Internal body temperature measuring sensor and internal body temperature measuring device

Abstract

To provide means capable of directly measuring temperature of a local site inside a skin surface of a body.SOLUTION: A body temperature measurement sensor includes a non-exposed sheath thermocouple and a metal capillary tube having an outer diameter of 0.5 mm or less. The metal capillary tube has a pointed tip that is a blind end and covers a tip region of the sheath thermocouple. A tip of the sheath thermocouple is subjected to integrated welding with an inner surface of the blind tip in a lumen of the metal capillary tube. A body temperature measurement device includes a body temperature measurement sensor and a temperature measurement instrument electrically connected thereto.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an internal body temperature measuring sensor and an internal body temperature measuring device including the same, for directly measuring the temperature of an internal body part that is percutaneously accessible. [Background technology]

[0002] Human body temperature is generally measured on the surface of the skin or mucous membranes, such as the surface of the skin under the armpits or the mucous membranes of the mouth or rectum. All of these measurements provide a single value representing the temperature of the whole body, which does not necessarily coincide with the temperature of deeper parts of the body.

[0003] On the other hand, in traditional Chinese medicine, it has long been known that stimulating specific areas on the skin surface (acupuncture points, pressure points) with moxibustion has beneficial effects such as relieving fatigue and promoting metabolism. It is particularly used in the field of preventive medicine, which focuses on maintaining and promoting health. Coupled with the social background of the arrival of an aging society and a growing awareness of healthy life expectancy, in recent years, various scientific investigations have been undertaken from physiological and other perspectives in order to clarify the effects of the treatment and to find further applications.

[0004] For example, moxibustion can be classified into several specific techniques, but by applying heat generated by lighting moxa to specific areas on the surface of the skin (moxibustion), it aims to improve the physical state of health by improving blood circulation, easing swelling, stiff shoulders, muscle pain, lower back pain, etc., and recovering from fatigue. The internal temperature of the skin directly below the moxibustion area rises during moxibustion, resulting in these improving effects, and if there is an increase in blood circulation in the capillaries at the moxibustion area, it can also be a factor in raising the temperature of that area.

[0005] For this reason, it is desirable to be able to easily collect local temperature information on relevant areas during moxibustion and use this information to determine the optimal moxibustion conditions (amount of moxa, equipment to be used, etc.) depending on the purpose.It would also be beneficial if changes such as improved blood circulation could be confirmed using quantitative indicators.

[0006] However, although research has been conducted on the burning temperature of moxa, to the best of the inventor's knowledge, no attention has been paid to devices for measuring the internal body temperature at the site of moxibustion during moxibustion. Furthermore, there is no known means for directly measuring the internal body temperature transcutaneously. Summary of the Invention [Problem to be solved by the invention]

[0007] In the above-mentioned background, an object of the present invention is to provide a means capable of directly measuring the temperature of a local area inside the skin surface of the body.

[0008] The inventors have attempted to create a means for directly and easily measuring the temperature of a local area below the surface of the skin, and have conducted various studies. As a result, they have arrived at a sensor with the following configuration, confirmed its effectiveness, and completed the present invention. That is, the present invention is as follows. [Means for solving the problem]

[0009] 1. A sensor for measuring body temperature, comprising a non-exposed sheathed thermocouple and a metal capillary tube having an outer diameter of 0.5 mm or less, the metal capillary tube having a sharp, blind end that covers the tip region of the sheathed thermocouple, and the tip of the sheathed thermocouple being welded and integrated with the inner surface of the blind end within the lumen of the metal capillary tube.

[0010] 2. The sensor for measuring internal body temperature according to 1 above, wherein the outer diameter of the metal thin tube is 0.2 mm to 0.5 mm.

[0011] 3. The sensor for measuring internal body temperature according to 1 or 2 above, wherein the length of the metal thin tube is 0.5 cm to 10 cm.

[0012] 4. The sensor for measuring internal body temperature according to any one of 1 to 3 above, wherein the non-exposed sheathed thermocouple is a non-grounded type.

[0013] 5. A sensor for measuring internal body temperature according to any one of 1 to 4 above, further comprising a relay electrical connection means at the rear of the metal thin tube, the relay electrical connection means comprising a front portion and a rear portion that are connected to each wire of the sheathed thermocouple and are detachable.

