JP2004016734A - Method and device for displaying metabolism by thermography system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermography system for indirectly measuring a metabolism index, and a device and a method for displaying a Ruler for thermography clinical diagnosis of diabetes mellitus. <P>SOLUTION: In a two-dimensional nonlinear ruler, by using the thermography system for recording digital data of distribution of substance surface temperature, a plurality of thermographic images before and after applying cold water stressors to a living-body precapillary circulation section placed in a specific environmental condition are taken, an internal metabolism situation and a blood stream situation are inferred from an animate heat-transfer theory on some temporary conditions, a series of parameters expressing functions of a living body internal metabolism system is calculated by analyzing heat-transfer equation of a living-body precapillary part in a spatial area and a time area, the metabolism index is measured with two important parameters in a metabolism system called an effective heat conductivity and a metabolism heat generation ratio of a periphery part by system identification technique, and the metabolism index for clinical diagnosis of diabetes mellitus is displayed by a statistical method on a monitor screen. <P>COPYRIGHT: (C)2004,JPO

Description

ここにρとＣはそれぞれ指組織の物質比重と比熱であり、Ｋ_ｅｆｆは有効熱伝導率であり、Ｑ_ｍは末梢部の代謝生熱率である。
【００４０】
（３）　式の空間領域での図５の指の径方向（ｒ）の一般解が（４）　式であり、体表面の境界条件を入れると（５）　式が得られる。

【００４１】
（５）　式により、定常状態の指の径ｒ方向の温度分布は距離の自乗に比例することを利用して、（６）　式も成り立つ。
Ｔ（ｒ）＝ａ_０＋ａ_１ｒ＋ａ_２ｒ^２　　　（６）
【００４２】
中心軸１５方向には主に心臓からの血液が末梢へ注入され、皮膚表面に注目し、定常状態の温度分布のみ考えると、中心軸１５方向Ｘの温度分布として（７）　式が導かれる。
Ｔ（ｘ）＝Ｋ_ｘ＋ｄ　　　　（７）
【００４３】
冷水負荷を掛けると、末梢部の温度が降下し、血管が収縮し、血液注入が減少する。それで、末梢部の温度バランスは崩れ、体温を維持するためには代謝が活発化し、血液の注入も時間的に段々回復し、（３）　式中のＫ_ｅｆｆとＱ_ｍも変化する。
【００４４】
そして、冷水負荷の終了後に末梢部の温度Ｔ　はＫ_ｅｆｆとＱ_ｍの変化によって調節される。この場合、解析を簡略するために中指１４の中心軸１５のＸ軸方向の温度分布が線形的な変化である（７）　式から分るように、径方向のＴ（ｒ，ｔ）のみ考えばよい。すると、（３）　式のＫ_ｅｆｆとＱ_ｍと（６）　式のパラメータａも時間的な関数として考えれば良い。
【００４５】
従って、最終的には体表面の温度分布に対して、（８）式が得られる。

さらに、（８）　式は体表面と周囲環境の熱交換を考えると、（９）　式が得られる。

（９）　式ではαが体表面と周囲環境の熱交換係数であり、Ｔ_ａが環境温度であり、Ａが放射面積であり、εが放射率であり、σがボルツマン定数である。
【００４６】
（８）　式と（９）　式を時間的に離散化すれば（１０）式と（１１）式になる。

それで、サーモグラフィ装置２で冷水負荷前後における生体末梢部位の各時刻の温度を記録し、環境温度と体温を測定しておけばＫ_ｅｆｆとＱ_ｍが求められる。
【００４７】
実測の結果を見ると、冷水負荷後に末梢部の代謝生熱率Ｑｍは（１２）式のような関数で表現できる。
ａｅ^−ｂｔ＝Ｑ_ｍ０−Ｑ_ｍ（ｔ）　　　（１２）
（１２）式のａは定常時の代謝率Ｑ_ｍ０及び冷水負荷直後の代謝率Ｑ_ｍで決定され、ｂは冷水負荷撤去後の定常状態に回復する速さを表現している。
【００４８】
Ｋ_ｅｆｆはＱ_ｍと同じような傾向にある。（３）　式のＫ_ｅｆｆの定義からも分るように冷水負荷後の末梢部の熱源は代謝と血液注入の二つであり、Ｋ_ｅｆｆは血液注入率を表現し、全身の代謝による生熱効率も表現する。すると、ａとｂが代謝系の働きを表すパラメータである。これで、システム同定技術により、最小二乗法で（１２）式のパラメータａとｂを求めるために（１２）式を（１３）式に変形する。
ｌｎａ−ｂｔ＝ｌｎ〔Ｑ_ｍ０−Ｑ_ｍ（ｔ）〕　　　（１３）
即ち：Ｙ（ｔ）＝Ａ＋Ｂｔ　　　（１４）
ここに、Ｙ（ｔ）＝ｌｎ〔Ｑ_ｍ０−Ｑ_ｍ（ｔ）〕、Ａ＝　ｌｎａ、Ｂ　＝ｌｎｂであり、ここでＡとＢを代謝機能指数と定義する。
【００４９】
また、本発明では上式で求めた代謝機能指数ａ及びｂを座標軸とし、表示手段４の画面上に表現し、臨床で血糖値を中心とする糖尿病総合診断で得られた統計的なデータに基づいて非線形的な曲線でルーラ（Ｒｕｌｅｒ　）を作成し、実測のａ　とｂ　の座標値を位置付ければ生体の代謝機能が観測され、糖尿病の臨床診断に糖尿病の型分けと重症度を直観的に判断することができる。
【００５０】
上述の（６）式の指の中心軸の二次元的な分布Ｔ（ｒ）を証明するためにＰｅｎｎｅｓが人の前腕で実測した実測値（℃）と、本発明の（７）式の同定値と計算値とを比較すると下記の表１に示す結果が得られた。図６に表１のデータを縦軸に温度（℃）を横軸に測定点半径ｒをプロットしたものである。
【００５１】
【表１】

