Body temperature measurement sensor and body temperature measurement instrument

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

[0005] , , ,

[0006]

[0001] The present invention relates to a sensor for measuring body temperature and a body temperature measuring device including the same for directly measuring the temperature of an internally accessible body site transcutaneously.

Background Art

[0002] Measurement of the temperature of the human body is generally performed on the surface of the skin or mucosa, such as the skin surface under the armpit, the oral cavity, or the rectal mucosa. All of these seek the body temperature as a representative value, and do not necessarily match the temperatures of deeper parts.

[0003] On the other hand, in traditional Chinese medicine, it has long been well known that the stimulation applied to specific sites (acupuncture points, acupressure points) on the skin surface by moxibustion has effects such as fatigue recovery and metabolism promotion. It is particularly used in the field of preventive medicine that focuses on maintaining and improving health. Along with the advent of an aging society and the deepening of awareness of healthy life expectancy, in recent years, scientific explorations from aspects such as physiology have been attempted to clarify the effects of the treatment and the possibility of further application.

[0004] For example, moxibustion can be classified into several specific techniques in detail. By applying the heat generated by igniting mugwort to specific sites on the skin surface (moxibustion), it aims to improve blood circulation, relieve swelling, shoulder stiffness, muscle pain, low back pain, etc., and recover fatigue, thereby improving the health status of the body. The skin internal temperature directly below the moxibustion site rises during moxibustion, and as a result, these improvement effects are brought about. Also, for example, if there is an increase in blood circulation in the capillaries at the moxibustion site, it becomes a factor causing an increase in the temperature of the site.

[0005] Therefore, it is desirable that local temperature information of related sites in moxibustion can be easily collected, and the optimal moxibustion conditions (amount of mugwort, instruments used, etc.) can be grasped according to the purpose using this information. Also, it is beneficial if changes such as improvement of blood circulation can be confirmed with a quantitative index.

[0006] However, while research has been conducted on the combustion temperature of moxa, to the best of the inventor's knowledge, there has been no interest in devices for measuring the internal body temperature at the site of moxibustion during treatment. Furthermore, no means are known to directly measure internal body temperature transcutaneously. [Overview of the project] [Problems that the invention aims to solve]

[0007] Against this background, the present invention aims to provide a means for directly measuring the temperature of a localized area located inside the skin surface of the body.

[0008] The inventors attempted to create a means to directly and easily measure the temperature of a localized area inward from the skin surface, and conducted various studies. As a result, they 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 internal body temperature, comprising a non-exposed sheathed thermocouple and a thin metal tube with an outer diameter of 0.5 mm or less, wherein the thin metal tube has a pointed tip that is a blind end and covers the tip region of the sheathed thermocouple, and the tip portion of the sheathed thermocouple is welded and integrated with the inner surface of the blind end within the lumen of the thin metal tube.

[0010] 2. The internal body temperature sensor described in item 1, wherein the outer diameter of the metal tube is 0.2 mm to 0.5 mm.

[0011] 3. A body temperature sensor according to item 1 or 2 above, wherein the length of the metal tube is 0.5 cm to 10 cm.

[0012] 4. A non-exposed sheathed thermocouple, which is an ungrounded type, for measuring internal body temperature, as described in any of the above 1 to 3.

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

[0014] 6. A body temperature measuring device comprising one of the body temperature measuring sensors described in 1 to 5 above and a temperature measuring instrument electrically connected thereto. [Effects of the Invention]

[0015] The present invention provides a means to directly measure local temperatures in areas inward from the skin surface of a human or other animal, thereby enabling the collection of internal body temperature data during moxibustion, as well as a means to detect physiological responses such as increased blood flow in local areas of the body caused by various stimuli applied to the body surface. [Brief explanation of the drawing]

[0016] [Figure 1] A photograph serving as a drawing shows the state immediately after laser welding of the tip region of a thin metal tube containing a sheathed thermocouple, in the manufacturing process of the internal body temperature measurement sensor of the present invention. [Figure 2] A photograph used as a substitute for a diagram, showing a thin metal tube that has been processed into a sharp tip by polishing a metal block. [Figure 3] Conceptual enlarged cross-sectional view of the tip region of the internal body temperature measurement sensor of the present invention. [Figure 4] A conceptual diagram of the internal body temperature measurement sensor of the present invention with the retaining metal tube and sleeve attached. [Figure 5] Photograph representing a drawing of the body temperature measurement sensor in Example 2. [Modes for carrying out the invention]

[0017] Thermocouples are temperature sensors that utilize the thermoelectric power generated at the junction of two different metals, and a wide variety of types are widely used in products requiring temperature measurement. The basic structure of a thermocouple is two wires (strands) of two different metals joined at one end. A "sheathed thermocouple" is a type in which the joint and a certain length of the two strands 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 is a type in which the joint of the strands (temperature sensing junction) that is placed under 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 include grounded type (where the temperature sensing junction is in contact with the inner wall of the sheath tip) and ungrounded type (where the temperature sensing junction is not in contact with the inner wall of the sheath tip). Both can be used in this invention, but the ungrounded type is more preferable due to its superior stability.

