for an electrode and/or temperature sensor that includes a three-dimensional profile. The three-dimensional profile of the electrode and/or the temperature sensor can improve contact between the electrode and/or temperature sensor and tissue of the body. For example, the three-dimensional profile can be of a raised height, which can cause the electrode and/or temperature sensor to contact the tissue before other portions of a medical device on which the electrode and/or temperature sensor are disposed. In some embodiments of the present disclosure, electrodes and/or temperature sensors can be arranged in arrays, each electrode and/or temperature sensor being connected to a processing unit via printed leads.
In some embodiments, and with reference to
With continued reference to
The shaft 22 can be an elongate, tubular, flexible member configured for movement within the body 16. The shaft 22 supports, for example and without limitation, sensors and/or electrodes mounted thereon, such as, for example, the position sensors 28, associated conductors, and possibly additional electronics used for signal processing and conditioning. The shaft 22 may also permit transport, delivery, and/or removal of fluids (including irrigation fluids, cryogenic ablation fluids, and bodily fluids), medicines, and/or surgical tools or instruments. The shaft 22 may be made from conventional materials such as polyurethane, and define one or more lumens configured to house and/or transport electrical conductors, fluids, or surgical tools. The shaft 22 may be introduced into a blood vessel or other structure within the body 16 through a conventional introducer. The shaft 22 may then be steered or guided through the body 16 to a desired location, such as the heart 18, using means well known in the art.
The position sensors 28 mounted in or on the shaft 22 of the catheter 12 may be provided for use in a variety of diagnostic and therapeutic purposes including, for example and without limitation, electrophysiological studies, pacing, cardiac mapping, and ablation. In an exemplary embodiment, one or more of the position sensors 28 are provided to perform a location or position sensing function. More particularly, and as will be described in greater detail below, one or more of the position sensors 28 are configured to provide information relating to the location (e.g., position and orientation) of the catheter 12, and the distal end portion 26 of the shaft 22 thereof, in particular, at certain points in time. Accordingly, in such an embodiment, as the catheter 12 is moved along a surface of a structure of interest of the heart 18 and/or about the interior of the structure, the position sensor(s) 28 can be used to collect location data points that correspond to the surface of, and/or other locations within, the structure of interest. These location data points can then be used for a number of purposes such as, for example and without limitation, the construction of surface models of the structure of interest.
For purposes of clarity and illustration, the description below will be with respect to an embodiment with a single position sensor 28. It will be appreciated, however, that in other exemplary embodiments, which remain within the spirit and scope of the present disclosure, the catheter 12 may comprise more than one position sensor 28 as well as other sensors or electrodes configured to perform other diagnostic and/or therapeutic functions. As will be described in greater detail below, the position sensor 28 can include a pair of leads extending from a sensing element thereof (e.g., a coil) that are configured to electrically couple the position sensor 28 to other components of the system 10, such as, for example, the medical device control system 14.
In some embodiments, electrical traces can be disposed underneath the electrode 100, which can form the temperature sensor 102. In some embodiments, the temperature sensor 102 can be a trace temperature sensor, which includes conductive electrical traces that are formed from an additive and/or subtractive manufacturing process. In an example, a first conductor lead 104-1 and a second conductor lead 104-2 can be disposed underneath the electrode 100. Additionally, a thermocouple conductor 106 can be disposed underneath the electrode 100. For example, the first conductor lead 104-1, second conductor lead 104-2, and/or the thermocouple conductor 106 can be disposed between a shaft on which the electrode 100 is disposed and the electrode 100. The first conductor lead 104-1, second conductor lead 104-2, and the thermocouple conductor 106 can be disposed underneath the electrode 100 and/or within the electrode 100, in some embodiments. The first conductor lead 104-1, second conductor lead 104-2, and the thermocouple conductor 106 can be formed via printing in some embodiments.
In an example, the electrode 100 can be formed on top of the first conductor lead 104-1, second conductor lead 104-2, and the thermocouple conductor 106 and/or around the first conductor lead 104-1, second conductor lead 104-2, and the thermocouple conductor 106. For example, by forming the electrode 100 around the first conductor lead 104-1, second conductor lead 104-2, and the thermocouple conductor 106, the first conductor lead 104-1, second conductor lead 104-2, and the thermocouple conductor 106 can be disposed within the electrode 100. In some embodiments, the electrode can be formed via an additive process, such as chemical vapor deposition (CVD).