【００５２】
また、本発明に依り、臨床的に収集した糖尿病患者のデータを用いて、図７に示してある冷水負荷後の温度回復曲線Ｔ（ｒ）も二次元的な分布を証明している。
【００５３】
図７（Ａ）、（Ｂ）は縦軸に温度（℃）を、横軸に冷水負荷時間をとったもので図７（Ａ）は冷水負荷状態を示す曲線を、図７（Ｂ）は冷水負荷後の所定時間経過時の統計的な経時温度分布を示し、曲線１６は二次元的分布を示している。
【００５４】
また、臨床的に実測した一人の糖尿病患者のデータを用いて、本発明の有効熱伝導率Ｋ_ｅｒｒと代謝生熱率Ｑ_ｍを所定時刻毎に実測した結果を下表２に示す。図８はこれらのデータのグラフを示している。
【００５５】
【表２】

【００５６】
表２に於いて、時刻０−は冷水負荷前の時刻であり０＋は冷水負荷後の時刻を表す。また、図８（Ａ）は縦軸に温度（℃）を横軸に温度負荷前後の時刻（分）をとったものであり、図８（Ｂ）は縦軸にＫ_ｅｆｆを、図８（Ｃ）は縦軸にＱ_ｍをとっている。これらのＴ，Ｋ_ｅｆｆ及びＱ_ｍの曲線１７，１８，１９は常に一定の傾向の曲線を示し、サーモグラフィ装置で糖尿病を診断できるパラメータは代謝機能指数の有効熱伝導率や代謝生熱率を用い得ることを示している。
【００５７】
次に、（１４）式で定義した血液注入率と代謝機能指数のパラメータＡとＢを座標軸として画面上にベゼール関数で臨床的に血糖値を中心とする糖尿病総合診断で得られた統計的なデータに基づいて糖尿病を型分けした非線形的な曲線を図９及び図１０の様に、表示手段の表示パターン曲線２０〜２３となるルーラを作成する。曲線２０から右側の領域が糖尿病の無い健常者の分布領域を示し、曲線２１乃至２３間が２型糖尿病患者の分布領域を示し、曲線２３から左側領域が１型糖尿病患者の分布領域を示している。又、２４は左側に行くに従って糖尿病が重くなる重症度合いを示す矢印である。
【００５８】
従って、本発明のサーモグラフィ装置による代謝機能表示方法及びその装置に依れば被検者の血液注入率と代謝機能指数を測定、演算して、図９に示す表示手段のルーラ上にＣＰＵのキーボード等の入力手段を介して入力させることで、二次元非線形的な糖尿病分類尺度から直観的に糖尿病の類型と健常者を見分けることが可能となる。
【００５９】
図１０は１５人の健常者と９４名の糖尿病患者の測定結果をルーラ上にプロットしたもので、健常者が二次元非線形的な曲線２０〜２３に入ることはないことが証明されている。
【００６０】
図１１の直線２５は縦軸に実測血糖値を横軸に代謝機能指数の自乗和をとった場合の相関関係を示すものであり、これらは血糖値の側面から、本発明の有効性を実証していることが解る。
【００６１】
【発明の効果】
本発明のサーモグラフィ装置の代謝機能表示方法及びその装置によればサーモグラフィを使っているので、採血する必要がなく、サーモグラフィ装置が取得した温度分布データはコンパクトなＰＣカード（ＣＦメモリカード）にデジタル記録してあるので、コンピュータで簡単に処理することができる。また冷水負荷により、生体内部の熱環境を強制的に変更し、代謝機能と血流状況が温度刺激によって誘発され、代謝系の活動状況が容易に観測される。生体伝熱理論に基づいた伝熱方程式により、末梢循環部位で内部の熱状況が体表面の温度状況と繋がり、体表面の温度から体内の生熱状況を推測することができる。空間領域と時間領域における伝熱方程式の解析により、生体内部の代謝系の働きを表現する一連のパラメータを算出することができる。更にシステム同定は代謝機能指数としての末梢部の有効熱伝導率と代謝生熱率とのパラメータを測定することもできる。またモニタ画面上に二次元パラメータを座標軸として作成した糖尿病のサーモグラフィ臨床診断用の代謝機能指数を表示するルーラにより、臨床診断の主な目的である糖尿病の型分けと重症度を直観的に判断することができる。
【図面の簡単な説明】
【図１】本発明のサーモグラフィ装置の代謝機能表示装置のシステムブロック図である。
【図２】本発明のサーモグラフィ装置の代謝機能表示装置の表示の為のフローチャート図である。
【図３】本発明に用いる測定室の略線的配置図である。
【図４】本発明のサーモグラフィ装置の代謝機能表示装置による温度計測部位の平面図である。
【図５】本発明のサーモグラフィ装置の被測定対象物となる人体の手の指の円柱形モデルを示す図である。
【図６】前腕の実測温度と最小自乗法での温度の同定値計算温度との関係を示す曲線図である。
【図７】冷水負荷後の温度回復曲線を示す図である。
【図８】実測した糖尿病患者の熱パラメータの分布曲線図である。
【図９】本発明の糖尿病の診断用スケールとなるルーラの表示パターンである。
【図１０】糖尿病診断結果の分布図である。
【図１１】代謝機能指数自乗和と実測血糖値との相関を示す図である。
【符号の説明】
１‥‥被測定対象物、２‥‥サーモグラフィ装置、３‥‥コンピュータ（ＣＰＵ）、４‥‥表示装置、６‥‥ＰＣカード（記憶手段）、７‥‥恒温冷水槽、８‥‥ＲＯＭ、９‥‥ＲＡＭ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for displaying a metabolic function by a thermographic device and a display device therefor, and in particular, to obtain a ruler for thermodiagnostic clinical diagnosis of diabetes by measuring a series of parameters expressing the function of the metabolic system by a non-blood sampling method. And a display device for displaying a metabolic function.
[0002]
[Prior art]
Conventionally, the clinical diagnosis of diabetes measures blood sugar level. Diabetes is a typical metabolic disease. Metabolism is an important function essential for the vitality of living organisms. In particular, the pancreas secretes insulin and releases it into blood and body fluids.
[0003]
This insulin also breaks down glucose to provide the energy needed for vital activity in the body. Undegraded glucose remains in blood and urine and is excreted outside the body. The amount of glucose in the blood is called the blood sugar level. Normally, there are two main types of diabetes classified by blood glucose level: type 1 diabetes and type 2 diabetes. Type 1 diabetes is absolutely deficient in insulin, and type 2 diabetes is relatively deficient in insulin. ing. This classification essentially evaluates the ability of the pancreas to secrete insulin. Insulin deficiency in the body is susceptible to various organ or systemic diseases, and various complications of diabetes occur.
[0004]
Diagnosis of the blood sugar level of diabetes actually used clinically is only indirectly measuring insulin through the blood sugar level, and because the blood sugar level is influenced by diet, physiological condition and exercise, The accuracy of evaluating the amount of insulin in the blood based on the blood sugar level is low, and the accuracy of the blood sugar level diagnostic method for diabetes is low.
[0005]
For example, in 1985, the World Health Organization (WHO) proposed a standard for diagnosing blood sugar levels in diabetes, and in 1997, the American Diabetes Task Force proposed a revision. However, according to statistics, the accuracy rate of diabetes diagnosis is about 60% for both proposals.
[0006]
In addition, various methods for measuring a living body temperature with a thermographic device have been conventionally proposed. However, these measurement methods are used when a simple local heating mechanism abnormality such as a tumor inside a living body is directly determined by pattern processing of a thermographic image.
[0007]
In the metabolic system of the living body, heat is generated as glucose is decomposed. This makes it possible to diagnose disorders such as metabolism in the living body and peripheral vascular circulation by using the thermographic device also for diabetes diagnosis.
[0008]
In the prior art, there is a diagnosis of diabetes using a thermographic apparatus that uses a temperature recovery rate. The temperature recovery rate (referred to as TR) is normally calculated as in the following equation (1).
_{TR = (T i -T 1)} / (T o -T 1) (1)
Here T _o is the steady state temperature of the immediately preceding temperature load, T ₁ is the temperature immediately after the temperature load, T _i is the temperature of the thermal load after i time.
[0009]
