Aggressive Temperature Sensor System

Abstract

Disclosed is a device (1), associated kit, and associated method for measuring temperature at one or more locations within an organ or tissue inside a human or animal body. The device includes a catheter tube (2) having a distal end for insertion into the body and a proximal end for remaining outside the body during use of the device. The device includes at least one resistance temperature sensor (3) within the tube and a plurality of electrical wires (4) within the tube connected to the at least one resistance temperature sensor (3). The plurality of electrical wires includes at least some electrical wires extending from the proximal end of the tube (2) through the tube. The device includes a connector (21) at the proximal end of the tube (2) for electrically connecting the plurality of electrical wires (4) to an external device. The resistive temperature sensor (3) includes a thermal resistor (11), a first terminal (12) and a second terminal (13), and is capable of measuring the temperature-dependent resistance of the thermal resistor between the first terminal and the second terminal, and each of the two terminals (12, 13) of the resistive temperature sensor (3) is directly connected to at least one of the plurality of electrical wires (4).

Description

Technical Field

[0001] Technical Field of the Invention The present invention relates to the field of interventional medical devices, and more particularly to sensor catheter devices. Specifically, the present invention relates to devices, related kits and / or systems for measuring temperature at one or more locations inside the body of a human or animal, and methods of manufacturing such devices.

Background Art

[0002] Background of the Invention In various medical procedures, there is a need for means and methods for accurately monitoring the temperature inside the body of an animal or human. Catheters are commonly used to measure characteristics at specific sites inside the body. For example, US 5,916,153 discloses a catheter for urethral insertion that includes a temperature sensor and a conductive wire embedded in the catheter wall.

[0003] Many catheters known in the art are adapted for use through the skin, such as intravascular use. However, the insertion of such catheters involves a risk of infection, especially at the tip of the catheter and at the insertion site where the epidermis is penetrated. Furthermore, in order to minimize damage to the body and its internal organs, a compact configuration and / or a high degree of miniaturization are highly desirable. For example, the sensor configuration should preferably fit into a catheter having a reasonably small diameter. For example, an organ may be very susceptible to damage by puncture. Also, when a catheter is inserted into an organ at an angle, for example, in the case of an entry vector having a substantial tangential component with respect to the outer surface of the organ, there is an additional risk of rupturing or cutting the vascular structure within the organ. Such puncture wounds, cuts and / or ruptures should generally be avoided or at least minimized, especially since such damage can potentially cause life-threatening internal bleeding. These considerations are particularly important for the liver, an organ that is particularly vulnerable to damage due to its high density of angiogenesis.

[0004] In the case of hyperthermia, the body temperature of a human or animal is artificially raised and maintained at the raised level. This approach can be used to target heat-sensitive cancer cells, but the raised temperature needs to be accurately controlled to avoid damage to healthy cells. Therefore, direct monitoring of the temperature within the body, especially within organs that are very susceptible to the effects of overheating, is necessary or at least desirable in such treatments. The liver has a very active metabolism and therefore monitoring the temperature within the liver is a top priority to prevent overheating. It will also be apparent that it may be advantageous to measure the temperature at multiple locations within the liver. However, as mentioned above, invasively measuring the temperature within the liver also carries a high risk that should be minimized.

[0005] In this technique, it is well-known to use optical detection to determine the temperature inside the body using a catheter device. For example, GB2308652 discloses a temperature-sensitive catheter including an optical fiber having a diffraction grating, and measures the temperature using the temperature dependence of the Bragg wavelength. This approach has the additional advantage that multiple Bragg gratings can be coupled to a single fiber at multiple locations within the catheter, for example using different grating frequencies. However, even if a compact device can be realized, this approach may have limited achievable measurement accuracy, and other dependencies such as the effect of strain on the Bragg wavelength may interfere with the measurement.

[0006] As another example, US9,289,606 discloses a catheter system for electropermeation-mediated therapy and similar physical therapies, in which the tip electrode includes a cavity, and the inner surface of the cavity is impregnated or coated with a thermochromic / thermotropic material whose color changes with temperature changes. Therefore, the electrode temperature can be monitored by analyzing the spectrum via an optical fiber.

[0007] US6,519,485 discloses a system for evaluating organ function. The tip of the optical fiber delivery assembly extends into or within an internal organ and irradiates the tissue. Further, the temperature is detected at the tip, and a collection fiber collects the light scattered, reflected, or emitted from the surrounding tissue. The intended use of this system is to rapidly detect changes in metabolism within an organ such as the liver, for example the onset of shock, before they appear in blood chemistry, cardiovascular metrics, or other health metrics typically monitored in a hospital environment. The temperature sensor can be implemented according to the disclosure of this prior art as a specific example, or as an electrically connected sensing element such as a thermistor, or by an optical-based technique such as infrared thermography. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0008] However, in this technology, there is still a need to provide means and methods for monitoring the temperature inside the body, for example, inside an organ. Preferably, the temperature is monitored at a plurality of spaced locations, for example, along the longitudinal segments of a catheter, such that local differences in temperature can be detected and / or an average calculation can be performed. As described above, a compact arrangement is highly preferred, for example, to avoid or minimize organ damage.

[0009] Summary of the Invention An object of the present invention is to provide a compact, simple, efficient, low-cost, and / or safe device for accurately measuring temperature at one or more locations along an insertion path inside the body of a human or animal, and to provide a method for easily, efficiently, and / or reliably manufacturing such a device. Means for Solving the Problems

[0010] Embodiments of the present invention have the advantage that they can accurately monitor the temperature inside the body of an animal or human, for example, the temperature of an organ.

[0011] Embodiments of the present invention have the advantage that they can monitor the temperature inside the body of an animal or human, for example, the temperature inside an organ, at different positions, for example, at a plurality of different depths, inside the target organ or tissue.

[0012] Embodiments of the present invention have the advantage that by incorporating a temperature sensor into a catheter structure, it is possible to appropriately separate the foreign object inserted into the body from the body while easily and quickly achieving thermal equilibrium between the sensor and the surrounding body tissue.

[0013] Embodiments of the present invention have the advantage that a compact structure, for example, a catheter structure with a small diameter, is provided, which effectively reduces the risk of infection and / or tissue damage caused by puncture, cutting, tearing, and / or laceration.

[0014] Embodiments of the present invention have the advantage that, for example, a soft and / or mechanically flexible (i.e., non-rigid) structure is provided to avoid or reduce tissue damage. For example, a catheter tube can form a soft and / or highly flexible package.

[0015] Embodiments of the present invention have the advantage that the temperature can be accurately and safely measured at a plurality of measurement points within the liver.