In some embodiments, the first conductor lead 104-1 and the thermocouple conductor 106 can be electrically coupled to one another. For example, as depicted in
In some embodiments, the thermocouple conductor 106 can be formed from a type K, type J, type T or other type of material that can be used for construction of a thermocouple. For example, type K materials can include Nickel-Chromium/Nickel-Alumel; type J materials can include Iron/Constantan; and type T materials can include Copper/Constantan. In some embodiments, other materials such as Platinum Rhodium/Platinum can be used in the thermocouple conductor 106. In some embodiments, the thermocouple conductor 106 can be formed by printing the conductor. The thermocouple conductor 106 can have a thickness in a range from 0.0002 to 0.008 inches and can have a width in a range from 0.0002 to 0.008 inches, in some embodiments.
In some embodiments, power can be provided to the electrode 100 via the first conductor lead 104-1 and the second conductor lead 104-2. By providing power to the electrode 100 via the first conductor lead 104-1 and the second conductor lead 104-2, the electrode 100 can be heated to a first temperature. In an example, a therapy can be performed by placing the electrode 100 on a tissue, such as a tissue of the heart, and heating the electrode to a particular temperature by providing power via the first conductor lead 104-1 and the second conductor lead 104-2. For example, power can be provided to the electrode 100 via the first conductor lead 104-1 and the second conductor lead 104-2, causing the electrode 100 to be heated to the particular temperature. Control over the power provided to the electrode 100 from the first conductor lead 104-1 and the second conductor lead 104-2 can be modulated via the medical device control system 14 discussed in
In some embodiments, the electrode 100 can serve as an ablation electrode and electricity can be transferred through the electrode 100 via the first conductor lead 104-1 and/or the second conductor lead 104-2. For example, in some embodiments, an external patch can be placed on a patient and electricity can be transferred from the external patch through the patient and to the electrode 100 via the first conductor lead 104-1 and/or the second conductor lead 104-2.
In some embodiments, a signal can be received via the electrode 100. In an example, the electrode 100 can be placed in contact with a tissue. The tissue can generate an electrical signal, which can be received by the electrode 100 and transferred to a computer (e.g., medical device control system 14) via the first conductor lead 104-1 and/or the second conductor lead 104-2.
In some embodiments, the first conductor lead 104-1 can be a multipurpose conductor. For example, the first conductor lead 104-1 can supply power to the electrode 100 and/or receive energy from the electrode 100 in the form of electrical signals generated by the heart and/or electricity transferred through the patient via the external patch. The first conductor lead 104-1 can also complete a circuit of the temperature sensor 102. For example, as a temperature of the electrode 100 changes and thus a temperature of the temperature sensor 102 changes, the thermocouple conductor 106 can convert the change in temperature to an electrical voltage, which can be analyzed to determine the temperature of the temperature sensor 102. For example, the temperature sensor 102 can be a thermocouple formed by the first conductor lead 104-1 and the thermocouple conductor 106. Although a thermocouple is given as an example of a temperature sensor herein, the temperature sensor can be any other type of temperature sensor, including thermistors, resistance temperature detectors, electrical thermometers, bimaterial thermometers, etc. In an example, thermistors can sense temperature based on resistance and can be formed via printing. Electrical thermometers can determine temperature as a result of a resistivity change due to temperature and can be formed via printing. Bimaterial thermometers can determine temperature via detection of mechanical motion based on different thermal expansion coefficients.
As a result of embodiments of the present disclosure, temperature at a tissue that comes into contact with the electrode 100 can be better measured. Furthermore, a cost of goods associated with the electrode 100 and associated temperature sensor can be reduced as a result of the incorporation of the electrode 100 and temperature sensor into one element and also through construction of the electrode and associated temperature sensor via additive manufacturing methods, as discussed herein. In some embodiments, the electrode and associated temperature sensor can be incorporated into a three-dimensional base, as further discussed in relation to
As depicted in
In some embodiments, the three-dimensional base 202 can be formed from a deformable material. For example, the three-dimensional base 202 can be formed from a metal, polymer, or other type of material, which can be deformed via application of heat and/or pressure to the material. In an example, if the three-dimensional base 202 is formed from a metal, the three-dimensional profile portion 206 can be formed by casting the three-dimensional base 202 and/or pressing the three-dimensional base 202 (e.g., via tool and die) to form the three-dimensional profile portion 206. In some embodiments where the three-dimensional base 202 is formed from a polymer, the polymer can be formed such that the three-dimensional profile portion 206 is formed in the three-dimensional base 202. For example, the polymer can be cast such that the three-dimensional base 202 includes the three-dimensional profile portion 206 and/or the polymer can be heated and/or pressure can be applied to the polymer to form the three-dimensional profile portion 206.
In some embodiments, the three-dimensional base 202 can be formed through an additive manufacturing process. For example, in some embodiments the three-dimensional base 202 can be formed by depositing material onto a mold through an additive process, such as printing, chemical vapor deposition, etc. In some embodiments, after the material has been deposited onto the mold, the material can be cured and the mold can be released from the material, thus forming the three-dimensional base 202. In some embodiments, the three-dimensional base can be formed via a subtractive process (e.g., laser etching, chemical etching, machining, etc.).