The heat generation mechanism inside a living body is quite complicated. The internal state cannot be easily determined only by the temperature recovery pattern. Such a test method for TR does not allow accurate clinical diagnosis of diabetes and cannot measure metabolic rate and the like. Therefore, clinically, in order to diagnose diabetes, blood is collected many times, and the present situation is to rely on biochemical methods such as measurement of blood sugar level in blood and insulin resistance test.
[0010]
In addition, a mathematical model is required to non-contactly diagnose the internal thermal function from the temperature of the surface of the object, and in the past, a mathematical model for inverse problem analysis was created and the internal thermodynamic parameters were determined. Was calculated. However, the inverse problem analysis method has various problems and has not been put to practical use.
[0011]
Various thermodynamic equations inside the object are theoretically made. Conventionally, Pennes' heat transfer equation has been used for measuring the heat of a living body. A general expression of Pennes' heat transfer equation is given by the following equation (2).
ρc∂T / ∂t = ∇ · (K∇T ) + W b C b ρ b (T a -T v) Q b + Q m (2)
Where ρ is the specific gravity of the substance, c is the specific heat of the substance, ∂ is the micromolecule, T is the temperature function, ∇ is the gradientr, K is the heat transfer constant of the substance, W _b is the blood infusion rate, C _b is the specific heat of blood, [rho _b blood density, _{T a} is the arterial blood temperature, _{T v} is venous blood temperature, the _{Q b} bloodstream variable and _{Q m} is a metabolic production heat rate.
[0012]
To solve this equation, it is necessary to measure the temperature at each position inside the object and calculate each material constant and variable, but it is desirable to measure the temperature inside the living body by non-invasive means. At present, each constant must be measured by using a temperature measurement method that is intrusive into the living body. In addition, the metabolic heat rate or the like cannot be measured as it is using the Pennes heat transfer equation as it is, and metabolic system parameters such as the biological metabolic function index cannot be specified by a non-invasive method.
[0013]
The metabolic rate and the like can be displayed numerically or in the form of a histogram, but intuitively based on a special display using the non-linear display means (ruler) created by the present invention. No way to do this has been proposed.
[0014]
[Problems to be solved by the invention]
In the prior art, the blood glucose level is used when diagnosing diabetes as described above, so the accuracy is low, blood collection is required, and the display of the diagnosis result is not intuitive. Neither can it represent a biological metabolic function. Therefore, an object of the present invention is to develop a system for measuring a biometabolic function index that has high accuracy, does not require blood collection, and displays an intuitive diagnosis result.
[0015]
The present invention uses a thermography apparatus, and pays attention to the amount of heat released during the degradation of glucose by insulin into the metabolic system, and refers to a metabolic function index that expresses the function of the metabolic system inside a living body in a non-blood-collecting thermographic temperature measurement method. Measure parameters, provide a new reference standard for clinical diagnosis of diabetes, create a two-dimensional metabolic index ruler for clinical diagnosis of diabetes thermography on the screen of the display means, and classify and classify diabetes. An intuitive display system is provided. Specifically, the following requirements are mainly solved.
(1) Intuitively display the type and severity of diabetes.
{Circle around (2)} The movement of the metabolic system in the living body is forcibly induced and recorded as temperature distribution data.
{Circle around (3)} The metabolic function index in the metabolic system is measured from the thermographic data.
[0016]
[Means for Solving the Problems]
The present invention relates to a metabolic function display device and a display method for detecting infrared rays from an object to be measured 1 via a thermographic device 2 and measuring a temperature from the object to be measured 1 to display a metabolic function. Using the blood infusion rate and metabolic function index as parameters above, and displaying a non-linear curve that classifies diabetes based on the statistical data obtained by the comprehensive diabetes judgment centering on blood glucose level on the secondary screen According to another aspect of the present invention, there is provided a metabolic function display device and a display method using a thermography device.
[0017]
According to the metabolic function display method and the display device of the thermographic device of the present invention, the metabolic function index ruler (display device) for diabetic thermography clinical diagnosis is formed on the screen of the display means using two-dimensional parameters as coordinate axes. The main purpose is to obtain an intuitive judgment of the type and severity of diabetes.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a metabolic function display method and a display device using the thermographic device of the present invention will be described in detail with reference to FIGS. 1 and 2 based on a system block and a flowchart at the time of measurement.