[0014] 6. An internal body temperature measuring device comprising an internal body temperature measuring sensor according to any one of items 1 to 5 above and a temperature measuring instrument electrically connected thereto. [Effects of the Invention]

[0015] The present invention provides a means for directly measuring the local temperature of a region inside the skin surface of a human or other animal, thereby enabling the collection of temperature data within the body during moxibustion, as well as a means for detecting physiological responses such as increased blood circulation in a local area of ​​the body due to various stimuli applied to the body surface. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a photograph showing the state of the tip region of a metal thin tube containing a sheathed thermocouple immediately after laser welding in the manufacturing process of the internal body temperature measurement sensor of the present invention. [Figure 2] A photograph used as a drawing showing a metal tube that has been polished from a block of metal to create a sharp tip. [Figure 3] FIG. 2 is a conceptual enlarged cross-sectional view of the tip region of the internal body temperature measurement sensor of the present invention. [Figure 4] 1 is a conceptual diagram of the internal body temperature measurement sensor of the present invention with the metal holding tube and sleeve attached. [Figure 5] Photograph of the internal body temperature measurement sensor of Example 2 DETAILED DESCRIPTION OF THE INVENTION

[0017] Thermocouples are temperature sensors that utilize the thermoelectric power generated at the junction between dissimilar metals, and a wide variety of them are widely used in products requiring temperature measurement. A thermocouple's basic structure consists of two wires (element wires) of different metals joined at one end. A "sheathed thermocouple" refers to a type in which the junction and a certain length of the two wires extending from it are enclosed in a sheath made of a heat-resistant material such as stainless steel, along with an insulator for protection. A "non-exposed" sheathed thermocouple refers to a type in which the junction of the wires (the temperature measurement junction), which is exposed to the temperature of the object being measured, is also completely enclosed within the sheath and is not exposed to the outside. Non-exposed sheathed thermocouples are classified as grounded (where the temperature measurement junction is in contact with the inner wall of the sheath tip) or non-grounded (where the temperature measurement junction is not in contact with the inner wall of the sheath tip). Either type can be used in this invention, but non-grounded types, which have superior stability, are preferred.

[0018] A variety of non-exposed sheathed thermocouples are commercially available. The temperature characteristics of the thermocouple used in this invention need only be such that it can measure the temperature inside the body. The measurable or suitable temperature range (usually very wide) and other characteristics are indicated in the specifications of each product, so an appropriate thermocouple can be selected. Commercially available thermocouples include E, K, J, T, and R types, which are determined by the combination of two metals. Since all of these types cover a temperature range far wider than the body temperature, they can be appropriately selected as long as a thermocouple with a sufficiently narrow sheath outer diameter is available. The most commonly used type is the K type, which consists of a chromel (anode) and an alumel (cathode) and is suitable for use in this invention. Furthermore, since a vast amount of data is publicly known about the electromotive force and other characteristics at the junction of two various metals (pure metals and alloys) as a function of temperature, thermocouples can also be fabricated using these.

[0019] The internal body temperature sensor of the present invention is fabricated with a needle-like pointed tip for easy insertion into the body. For this purpose, a thin tube made of a metal such as stainless steel that can provide a sharp, blind tip is used, and the tip region of the non-exposed sheathed thermocouple is housed in the lumen. Since this metal thin tube will be inserted into the body of the patient or subject like a needle, it is preferable that it be as thin as possible to avoid strain.

[0020] Because the outer diameter of the metal capillary tube is small, the inner diameter of its lumen is also very small, so it is preferable that the non-exposed sheathed thermocouple inserted therein also has as small an outer diameter as possible. In the examples described below, a commercially available non-exposed sheathed thermocouple with an outer diameter of 0.08 mm is used, but there is no particular lower limit to the outer diameter as long as it is available. For example, if a thermocouple with an outer diameter of 0.05 mm is available, it can be used, and there is no particular lower limit.

[0021] The metal capillary tube is intended to provide the internal body temperature measurement sensor of the present invention with sufficient strength to prevent deformation during normal handling (insertion into the skin, cleaning, sterilization, storage, etc.). Furthermore, there is no particular lower limit to the outer diameter of the metal capillary tube, as long as it has a lumen with an inner diameter large enough to allow a non-exposed sheathed thermocouple to pass through and is strong enough to prevent deformation due to resistance from the body when inserted into the body. Furthermore, the inner diameter of the metal capillary tube depends on how thin the thermocouple is, and there is no particular lower limit. Currently, sheathed thermocouples with an outer diameter of 0.08 mm, for example, are commercially available, and therefore a metal capillary tube with an inner diameter larger than 0.08 mm would be suitable in this regard.