[0016] Embodiments of the present invention have the advantage that accurate monitoring of the temperature inside the body can be achieved, and thus, based on these measured values, the thermal parameters of hyperthermia treatment can be controlled to achieve good treatment effectiveness while avoiding potential lethal overheating of the body or particularly heat-sensitive organs inside the body.

[0017] Embodiments of the present invention have the advantage that simple and reliable temperature sensors, such as standard resistance temperature detectors (RTDs) like PT100 or PT1000 sensors, are used. For example, the prior art may rely on more complex temperature conversion approaches, such as optical detection of temperature-dependent optical properties, which can be error-prone, less reliable, more costly, less accurate, and / or more difficult to read out and / or calibrate.

[0018] Embodiments of the present invention have the advantage that a plurality of temperature measurement points can be provided along the detection region of the catheter, and at each measurement point, a 3-wire or 4-wire readout method can be used without the need for 3 or 4 wires per measurement point extending along the length of the catheter. Since the number of wires required can be effectively reduced, the diameter of the catheter can also be kept small.

[0019] Embodiments of the present invention have the advantage that a reliable temperature measurement within an organ or tissue can be obtained by averaging the temperatures measured at a plurality of measurement points.

[0020] Embodiments of the present invention have the advantage that the temperature within an organ or tissue can be characterized in detail by determining the temperature at a plurality of measurement points within the organ or tissue.

[0021] The above object is achieved by an apparatus and method according to embodiments of the present invention. In a first aspect, the present invention relates to an apparatus for measuring the temperature at one or more locations within an organ or tissue inside the body of a human or animal. The apparatus comprises a catheter tube having a distal end and a proximal end, the distal end being adapted to be inserted into or onto an organ or tissue of the body, and the proximal end remaining outside the body during use of the apparatus. The apparatus comprises at least one resistance temperature sensor within the tube and a plurality of electrical wires within the tube connected to the at least one resistance temperature sensor. The plurality of electrical wires may include at least some electrical wires extending through the tube from the proximal end of the tube and may include wire segments extending between pairs of resistance temperature sensors. The apparatus comprises a connector at the proximal end of the tube for electrically connecting at least a portion of the plurality of electrical wires to an external device. The resistance temperature sensor includes a thermal resistor, a first terminal, and a second terminal, and the temperature-dependent resistance of the thermal resistor can be measured between the first terminal and the second terminal. Each of the two terminals of each resistance temperature sensor is directly connected (e.g., soldered) to at least one of the plurality of electrical wires.

[0022] In an apparatus according to an embodiment of the present invention, the plurality of electrical wires may be helically twisted together.

[0023] In an apparatus according to an embodiment of the present invention, the thermal resistor may be a platinum resistor, such as a PT100 resistor or a PT1000 resistor.

[0024] In an apparatus according to an embodiment of the present invention, the resistance temperature sensor may include a thin film substrate. In the device according to an embodiment of the present invention, the thermal resistor may include an elongated conductive metal trace arranged in a serpentine pattern on a substrate.

[0025] In the device according to an embodiment of the present invention, the resistance temperature sensor may have a thickness in the range of 50 μm to 150 μm, a width in the range of 100 μm to 700 μm, for example in the range of 100 μm to 350 μm, and a length in the range of 1 mm to 10 mm.

[0026] In the device according to an embodiment of the present invention, the electrical wire (for example, each electrical wire) may have a diameter in the range of 10 μm to 100 μm, for example in the range of 30 μm to 80 μm.

[0027] In the device according to an embodiment of the present invention, the catheter tube may have an outer diameter in the range of 463 μm to 820 μm and an inner diameter in the range of 260 μm to 514 μm.

[0028] In the device according to an embodiment of the present invention, at least one resistance temperature sensor may be a plurality of resistance temperature sensors.

[0029] In the device according to an embodiment of the present invention, a first plurality of electrical wires (for example, among the plurality of electrical wires) may connect a plurality of resistance temperature sensors in series so that current flows through the plurality of resistance temperature sensors during operation of the device. The first plurality of electrical wires - a first wire extending from the proximal end of the tube to the first terminal of the first resistance temperature sensor in the series connection, - a second wire extending from the proximal end of the tube to the second terminal of the last resistance temperature sensor in the series connection, - a plurality of wire segments, each connecting the second terminal of the previous resistance temperature sensor in the series connection to the first terminal of the next resistance temperature sensor in the series connection (where "previous" and "next" refer to a pair of adjacent sensors in the series connection) comprise or consist of.

[0030] In the device according to an embodiment of the present invention, at least one of the two terminals of the resistance temperature sensor may be directly connected (e.g., soldered) to at least two of the plurality of electrical wires extending from the proximal end of the tube so that each resistance temperature sensor is read using a 3-wire or 4-wire readout configuration.

[0031] In the device according to an embodiment of the present invention, a second plurality of electrical wires (e.g., among the plurality of electrical wires) for measuring a voltage difference may extend from the proximal end of the tube and be connected to a plurality of resistance temperature sensors. The second plurality of electrical wires may include - a first wire extending from the proximal end of the tube and connected to a first terminal of a first resistance temperature sensor in a series connection, - a second wire extending from the proximal end of the tube and connected to a second terminal of the last resistance temperature sensor in a series connection, - a plurality of wires extending from the proximal end of the tube and connected to corresponding ones of the wire segments or to the terminals to which the wire segments (43) are connected and may consist of or include the same.

[0032] The first plurality of wires and the second plurality of wires may mean separate sets of wires.

[0033] The device according to an embodiment of the present invention may include structural wires in the tube, for example, to reduce the flexibility of the tube and / or increase the axial rigidity of the tube without substantially increasing its bending stiffness. The structural wires may advantageously provide additional strength to the tube and / or increase safety when pulling out the inserted device from the body, for example, preventing the tube from being damaged when pulled back.

[0034] In the device according to an embodiment of the present invention, the structural wire may be made of tungsten or a tungsten alloy. In the device according to an embodiment of the present invention, the structural wire may include or consist of stainless steel, such as SS316, carbon fiber, titanium, gold, another metal or metal alloy, and / or polymer fiber. The embodiments are not necessarily limited to these exemplified materials.

[0035] In the device according to an embodiment of the present invention, the thickness of the structural wire may be in the range of 40 μm to 150 μm.