FIG. 1 is a system block diagram used in the present invention, and FIG. 2 is a flowchart at the time of measurement. In FIG. 1, reference numeral 1 denotes an object to be measured, and the object to be measured 1 is measured in an environment arranged in a predetermined environment temperature setting area 5.
[0019]
The object to be measured 1 is imaged by the thermographic device 2 and the infrared temperature of the surface emitted from the object to be measured 1 is measured.
[0020]
The thermography apparatus 2 has a storage means 6 such as a PC card. Temperature data measured by the thermographic device 2 is supplied to a computer system (hereinafter, referred to as a CPU) 3. The CPU 3 has a display device 4 such as an ordinary LCD, and storage means such as a ROM 8 and a RAM 9. Measured temperature data is stored in the RAM 9 and the like, and analysis and calculation are performed based on the measured temperature data. .
[0021]
The object 1 to be measured arranged in the environmental temperature setting area 5 is applied with a chilled water load based on cold water of a predetermined temperature arranged in the constant temperature cold water tank 7 so that the internal temperature of the object 1 to be measured is changed to the surface. A process to induce the user is performed.
[0022]
Next, a schematic process operation of the present invention will be described based on the flowchart shown in FIG.
In FIG. 2, a case will be described in which the object to be measured 1 is a living body, and classification of diabetes and determination of the severity are measured using a thermographic device.
[0023]
First, to induce movement of the living body metabolism to be the object 1 to be measured as shown in the first step S ₁ to the forced body surface by means of applying a temperature load to the living body peripheral sites. However, the temperature of the cold water for the temperature load is selected and fixed so that the difference with respect to the external environment temperature becomes an optimum value, and the time of the temperature load is also fixed. The temperature information appearing on the body surface is recorded by the thermographic device 2 immediately before the cold water load and at multiple times after the cold water load, and stored in the PC card 6 built in the device 2.
[0024]
For example of the living body to the second as shown in step S ₂ if Kakusure, finger center temperature is detected automatically.
[0025]
Based on the following third step S ₃ to fifth step S ₅ in the conventional Pennes equation, making simplified and heat transfer equations from at several assumptions. Further, the heat transfer equation is decomposed into a space domain and a time domain and analyzed to calculate parameters in space at each time (third step S ₃ ). Then, the temperature inside the body is calculated from the temperature distribution on the body surface. Guess the distribution. Specifically, calculation of a parameter in the time domain of the average temperature of the finger (fourth step S ₄ ) is performed. Further, the effective heat conductivity of the peripheral part and the metabolic heat rate called the metabolic function index are measured by the system identification technique (fifth step S ₅ ).
[0026]
Thermography clinical diagnosis of the next sixth diabetes overall diagnosis obtained in statistical display device 4 on the screen based on the data diabetes nonlinear curve of the two-dimensional around the blood glucose level in clinical step S ₆ A metabolic function index ruler for By using this ruler to intuitively display the type and severity of diabetes, a non-blood sampling system for metabolic function index and a metabolic function ruler for clinical diagnostics of diabetes using a thermography device. (Display device) can be provided.
[0027]
According to the metabolic index measurement method and the metabolic index ruler for diabetes by the thermographic device described in the above flowchart,
[0028]
{Circle around (1)} By applying a cold water load and forcibly changing the thermal environment inside a living body, the metabolic function and the blood flow state are induced by the temperature stimulus, and the activity state of the metabolic system can be easily observed. If the internal metabolic function has a correlation with the body surface temperature state, the temperature information on the body surface measured in a non-contact manner by the thermographic device includes the internal metabolic function information. In the present invention, since a thermographic device is used, it is not necessary to collect blood, and the temperature distribution data taken by the thermographic device is digitally stored in the PC card 6, which is convenient for processing by the CPU 3. In addition, fixing the difference between the cold water temperature and the environmental temperature and the temperature load time can be considered to be the same load amount in summer and winter.
[0029]
{Circle around (2)} By a heat equation based on the theory of biological heat transfer, a thermal change inside the living body can be estimated from a temperature change on the body surface. By analyzing the heat equation in the spatial domain, a series of parameters expressing the function of the metabolic system inside the living body can be calculated. The system identification can measure the parameters of the effective thermal conductivity and the metabolic heat rate of the peripheral part as the metabolic function index by the least squares error method.
[0030]