[0018] Various types of non-exposed sheathed thermocouples are commercially available. The temperature characteristics of the thermocouple used in this invention only need to be capable of measuring body temperature. The measurable or suitable temperature range (usually very wide) and other characteristics are indicated in the specifications of each product, so they can be selected as appropriate. Commercially available thermocouples come in E, K, J, T, and R types, depending on the combination of two metals, and all of them cover a much wider temperature range than body temperature. As long as a sufficiently small outer diameter sheath is available, they can be selected and used as appropriate. The K type is widely used in industry, and it consists of chromel (anode) and alumel (cathode), and can be suitably used in this invention. Furthermore, a vast amount of data on electromotive force and other properties at the junction of various metals (pure metals and alloys) according to temperature is publicly known, so it is also possible to manufacture them using these.

[0019] The sensor for measuring body temperature of the present invention is made to have a pointed tip in a needle shape 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 tip with a blind end is used, and the tip region of a non-exposed type sheath thermocouple is housed in its lumen. Since this metal thin tube is the part that is inserted into the body of a patient or subject as a needle type, it is preferably as thin as possible so as not to cause a burden.

[0020] Due to the thinness of the outer diameter of the metal thin tube, the inner diameter of its lumen also becomes very small. Therefore, it is preferable that the non-exposed type sheath thermocouple inserted therein also has an outer diameter as thin as possible. In the examples described later, a commercially available non-exposed type sheath thermocouple with an outer diameter of 0.08 mm is adopted. However, since there is no particular lower limit for the outer diameter as long as it is available, for example, if a non-exposed type sheath thermocouple with an outer diameter of 0.05 mm is available, it can be adopted, and there is no particular lower limit.

[0021] The metal thin tube is for imparting sufficient strength to the sensor for measuring body temperature of the present invention so that it does not deform during normal handling (such as insertion into the skin, washing, sterilization, storage, etc.). Also, as long as it has a lumen with an inner diameter through which a non-exposed type sheath thermocouple can pass and has sufficient strength not to deform due to the resistance received from the body during insertion into the body, there is no particular lower limit for the outer diameter of the metal thin tube. Also, the inner diameter of the metal thin tube depends on how thin a thermocouple is adopted and there is no particular lower limit. Currently, for example, a sheath thermocouple with an outer diameter of 0.08 mm is commercially available. Therefore, a metal thin tube with an inner diameter larger than 0.08 mm meets this requirement.

[0022] The insertion of the sensor for measuring body temperature of the present invention into the body can be performed by direct insertion (substantially perpendicular to the skin surface), lateral insertion (substantially parallel to the skin surface), or at an intermediate angle between them, and in some cases, at different angles. Since the metal tube is the part that penetrates the skin, as long as it can maintain a strength that does not deform during insertion and a non-exposed sheath thermocouple can pass through the lumen, a smaller outer diameter is preferred so that the patient or subject feels as little pain as possible. For this reason, the outer diameter of the metal tube is preferably 0.5 mm or less, more preferably 0.4 mm or less, still 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 tube. For example, it can be set within a range such as 0.5 cm, 1 cm, 1.5 cm, 2 cm, 3 cm, 5 cm, 10 cm, etc.

[0024] In order to produce a pointed metal tube at the tip, for example, a needle tube for a medical injection needle can be used, which is preferable in terms of material. The production can be carried out as follows. That is, the tip of the non-exposed sheath thermocouple is inserted from the proximal side of the needle tube to near the front of the blade surface of the needle tube. In that state, laser irradiation is applied to the needle tip to melt the metal (stainless steel), which is the material of the needle tube. As a result, metal beads on minute droplets are formed at the needle tip, the needle tip, which was an oblique open end, becomes a blind end, and at the same time, the sheath of the non-exposed sheath thermocouple contacts the molten metal and is welded thereto. Next, the metal mass at the needle tip is polished to form a pointed needle tip. Thus, a sensor for measuring body temperature is obtained, and by connecting the terminal at the tip of the cord extending from the proximal side of the sheath to an appropriate thermometer for the thermocouple suitable for measuring the temperature near the body temperature, a body temperature measuring device can be constructed.