[0036] The device according to an embodiment of the present invention may include one or more filling materials that fill the tube, i.e., fill the void(s) in the tube that are not occupied by other device features, such as the otherwise empty space within the tube. For example, the one or more filling materials may include a deformable filling material. For example, different sections (e.g., separated longitudinally) may be filled with different filling materials having, for example, different properties. For example, the flexibility of at least one section may be higher than the flexibility of at least one other section. For example, the tube may include flexible and non-flexible (i.e., less flexible or substantially rigid) sections.

[0037] The device according to an embodiment of the present invention includes an integrated circuit operatively connected to a connector for storing data to provide the data to an external device upon connection. The data includes identification information and / or calibration information and / or sterilization information and / or sensor logging information.

[0038] The device according to an embodiment of the present invention may include at least one optical fiber. During use of the device, the optical fiber sends an optical signal to an organ or tissue and collects the return optical signal from the organ or tissue, whereby, in addition to temperature, one or more other physiological parameters of the organ or tissue can be monitored via the optical fiber.

[0039] In a second aspect, the present invention relates to an apparatus according to an embodiment of the first aspect of the present invention and - a needle for piercing the skin, - a guide sheath for inserting a tube into the body through the skin puncture, - a reading device for providing temperature values based on currents and / or voltages measured using a plurality of electrical wires when operatively connected to a connector. It comprises one or more selected from among.

[0040] In a third aspect, the present invention relates to a method of manufacturing an apparatus according to an embodiment of the first aspect of the present invention. The method includes - fabricating or obtaining one or more resistance temperature sensors, each resistance temperature sensor including an elongated conductive metal trace on a thin film substrate, the metal trace being arranged in a serpentine pattern between a first terminal and a second terminal, - connecting a plurality of electrical wires to the one or more resistance temperature sensors, and - inserting the one or more resistance temperature sensors and the plurality of electrical wires into a catheter tube such that at least some of the electrical wires remain accessible (through the proximal end of the tube), - mechanically connecting a connector to the proximal end of the tube such that an external device can be operatively connected to the one or more resistance temperature sensors via the connector, and electrically connecting the connector to the plurality of electrical wires.

[0041] The above and other aspects of the present invention will become apparent from and be elucidated with reference to the embodiments described hereinafter.

[0042] The independent claims and the dependent claims describe specific preferred features of the present invention. The features of the dependent claims can be combined, as appropriate, with the features of the independent claims and with the features of other dependent claims, and are not necessarily limited to those explicitly described in the claims.

Brief Description of the Drawings

[0043]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0044] The drawings are schematic and non-limiting. Elements in the drawings are not necessarily drawn to an exact scale; for example, an element may be exaggerated for illustrative purposes or the scale may be reduced in order to keep the drawings clear and understandable. The present invention is not necessarily limited to the specific embodiments of the present invention shown in the drawings. The reference signs in the claims should not be construed as limiting the scope. The same reference signs in different drawings may indicate the same or similar elements.

[0045] Detailed Description of Embodiments The present invention is limited only by the appended claims, regardless of the embodiments as specific examples described below. The appended claims are expressly incorporated into this detailed description, and each claim, and each combination of claims recognized by the dependent structures defined by the claims, constitutes another embodiment of the present invention.

[0046] The term "comprise" used in the claims is not limited to the features, elements or steps described thereafter, and does not exclude additional features, elements or steps. Thus, it identifies the presence of the described features without precluding the further presence or addition of one or more features.

[0047] Recitations of order such as first, second, etc. in this specification and / or in the claims may be used to distinguish similar elements and are not necessarily intended to define an order in any sense, including temporal, spatial, ranking or any other manner. Such terms may be interchangeable in appropriate circumstances and embodiments of the invention may be related to sequences other than those explicitly recited or shown herein.

[0048] Recitations of space such as top, bottom, upper, lower, etc. in this specification and / or in the claims are used for illustrative purposes and are not necessarily solely for the purpose of describing relative position. As will be apparent to those skilled in the art, embodiments may be related to other positional arrangements of elements described with reference to such space recitations where relative positional relationships are not required to achieve the desired technical effect, i.e., to solve the underlying objective technical problem. Thus, such terms may be interchangeable in appropriate circumstances and it is clear that embodiments of the invention may function in orientations other than those described or shown herein.

[0049] In this detailed description, various specific details are set forth. Embodiments of the invention may be practiced without these specific details. Further, well-known features, elements, and / or steps are not necessarily described in detail for the sake of clarity and conciseness of this disclosure.

[0050] Throughout this specification, when "one embodiment" or "an embodiment" is mentioned, it means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, the appearance of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification does not necessarily refer to the same embodiment, although it may. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, as would be apparent to one skilled in the art from this disclosure. The references "embodiment" or "in an embodiment" should be interpreted in the same manner.

[0051] Various features of the invention may be grouped together in a single embodiment, drawing, or description thereof for the purpose of simplifying the disclosure and facilitating understanding of aspects of the invention. This should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, aspects of the invention may reside in fewer than all features of a single foregoing disclosed embodiment, as expressly recited in the description. Thus, the claims following the detailed description are expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of the invention.

[0052] Furthermore, although some embodiments described herein include some features and not other features included in other embodiments, as will be understood by one of ordinary skill in the art, combinations of features of different embodiments are intended to be within the scope of the invention and to constitute different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0053] In the description provided herein, numerous specific details are set forth. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In other instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this description.

[0054] In a first aspect, the present invention relates to an apparatus for measuring temperature at one or more locations inside the body of a human or animal. For example, the apparatus may be adapted to monitor the temperature of an organ or tissue inside the body.

[0055] Figures 1 and 2 show, as specific examples, an apparatus 1 according to an embodiment of the present invention. The apparatus may be a catheter, or may include a catheter, or may be regarded as a catheter. The apparatus includes a catheter tube 2, in particular, a thin tube, such as a long and thin hollow tube, adapted to be inserted into the body of a human or animal, for example, into an organ of a subject.

[0056] The catheter tube 2, for example an elongated catheter body, typically includes a central channel (or more precisely, the central channel is formed by the surrounding tube). The catheter tube 2 may include multiple channels, for example so that the device can be used simultaneously (or concurrently) for multiple functions, and in this case the different functionalities are provided by adapting different channels. For example, additional channels may be adapted for the injection or extraction of fluids into the body and guide optical fibers for measurements inside the body mediated (or for example converted) by optical phenomena. However, in a preferred embodiment, the catheter tube 2 includes a single channel and may be, for example, a cylindrical body whose cross-section is not partitioned (for example, radially partitioned, angularly partitioned) (not limited to other elongated shapes, for example those having an elongated prism shape or a non-uniform cross-sectional shape, for example a flexible catheter may be deformable into a number of non-standard shapes). It is desirable that the diameter of the catheter tube be as small as possible, and it may not be optimal to implement multiple channels in the device. However, depending on the application, the ability to implement additional functions may offset the drawback of an increased diameter, for example especially when the option is to insert an additional catheter into the body.

