JP3321266B2 - Biological recess sounding device, sounding probe and calibration adapter for the device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the depth of a concave portion of a living tissue, and to an improvement of a sounding probe and a calibration adapter used in the apparatus.

[0002]

2. Description of the Related Art The applicant of the present invention has disclosed a device for measuring the depth of a periodontal pocket formed between a tooth and its surrounding gingiva, as well as the depth of a concave portion of a living tissue such as an ear canal, a nasal cavity, an anus, and a urethra. 5
It has already been filed as -50081. In this method, a sounding probe having a sufficiently large impedance compared to the impedance of the living tissue is inserted into the living body recess, and the impedance value of the part of the sounding probe not shorted by the living tissue is detected. , That is, the depth of the living body concave portion is measured.

[0003]

The high impedance material used for the above-mentioned sounding probe includes, for example, conductive plastics, conductive rubber, and conductive ceramics. The slight difference between the two causes a considerable variation in the impedance when completed. Therefore, in actual use, it is necessary to calibrate for each sounding probe to remove the influence of the variation.

The present invention has been made in view of this problem, and has been made to provide a device which is easy to use and easy to calibrate.

[0005]

In order to achieve the above-mentioned object, a living body depression measuring device according to a first aspect of the present invention uses an impedance value from a base of a sounding probe to one predetermined reference position. Conversion formula L = L0− for converting the insertion amount from the impedance value obtained during measurement as a reference
There is provided an arithmetic unit comprising: (L0−S1) · R / RS1; and a unit that substitutes the impedance value obtained by the measurement into the conversion formula to calculate the depth of the living body concave portion. The meaning of the symbols in the above formula will be described later.

In the second invention, the relationship between the insertion amount and the impedance value obtained at the time of measurement is defined by using the respective impedance values from the base of the sounding probe to two predetermined reference positions. Linear equation L = aR
The calculation unit includes means for calculating + b and means for calculating the depth of the living body concave portion by substituting the impedance value obtained by the measurement into the linear expression. The meaning of the symbols in the above equation and how to find the equation will be described later.

Further, a reference position can be displayed on the sounding probe so as to be suitable for the above-described processing.

In order to obtain the above-mentioned conversion formula or linear formula, an insertion hole having a depth capable of being inserted from the tip of the sounding probe to the reference position is formed in a body made of a conductive material. A calibration adapter configured to short-circuit from the tip of the sounding probe to the reference position when the sounding probe is inserted into the probe can be used.

[0009]

[Function] Since the sounding probe has a sufficiently large impedance compared to the impedance of the living tissue, when the sounding probe is inserted into the concave portion of the living tissue, the inserted portion is short-circuited by the living tissue. , The impedance of the remaining non-inserted portion is detected as the impedance value of the measurement circuit. Therefore, the insertion amount can be calculated by calculating backward from this, but in the present invention, calibration is performed for each sounding probe by obtaining a conversion formula or a linear expression prior to measurement, and the impedance of each sounding probe is measured. The effect of the variation is eliminated.

In the first invention, the following conversion formula is used in calculating the insertion amount. That is, in FIG.
Is a sounding probe, the total length of the probe 1 is L ₀ , the reference position is P ₁ , and the length from the tip to the reference position P ₁ (that is, the insertion amount).
Is S ₁ , and the impedance value obtained at the insertion amount S ₁ is R
S ₁ , P is an arbitrary measurement position, L is an insertion amount up to the position P,
Assuming that the impedance value obtained when the insertion amount is L is R, the following equation (1) is established. When this is modified, equation (2) is obtained.

R / (L ₀ −L) = RS ₁ / (L ₀ −S ₁ ) (1) L = L ₀ − (L ₀ −S ₁ ) · R / RS ₁ (2)

[0012] The equation (2) is the conversion formula obtained at that time by inserting first to the reference position P ₁ impedance value R
When S ₁ is obtained, L ₀ and S ₁ are known, so that the insertion amount L at that time can be calculated by measuring the impedance value R when inserted to an arbitrary measurement position P. Note that, here, only one point is used as a reference position on the assumption that the impedance changes linearly at a constant rate over the entire length of the sounding probe 1 and that the impedance is zero at the base 1a.
If this precondition is not satisfied, an error will occur. Thus, clinically the most important position as the reference position P _1, for example, it is desirable to select the measurement is long if the position of about 3mm from the tip of the periodontal pocket, thereby eliminating the error at least near the it can.