[0025] Also, when the length of the metal tube is set short, for convenience in holding by hand, a holding metal tube can be fitted and connected (welded, etc.) to the outer peripheral surface of the proximal end of the metal tube so that the part is not assumed to penetrate the skin. Further, for more convenient handling, an appropriate 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 arbitrarily around its axis by hand without generating mechanical resistance due to twisting of the cord when inserted into the skin. This is because inserting it while rotating it in this way reduces the frictional resistance that the needle tip receives from the body, making smooth insertion easier and avoiding unnecessary irritation to the body.

[0027] Therefore, it is preferable that the internal body temperature sensor of the present invention is configured to have a relay electrical connection means, which includes two easily detachable parts, as a connector interposed behind the metal tube, and that the two strands of the internal body temperature sensor extend to and connect to a temperature measuring device via the means provided in the middle of the cord. The specific structure of the means is arbitrary as long as it electrically connects each of the two types of strands extending from the tip side of the internal body temperature sensor of the present invention to the same type of strand leading to the temperature measuring device on a one-to-one basis. For example, this could be a combination of two pin-type terminals and corresponding socket-type terminals, or a snap-in type consisting of a plug with the inner and outer circumferential surfaces of the tube as terminals, and a socket with a cylindrical surface in contact with the outer circumferential surface and pins in contact with the inner circumferential surface as corresponding terminals, but is not limited to these. The mounting position of the detachable relay electrical connection means can be at the rear of the metal tube. Here, "rear of the metal tube" refers to the vicinity of the rear of the metal tube (or the retaining metal tube or sleeve, if one 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 tip of the sensor needle into the body, making it possible to smoothly insert the sensor needle while freely rotating it around its axis by hand. After insertion is complete, the front and rear parts of the means are reconnected and temperature measurement is performed. By providing this means, the tip of the body temperature measurement sensor can be separated from the cord, making it easier to manage, such as cleaning, sterilization, and storage.

[0028] Since various types of temperature measuring instruments are known and commercially available for use with thermocouples, which act as sensors, the body temperature measuring device of the present invention can be constructed by combining a temperature measuring instrument that is compatible with the type of thermocouple used and suitable for measuring temperatures near body temperature with the body temperature measuring sensor of the present invention. [Examples]

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

[0030] Fabrication of a sensor for measuring internal body temperature A K-type sheathed thermocouple with a single temperature sensing junction and an outer diameter of 0.08 mm (AEROPAK®, manufactured by Okazaki Seisakusho Co., Ltd.) was used. This sheathed thermocouple has a non-grounded temperature sensing junction (the temperature sensing junction does not contact the inner wall of the sheath tip) sealed inside the sheath along with magnesium oxide as an insulator. The sheath material is an alloy equivalent to Inconel® 600 (main components by mass %: Ni: 76, Cr: 15.5, Fe: 8.0).

[0031] A thin needle tube (outer diameter 0.2 mm, inner diameter 0.1 mm) for insulin injection was prepared as a thin metal tube, and the above-mentioned sheathed thermocouple was inserted from the rear end until its tip was close to the edge of the needle tube where the cutting surface is formed at an angle. Laser welding was performed on the tip of the needle tube at that position. As a result, the tip of the needle tube melted, and a spherical metal mass was formed at the tip of the needle tube as shown in Figure 1, thereby closing the tip of the lumen and creating a blind end, and at the same time the tip of the sheath, which had been inserted close to the tip region 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 that tapers from the non-welded surface of the needle tube to a pointed tip, as shown in Figure 2, and this became the body temperature measurement sensor of the present invention. The length from the base end of the needle tube to the pointed tip was approximately 1.5 cm. A conceptual enlarged cross-sectional view of the tip region 1 of the sensor is shown in Figure 3. In Figure 3, 2 is a thin metal tube (needle tube), and the lumen becomes a blind end at the tip due to laser irradiation. A sheathed thermocouple is housed in the lumen, and the sheathed thermocouple is welded to the metal of the needle tube at the tip of the sheath 3. Inside the sheath 3, there is a temperature sensing junction in a position that does not contact the inner surface of the tip side of the sheath 3, and two different lead wires (strands) 4a and 4b made of different metals extend from the temperature sensing junction to an end connector (not shown).

[0032] For ease of handling, the above-mentioned internal body temperature sensor was inserted from one end into a retaining metal tube (stainless steel, outer diameter 0.88 mm, inner diameter 0.58 mm, length 7 cm), and the other end was extended to near the base (approximately 15 mm). At that position, the contact area between the base of the needle tube and the retaining metal tube was welded to integrate them. Subsequently, a stainless steel tube (approximately 3 cm in length, maximum outer diameter approximately 4 mm) was fitted as a sleeve to the handle end of the retaining metal tube, and the joint between the retaining metal tube and the sleeve was welded. This resulted in a needle-shaped internal body temperature sensor that is easy to handle by hand. Figure 4 conceptually illustrates this, with the retaining metal tube 6 connected to the base end of the needle tube 2 that forms the outer surface of the tip region 1 of the sensor, and the sleeve 7 attached to the retaining metal tube 6. The two lead wires of the thermocouple pass through the cord 8 extending from the sleeve 7 to the base end, and these are connected to the terminals of the end connector 9. The end connector 9 is connected to a commercially available temperature measuring instrument that corresponds to the thermocouple used. [Examples]