[0057] The tube 2 may have a diameter corresponding to 21G to 26G, preferably 22G to 24G, for example 23G, in the Birmingham wire gauge (stainless steel wire gauge) ("G" simply refers to the conventional "gauge" in the art and is not a conventional unit of measurement). In other words, the tube may have an outer nominal diameter in the range of 463μm to 820μm, preferably in the range of 717μm to 566μm, for example in the range of 0.63 to 0.65mm (for example 641μm, for example 641.4μm).

[0058] The tube 2 has a distal end that is closed and intended to be inserted into the body, and a proximal end (different from the first end) that is intended to remain outside the body during normal use of the device. For example, at the proximal end, the tube can contact a connector. The terms "distal" and "proximal" are used merely to distinguish these ends and are not intended to imply any other characteristics.

[0059] The tube 2 may be made of a medical-grade material, such as a medical-grade polymer material, or may include a medical-grade material, such as a medical-grade polymer material. In particular, such a medical-grade material may be inert or substantially inert, non-reactive or substantially non-reactive with respect to body fluids and, preferably, other fluids to which it may be exposed during normal use. The material may include silicone rubber material, nylon material, polyurethane material, polyvinyl chloride material, polyethylene terephthalate (PET) material, latex material, and / or thermoplastic elastomer material. For example, the tube may advantageously be made of or may include silicone, which is inert and non-reactive.

[0060] The silicone rubber material may be polydimethylsiloxane (PDMS, also called dimethyl polysiloxane), or may include it. A suitable biomedical-grade elastomer material may be commercially available under the name SILASTIC Q7-4750 from Dow Corning. Another preferred material may be polyimide and / or polyurethane. The tube may be specially processed, for example platinum-cured, to improve (enhance) its biocompatibility.

[0061] The tube may be a composite (or combination) of a plurality of materials, for example a bulk material (such as the above material), for example silicone and / or natural latex, and a coating applied to at least the outer (external, radially outward) surface of the tube. Such a coating may consist of, or include, for example polytetrafluoroethylene, and / or a hydrogel and / or a silicone elastomer. The coating may be, or include, a hydrophilic surface coating that creates a lubricious film layer when wet so that the tube can be inserted into the body more easily and safely.

[0062] Generally, the tube material, the plurality of materials and / or the coating(s) may include a wide range of materials, such as polymer materials, that have good biocompatibility when exposed to blood and / or interstitial fluid.

[0063] The tube may be a flexible tube known in the art for use, for example, as a soft catheter. Even if the tube can be considered flexible, the specific stiffness of the tube may vary depending on the embodiment, for example according to the specific requirements for the intended use. Further, the tube preferably has a small diameter, for example to avoid or reduce possible body damage, so the stiffness of the tube itself may not be optimal and, as will be further described below, can be increased by a wire and / or material that fills the tube. The length of the tube 2 may be substantially longer than that shown in FIG. 1 (shown by the dashed line), and it should be noted that the flexibility of the tube may be exaggerated at the bend as shown.

[0064] Device 1 comprises at least one resistance temperature sensor 3, which is a temperature sensor including an electrical conductor 11 (also called a thermal resistor), and the electrical conductor has a temperature-dependent resistance so that the temperature of the conductor, which is assumed to be in thermal equilibrium with its environment, for example, can be determined by measuring the resistance of the electrical conductor. For example, the resistance temperature sensor (or at least one of the resistance temperature sensors, for example, each of the resistance temperature sensors) may be (or may include) a thermistor or a resistance temperature detector (RTD). This (or each) resistance temperature sensor 3 includes a first terminal 12 and a second terminal 13 (i.e., electrical connection points), and the temperature-dependent resistance can be measured between these terminals. For example, terminals 12 and 13 may be bond pads to which wires can be soldered.

[0065] In particular, the resistance temperature sensor may be (or may include) a thermal resistor 11. The thermal resistor 11 may be a platinum resistor, for example, made of platinum or a platinum alloy. The platinum material may be substantially pure or may be doped to adjust its properties. The advantage of platinum is that it has a sufficiently strong and stable (for example, repeatable) resistance-temperature relationship and good linear behavior near body temperature. Furthermore, platinum is inert in the human body, for example, biocompatible and hypoallergenic.

[0066] The thermal resistor may have a resistance of about 1000 Ω (for example, 1 kΩ) (ignoring the normal error margins in manufacturing, for example, at a specific reference temperature). For example, the resistance temperature sensor 3 may be a PT1000 sensor. However, the thermal resistor according to embodiments of the present invention may have different values, for example, about 100 Ω (for example, 0.1 kΩ), or any value in the range of, for example, 10 Ω to 10,000 Ω, preferably in the range of 50 Ω to 5 kΩ (at the temperature of interest, for example, the reference body temperature).

[0067] The thermal resistor 11 may include a conductive, for example metallic, trace on a substrate. In particular, in a preferred embodiment, the substrate may be a thin film substrate. For example, the thin film substrate may have a thickness in the range of 25 μm to 250 μm, preferably in the range of 75 μm to 125 μm, for example about 100 μm.

[0068] For example, the thermal resistor may be fabricated using thin film lithography. Thus, the thermal resistor may be formed by depositing a conductive material, for example a metal (such as platinum), on a thinned semiconductor substrate, for example a thinned silicon wafer, and patterning this using high resolution photolithography techniques to form a trace. For example, the thickness of the conductive material layer forming the resistive element may be as little as 1 nm to 100 nm, for example in the range of 1 nm to 10 nm. The thermal resistor may be fabricated using, for example, deep reactive ion etching to accurately define the shape of the thermal resistor element. The thermal resistor may have dimensions such that it fits within the tube 2 (i.e., refers to the thickness, width and length of the substrate on which the resistive element is provided), for example a thickness substantially determined by the thickness of the thin film substrate, for example a thickness of 100 μm, and a width in the range of 100 μm to 700 μm, for example in the range of 100 μm to 350 μm, for example in the range of 150 μm to 250 μm, for example a width of 190 μm. The length of the thermal resistor 11 may be substantially determined by the length of the conductive trace required to achieve the desired resistance. In order to measure the temperature at a specific location within the body, i.e., to achieve a high spatial resolution of temperature measurement, the length of the thermal resistor 11 is preferably as short as possible, provided that it still provides sufficient resistance and temperature dependence. For example, the length (of the substrate) may be in the range of 1 mm to 10 mm, for example in the range of 2 mm to 5 mm, for example 3 mm.