As described above, in the first invention, an error occurs at a position other than the reference position P ₁ , and there is a possibility that the error increases as the distance from the reference position increases. In the second invention, such an error is reduced. Can be. That is, in FIG. 2, with 2 points of P ₁ and P ₂ as the reference position, the impedance value RS ₁ and RS ₂ when the respective insertion amount S ₁ and S ₂
Is measured, and the following equations (3) and (4) are obtained. Therefore, by solving the simultaneous equations of equations (3) and (4), the constant a
And b can be obtained, and a linear expression that defines the relationship between the insertion amount L and the impedance value R obtained at the time of measurement as in Expression (5) is obtained.

L ₀ -S ₁ = aRS ₁ + b (3) L ₀ -S ₂ = aRS ₂ + b (4) L = aR + b (5)

[0015] Then, the impedance value R when inserted to an arbitrary position P is measured, and this is substituted into the equation (5).
The insertion amount L at that time can be calculated,
In the equation (5), the constant of the change rate of the impedance over the entire length of the sounding probe 1 and the impedance at the base 1a, that is, the insertion amount of zero, are incorporated.

The solid line in FIG. 3 illustrates this equation (5) as a graph, and the broken line and the dashed line illustrate the case where the impedance value does not change linearly. The broken line gradually changes with the same tendency. The case and the chain line show the case where the change rate changes periodically. As described above, even if the change in impedance is not linear, since the two positions P1 and P2 are used as the reference positions, an error at least in the vicinity of the positions P1 and P2 can be eliminated.
An error is less likely to occur than in the first invention, and the accuracy is greatly improved. In addition, as the reference positions P1 and P2,
In the measurement of the periodontal pocket, for example, a position about 3 mm from the tip and a position about 5 mm from the important tip are selected as described above.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be applied to the measurement of the depth of various kinds of living body recesses.

FIG. 4 shows a sounding probe and its holder.
FIG. 5 is a diagram showing a measuring procedure, and FIG. 6 is a block diagram of the measuring device. In the drawing, 1 is a sounding probe, 2 is a holder, 3
Is a scale provided on the surface of the probe 1 by an appropriate means, for example, in an annular shape every 1 mm, 4 is a periodontal pocket, 5 is a power supply for measuring voltage, 6 is an ammeter, 7 is a soft tissue 8 in the oral cavity of a patient. The oral electrode 9 brought into contact with is a tooth. The scale 3 is not provided over the entire length, for example, 3 mm and 5 m from the tip.
m, etc., it can be provided only in a portion that is a reference position or a particularly important portion.
Can be easily visually inserted to a predetermined reference position.

The probe 1 has an elongated shape suitable for being inserted into the periodontal pocket 4, and the holder 2 is formed of a good conductor such as a metal whose surface is coated with an insulator. Tip 1
Is made of a high-impedance material having a sufficiently large impedance compared to the impedance of the periodontal tissue.
This material has a length L ₀ of 10 mm and a total of 10
A material having a high resistance value of about 1000 kΩ, for example, a material having a conductive film coated on a high-resistance material such as a conductive plastic or an insulator, a conductive rubber, a conductive ceramic, or the like is used.

For measuring the periodontal pocket, the probe 1
The material described above does not require much flexibility, but if other biological concavities are targeted, it is desirable to use a flexible elastic material so as to be able to cope with a curved biological concavity.
Further, the entire probe 1 is not made of a high-impedance material, but may be one in which a high-impedance material is coated on the outer periphery of an insulator.

When measuring the depth of the periodontal pocket 4 using such a depth-measuring probe 1, the probe 1 is inserted into the periodontal pocket 4 as shown in FIG. The tissue around the tooth 9 is usually in close contact with the tooth 9, and when there is a gap, it is filled with pus and exudate. Therefore, when the probe 1 is inserted into the periodontal pocket 4 as shown in the figure, The tip of the probe 1 from the tip to the portion in contact with the pocket edge 4a of the periodontal pocket 4 is short-circuited by the periodontal tissue or the filling liquid.

