JPH08182681A - Bone strength measuring device - Google Patents

Abstract

PURPOSE: To indicate the strength estimate to serve as the criteria of bone strength, in ranked condition. CONSTITUTION: The device has an acceleration sensor (a), a shock exciter (b), a frequency analysis means (c), an operation means (d), a stotrage means (e), a rank sorting means (f), and a display means (g). The sensor (a) is attached to one end of an arm bone (h). The exciter (b) adds shock with constant force to the other end of the arm bone (h). The analysis means (c) finds the transmitting function with every frequency, based on the output signal of the sensor (a). The operation means (d) operates the natural frequency f0 of the arm bone (h), and estimates the bone strength H by multiplying this frequency f0 by the length L of the arm bone (h). The storage means (e) makes the bone strength index data where the natural frequency and the length L of the arm bone are multiplied, and stores this index data, classifying them into a plurality of ranks. The rank sorting means (f) sorts the rank corresponding to the bone strength (h) operated with the operation means (d) from among the plural stored in the storage means (e). The display means (g) indicates the rank sorted with the rank sorting means (f).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bone strength measuring device, and more particularly to a device capable of simply and quickly measuring a rough value of bone strength.

[0002]

2. Description of the Related Art Recently, as an apparatus for diagnosing a living body of bone, a vibration is applied to the living body of bone instead of radiographing means, a response vibration of the living body is detected, and a frequency analysis of the applied and responsive vibration is performed to detect the living body An apparatus for diagnosing the above condition has been proposed, and one example thereof is Japanese Patent Laid-Open No. 4-204249.
No. 6,086,045.

The bone diagnosis device disclosed in this publication includes an impulse hammer having a force sensor, a bone vibration detector having a pressure and acceleration sensor, and a pressure display device for displaying the pressure value of the pressure sensor. And a vibration analysis processing device. Then, the vibration analysis processing device creates means for creating a power spectrum of the impact vibration applied to the bone body by the impulse hammer, and a power spectrum of the response vibration detected by the acceleration sensor of the bone vibration detector. It has means, means for creating a bone response function from these two power spectra, and means for storing each created data.

The bone diagnosing device constructed as described above is for quantitatively evaluating the bone from the bending vibration of the bone.
Focusing on the fact that the natural frequency of bone when shock vibration is applied from the outside of the living body varies depending on the state of the bone, and detecting the natural frequency of bone as a peak value from the spectrum of the response function The bone is diagnosed by comparing it with the one described above.

By the way, the bone body is usually composed of a bone main body and soft tissues such as muscles and skins that surround the outer periphery of the bone body, and a response vibration when an impact vibration is applied from the outside of the bone body is Not only the response vibration of the bone body but also the response vibration of the soft tissue is included, and it is difficult to accurately extract the natural frequency of the bone body. Therefore, in the bone diagnosis device disclosed in the above publication, by applying a constant pressure to the bone vibration detector, by suppressing the response vibration of the soft tissue, the response vibration of the bone body (bending vibration) is extracted, Although the accuracy of bone diagnosis is improved, such a bone diagnosis apparatus has technical problems described below.

[0006]

That is, the bone diagnosing device disclosed in the above publication uses the correlation between the natural frequency and the bone strength to perform bone diagnosis, and the bone strength itself. Since it is not a device for measuring bone, for example, it is expected to be used as a measure of bone strength by measuring a large number of people in a short time in a medical examination at a fitness club, school, etc. Conventional devices of this type, including bone diagnostic devices, have not been considered for use in such applications.

Further, in particular, in the device disclosed in the above publication, the force sensor is built in the impulse hammer, so that the device becomes expensive, which is one of the factors that hinder the spread in the above-mentioned fields. . The present invention has been made in view of such conventional problems, and an object thereof is to provide a bone strength measuring device capable of simply and quickly measuring a rough value of bone strength. To do.

[0008]

In order to achieve the above object, the present invention provides an acceleration sensor attached to one end of a humerus, and an impact exciter for applying an impact of a constant force to the other end of the humerus. Frequency analysis means for obtaining a response spectrum based on the output signal of the acceleration sensor, and the natural frequency of the humerus is calculated based on the output of the frequency analysis means, and this natural frequency is multiplied by the length of the humerus. A bone strength measuring device comprising a calculation means for estimating and calculating the bone strength, a storage means for storing the bone strength index data obtained by multiplying the natural frequency by the length of the humer in a plurality of ranks,
It is characterized by further comprising rank selecting means for selecting a rank corresponding to the bone strength calculated by the calculating means from the plurality, and display means for displaying the rank selected by the rank selecting means. The acceleration sensor is fixed to a scissors-like holder, and can press the arm bone through the holder.

[0009]

According to the bone strength measuring device having the above structure, when an acceleration sensor is attached to one end side of the humerus and a constant force signal is applied to the other end side by an impact exciter, frequency analysis is performed from the output signal of the acceleration sensor. The response spectrum is obtained by the means, the natural frequency is obtained from the response spectrum by the calculation means, and the bone strength obtained by multiplying the natural frequency by the length of the arm bone is estimated and calculated. When the bone strength is obtained, the rank selecting means stores the bone strength index data obtained by multiplying the natural frequency by the length of the humerus into a plurality of ranks, and the storing means stores the rank corresponding to the bone strength. Be sorted. Then, the selected rank is displayed on the display means. In this case, if the acceleration sensor is fixed to the clothespin-shaped holder and the acceleration sensor is pressed against the arm bone through the holder as in the structure of claim 2, the sensor can be attached very easily. Become.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. 1 to 3 show an embodiment of a bone strength measuring device according to the present invention. FIG.
Shows a functional configuration diagram of a bone strength measuring device according to the present invention. The bone strength measuring device includes an acceleration sensor a, an impact shaker b, a frequency analysis means c, a calculation means d, and a storage means. e, rank selection means f, and display means g.