[0069] The thermal resistor 11 may be a serpentine pattern, for example, an elongated (thin, large length) conductor arranged in a right-angled zigzag pattern as shown in FIG. 1. "Serpentine" means following a winding and / or complex path, for example, such that the length of the thermal resistor is large compared to the area of the convex envelope of the thermal resistor.

[0070] For example, the thermal resistor 11 may include a thin serpentine platinum track of appropriate thickness and a width of about 10 μm. Such a thin serpentine platinum track can be fabricated using a lift-off process and physical vapor deposition, as described by Ceyssens et al. in "Extracellular matrix proteins as temporary coating for thin-film neural implants", Journal of neural engineering 14.1 (2017). Further, when polyimide is used as the substrate in this prior art document, the same approach can be applied to a thinned silicon substrate, even if it is not similar. For example, the thinned silicon substrate may have lower flexibility than polyimide, which can advantageously improve the stability of the thermal resistor under different mechanical loading conditions.

[0071] The thermal resistor may include, for example, additional biocompatible insulating layers deposited on the resistor and / or substrate, such as oxides, nitrites, and / or polymers (such as poly(p-xylylene) polymers like parylene-C), for passivation and / or electrical insulation to prevent current flow through, for example, the body of a human or animal. Further, such layer(s) can reduce the amount of water vapor and / or body fluid that diffuses through the package to the electroactive device. Such layer(s) can also act as a solder mask to prevent reflow of solder on the resistor. Such layer(s) may be deposited by physical vapor deposition, such as RF plasma-driven sputtering, atomic layer deposition, chemical vapor deposition, or other suitable techniques well known in the art.

[0072] The device includes a plurality of electrical wires 4 (multiple leads), which extend from the proximal end of the tube, through the tube 2, to at least one resistance temperature sensor 3 and are connected to the at least one resistance temperature sensor 3 (intended to remain outside the body during normal use of the device). The electrical wire 4 (for example, each electrical wire) may be (or may include) one made of a suitable conductive metal, such as a highly conductive metal. The wire may be an insulated electrical wire, for example, may include a conductive core material within an electrical insulation sheath material. The electrical insulation sheath (or additional sheath material) may also be adapted to prevent diffusion of the conductive core material from the wire. The electrical insulation sheath may be one that includes (or consists of) polyimide. The wire may be coated with a further material to form an insulation (dielectric) and / or biocompatibility improvement layer, for example, a moisture and / or diffusion barrier such as a poly(p-xylylene) polymer, such as parylene-C.

[0073] Referring to FIG. 5, the electrical wire may be disposed on the back side of the substrate of the temperature sensor 3, i.e., on the side opposite to the side of the substrate where the thermal resistor is located. In other words, by not covering the thermal resistor 11 with the wire, for example, heat exchange with the surrounding tissue (e.g., through conduction through a tube and optionally a filling material within the tube) is not hindered, and / or inductive interference with the resistor is avoided, and / or the thermal resistor (e.g., formed of a thin metal layer) is protected from mechanical damage. "Disposed on the back side" should be interpreted as "substantially disposed on the back side", and similarly "not covering" should be interpreted as "substantially not covering", i.e., it will be clear that a small area on the front side where the wire connects to the terminals 12, 13 can be considered.

[0074] For example, the wire may include copper, gold, platinum, aluminum, and / or other suitable metals. The advantages of gold and / or platinum (or their alloys) wires are that they can achieve good biocompatibility and medical-grade safety. The advantage of copper (or its alloy) wires is that they can achieve good electrical conductivity at a lower cost. The tube material, the coating or sheath of the wire, and / or the layer covering the contact point (i.e., the location where a connection is formed between one or more wires and the terminals of the resistance temperature sensor 3) may be adapted to prevent the diffusion of the wire material (e.g., copper) into the human or animal body when the device is inserted into the body, i.e., to ensure biocompatibility and safety.

[0075] The wire among the plurality of electrical wires may have a diameter in the range of 10 μm to 100 μm, for example, in the range of 30 μm to 80 μm, preferably in the range of 40 μm to 60 μm, for example, 49 μm, 50 μm or 51 μm. For example, each such electrical wire may include a copper core having a diameter of 45 μm insulated by a sheath layer having a thickness of 2 μm, for example, a polyimide layer.

[0076] Of the plurality of electrical wires, the wires are preferably twisted, for example loosely wound, for example configured as a helix around a common axis, to reduce the effect of inductively induced electromagnetic noise, for example by effectively reducing the area between the wires to zero. Further, twisting the wires can advantageously avoid the strain applied to the wires when the tube is bent.

[0077] Each of the two terminals of at least one resistance temperature sensor 3, or each of at least one resistance temperature sensor 3, is directly connected to at least one wire, for example by soldering. Preferably, at least one of the two terminals of at least one resistance temperature sensor 3, or each of at least one resistance temperature sensor 3, is directly connected, for example soldered, to at least two wires so as to enable the (each) resistance temperature sensor to be read using a three-wire readout configuration well-known in the art. Even more preferably, each of the two terminals of at least one resistance temperature sensor 3, or each of at least one resistance temperature sensor 3, is directly connected, for example soldered, to at least two wires so as to enable the (each) resistance temperature sensor to be read using a four-wire readout configuration well-known in the art. In such a four-wire readout technique, a first pair of wires respectively connected to the first and second terminals of the resistance temperature sensor conduct current through a resistor, and the corresponding voltage difference across the resistor is measured between a second pair of wires respectively connected to the two terminals. Thereby, advantageously, the resistance, and thus the temperature, can be measured with high precision regardless of changes in the resistance of the wires.

[0078] In the case of a three-wire readout configuration of an RTD, as is widely known in the art, two wires are connected to one terminal of the resistance temperature sensor, and a third wire is connected to the other terminal of the resistance temperature sensor. In such a configuration, it is known that the resistances of the three wires are substantially equal to each other (for example, equal in length and identical in characteristics such as diameter, conductivity, material, etc.). Therefore, the total resistance of the sensor, the third wire, and the first wire, or additionally or alternatively, the total resistance of the sensor, the third wire, and the second wire, can be measured. Further, since the total resistance of the first wire and the second wire is also known (equal for each lead wire), it can be measured. Thus, the resistance of the sensor can be determined. With this approach, as long as it can be assumed that the resistances of the three wires are equal, the resistance of the lead wires can be compensated for.