In some embodiments, an electrode 210 can be formed on top of the three-dimensional base 202. In an example, the electrode 210 can be formed from a metallic material, in some embodiments. For instance, the electrode 210 can be formed from gold, platinum, silver, etc. As depicted, the electrode 210 can be of an elongate rectangular shape in some embodiments. However, the electrode 210 can be of another shape, which can be circular, square, rectangular, polygonal, triangular, elliptical, pyramidal, hourglass, etc.
In some embodiments, a tie layer 212 can be disposed between the three-dimensional base 202 and the electrode 210, which can help to bond the electrode 210 to the three-dimensional base 202. The tie layer 212 can be formed from a conductive material such as a metal. In an example, the tie layer 212 can be formed from a metal such as nickel, sputtered chrome, etc. A dielectric layer can be disposed beneath the tie layer, insulating the electrode 210 and the dielectric layer from the three-dimensional base 202. In some embodiments, the electrode 210 can be formed as described in U.S. application Ser. No. 15/331,562, which is hereby incorporated by reference as though fully set forth herein.
As discussed herein, an electrode and/or temperature sensor can be formed with a three-dimensional profile using additive methods. In some embodiments, however, the electrode and/or temperature sensor can be formed with a three-dimensional profile via pressing a substrate blank, as discussed below.
In some embodiments, a three-dimensional profile portion 228-b, 228-c (
In some embodiments, the three-dimensional profile portion 228-b can have a stepped profile. For example, as depicted in
In some embodiments, the upwardly extending walls of the first profile portion 232-1 and/or the second profile portion 232-2 can extend upwards at an angle that is perpendicular to the planar piece of material 222-b. In some embodiments and as depicted, the walls of the first profile portion 232-1 and/or the second profile portion 232-2 can extend upwards at an angle that is between an angle that is parallel with the planar piece of material 222-b and an angle that is perpendicular to the planar piece of material 222-b. In an example, the walls of the first profile portion 232-1 and the second profile portion 232-2 can be frustoconical in shape.
In some embodiments, an electrode can be disposed on the face 226-b contained by the sketch 224-b. For example, an electrode can be formed on a portion of the face 226-b via an additive manufacturing process, as previously discussed herein. By forming the electrode on the portion of the face 226-b, the electrode can be elevated from a surface of the planar piece of material 222-b. This can create a stand-off to a geometry of a medical device on which the electrode is disposed, allowing for a better contact between the electrode disposed on the face 226-b and tissue.
In some embodiments, the electrode can be formed on the face 226-b, the first profile portion 232-1, the profile interface 234-b, and/or the second profile portion 232-2. For example, the electrode can be disposed on one or more portions of the three-dimensional profile portion 228-b. In an example, the electrode can be disposed on portions of the three-dimensional profile portion 228-b that extend upward from the planar piece of material 222-b. In some embodiments, the electrode can be formed on the face 226-b, the first profile portion 232-1, the profile interface 234-b, and/or the second profile portion 232-2 via an additive manufacturing process.
As discussed in relation to
One or more sketches can be made on the planar piece of material 250-a, which in some embodiments can outline and/or define an area where an electrode can be disposed. For example, sketches 252-1, 252-2, 252-3, 252-4, 252-5, 252-6, hereinafter referred to in the plural as sketches 252, can be made on the planar piece of material 250-a. For example, as previously discussed herein, the area contained and/or defined by the sketches 252 can be prepared (etched, coated, etc.) in order to prepare the area for application of one or more layers of coatings, which can form an electrode. For example, an electrode can be disposed in the area contained by the sketch 252 via an additive manufacturing process, as discussed herein.
In some embodiments, a three-dimensional profile portion can be formed in the substrate blank 250-a, as previously discussed. The three-dimensional profile portion, further depicted and discussed in relation to
In some embodiments, the first three dimensional profile portion 260-1 can extend from the first edge 256 parallel with the longitudinal axis bb and toward the second edge, before crossing over the longitudinal axis bb at an angle. In some embodiments, the second three dimensional profile portion 260-2 can extend from the first edge 256 parallel with the longitudinal axis bb and toward the second edge 258, before crossing over the longitudinal axis bb at an angle. In an example, the first and second three-dimensional profile portions 260-1, 260-2 can intersect on the longitudinal axis aa. As depicted, in
As depicted, the three-dimensional profile portions 260-1, 260-2 can include profile walls and faces that form the three-dimensional portions 260-1, 260-2. For example, with respect to the first three-dimensional profile portion 260-1, this profile portion can include a first profile wall 264-1 and a second profile wall 264-2 that extend from a surface of the substrate blank 250-b. A profile face 266 can extend across the top of each profile wall 264-1, 264-2, thus defining the profile space 262-1.