[0022] The internal temperature measurement sensor of the present invention can be inserted into the body at different angles, such as straight (almost perpendicular to the skin surface), horizontal (almost parallel to the skin surface), or intermediate angles. Because the metal capillary tube is the part that is inserted into the skin, it is preferable for it to have a small outer diameter to minimize pain to the patient or subject, as long as it is strong enough to avoid deformation during insertion and allows a non-exposed sheathed thermocouple to pass through the lumen. Therefore, the outer diameter of the metal capillary tube is preferably 0.5 mm or less, more preferably 0.4 mm or less, even more preferably 0.3 mm or less, particularly preferably 0.25 mm or less, and especially preferably about 0.20 mm.

[0023] There is no particular limitation on the length of the metal capillary, and it can be set within the range of, for example, 0.5 cm, 1 cm, 1.5 cm, 2 cm, 3 cm, 5 cm, 10 cm, etc.

[0024] To fabricate a sharp metal capillary tube, for example, a needle tube for a medical injection needle can be used, which is preferable from a material perspective. Fabrication can be performed, for example, as follows: The tip of a non-exposed sheathed thermocouple is inserted from the base of the needle tube until it is close to the cutting edge of the needle tube. In this state, a laser is applied to the tip to melt the metal (stainless steel) from which the needle tube is made. This forms a tiny droplet-like metal lump at the needle tip, turning the previously oblique open end into a blind end. At the same time, the sheath of the non-exposed sheathed thermocouple comes into contact with and is welded to the molten metal. The metal lump at the needle tip is then polished to form a sharp, needle-like tip. This produces an internal temperature sensor. Connecting the terminal at the end of the cord extending from the base of the sheath to an appropriate thermocouple thermometer suitable for measuring temperatures near body temperature can be used to construct an internal temperature measurement device.

[0025] Furthermore, when the length of the metal capillary tube is set short, in order to make it easier to hold in the hand, a holding metal tube, which is not the part that is expected to be inserted into the skin, can be fitted over the outer periphery of the proximal end of the metal capillary tube and connected to it as an integrated unit (by welding, etc.). For further ease of handling, a suitable sleeve made of a tubular object with a larger outer diameter can be provided at the proximal end of the holding metal tube.

[0026] Furthermore, it is even more preferable that the internal body temperature sensor of the present invention can be rotated freely around its axis by hand without causing mechanical resistance due to twisting of the cord when inserting it into the skin. This is because rotating the sensor while inserting it reduces the frictional resistance that the needle tip receives from the body, making it easier to insert the sensor smoothly and without causing any unnecessary irritation to the body.

[0027] For this reason, the internal temperature sensor of the present invention is preferably configured with a connector located behind the metal capillary tube, which includes an intermediate electrical connection means including two easily detachable parts, and the two wires of the internal temperature sensor are connected to the temperature measuring device via this means located midway along the cord. The specific structure of this means is arbitrary, as long as it electrically connects each of the two types of wires extending from the tip of the internal temperature sensor of the present invention to the same type of wire leading to the temperature measuring device in a one-to-one relationship. Examples include, but are not limited to, a combination of two pin-type terminals and corresponding socket-type terminals, or a fitting-type connector consisting of a plug with terminals on the inner and outer circumferential surfaces of the tube and a socket with corresponding terminals, each of which has a cylindrical surface contacting the outer circumferential surface and a pin contacting the inner circumferential surface. The detachable intermediate electrical connection means may be attached to the rear of the metal capillary tube. Here, "rear of the metal capillary tube" refers to the vicinity of the rear of the metal capillary tube (if a holding metal tube or further sleeve is provided), and may be fixed to the rear of them. By providing this means, the front and rear parts of the means can be separated when inserting the sensor needle tip into the body, making it possible to rotate the sensor needle tip freely around its axis by hand and insert it smoothly. After insertion is complete, the front and rear parts of the means are joined together to measure the temperature. By providing this means, the tip side of the internal temperature measurement sensor can be separated from the cord, making it easier to manage, such as cleaning, sterilization, and storage.