[0079] In the case of a four-wire readout configuration of an RTD, as is widely known in the art, two wires are connected to one terminal of the resistance temperature sensor, and two wires are connected to the other terminal of the resistance temperature sensor. One pair of wires (connected to the first and second terminals respectively) can be used to supply the current used for measurement (for example, a known constant current), and the other pair of wires can be used to measure the corresponding voltage drop across the resistance sensor.

[0080] Referring to FIG. 3, the plurality of electrical wires 4 may include a first plurality of electrical wires 41, 43 for serially connecting the plurality of resistance temperature sensors 3 to pass a current I through the plurality of resistance temperature sensors 3 during operation of the device. Accordingly, the first plurality of wires 41, 43 includes a first wire extending from the proximal end of the tube (for example, from the connector) to the first terminal of the first resistance temperature sensor in the serial connection, and a second wire extending from the proximal end of the tube (for example, from the connector) to the second terminal of the last resistance temperature sensor in the serial connection, and each of the plurality of wire segments 43 connects the second terminal of the previous resistance temperature sensor in the serial connection to the first terminal of the next resistance temperature sensor in the serial connection.

[0081] Furthermore, the plurality of electrical wires 4 may include a second plurality of electrical wires 42 (different from the first plurality of electrical wires) for measuring the voltage difference between a pair of terminals of each sensor 3. However, in order to reduce the number of wires extending through the tube (especially simultaneously through any cross-section of the tube), the voltage difference between the second terminal of a sensor and the first terminal of the next sensor connected in series may be ignored. Since the wire segments for connecting pairs of sensors in series may be relatively short, the resistance of these wire segments can advantageously be ignored. Thus, the second plurality of wires 42 includes a first wire extending from the proximal end of the tube (e.g., from a connector) to the first terminal of the first resistance temperature sensor in the series connection, a second wire extending from the proximal end of the tube (e.g., from a connector) to the second terminal of the last resistance temperature sensor in the series connection, and a plurality of wires extending from the proximal end of the tube (e.g., from a connector) to the corresponding each wire segment of the wire segments 43 (or either one of the terminals to which the wire segment is connected). Since the distance between adjacent sensors may be negligible compared to the longer leads from the proximal end of the tube to the first sensor in the series connection, this approach provides an advantageous way to compensate for the resistance of the longer lead wire portion (which may be variable in some cases depending on ambient factors such as temperature) while reducing the total number of wires extending through the longer draw-in portion of the tube by ignoring the potential effects of the shorter wire segments. In other words, for n sensors in the tube, good accuracy can be achieved without the need for 3.n or 4.n wires. For example, in the case of this approach, n + 3 wires are sufficient to obtain accurate and robust measurement values.

[0082] Furthermore, the device may include a structural wire 5 (e.g., extending over a substantial portion of the length of the tube, such as over the entire length, inside the tube 2) in order to increase the axial rigidity of the device (of the tube) while substantially maintaining its low bending rigidity. The structural wire 5 can provide some rigidity to the tube while allowing the tube to bend to some extent (i.e., a "structural" wire can mean a wire that provides some axial rigidity to the device). The structural wire may be made of a metal or metal alloy, such as tungsten or a tungsten alloy. For example, the tube 2 may have an outer diameter in the range of 463 μm to 820 μm, such as 641 μm, and an inner diameter in the range of 260 μm to 514 μm, such as about 310 μm, about 320 μm or about 337 μm. The wall thickness may be in the range of 102 μm to 283 μm, such as 152 μm. In the case of a tube made of (or including) a medical grade silicone, the tube may have negligible rigidity. Thus, the structural wire 5 can help provide some rigidity. For example, the structural wire 5 may have a thickness (diameter) in the range of 40 μm to 150 μm, such as in the range of 60 μm to 100 μm, such as in the range of 70 μm to 90 μm, such as 80 μm. For example, the tube 2 may include a medical grade silicone material (such as PDMS), may have an outer diameter of about 640 μm and an inner diameter of about 310 μm, and the structural wire 5 may be a tungsten wire with a diameter of about 80 μm. This combination has been found to provide sufficient internal space to accommodate the sensor and the wire even with a small outer diameter, while providing good rigidity, i.e., a good balance between flexibility and rigidity.

[0083] The electrical wire 4 may be provided twisted along the structural wire (e.g., coaxially and loosely wound), or the electrical wire 4 may be twisted around the structural wire, for example, the electrical wire may form a helix around the structural wire as an axis.

[0084] The structural wire 5 may preferably be made of a radiation-impermeable material that blocks or at least strongly attenuates, for example, ionizing radiation such as X-rays. Tungsten (or its alloy) has good elastic properties (Young's modulus, shear modulus, bulk modulus) to provide some rigidity to the device, has good radiation impermeability to enable accurate positioning of the tubes inside the body and related sensors using fluoroscopy (e.g., real-time video obtained by X-ray imaging), and may have the advantage of good biocompatibility.

[0085] device 1 may include at least one filling material 6 that fills the tube 2 (filling the voids in the tube not occupied by other features as described above). For example, the filling material may include a deformable filling material that may be, for example, a silicone rubber material, a nylon material, a polyurethane material, a polyvinyl chloride material, a polyethylene terephthalate (PET) material, a latex material, and / or a thermoplastic elastomer material. For example, the deformable Filling material may advantageously consist of or include silicone, which is inert and non-reactive. The filling material may be or include PDMS and / or polyimide and / or polyurethane. The filling material may be or include a material similar to or the same as the material constituting the tube 2 (although the embodiments are not limited thereto). For example, the filling material may include an optically transparent low-consistency silicone elastomer such as the MED6015 product commercially available from NuSil Technology LLC (USA).

[0086] The filling material can advantageously ensure that the distance between one or more temperature sensors within the tube is kept fixed and can provide good thermal conductivity between the temperature sensors and the surrounding tissue when the device is inserted into the body. Further, the filling material can reduce the flexibility of the tube to facilitate insertion into the body, can improve the electrical insulation of components within the device, and / or can improve the biological safety of the device.

[0087] Different (longitudinal) sections of the tube may be filled with different filling materials, for example, to provide different bending rigidities in different sections.

[0088] Referring to FIG. 4, the device 1 may include yet another tube 20 into which the tube 2 can be inserted and / or through which the tube 2 can be inserted. Thus, this yet another tube 20 may have a larger diameter than the tube 2 and may have a higher rigidity, for example, to assist in guiding the tube 2 through a puncture of a needle.