The probe 1 is made of a high-impedance material, and the impedance of the soft tissue 8 and the filling liquid which is sufficiently smaller than this is substantially negligible.
The current flowing through the measuring circuit is determined by the impedance of the remaining portion of the probe 1 not inserted into the periodontal pocket 4, and the impedance value of the remaining portion of the probe 1 is detected from the current value. That is, the length of the portion of the probe 1 inserted into the periodontal pocket 4 and the length of the portion not inserted can be clearly distinguished by using the portion in contact with the pocket edge 4a as a boundary. The length of the portion inserted into the pocket 4 can be calculated from the detected impedance value by using the conversion formula of (1) or the linear expression of the formula (5). Is obtained, the depth L of the pocket 4 can be known from the impedance value at the time of reaching the value.

Next, the basic configuration and operation of the measuring apparatus will be described with reference to the block diagram of FIG. 11 is an oscillator of a signal for measurement, 12 is a current detection resistor, 13 is a buffer, 14 is a filter, 15 is an AC-DC converter, 16 is an A / D converter, 17 is a CPU, 18 is a display unit, and 19 is an operation unit. , 2
0 is a memory. The oscillator 11 is, for example, 400 Hz to 1
It oscillates a high frequency of about 00 kHz.
The voltage generated in 2 is fetched through a buffer 13 and hum and various noises of the power supply are removed by a filter 14, then converted into a direct current by a converter 15, digitized by an A / D converter 16 and input to a CPU 17.

The CPU 17 calculates the insertion amount of the probe 1 into the periodontal pocket 4 from the detected current value using a conversion formula or a primary formula, and further displays the calculation result as necessary on the display unit 18.
To be displayed. Note that the CPU 17 stores in advance a program for obtaining a conversion equation or a linear equation prior to actual measurement, and calculating an insertion amount at the time of measurement using these equations.

In addition to such basic operations, by operating an operation unit 19 such as a foot switch, for example,
The following operation can be performed. That is, the surgeon checks the value sequentially displayed on the display unit 18 and the scale 3 of the probe 1, and determines that the values match, and that the tip of the probe 1 has reached the bottom of the periodontal pocket 4. When the operation unit 19 is operated at that time, the data at that time is stored in the memory 20, and the data is printed out by operating, for example, a printer (not shown) as necessary. These are provided by the CPU 17 so that various desired functions can be exhibited in advance.
By implementing the control program described above, it is possible to appropriately implement the control program.

In the illustrated embodiment, the probe 1 has a different thickness depending on the part, and the rate of change of the impedance value with respect to the insertion amount is not uniform. In this case, a linear equation is used to reduce the error. It is desirable to adopt the method of the second invention using

FIG. 7 shows a convenient calibration adapter 25 used for calibration for obtaining a conversion equation or a linear equation prior to measurement.
FIG. This is, for example, a bottomed cylindrical body having an insertion hole 27 formed in a main body 26 made of a conductive material such as a metal. The depth D of the insertion hole 27 is set to a depth at which the sounding probe can be inserted to the reference position. Selected. Therefore, as shown by the chain line, for example, if the adapter 25 is placed on the oral electrode 7 and the sounding probe 1 is inserted into the insertion hole 27, the sounding probe 1
Is short-circuited from the leading end to a predetermined reference position, and the state is the same as when inserted to the reference position, so that the calibration operation can be easily performed.

Actually, ones having insertion holes 27 having dimensions corresponding to the insertion amounts S ₁ and S ₂ in FIG. 1 or FIG. 2 are individually prepared. It is also possible to adopt a structure in which the insertion holes are arranged in the same main body.

[0029]

As is apparent from the above description, in the first invention of this application, a sounding probe having a sufficiently large impedance as compared with the impedance of a living tissue is inserted into a living body recess and detected. In a living body concave depth measuring device that measures the depth of a living body concave portion from an impedance value, a conversion formula is obtained based on an impedance value from a base of the sounding probe to one predetermined reference position, and the conversion formula is obtained. This is to calculate the depth of the living body concave portion using the equation. Therefore, calibration is performed for each sounding probe by calculating the conversion formula before measurement,
The measurement accuracy can be improved by eliminating the influence of the variation in the impedance of each sounding probe.

According to the second invention, a linear expression is obtained by using respective impedance values up to two reference positions selected in advance, and the depth of the living body concave portion is calculated by using the linear expression. Things. Therefore, the measurement accuracy is improved and the error can be further reduced more easily than in the first embodiment.