[0028] There are various known and commercially available temperature measuring devices that can be combined with the thermocouple sensor, depending on the type of thermocouple. Therefore, the internal temperature measuring device of the present invention can be constructed by combining a temperature measuring device that is compatible with the type of thermocouple used and is suitable for measuring temperatures near body temperature with the internal temperature measuring sensor of the present invention. [Example]

[0029] The present invention will be specifically described below with reference to examples, but it is not intended that the present invention be limited to these examples. [Example]

[0030] Fabrication of a sensor for measuring internal body temperature A K-type sheathed thermocouple (AEROPAK (registered trademark), manufactured by Okazaki Manufacturing Co., Ltd.) with an outer diameter of 0.08 mm and equipped with a single temperature measurement junction was used. This sheathed thermocouple had a non-grounded temperature measurement junction (the temperature measurement junction was not in contact with the inner wall of the sheath tip) enclosed within the sheath together with magnesium oxide as an insulator, and the sheath material was an alloy equivalent to Inconel (registered trademark) 600 (main components by mass %: Ni: 76, Cr: 15.5, Fe: 8.0).

[0031] A thin needle tube (0.2 mm outer diameter, 0.1 mm inner diameter) for insulin injection was prepared as the metal capillary tube. The above-mentioned sheathed thermocouple was inserted from the rear end of the needle tube to a point just before the cutting edge formed at an angle at the tip of the needle tube. At this point, laser welding was performed on the tip of the needle tube. This melted the tip of the needle tube, forming a spherical metal mass at the tip of the needle tube as shown in Figure 1. This closed the distal end of the lumen, creating a blind end. At the same time, the tip of the sheath, which had been inserted near the distal end of the needle tube, was welded to this blind end. This metal mass at the tip of the needle tube was polished to form a needle-shaped tip tapering from the unwelded surface of the needle tube to a sharp tip, as shown in Figure 2, to form the internal temperature sensor of the present invention. The length from the base end of the needle tube to the sharp tip was approximately 1.5 cm. Figure 3 shows a conceptual enlarged cross-sectional view of the tip region 1 of the sensor. In Figure 3, 2 is a metal capillary tube (needle tube), and the lumen at the tip is blinded by laser irradiation. A sheathed thermocouple is housed in the lumen, and is welded to the metal of the needle tube at the tip of the sheath 3. Within the sheath 3, there is a temperature measurement junction at a position that is not in contact with the inner surface of the tip side of the sheath 3, and lead wires (element wires) 4a and 4b made of two different metals extend from the temperature measurement junction to an end connector (not shown).

[0032] For ease of handling, the internal temperature sensor was inserted into a holding metal tube (stainless steel, outer diameter 0.88 mm, inner diameter 0.58 mm, length 7 cm) from one end and extended from the other end to the base (approximately 15 mm). At this point, the base of the needle tube and the holding metal tube were welded together. A stainless steel tube (approximately 3 cm long, maximum outer diameter 4 mm) was then fitted as a sleeve around the proximal end of the holding metal tube, and the joint between the holding metal tube and the sleeve was welded. This resulted in a needle-shaped internal temperature sensor that is easy to handle. Figure 4 conceptually illustrates this. The base of the needle tube 2, which forms the outer surface of the sensor's tip region 1, is connected to a holding metal tube 6, to which a sleeve 7 is attached. A cord 8 extending from the sleeve 7 to the base carries the two leads of the thermocouple, which are connected to the terminals of an end connector 9. The end connector 9 is connected to a commercially available thermometer compatible with the thermocouple used. [Example]

[0033] A round, pluggable connector 10 (manufactured by Remo Japan Co., Ltd.) was prepared as a detachable relay electrical connection means. The pluggable connector 10 consists of a front portion 10f and a rear portion 10b that are detachably fitted together. The front portion 10f has pins as terminals, and the rear portion 10b has corresponding sockets as terminals. In the internal temperature measurement sensor of Example 1, the cord was cut at the rear of the sleeve 7. The connector 10 was separated into front and rear halves, and two wires from the sleeve were connected to each terminal on the front portion 10f and then fixed to the rear end of the sleeve 7. Next, the cut ends of the wires at the cut portion of the cord extending to the temperature measuring device were connected to each terminal on the rear of the rear portion 10b of the connector 10, so that the type of each wire connected to the front portion 10f matched the type of each wire on the cord leading to the temperature measuring device, completing the internal temperature measurement sensor (Figure 5). Because the rear portion 10b of connector 10 can be detached from the front portion 10f, when inserting the needle tip into the skin, the needle tip can be rotated freely by hand without being hindered by the cord, and after insertion, the front portion 10f of connector 10 can be inserted into the rear portion 10b to connect the two and enable temperature measurement. After use for internal temperature measurement, the connector 10 can be separated from the rear portion 10b and only the portion from the front portion 10f to the tip can be cleaned, sterilized, stored, etc. [Example]