In some embodiments, although not depicted, one or more electrodes can be disposed and/or formed on the sketches 252. For example, an electrode can be formed on a portion of the three-dimensional profile portions 260-1, 260-2. The electrode can be disposed along the three-dimensional profile portions 260-1, 260-2 in one or more discrete locations (e.g., spot electrodes). In some embodiments, the electrodes can be formed along an entire length and/or portions of the length of each one of the three-dimensional profile portions 260-1, 260-2. Although
As discussed in relation to
The flexible tip portion 270 can form a planar array (or ‘paddle’ configuration) of microelectrodes 274, which comprises four side-by-side, longitudinally-extending arms 274, 276, 278, 280, which can form a flexible framework on which the microelectrodes 272 are disposed. The four microelectrode-carrier arms comprise a first outboard arm 274, a second outboard arm 276, a first inboard arm 278, and a second inboard arm 280. These arms can be laterally separated from each other.
Each of the four arms can carry a plurality of microelectrodes 272. For example, each of the four arms can carry microelectrodes 272 spaced along a length of each of the four arms. Although the high density electrode mapping catheter 268 depicted in
In some embodiments, the microelectrodes 272 can be used in diagnostic, therapeutic, and/or mapping procedures. For example and without limitation, the microelectrodes 272 can be used for electrophysiological studies, pacing, cardiac mapping, and ablation. In some embodiments, the microelectrodes 272 can be used to perform unipolar or bipolar ablation. This unipolar or bipolar ablation can create specific lines or patterns of lesions. In some embodiments, the microelectrodes 272 can receive electrical signals from the heart, which can be used for electrophysiological studies. In some embodiments, the microelectrodes 272 can perform a location or position sensing function related to cardiac mapping. Additional details on one type of planar electrode array are discussed in relation to U.S. application Ser. No. 15/331,562, which is incorporated by reference as though fully set forth herein.
In some embodiments, the microelectrodes 272 can include a temperature sensor such as that depicted and discussed in relation to
In some embodiments, the microelectrodes 272 can be three-dimensional electrodes, such as those discussed in relation to
The embodiments disclosed herein, for example, those discussed in relation to
In some embodiments, each one of the radially expanding members 306-1, 306-2, 306-3, 306-4 can include an electrode 312-1, 312-2, 312-3, 312-4 disposed thereon. As the radially expanding members 306-1, 306-2, 306-3, 306-4 expand, the electrode 312-1, 312-2, 312-3, 312-4 can contact a lumen in which the radial ablation tip 302 is disposed. For example, the radial ablation tip 302 can be disposed in a renal artery and the radial ablation tip 302 can be expanded to cause the electrodes 312-1, 312-2, 312-3, 312-4 to contact an inner wall of the renal artery. Upon contact with the inner wall, the electrodes 312-1, 312-2, 312-3, 312-4 can perform a sensing and/or therapeutic function. For example, the electrodes 312-1, 312-2, 312-3, 312-4 can sense electrical signals passing along the renal artery and/or can perform an ablation to the renal artery.
In some embodiments, the electrodes 312-1, 312-2, 312-3, 312-4 can include a temperature sensor such as that depicted and discussed in relation to
In some embodiments, the electrodes 312-1, 312-2, 312-3, 312-4 can be three-dimensional electrodes, such as those discussed in relation to
The temperature sensors 330-1a, 330-2a, 332-1a, 332-2a can be printed on the exterior surface 328a, as further discussed below. In some embodiments, the temperature sensors 330-1a, 330-2a, 332-1a, 332-2a can be printed on a substrate (e.g., film) and the film can be disposed on the exterior surface 328a. In an example, the temperature sensors 330-1a, 330-2a, 332-1a, 332-2a can be disposed in a particular array on the catheter tube 322a. In an example, the temperature sensors 330-1a, 330-2a are disposed on the catheter tube 322a such that they are axially aligned with one another. Likewise, the temperature sensors 332-1a, 332-2a are disposed on the catheter tube 322a such that they are axially aligned with one another.
Although four temperature sensors 330-1a, 330-2a, 332-1a, 332-2a are depicted, any number of temperature sensors can be disposed on the catheter tube 322a. For example, a number of temperature sensors 330-1a, 330-2a, 332-1a, 332-2a disposed on the catheter tube 322a can be in a range from 1 to 100 temperature sensors 330-1a, 330-2a, 332-1a, 332-2a. In some embodiments, the temperature sensors 330-1a, 330-2a, 332-1a, 332-2a can be equally distributed about the exterior surface 328a of the catheter tube 322a and/or arranged in particular patterns about the exterior surface 328a to enable a temperature profile to be constructed based on readings from the various temperature sensors.