Further, when the reference position is displayed on the sounding probe, it is easy to insert the sounding probe to a predetermined reference position at the time of calibration or measurement, and further, the reference position is displayed on the body made of a conductive material. By using the calibration adapter having an insertion hole having a depth corresponding to the position, the calibration operation can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of conversion formula calculation.

FIG. 2 is an explanatory diagram of calculating a linear expression.

FIG. 3 is a graph showing a relationship between an insertion amount of a sounding probe and an impedance value.

FIG. 4 is a side view of a sounding probe according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of a measurement procedure of the embodiment.

FIG. 6 is a block diagram of the measuring apparatus of the embodiment.

FIG. 7 is a perspective view of one embodiment of a calibration adapter.

[Explanation of symbols]

P _1, P ₂ reference position RS _1, RS ₂ reference impedance value at the position S _1, S ₂ reference inserted at the position quantity P measurement position R insertion amount 1 Sounding stylus 1a base 3 in the impedance value S measuring position in the measuring position Scale 4 Periodontal pocket (biological recess) 7 Oral electrode 8 Soft tissue 17 CPU 25 Calibration adapter 26 Main body 27 Insertion hole

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-149295 (JP, A) JP-A-61-280856 (JP, A) Fully open 1984-188407 (JP, U) Really open 1962 166822 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 5/053 A61B 5/107 A61C 19/04

Claims (4)

(57) [Claims] An impedance value of a sounding probe having a sufficiently large impedance as compared with the impedance of a living tissue, and an impedance value of a portion of the sounding probe inserted into the recess of the living body which is not short-circuited by the living tissue are detected. And a calculating part for calculating the insertion amount of the sounding probe, that is, the depth of the living body concave part, wherein the living body concave part sounding device is provided from a base part of the sounding probe to one predetermined reference position. A conversion formula L = L0− (L0−) for converting the insertion amount from the impedance value obtained at the time of measurement based on the impedance value.
S1) A living body characterized in that a means for determining R / RS1 and a means for calculating the depth of a living body concave portion by substituting the impedance value obtained by the measurement into the conversion formula are provided in the arithmetic section. Depth sounding device. Here, L is the insertion amount to an arbitrary position L0 is the total length of the sounding probe S1 is the length from the tip of the sounding probe to the reference position R is the impedance value obtained when the insertion amount is L RS1 .... Impedance value obtained when the insertion amount is S1 2. A sounding probe having a sufficiently large impedance as compared with the impedance of a living tissue, and an impedance value of a portion of the sounding probe inserted into the recess of the living body which is not short-circuited by the living tissue is detected. And a calculating unit for calculating the insertion amount of the sounding probe, that is, the depth of the living body concave portion, the living body concave sounding device comprising: a base unit of the sounding probe to two pre-selected reference positions. A linear equation L = a that defines the relationship between the insertion amount and the impedance value obtained at the time of measurement using each impedance value
A living body concavity depth measuring apparatus, wherein a means for calculating R + b and a means for substituting the impedance value obtained by the measurement into the linear expression to calculate the depth of the living body concavity are provided in the arithmetic unit. Here, L: an insertion amount up to an arbitrary position R: an impedance value obtained when the insertion amount is L a, b: a constant L0 obtained by solving a simultaneous equation of the following equations (a) and (b): ... Total length of sounding probe S1, S2 ... Length from tip of sounding probe to reference position RS1, RS2 ... Impedance values obtained at insertion amounts S1 and S2 L0-S1 = aRS1 + b ... (B) L0-S2 = aRS2 + b (b) 3. A sounding probe having a sufficiently large impedance as compared with the impedance of a living tissue, and an impedance value of a portion of the sounding probe inserted into the recess of the living body which is not short-circuited by the living tissue is detected. An insertion amount of the sounding probe, that is, a sounding probe used in a living body depression measuring device having a calculating unit for calculating the depth of the living body concave portion, wherein a reference position is displayed on the surface. Sounding probe for a living body recess sounding device. 4. An insertion hole having a depth capable of being inserted from the tip of the sounding probe to a reference position is formed in a main body made of a conductive material, and the sounding probe is inserted when the sounding probe is inserted into the insertion hole. A calibration adapter for a living body recess sounding device, wherein the adapter is configured to short-circuit from a tip of a probe to a reference position.