[0034] 2. Measuring subcutaneous temperature using an internal body temperature sensor Using the needle-shaped internal temperature sensor fabricated in Example 2, its terminals were connected to a commercially available thermocouple temperature measuring device to measure subcutaneous temperature changes due to moxibustion at acupuncture points on the human body. After approval by the Ethics Committee of Takarazuka University of Health Sciences, a Heisei Medical School educational institution, six faculty members from Takarazuka University of Health Sciences who agreed to participate in the study were used as subjects. Moxibustion was administered at six acupuncture points: Right Jialing, Right Jinshu, Zhongguan, Guanyuan, Right Shou Sanli, and Right Zusanli. The temperature sensor was inserted horizontally approximately 5 mm below the skin, with its tip positioned directly below each acupuncture point. The subjects experienced almost no pain during insertion. In this state, the baseline subcutaneous temperature at each point was measured. Next, a moxa ball (1.0 mg, for a moxa temperature of approximately 67°C) half the size of a rice grain was placed on the skin surface (acupuncture point) located at the tip of the sensor, and moxibustion was performed by igniting it.The subcutaneous temperature after moxibustion was then measured.

[0035] The subcutaneous temperatures at each acupoint were as follows: Right shoulder point: 32.10°C before moxibustion, 46.99°C after moxibustion; Right kidney point: 31.70°C before moxibustion, 50.95°C after moxibustion; Zhongguan point: 33.10°C before moxibustion, 46.84°C after moxibustion; Guanyuan point: 32.17°C before moxibustion, 42.73°C after moxibustion; Right hand Sanli point: 30.43°C before moxibustion, 43.32°C after moxibustion; Right foot Sanli point: 31.53°C before moxibustion, 54.84°C after moxibustion. The mean temperature difference before and after moxibustion at each acupoint was 16.12±4.57°C.

[0036] In this way, by using the internal body temperature measurement sensor of the present invention, direct measurement of subcutaneous temperature can be easily performed without causing the subject to feel any substantial pain. [Industrial Applicability]

[0037] The present invention provides a means for directly and easily measuring the local temperature of a region inside the skin surface of a human or other animal, thereby providing a measuring means that enables the collection of temperature data within the body during, for example, moxibustion, as well as a means that enables the quantitative detection of physiological responses such as increased blood circulation in a local area of ​​the body due to various physical or chemical stimuli applied to the body. [Explanation of symbols]

[0038] 1. Tip of the internal body temperature measurement sensor 2...Metal thin tube (needle tube) 3. Sheath 4a, 4b Lead wire (bare wire) 5. Temperature measuring junction 6...Metal tube for holding 7 Sleeve 8··Code 9··End connector 10f··Front part of the snap-in connector 10b Rear part of the mating connector

Claims

1. A sensor for measuring body temperature comprising a non-exposed sheathed thermocouple and a metal capillary tube having an outer diameter of 0.5 mm or less, the metal capillary tube having a sharp, blind end that covers the tip region of the sheathed thermocouple, and the tip of the sheathed thermocouple being welded and integrated with the inner surface of the blind end within the lumen of the metal capillary tube.

2. 2. The sensor for measuring internal body temperature according to claim 1, wherein the outer diameter of the metal thin tube is 0.2 mm to 0.5 mm.

3. 3. The sensor for measuring internal body temperature according to claim 1, wherein the length of the metal capillary is 0.5 cm to 10 cm.

4. 2. The internal body temperature sensor of claim 1, wherein the unexposed sheathed thermocouple is an ungrounded type.

5. 2. The sensor for measuring body temperature according to claim 1, further comprising a relay electrical connection means at the rear of the metal capillary tube, the relay electrical connection means comprising a front portion and a rear portion that are detachable and connected to each wire of the sheathed thermocouple.

6. An internal body temperature measuring device comprising the internal body temperature measuring sensor of claim 1 and a temperature measuring device electrically connected thereto.

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