In some embodiments, a size of each one of the temperature sensors 330-1a, 330-2a, 332-1a, 332-2a with respect to a surface area of a tip of a catheter can be approximately one percent of the total tip area. For example, where the tip of the catheter has a dimension of 2 millimeters by 4 millimeters (e.g., 8 millimeters2), each one of the temperature sensors 330-1a, 330-2a, 332-1a, 332-2a can have a surface area that is 1 percent of the total 8 millimeters2 surface area. In some embodiments, the temperature sensors 330-1a, 330-2a, 332-1a, 332-2a can be disposed on the surface of the tip of the catheter with a density of 1 temperature sensor per 1 to 4 millimeters2 of surface area. In some embodiments, the tip of the catheter can include preferably 1 temperature sensor per 1.55 millimeters2 of surface area.
In some embodiments, the temperature sensors 330-1a, 330-2a can be thermocouples. As diagrammatically represented, the temperature sensors 330-1a, 330-2a are thermocouples. In an example, the thermocouples 330-1a, 330-2a can be connected to a processing unit (e.g., computer) via a first lead and a second lead. For example, with reference to thermocouple 330-1a, the thermocouple 330-1a can be connected to the processing unit via a first lead 334-1a and a second lead 334-2a. A first thermocouple element 338-1a can be electrically coupled with the first lead 334-1a and a second thermocouple element 338-2a can be electrically coupled with the second lead 334-2a. As further discussed below, the first thermocouple element 338-1a can be electrically coupled with the second thermocouple element 338-2a. The first thermocouple element 338-1a and the second thermocouple element 338-2a can be formed from dissimilar metals and one of the metals can be a type of metal that produces a temperature dependent electrical response (e.g., Seebeck effect).
In some embodiments, the temperature sensors 332-1a, 332-2a can be resistance temperature detectors (RTDs), as diagrammatically represented. In an example, the RTDs 332-1a, 332-2a can be connected to a processing unit (e.g., computer) via a first lead and a second lead. For example, with reference to RTD 332-1a, the RTD 332-1a can be connected to the processing unit via a first lead 336-1a and a second lead 336-2a.
Direct-write electronic additive manufacturing, such as aerosol jet, micropen and/or ink-jet application of conductive traces and dielectrics, and materials such as high conductivity inks, can be used in embodiments of the present disclosure to enable the replacement of higher cost/labor intensive EP catheter components. These may include elements such as conductors and rings, but also more complicated elements such as temperature sensors, magnetic pick-up coils and force sensors. For example, temperature sensors such as the thermocouples 330-1a, 330-2a and/or the RTDs 332-1a, 332-2a can be disposed on the EP catheter components (e.g., catheter tube 322a).
Printed temperature sensors such as those discussed in Honda et. Al. “Printed Wearable Temperature Sensors for Health Monitoring”, Sensor IEEE, 2014 can be included on the catheter components. In general, the temperature sensing array can have a temperature sensing element, conducting lead, and processing electronics, which can analyze a signal generated by the temperature sensing element.
The location and distribution of temperature sensors in the array may be optimized for prediction of both contact area and to provide initial/boundary conditions for thermal modeling of lesion depth, size etc. The temperature sensing element can be resistance based (e.g., RTD) or voltage based (e.g., thermocouple).
The process used to print the temperature sensor and associated leads onto the catheter shaft, tip or balloon can include processes for direct write printing of electronics including aerosol jet, micro-dispensing (micropen), and ink jet. Although direct write printing may be preferred, screen print and plating may also be used.
For resistance temperature detectors (RTD), these are typically comprised of a metallic trace printed in a serpentine geometry. The impedance of the RTD should be significantly higher than the leads (i.e. measured resistance predominately across sensor). The temperature dependence of the resistivity generally has two components. The first is the inherent temperature dependence of the metal bulk resistivity. The second contribution arises from the thermal expansion coefficient of the sensor construction (strain dependence of resistance). For an RTD, the relationship between a change in resistance (ΔR) and temperature is given by:
ΔR=RoαΔT
where Ro, is the resistance at temperature To, ΔT=T−To, and α is the temperature coefficient of resistance.
For most conducting metals, the temperature coefficient is approximately 0.004/° C. As an example, a 1000 ohm thermistor will have a 4 ohm increase in resistance for every degree Celsius change.
For an RTD the temperature sensitive composition can be any material which is electrically conducting and printable thru direct write printing techniques. Examples of these can include conducting inks such as those based on silver, gold, copper, platinum and carbon, to name a few. Metals can be preferred, and platinum can be particularly preferred due to the relatively high temperature coefficient and reduced sinter-ability, which can enable higher impedance elements.
The geometry of the RTD resistive formulation can be optimized for temperature sensitivity and signal stability. For thermocouples, the temperature sensing element can be comprised of a printed union of two dissimilar metals known to produce a temperature dependent open circuit voltage (Seebeck effect). These can include metal combinations of standard thermocouples including types E, 3, K, R, S and T. In addition, metal combinations can also include less conventional metal combinations that are more amenable to direct write printing.