[0089] The device may include, at the proximal end of the tube, a connector 21, for example a cable mount plug connector, for electrically connecting a plurality of electrical wires 4 to an external reading device 30 for reading the sensor. The connector may be a push-pull type connector, i.e., a push-pull cable mount plug. The connector may include solder pins to which the electrical wires are connected (soldered). The connector may be made of (or include) a plastic material (plural plastic materials). Preferably, the connector is resistant to high temperatures and is suitable for withstanding, for example, autoclave sterilization (for example in accordance with IEC60601-1). Preferably, the connector is waterproof and can withstand the ingress of fluid, for example, in both the mated and unmated states (for example in accordance with IP68). Preferably, the connector has a high insulation resistance, for example at least 10 MΩ, for example at least 100 MΩ. For example, the connector may include a circular connector such as the JMX series connector commercially available from Souriau SAS (FR), for example, the 6-pin JMXFH1G06MSUDSU connector. The connector may include a push-pull plastic plug having a sealed cable ground back shell.

[0090] The device 1, for example a connector, may also include an integrated circuit for storing data and for providing this data to the reading device 30 via the connector when connected. For example, the integrated circuit may be adapted to store identification information such as a unique identification number or tag, and / or for example sensor or calibration information for each sensor, and / or for example sterilization time and / or parameters used in the sterilization process, such as identification information of the operator or the device used for sterilization, sterilization protocol identifier, sterilization temperature, sterilization time, etc. The integrated circuit may also be adapted to store this information received from the calibration unit in a writable memory. The integrated circuit (writable memory) may be a programmable read-only memory (i.e., writable only once), for example, to protect the integrity of the stored information, but in other embodiments, other types of memory, such as flash memory, may be used. For example, the integrated circuit may be adapted to record temperature readings, for example, for recording temperature measurement values during treatment and / or for storing other relevant information such as manufacturing data, packaging data, sterilization data, etc.

[0091] The connector may include a reading circuit 30, for example, a plurality of operational amplifiers 31 connected to a second plurality of wires 42 in a differential reading configuration, and may provide the processed reading data to an external device. However, such a reading circuit 30 may be incorporated not in the connector but in an external reading device, and the function of the reading circuit may be divided between components incorporated in the device 1 and components incorporated in the external device.

[0092] The device 1 may be provided with an overmolded strain relief 22 to relieve stress and / or tension between the (for example rigid) connector and the flexible tube 2 and / or further other tubes 20.

[0093] The device 1 may also comprise an optical fiber for delivering an optical signal (such as provided via the proximal end of the device) to an organ or tissue, for example via the transparent portion of a tube at its distal end (but not limited thereto), and collecting the return optical signal from the organ or tissue. The return optical signal may be transmitted and / or reflected by the organ or tissue and may be refracted, diffracted, attenuated, scattered and / or changed, for example by interaction with the organ tissue. Thus, in addition to temperature, one or more other physiological parameters of the organ or tissue can be monitored via the optical fiber(s). For example, the spectral characteristics of the organ or tissue can be monitored. For example, one or more other physiological parameters may include oxygenation, for example the levels of oxygenated and / or deoxygenated hemoglobin. The device may also comprise one or more other optical elements, such as diffraction gratings, couplers, microlenses, reflectors, beam splitters, etc., which are well known in the art.

[0094] Embodiments of the present invention may relate to a kit comprising the above-described device 1, a needle for puncturing the skin, and / or a guide sheath for inserting the tube 2 into the body through the skin puncture.

[0095] Embodiments of the present invention may relate to a system (e.g., a kit) comprising the above-described device 1 and a reading device 30 for providing a temperature value based on the current and / or voltage measured by a plurality of electrical wires 4. The reading device may receive calibration data from an integrated circuit within the device and be adapted to take this calibration data into account when determining the temperature value. The reading device may be adapted to periodically determine the temperature value, for example, to monitor the temperature change within the body over time. The reading device 30 may comprise a plurality of operational amplifiers 31 connected in a differential reading configuration to a second plurality of wires 42 via a connector 21, for example, during operation of the device, and may provide the processed reading data, for example, as a digital signal or via a display. The reading device 30 may also comprise a current source 32, for example, an adjustable current source adapted to maintain a substantially constant current flowing through a first plurality of wires 41. As will be apparent to those skilled in the art, other features of such a reading device, well known in the art, such as a reading bridge configuration, an analog-to-digital converter, digital communication means, a power supply, and / or a user interface, may be included.

[0096] The system may generally be a system for monitoring the function of an organ inside the body of a human or animal, for example, the liver, in which case the device 1 is adapted to be inserted into the organ and collect data regarding one or more physiological parameters of the organ, including one or more temperatures within the organ. Other physiological parameters may also be monitored, for example, via an optical fiber (s). For example, the reading device may include an optical fiber, a light source (e.g., one or more laser diodes), and / or a photodetector.

[0097] In yet another aspect, the present invention relates to a method of manufacturing an apparatus according to an embodiment of the first aspect of the present invention. The method includes fabricating or obtaining one or more resistance temperature sensors 3, each resistance temperature sensor including an elongated conductive metal trace on a thin film substrate. The metal trace is arranged in a serpentine pattern between two electrical connection terminals. The method includes connecting a plurality of electrical wires 4 to the one or more resistance temperature sensors (3), for example via the electrical connection terminals. The method includes inserting the one or more resistance temperature sensors and the plurality of electrical wires into a catheter tube 2 such that at least some of the electrical wires remain accessible at the proximal end of the tube. The method includes mechanically connecting a connector 21 to the proximal end of the tube and electrically connecting the connector 21 to the plurality of electrical wires such that an external device for reading out the sensors can be operatively connected to the one or more resistance temperature sensors via the connector 21. The method may also include inserting a structural wire into the tube to reduce its flexibility. The method may also include, optionally (but not limited to), twisting the plurality of electrical wires around the structural wire in a helical configuration. The method may also include filling the tube with a filling material after inserting the components into the tube.

[0098] Other features of the method according to embodiments of the present invention, or details of the above features, will be apparent in view of the description provided in the foregoing description of the apparatus according to embodiments of the present invention, and vice versa.