(3) In addition, the metabolic function index ruler for clinical diagnosis of diabetes thermography, which is created on the screen of the display device 4 using two-dimensional parameters as coordinate axes, makes it possible to intuitively classify the type and severity of diabetes, which are the main purposes of clinical diagnosis. Can be determined.
[0031]
Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS.
First, general external conditions and ambient temperature for implementing the present invention will be described.
When measuring temperature with a thermographic device, general external conditions are required.
For example, when measuring in the inspection room 10 shown in FIG. 3, a thick black curtain shuts out the infrared rays outside, closes the door, and when the indoor temperature reaches the target value, the cooler 11 or a lamp that emits infrared rays. And start the measurement after the person does not move. FIG. 3 shows the arrangement of the measurement chamber. In a state where the living body of the DUT 1 is stabilized in both mind and body, first, the environment temperature is acclimated to about 15 minutes. Then, both hands 13 are placed on the hand rest 12 having a height substantially equal to that of the heart, and a single thermal image is taken by the thermography apparatus 2 from directly above the back of the hand. Subsequently, both hands are immersed in the cold water in the constant temperature cold water tank 7 for one minute to apply a temperature load. Then take a single temperature image every few minutes.
[0032]
The ambient temperature of the measurement room is set to 25 ± 2 ° C in summer and 20 ± 2 ° C in winter with respect to the normal 22 ° C average annual room temperature in order to make it easier to respond to summer and winter. The difference in temperature fluctuation between the start time and the end time is ± 0 in both summer and winter. Keep within 5 ° C. The temperature acclimatization time of the living body of the measurement object is 10 minutes in summer and 20 minutes in winter.
[0033]
The optimum value of the chilled water temperature for the temperature load is the difference between the ambient temperature and 15 ° C., which is 10 ± 1 ° C. in summer and 5 ± 1 ° C. in winter. However, in practice, it is difficult to strictly maintain the environmental temperature determined above, so the parameters are calculated with temperature compensation. In this case, a large error occurs, so if possible, start over from a strictly determined environmental condition.
[0034]
Next, the principle of measuring the metabolic function index by the thermography device 2 and its heat transfer equation will be described.
The metabolic pancreas secretes insulin and releases it into blood and body fluids. This insulin further breaks down glucose and generates heat as the glucose breaks down, and this generated heat is transferred to the body surface and manifests itself as body surface temperature. The local temperature of the human body is mainly due to blood flow and local metabolism. Thermal energy from systemic metabolism affects the temperature at peripheral sites by blood flow, and local metabolism in the peripheral circulation also affects the temperature at those sites.
[0035]
The metabolic function in the human body, especially in the microcirculation, can be determined by using the finger of the hand, which is a peripheral part, of the local temperature. The finger of the hand is small in size and is optimal as a cylindrical model.
[0036]
Therefore, the finger of the hand is selected as the measurement execution part, and the temperature of the back part of the hand is measured. In the finger of a hand, dynamic state information of blood flow and metabolism in which arteries and veins are juxtaposed is included. The temperature measurement point is measured from the center of the fingertip of the middle finger on the back part of the hand to the center of the back part of the hand. FIG. 4 shows a temperature measurement site on the thermography of the middle finger 14 of the person.
[0037]
In order to create a heat transfer equation, the structure of a finger of a human hand is considered using a cylindrical model shown in FIG. In this middle finger model, measurement is performed at a plurality of points P _{1 to} P ₆ on the center line 15 of the middle finger 14. The temperature distribution (T) of the finger of the hand is a function of the spatial position, and is a function of time that changes over time. The finger temperature is generated by the heat energy injected from the heart into the blood and the heat energy generated by metabolism in the peripheral circulation. In some cases, heat energy is radiated due to heat radiation from the skin surface due to heat exchange with the environment, and a dynamic equilibrium state is established with the internal temperature of the living body.
[0038]
For the middle finger 14 of the distal finger part of the middle finger model described above, the Pennes equation defines the effective heat conductivity K _eff by considering heat transfer by blood flow and heat transfer of the tissue in a lump, and defines the following temporary conditions. When the expression in the cylindrical coordinate system is omitted and the analysis of the θ dimension is omitted, a simple equation of the equation (3) is established.
[0039]
(A) The finger tissue is a substance having a uniform medium and isotropic thermal characteristics, ΔT / Δθ = 0, and K _eff and Q _m are spatial constants.
(B) The center temperature in the body is a constant.