A preferred metal combination for a direct write printed thermocouple can be platinum and gold. For thermocouples, the processing electronics can also include the necessary temperature compensation for any additional dissimilar metal combinations within the circuitry.
The catheter tube 322b can include a plurality of temperature sensors 330-1b, 330-2b, 332-1b, 332-2b, in some embodiments. The catheter tube 322b can be a portion of a catheter shaft and/or connected to a portion of a catheter shaft. In some embodiments, the catheter tube 322b can have a proximal end 324b and a distal end 326b, and can extend along a longitudinal axis and can define a lumen that extends therethrough. In some embodiments, the temperature sensors 330-1b, 330-2b, 332-1b, 332-2b can be disposed on an exterior surface 328b of the catheter tube 322b.
In some embodiments, the temperature sensors 330-1b, 330-2b can be thermocouples. In an example, the thermocouples 330-1b, 330-2b can be connected to a processing unit (e.g., computer) via a first lead and a second lead. For example, with reference to thermocouple 330-1b, the thermocouple 330-1b can be connected to the processing unit via a first lead 334-1b and a second lead 334-2b. A first thermocouple element 338-1b can be electrically coupled with the first lead 334-1b and a second thermocouple element 338-2b can be electrically coupled with the second lead 334-2b. As further discussed below, the first thermocouple element 338-1b can be electrically coupled with the second thermocouple element 338-2b. Likewise, the temperature sensors 332-1b, 332-2b can be connected to the processing unit via leads 336-1b, 336-2b.
In some embodiments, the hollow cylindrical body 354 can define a lumen 358 in which a member (e.g., elongate tubular member, catheter tube 360) can be inserted. In some embodiments, the member can be any number of devices. In an example, the member can be an elongate member, such as an elongate tubular member that includes a fluid lumen, etc. However, for purposes of discussion, the member is discussed as a catheter tube 360 herein. In some embodiments, the catheter tube 360 can include features that are similar or the same as those discussed in relation to
In some embodiments, as discussed herein, the temperature sensors 362 can be distributed across a surface of the catheter tube 360, such that a temperature across multiple areas of the ablation tip 352 can be determined. In some embodiments, a thermally insulating layer can be disposed between the surface of the catheter tube 360 and the temperature sensors 362 and/or the catheter tube 360 can be formed from a thermally insulating material. Accordingly, this can increase an accuracy at which the temperature sensors 362 collect temperature data from the ablation tip 352, because the main source of thermal activity measured by the temperature sensors 362 will come from the ablation tip 352 and not the catheter tube 360, which is thermally insulated from the temperature sensors 362.
As depicted, in some embodiments, the ablation tip can include irrigation ports 366-1, 366-2, 366-3. However, in some embodiments, no irrigation ports 366-1, 366-2, 366-3 can be included in the ablation tip 352. In some embodiments, based on a determination of a temperature of the ablation tip 352 made from a signal obtained from one of the RTDs 362, an energy supplied to the ablation tip 352 and/or an amount of irrigation fluid supplied via the irrigation ports 366-1, 366-2, 366-3 can be adjusted. As previously discussed in relation to
As depicted, the temperature sensors 386 can be concentrically disposed along the ablation balloon 382 along an outer most circumference of the ablation balloon 382. For example, the temperature sensors 386 can be uniformly disposed about a point 388 on the axis cc. For example, the temperature sensors 386 can be disposed on the ablation balloon 382 at a same axial distance along the axis cc. Alternatively, in some embodiments, the temperature sensors 384 can be disposed at varying axial distances along the axis cc. For example, some of the temperature sensors 394 can be disposed proximally or distally with respect to the point 388 on the axis cc.
Each one of the temperature sensors can be electrically coupled with a processing unit via a pair of leads. In an example, with reference to the temperature sensor 386-4, the temperature sensor 386-4 can be coupled with the processing unit via a first lead 390-1 and a second lead 390-2.
In some embodiments, the temperature sensors 410 can be printed on an exterior surface or an interior surface of the ablation tip 402, as discussed herein. In an example, where the temperature sensors 410 are printed on an interior surface of the ablation tip 402, the ablation tip 402 and specifically the hollow cylindrical body 404 and the domed tip 406 can define a lumen. For example, an interior surface of the hollow cylindrical body 404 and an interior surface of the domed tip 406 can define the lumen. The temperature sensors 410 can be placed on the interior surface, such that the temperature sensors 410 are in contact with the ablation tip 402. In some embodiments, the temperature sensors 410 can be placed on the exterior surface of the ablation tip 402. Accordingly, as the ablation tip 402 is heated to perform an ablation, the temperature sensors 410 can measure a temperature of the ablation tip 402. In some embodiments, as discussed herein, the temperature sensors 410 can be distributed across an interior or exterior surface of the ablation tip 402, such that a temperature across multiple areas of the ablation tip 402 can be determined.