Claims

1. An apparatus (1) for measuring temperature at one or more locations within an organ or tissue inside the body of a human or an animal, the apparatus comprising: - a catheter tube (2) having a distal end and a proximal end, the distal end being adapted to be inserted into or onto the organ or tissue of the body, and the proximal end being adapted to remain outside the body during use of the apparatus, the apparatus further comprising: - a plurality of resistance temperature sensors (3) within the tube; - a plurality of electrical wires (4) within the tube connected to the plurality of resistance temperature sensors (3); - a connector (21) at the proximal end of the tube (2) for electrically connecting at least a part of the plurality of electrical wires (4) to an external device; Each of the plurality of resistance temperature sensors (3) includes a thermal resistor (11), a first terminal (12), and a second terminal (13), and is capable of measuring the temperature-dependent resistance of the thermal resistor between the first terminal and the second terminal. Each of the two terminals (12, 13) of the resistance temperature sensor (3) is directly connected to at least one of the plurality of electrical wires (4). A first plurality of electrical wires (41, 43) serially connect the plurality of resistance temperature sensors (3) so that current can flow through the plurality of resistance temperature sensors during operation of the apparatus. The first plurality of electrical wires includes: - a first wire extending from the proximal end of the tube to the first terminal of the first resistance temperature sensor in the series connection; - a second wire extending from the proximal end of the tube to the second terminal of the last resistance temperature sensor in the series connection; - a plurality of wire segments (43), each connecting the second terminal of the previous resistance temperature sensor in the series connection to the first terminal of the next resistance temperature sensor in the series connection, or consisting of; The apparatus further comprises n + 3 electrical wires (4) for n (n is a natural number greater than or equal to 2) resistance temperature sensors (3) within the tube. An apparatus in which at least one of the two terminals (12, 13) of the resistance temperature sensor (3) is directly connected to at least two of the plurality of electrical wires extending from the proximal end of the tube (2) such that each resistance temperature sensor (3) is read using a three-wire or four-wire readout configuration. A device (1) for measuring the temperature at one or more locations within an organ or tissue inside the body of a human or animal, said device comprising: - a catheter tube (2) having a distal end and a proximal end, said distal end being adapted to be inserted into or onto said organ or tissue of said body, said proximal end being adapted to remain outside said body during use of said device, said device further comprising: - a plurality of resistance temperature sensors (3) within said tube; - a plurality of electrical wires (4) within said tube connected to said plurality of resistance temperature sensors (3); - a connector (21) at said proximal end of said tube (2) for electrically connecting at least a portion of said plurality of electrical wires (4) to an external device, each of said plurality of resistance temperature sensors (3) includes a thermal resistor (11), a first terminal (12), and a second terminal (13), and is capable of measuring the temperature-dependent resistance of said thermal resistor between said first terminal and said second terminal, and each of said two terminals (12, 13) of said resistance temperature sensor (3) is directly connected to at least one of said plurality of electrical wires (4), a first plurality of electrical wires (41, 43) serially connect said plurality of resistance temperature sensors (3) such that current can flow through said plurality of resistance temperature sensors during operation of said device, said first plurality of electrical wires comprising: - a first wire extending from said proximal end of said tube to said first terminal of a first resistance temperature sensor in said series connection; - a second wire extending from said proximal end of said tube to said second terminal of a last resistance temperature sensor in said series connection; - a plurality of wire segments (43), each connecting said second terminal of a previous resistance temperature sensor in said series connection to said first terminal of a next resistance temperature sensor in said series connection, or consisting of, said device further comprises n + 3 electrical wires (4) for n (n is a natural number greater than or equal to 2) resistance temperature sensors (3) within said tube, a second plurality of electrical wires (42) extending from said proximal end of said tube (2) and connected to said plurality of resistance temperature sensors (3) for measuring a voltage difference, said second plurality of electrical wires comprising: - a first wire extending from said proximal end of said tube and connected to said first terminal of a first resistance temperature sensor in said series connection; - A second wire extending from the proximal end of the tube and connected to the second terminal of the last resistance temperature sensor in the series connection; - A device comprising or consisting of a plurality of wires extending from the proximal end of the tube and connected to corresponding ones of the wire segments (43) or to the terminals to which the wire segments are connected. **Claim 3** The device according to claim 1 or 2, wherein the plurality of electrical wires (4) are helically twisted together. **Claim 4** The device according to any one of claims 1 to 3, wherein the thermal resistor (11) is a platinum resistor, a PT100 resistor or a PT1000 resistor. **Claim 5** The device according to any one of claims 1 to 4, wherein the resistance temperature sensor (3) includes a thin film substrate, and the thermal resistor (11) is an elongated conductive metal trace arranged in a meandering pattern on the substrate. **Claim 6** Each of the plurality of resistance temperature sensors (3) has a thickness in the range of 50 μm to 150 μm, a width in the range of 100 μm to 700 μm, and a length in the range of 1 mm to 10 mm. The diameter of the electrical wire (4) is in the range of 10 μm to 100 μm or in the range of 30 μm to 80 μm. The catheter tube (2) has an outer diameter in the range of 463 μm to 820 μm and an inner diameter in the range of 260 μm to 514 μm. The device according to any one of claims 1 to 5. **Claim 7** The device according to any one of claims 1 to 6, comprising a structural wire (5) within the tube (2) for increasing the axial rigidity of the tube (2) and / or a filling material (6) for filling the tube (2). **Claim 8** The device according to claim 7, wherein the structural wire (5) is made of tungsten or a tungsten alloy and / or has a thickness in the range of 40 μm to 150 μm. **Claim 9** The device according to any one of claims 1 to 8, comprising an integrated circuit operatively connected to the connector (21) for storing the data to provide the data to the external device upon connection, the data including identification information and / or calibration information and / or sterilization information and / or sensor logging information. **Claim 10** The device according to any one of claims 1 to 9, further comprising at least one optical fiber, wherein the optical fiber, during use of the device, sends an optical signal to the organ or tissue and collects a return optical signal from the organ or tissue, whereby, in addition to temperature, one or more other physiological parameters of the organ or tissue can be monitored via the optical fiber.

11. A kit comprising the device (1) according to any one of claims 1 to 10, and - a needle for piercing the skin, - a guide sheath for inserting the tube (2) into the body through the skin puncture, - a reading device (30) for providing a temperature value based on the current and / or voltage measured using the plurality of electrical wires (4) when operatively connected to the connector (21). One or more selected from the above.

12. A method of manufacturing the device according to any one of claims 1 to 10, the method comprising: - producing or obtaining the plurality of resistance temperature sensors (3), each resistance temperature sensor comprising an elongated conductive metal trace on a thin film substrate, the metal trace being arranged in a meandering pattern between a first terminal (12) and a second terminal (13), the method further comprising: - connecting a plurality of electrical wires (4) to the plurality of resistance temperature sensors (3); - inserting the plurality of resistance temperature sensors and the plurality of electrical wires into a catheter tube (2) such that at least some of the electrical wires remain accessible at the proximal end of the tube; - mechanically connecting a connector (21) to the proximal end of the tube such that an external device can be operatively connected to the plurality of resistance temperature sensors via the connector (21), and electrically connecting the connector to the plurality of electrical wires.

Images