Here is a substance specific gravity and specific heat of ρ and C respectively finger tissue, K _eff is the effective thermal conductivity, Q _m is a metabolic production heat rate of peripheral portion.
[0040]
The general solution in the radial direction (r) of the finger in FIG. 5 in the spatial domain of the equation (3) is the equation (4), and the equation (5) is obtained by inserting the boundary condition of the body surface.

[0041]
By using the expression (5), the fact that the temperature distribution in the direction of the radius r of the finger in the steady state is proportional to the square of the distance, the expression (6) also holds.
T (r) = a ₀ + a ₁ r + a ₂ r ² (6)
[0042]
In the direction of the central axis 15, blood from the heart is mainly injected into the periphery, and focusing on the skin surface and considering only the steady state temperature distribution, the following equation (7) is derived as the temperature distribution in the central axis 15 direction X.
T (x) = _Kx + d (7)
[0043]
Applying a cold water load lowers peripheral temperatures, contracts blood vessels, and reduces blood infusion. Therefore, the temperature balance in the peripheral part is lost, metabolism is activated in order to maintain body temperature, blood infusion gradually recovers, and K _eff and Q _{m in} equation (3) also change.
[0044]
Then, after the end of the cold water load, the peripheral temperature T 2 is adjusted by the change of K _eff and Q _m . In this case, in order to simplify the analysis, the temperature distribution in the X-axis direction of the center axis 15 of the middle finger 14 is a linear change. Just fine. Then, K _eff and Q _{m in} equation (3) and parameter a in equation (6) may be considered as a temporal function.
[0045]
Therefore, finally, equation (8) is obtained for the temperature distribution on the body surface.