As depicted, in some embodiments, the ablation tip can include irrigation ports 412-1, 412-2, 412-3. However, in some embodiments, no irrigation ports 412-1, 412-2, 412-3 can be included in the ablation tip 402. In some embodiments, based on a determination of a temperature of the ablation tip 402 made from a signal obtained from one of the temperature sensors 410, an energy supplied to the ablation tip 402 and/or an amount of irrigation fluid supplied via the irrigation ports 412-1, 412-2, 412-3 can be adjusted. As previously discussed in relation to
Some embodiments of the present disclosure can include a multiplexing chip, which can be used to cycle through the first temperature sensor 422-1 and the second temperature sensor 422-2. For example, the first temperature sensor 422-1 and/or the second temperature sensor 422-2 can be activated via the multiplexing chip, allowing for a temperature to be determined via the first temperature sensor 422-1 and/or the second temperature sensor 422-2.
In some embodiments, the computing device 436 can include a processor 438 and memory 440. The memory 440 can be a non-transitory computer readable medium that stores instructions executable by the processor 438 to perform a particular function. For example, the memory 440 can store instructions that are executable by the processor 438 to analyze the signals received from the thermocouple 432.
In some embodiments, the array 450 of temperature sensors 452-1, 452-2, . . . , 452-8 can be disposed on a substrate 462. In some embodiments, the substrate 462 can be a surface associated with a catheter ablation tip. For example, the substrate 462 can be an interior surface of an ablation tip and/or an exterior surface of the ablation tip. In some embodiments, the substrate 462 can be a planar sheet of material (e.g., film) on which the temperature sensors 452-1, 452-2, . . . , 452-8 and associated leads are formed. In some embodiments, where the substrate 462 is a planar sheet of material on which the temperature sensors 452-1, 452-2, . . . , 452-8 and associated leads are formed, the substrate can be adhered to an interior or exterior surface of the catheter ablation tip.
In some embodiments, where the array 450 of temperature sensors 452-1, 452-2, . . . , 452-8 is disposed on a catheter ablation tip, the common return lead 454 can be electrically coupled with the catheter ablation tip. In an example, the catheter ablation tip can include one or more tip leads that extend proximally along the catheter shaft. Accordingly, the one or more tip leads can act as return leads that are electrically coupled to the catheter ablation tip and thus to the common return lead 454. Additionally, in some embodiments, a radiofrequency (RF) signal that is used to drive the ablation tip can provide power to the temperature sensors 452-1, 452-2, . . . , 452-8. Accordingly, power can be provided to each one of the temperature sensors 452-1, 452-2, . . . , 452-8 via the RF signal and each one of the temperature sensors 452-1, 452-2, . . . , 452-8 can include a proximally extending return lead (e.g., proximally extending return lead 460) that in some embodiments can be electrically coupled to the catheter ablation tip. In such an embodiment, the array may or may not utilize the source leads 456-1, 456-2, . . . , 456-8 to provide power to each one of the temperature sensors 452-1, 452-2, . . . , 452-8.
In some embodiments, each one of the radially expanding members 474-1, 474-2, 474-3, 474-4 can include one or more electrodes 478 disposed thereon. Only electrode 478 is depicted for ease of clarity. As the radially expanding members 474-1, 474-2, 474-3, 474-4 expand, the electrode(s) 478 can contact a lumen in which the radial ablation tip 472 is disposed. For example, the radial ablation tip 472 can be disposed in a renal artery and the radial ablation tip 472 can be expanded to cause the electrode(s) 478 to contact an inner wall of the renal artery. Upon contact with the inner wall, the electrode(s) 478 can perform a sensing and/or therapeutic function. For example, the electrode(s) 478 can sense electrical signals passing along the renal artery and/or can perform an ablation to the renal artery. In some embodiments, the electrode(s) 478 can be three-dimensional electrodes, such as those discussed in relation to
In some embodiments, the electrode(s) 478 can include one or more electrical leads 480 that connect the electrode 478 to a contact pad 482, which can be disposed on a proximal end of one of the radially expanding members 474-1, 474-2, 474-3, 474-4 (e.g., radially expanding member 474-1). As depicted the one or more electrical leads 480 can extend from the electrode 478 proximally down the radially expanding member 474-1. The electrical leads and their construction is further discussed herein, in relation to
In some embodiments, the electrode(s) 478 can include a temperature sensor 484 such as that depicted and discussed in relation to
In some embodiments, the dielectric material 504 may not coat an entirety of the understructure. For example, the dielectric material 504 can be disposed along each radially expanding member up to a distal transition point 508 of each one of the radially expanding members 502-1, 502-2, 502-3, 502-4. With respect to the radially expanding member 502-1, the dielectric material 504 can coat the connective member portion 506-1 of the radially expanding member 502-1, a proximal transition portion 512-1 of the radially expanding member 502-1, and a central portion 514-1 of the radially expanding member 502-1. The dielectric coating 504 can stop at a transition between the distal transition portion 510-1 and the central portion 514-1. In an example, further steps can include depositing a temperature sensor and/or an electrode along the dielectric material 504. In some embodiments, where a temperature sensor and/or electrode are deposited on distal transition portion 510-1, the dielectric material 504 can be extended further distally along each one of the radially expanding members 502-1, 502-2, 502-3, 502-4, for example, such that it covers the distal transition portion 510-1, thus providing for an insulating material between the temperature sensor and/or electrode and the understructure forming the radially expanding members 502-1, 502-2, 502-3, 502-4.