[0033] A round snap-in connector 10 (manufactured by LEMO Japan Co., Ltd.) was prepared as a detachable intermediate electrical connection means. The snap-in connector 10 consists of a front part 10f and a rear part 10b that are detachably snapped together. The front part 10f is equipped with pins, which are terminals, and the rear part 10b is equipped with corresponding sockets, which are terminals. In the body temperature measurement sensor of Embodiment 1, the cord was cut at the rear of the sleeve 7. The connector 10 was separated into front and rear parts, and each of the two strands from the sleeve side was connected to each terminal of the front part 10f, and then fixed to the rear end of the sleeve 7. Next, the cut ends of the strands at the cut portion of the cord extending to the temperature measuring device were connected to each terminal at the rear of the rear part 10b of the connector 10, such that the types of strands connected to the front part 10f matched the types of strands on the cord side going to the temperature measuring device, thus forming a body temperature measurement sensor (Figure 5). Since the rear portion 10b of the connector 10 can be detached from the front portion 10f, when inserting the needle tip into the skin, the needle tip can be freely rotated by hand without being hindered by the cord, allowing for smooth insertion. After insertion, the front portion 10f of the connector 10 can be inserted into the rear portion 10b to connect the two and enable temperature measurement. After use for measuring internal body temperature, the rear portion 10b and subsequent parts of the connector 10 are separated, and only the front portion 10f and tip are cleaned, sterilized, and stored. [Examples]

[0034] 2. Measurement of subcutaneous temperature using a sensor for measuring internal body temperature. Using the needle-shaped body temperature sensor fabricated in Example 2, we attempted to measure subcutaneous temperature changes caused by moxibustion at acupoints on the human body by connecting its terminals to a commercially available thermocouple thermometer. With the approval of the Ethics Committee of Takarazuka Medical University, a private educational institution, six faculty members from Takarazuka Medical University who agreed to participate in the research were used as measurement subjects. The moxibustion sites were six acupoints: right shoulder well, right kidney, middle halve, right guanyuan, right hand 36, and right foot 36. The temperature measurement sensor was adjusted so that its tip was positioned directly below each acupoint and inserted horizontally into the subcutaneous tissue to a depth of approximately 5 mm. The subjects felt almost no pain during insertion. In this state, the baseline subcutaneous temperature at each site was measured. Next, a 1.0 mg (approximately 67°C) shaped moxa cone (made by pinching and shaping moxa between the fingers) 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 site were as follows: Right Jianjing: 32.10°C before moxibustion, 46.99°C after moxibustion; Right Shenshu: 31.70°C before moxibustion, 50.95°C after moxibustion; Zhongwan: 33.10°C before moxibustion, 46.84°C after moxibustion; Guanyuan: 32.17°C before moxibustion, 42.73°C after moxibustion; Right Shousanli: 30.43°C before moxibustion, 43.32°C after moxibustion; Right Zusanli: 31.53°C before moxibustion, 54.84°C after moxibustion. The average temperature difference before and after moxibustion at each acupoint was 16.12 ± 4.57°C.

[0036] By using the internal body temperature measurement sensor of the present invention, it was possible to easily measure the subcutaneous temperature directly without causing the subject to feel any pain. [Industrial applicability]

[0037] The present invention provides a means for directly and easily measuring local temperatures in areas inward from the skin surface of a human or other animal, thereby providing a measurement means that enables the collection of internal body temperature data, for example, during moxibustion, and also provides a means that enables the quantitative detection of physiological responses, such as increased blood flow in local areas of the body, caused by various physical or chemical stimuli applied to the body. [Explanation of Symbols]

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

Claims

1. A sensor for measuring internal 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 tip which is a blind end and covers a tip region of the sheathed thermocouple, and the tip portion of the sheathed thermocouple is 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 metallic thin tube is 0.2 mm to 0.5 mm.

3. 3. The sensor for measuring internal body temperature according to claim 1 or 2, wherein the length of said metallic thin tube is 0.5 cm to 10 cm.

4. 2. The sensor for measuring internal body temperature according to claim 1, wherein said unexposed sheathed thermocouple is an ungrounded type.

5. 2. The sensor for measuring internal body temperature according to claim 1, further comprising an intermediate electrical connection means, the intermediate electrical connection means including a front portion and a rear portion connected to each wire of the sheathed thermocouple and detachable, at the rear of the metal thin tube.

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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