Equation (8) gives equation (9) in consideration of heat exchange between the body surface and the surrounding environment.

In equation (9), α is the heat exchange coefficient between the body surface and the surrounding environment, _Ta is the ambient temperature, A is the radiation area, ε is the emissivity, and σ is the Boltzmann constant.
[0046]
If the equations (8) and (9) are discretized in time, the equations (10) and (11) are obtained.

So, the temperature of each time biometric peripheral sites before and after the cold water load recorded by thermography apparatus 2, K _eff and Q _m are obtained if by measuring the ambient temperature and body temperature.
[0047]
Looking at the results of the actual measurement, the metabolic heat rate Qm in the peripheral part after the cold water load can be expressed by a function such as equation (12).
^{_{ae -bt = Q m0 -Q m (}} t) (12)
In the equation (12), a is determined by the metabolic rate Q _{m0 in} the steady state and the metabolic rate Q _m immediately after the cold water load, and b represents the speed of recovery to the steady state after the cold water load is removed.
[0048]
K _eff tends to be similar to Q _m . As can be seen from the definition of K _eff in equation (3), the peripheral heat sources after cold water loading are metabolism and blood infusion, and K _eff expresses the blood infusion rate and the _biothermal efficiency due to whole body metabolism. Also express. Then, a and b are parameters representing the function of the metabolic system. With this, the equation (12) is transformed into the equation (13) in order to obtain the parameters a and b of the equation (12) by the least squares method using the system identification technique.
lna-bt = ln _[Q m0 _-Q m (t)] (13)
That is: Y (t) = A + Bt (14)
Here, Y (t) = ln _[Q m0 _-Q m (t)], A = lna, a B = LNB, here defined as the metabolic function index A and B.
[0049]
Further, in the present invention, the metabolic function indices a and b obtained by the above equation are used as coordinate axes, expressed on the screen of the display unit 4, and converted into statistical data obtained by clinical diagnosis of diabetes centering on blood glucose level in clinical practice. A ruler is created with a non-linear curve based on this, and if the measured a and b coordinate values are located, the metabolic function of the living body is observed, and intuition of the type and severity of diabetes is used for clinical diagnosis of diabetes. Can be determined.
[0050]
In order to prove the two-dimensional distribution T (r) of the central axis of the finger in the above equation (6), an actual measurement value (° C.) actually measured by Pennes on a human forearm and identification of the equation (7) of the present invention. When the values were compared with the calculated values, the results shown in Table 1 below were obtained. FIG. 6 is a graph in which the data in Table 1 is plotted on the ordinate and the temperature (° C.) is plotted on the abscissa and the measurement point radius r is plotted on the abscissa.
[0051]
[Table 1]

[0052]
Further, according to the present invention, the temperature recovery curve T (r) after the cold water load shown in FIG. 7 also proves a two-dimensional distribution using the clinically collected data of the diabetic patients.
[0053]
7 (A) and 7 (B) show the temperature (° C.) on the vertical axis and the cold water load time on the horizontal axis. FIG. 7 (A) is a curve showing the cold water load state, and FIG. It shows the statistical temperature distribution over time after the lapse of a predetermined time after the cold water load, and the curve 16 shows the two-dimensional distribution.
[0054]
Further, by using the clinically measured by one of the diabetic patient data, the results of actual measurement for each predetermined time the effective thermal conductivity K _err and metabolic production Netsuritsu Q _m of the present invention shown in Table 2 below. FIG. 8 shows a graph of these data.
[0055]
[Table 2]