Large electrodes (which have low impedance) can cover comparatively large areas of the myocardium and/or other tissue and can blur an electrogram map, as a result from electrical signals being collected from a larger area of the tissue surface. This can make diagnosis of a particular condition difficult or inaccurate, because the electrode may not be able to pinpoint an area producing a particular electrical signal. For example, the electrode may be disposed over a larger area, which can cause the electrode to collect electrical signals not from one particular area, but over the larger area. However, smaller electrodes can increase an impedance associated with the electrode. While prior attempts have been made to add coatings or surface area modifications to increase the overall surface area without changing the electrode size, this requires additional processing steps and/or harsh chemicals.
To overcome the electrode size versus impedance issue, some embodiments can include an electrode that can protrude from a surface of a substrate associated with a medical device. In some embodiments, the substrate can be disposed on a distal portion of a catheter. In some embodiments, the substrate can be disposed on an end effector located at a distal portion of the catheter. In some embodiments, the electrode can be include a spherical cap and/or can be configured as a cylindrical shape, versus a planar circle and/or oval, which can lower the overall impedance, help ensure better tissue contact, and can be accomplished with minimal extra process steps and/or harsh chemicals.
As depicted in
The elevated electrode 542 can be configured as a spherical cap, in some embodiments, as depicted in
In some embodiments, the elevated electrode 542 can be formed from a conductive material. For example, in some embodiments, the elevated electrode 542 can be formed from gold. However, solely constructing the elevated electrode 542 from gold can add additional cost to construction and can provide for a more complicated process associated with construction of the elevated electrode. Further, a total height of the electrode can be limited when the elevated electrode 542 is constructed entirely from a material, such as gold. In some embodiments, as depicted in
As further depicted in
One or more embodiments of the present disclosure can be combined. For example, embodiments of the present disclosure can provide an electrode and temperature sensor that is incorporated into one element. In some embodiments, the electrode and temperature sensor that is incorporated into one element can include a three-dimensional profile, as discussed herein. In some embodiments, the electrode and temperature sensor can be arranged in an array with each electrode and/or temperature sensor being connected to a processing unit via printed leads. Embodiments are described herein of various apparatuses, systems, and/or methods. Numerous specific details are set forth to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and depicted in the accompanying drawings. It will be understood by those skilled in the art, however, that the embodiments may be practiced without such specific details. In other instances, well-known operations, components, and elements have not been described in detail so as not to obscure the embodiments described in the specification. Those of ordinary skill in the art will understand that the embodiments described and illustrated herein are non-limiting examples, and thus it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments, the scope of which is defined solely by the appended claims.
Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” or “an embodiment”, or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment(s) is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in an embodiment,” or the like, in places throughout the specification, are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, or characteristics of one or more other embodiments without limitation given that such combination is not illogical or non-functional.
It will be appreciated that the terms “proximal” and “distal” may be used throughout the specification with reference to a clinician manipulating one end of an instrument used to treat a patient. The term “proximal” refers to the portion of the instrument closest to the clinician and the term “distal” refers to the portion located furthest from the clinician. It will be further appreciated that for conciseness and clarity, spatial terms such as “vertical,” “horizontal,” “up,” and “down” may be used herein with respect to the illustrated embodiments. However, surgical instruments may be used in many orientations and positions, and these terms are not intended to be limiting and absolute.
Although various embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of this disclosure. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the devices. Joinder references (e.g., affixed, attached, coupled, connected, and the like) are to be construed broadly and can include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relationship to each other. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure can be made without departing from the spirit of the disclosure as defined in the appended claims.
Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
Filing Document | Filing Date | Country | Kind |
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PCT/US18/46953 | 8/17/2018 | WO | 00 |
Number | Date | Country | |
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62546911 | Aug 2017 | US |