[0056]
In Table 2, time 0- is the time before the cold water load, and 0+ is the time after the cold water load. 8A shows the temperature (° C.) on the vertical axis, and the time (minutes) before and after the temperature load on the horizontal axis, and FIG. 8B shows K _eff on the vertical axis and FIG. C) is taking a _{Q m} on the vertical axis. Curve 17, 18 and 19 of these T, K _eff and Q _m always shows the curves of constant tendency, parameters that can diagnose diabetes thermography apparatus using the effective thermal conductivity and metabolic production heat rate of metabolic function index It shows that you get.
[0057]
Next, using the parameters A and B of the blood infusion rate and the metabolic function index defined by the equation (14) as coordinate axes, a statistically obtained clinically obtained by a comprehensive diagnosis of diabetes centering on a blood glucose level by using a Besere function on a screen. As shown in FIG. 9 and FIG. 10, rulers are formed from the non-linear curves obtained by classifying the diabetes based on the data into the display pattern curves 20 to 23 of the display means. The area on the right side of the curve 20 indicates the distribution area of healthy subjects without diabetes, the area between the curves 21 to 23 indicates the distribution area of type 2 diabetes patients, and the area on the left side of the curve 23 indicates the distribution area of type 1 diabetes patients. I have. Numeral 24 is an arrow indicating the degree of severity of diabetes becoming more severe toward the left.
[0058]
Therefore, according to the metabolic function display method and the apparatus according to the present invention, the blood injection rate and the metabolic function index of the subject are measured and calculated, and the CPU keyboard is displayed on the ruler of the display means shown in FIG. And the like, it is possible to intuitively distinguish the type of diabetes from a healthy person from the two-dimensional nonlinear diabetes classification scale.
[0059]
FIG. 10 is a plot of measurement results of 15 healthy subjects and 94 diabetic patients on a ruler, and it has been proved that healthy subjects do not enter the two-dimensional nonlinear curves 20 to 23.
[0060]
The straight line 25 in FIG. 11 shows the correlation when the measured blood glucose level is plotted on the vertical axis and the sum of the squares of the metabolic function index is plotted on the horizontal axis. These demonstrate the effectiveness of the present invention from the aspect of the blood glucose level. You know what you are doing.
[0061]
【The invention's effect】
According to the method for displaying the metabolic function of the thermographic apparatus and the apparatus according to the present invention, since thermography is used, it is not necessary to collect blood, and the temperature distribution data obtained by the thermographic apparatus is digitally recorded on a compact PC card (CF memory card). It can be easily processed by computer. In addition, the cold water load forcibly changes the thermal environment inside the living body, the metabolic function and blood flow are induced by the temperature stimulus, and the activity of the metabolic system can be easily observed. By the heat transfer equation based on the biological heat transfer theory, the internal heat situation at the peripheral circulation site is connected to the body surface temperature situation, and the body heat state can be estimated from the body surface temperature. By analyzing the heat transfer equations in the space domain and the time domain, a series of parameters expressing the function of the metabolic system inside the living body can be calculated. Furthermore, the system identification can also measure the parameters of the effective thermal conductivity and the metabolic heat rate of the peripheral part as the metabolic function index. In addition, a ruler that displays the metabolic function index for clinical thermodiagnosis of diabetes created using two-dimensional parameters as coordinate axes on the monitor screen makes it possible to intuitively determine the type and severity of diabetes, which is the main purpose of clinical diagnosis. be able to.
[Brief description of the drawings]
FIG. 1 is a system block diagram of a metabolic function display device of a thermographic device according to the present invention.
FIG. 2 is a flow chart for displaying a metabolic function display device of the thermographic device according to the present invention.
FIG. 3 is a schematic layout view of a measurement chamber used in the present invention.
FIG. 4 is a plan view of a temperature measurement site by the metabolic function display device of the thermographic device according to the present invention.
FIG. 5 is a diagram showing a cylindrical model of a finger of a human hand to be measured by the thermographic apparatus of the present invention.
FIG. 6 is a curve diagram showing the relationship between the measured temperature of the forearm and the temperature at which the identification value of the temperature is calculated by the least square method.
FIG. 7 is a diagram showing a temperature recovery curve after a cold water load.
FIG. 8 is a distribution curve diagram of actually measured thermal parameters of a diabetic patient.
FIG. 9 is a display pattern of a ruler serving as a diagnostic scale for diabetes according to the present invention.
FIG. 10 is a distribution diagram of diabetes diagnosis results.
FIG. 11 is a diagram showing the correlation between the sum of the squares of the metabolic function index and the actually measured blood glucose level.
[Explanation of symbols]
1 target object, 2 thermography device, 3 computer (CPU), 4 display device, 6 PC card (storage means), 7 constant temperature cold water tank, 8 ROM 9 ‥‥ RAM

Claims (4)

In a metabolic function display method of detecting infrared rays from a measured object via a thermographic device and measuring a temperature from the measured object to display a metabolic function,
Using the blood injection rate and the metabolic function index as parameters on the coordinate axis, and displaying a non-linear curve that types diabetes based on the statistical data obtained in the comprehensive diabetes judgment centering on blood glucose level on the secondary screen A method for displaying a metabolic function using a thermographic device. In a metabolic function display device, which detects infrared rays from a measured object via a thermographic device, measures temperature from the measured object, and displays a metabolic function.
Using the blood injection rate and the metabolic function index as parameters on the coordinate axis, and displaying a non-linear curve that types diabetes based on the statistical data obtained in the comprehensive diabetes judgment centering on blood glucose level on the secondary screen A metabolic function display device based on thermography, characterized in that: In a metabolic function display method of detecting infrared rays from a measured object via a thermographic device and measuring a temperature of the measured object to display a metabolic function,
Storing temperature image data captured by the thermographic device at a time before and after the temperature load is applied to the object to be measured in storage means,
From the temperature image data stored in the storage means, the internal heat generation state of the object to be measured is estimated using a heat transfer equation, and the heat transfer equation is decomposed and analyzed to form a series of parameters expressing the function of the metabolic system. An arithmetic step of calculating via a computer;
Measuring the effective heat conductivity and the metabolic heat rate as metabolic function index parameters from the internal heat generation distribution obtained in the calculation step,
The metabolic function index and the blood infusion rate are used as parameters, and a secondary curve is displayed on the secondary screen based on the statistical data obtained by the comprehensive diabetes judgment centering on the blood glucose level. A metabolic function display method using a thermographic device. In a metabolic function display device, which detects infrared rays from an object to be measured via a thermographic device, measures the temperature of the object to be measured, and displays a metabolic function,
Storage means for storing temperature image data captured by the thermography device at times before and after applying a temperature load to the object to be measured,
From the temperature image data stored in the storage means, the internal heat generation state of the object to be measured is estimated using a heat transfer equation, and the heat transfer equation is decomposed and analyzed to form a series of parameters expressing the function of the metabolic system. Calculating means for calculating via a computer;
Measuring means for measuring the effective heat conductivity and metabolic heat rate as metabolic function index parameters from the internal heat generation distribution obtained by the arithmetic means,
The metabolic function index and the blood infusion rate are used as parameters, and a secondary curve is displayed on the secondary screen based on the statistical data obtained by the comprehensive diabetes judgment centering on the blood glucose level. A metabolic function display method using a thermographic device.

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