The acceleration sensor a is attached to one end of the arm bone h to be measured. The impact vibration device b applies a constant force impact to the other end of the arm bone h. Frequency analysis means c
Calculates the transfer function for each frequency based on the output signal of the acceleration sensor a. The calculation means d calculates the natural frequency f ₀ of the arm bone h based on the output of the frequency analysis means c, and estimates the bone strength H obtained by multiplying the natural frequency f ₀ and the length L of the arm bone h. Calculate

The storage means e creates bone strength index data by multiplying the natural frequencies and the length of the arm bones collected in advance, and divides the bone strength index data into a plurality of ranks. I remember. The rank selection means f is
The rank corresponding to the bone strength h calculated by the calculation means d is selected from a plurality of ranks stored in the storage means e. The display means g displays the rank selected by the rank selecting means f.

FIG. 2 shows a more specific structure of the bone diagnostic apparatus according to the present invention. The bone strength measuring device shown in FIG. 1 includes a device body 10, a vibrating table 12, and a sensor holder 1.
And 4. The vibrating table 12 has a box-shaped case 16 and an impact shaker 18 incorporated in the case 16. The impact shaker 18 includes an arm 18a swingably supported by the housing 16, a hammer 18b fixed to one end of the arm 18a, and an electromagnetic solenoid 18c provided at the other end of the arm 18b. And the electromagnetic solenoid 18c is energized, the hammer 1
The end of the arm 18a provided with 8b is adapted to rotate upward.

A through hole 16a is formed on the upper surface of the housing 16 so as to correspond to a position where the hammer 18b abuts when the arm 18a rotates upward.
An impact transmission pad 20 supported by a flexible member is arranged in a so as to close it. In the vibrating table 12 configured in this way, the back muscles are straightened, the chair is seated on the chair, the elbows are bent at a substantially right angle, and the arms are placed on the upper surface of the housing 16. so,
When the electromagnetic solenoid 18c is driven, it is possible to apply a constant force impact to the elbow, that is, one end of the humerus (ulna) on the little finger side by the hammer 18b.

The sensor holder 14 is composed of a washing scissors-shaped main body 14a and an acceleration sensor 14b fixed to the inner surface of the tip of the main body 14a. The tip of the scissors-shaped main body 14a is placed on the wrist side. It is attached to the end of (1) (the part of the base of the little finger that is muffled), and the acceleration sensor 14b is used such that it is pressed against one end of the humerus (ulna) on the little finger side.

On the other hand, the apparatus main body 10 in this embodiment is
It is mainly composed of a microcomputer, and has an amplifier 10a connected to the acceleration sensor 14b of the sensor holder 14, an A / D converter 10b connected to the amplifier 10a, and a CPU 10c. CPU10
A keyboard 10d, a printer 10e, and a display device 1 are included in c.
0f, ROM 10g and RAM 10h are connected.
Further, the electromagnetic solenoid 18c of the impact shaker 18 is connected to the CPU 10c via the interface 10i.

In the bone strength measuring device constructed as described above, the sensor holder 14 is attached to the subject in the above-mentioned state.
By attaching the CPU 10c to the interface 10i
When the electromagnetic solenoid 18c is driven via the, the hammer 18b applies shock vibration of a constant force to the humerus (ulna). When such shock vibration is applied to the humerus (ulna), bending vibration occurs in the humerus (ulna), and this vibration is detected by the acceleration sensor 14b.

The analog signal detected by the sensor 14b is amplified by the amplifier 10a and then amplified by the A / D converter 10.
The signal is converted into a digital signal by b, is input to the CPU 10c, and is temporarily stored in the RAM 10h. CPU 10c is R
Based on an analysis processing procedure such as a fast Fourier transform program stored in advance in the OM 10g, the data stored in the RAM 10h is read and the response spectrum is calculated.

The obtained response spectrum is obtained as the magnitude of the response spectrum by, for example, calculating the amplitude, and the peak value is calculated by comparing the magnitudes of the response spectra, and the peak value is calculated. The frequency having the peak value is stored in the RAM 10h as the natural frequency f ₀ of the humerus (ulna). At this time, the length L of the humerus (ulna) is measured using an appropriate scale, and this measured value is input from the keyboard 10d and similarly stored in the RAM 10h. In this way, when the natural frequency f ₀ and the length L of the humerus (ulna) are obtained,
In the CPU 10c, the natural frequency f ₀ is multiplied by the length L, and a calculation process for estimating the strength H of the humerus (ulna) is executed.

On the other hand, in the RAM 10h, based on the natural frequency collected in advance and the length of the arm bone, bone strength index data is created by multiplying these, and the bone strength index data is divided into a plurality of ranks. Is remembered. FIG. 3 shows an example of this bone strength index data and ranking.

The bone strength index data shown in the figure is in a state almost represented by a normal distribution curve, and the center thereof is set as a standard area of bone strength, and before and after that, a slightly inferior area of bone strength and a bone strength of Regions with slightly superior bone strength and regions with inferior bone strength and superior bone strength are set in front of and behind these regions, and are ranked in five levels.

The ranking is not limited to five levels, and it can be divided into more or less than this, for example, ranking by gender, age, height, and weight. Yes, and even
It is also possible to make a ranking by combining these.

When the strength H of the humerus (ulna) is estimated and calculated by the CPU 10c as described above, a comparison calculation of which rank of the estimated and calculated strength H is located is performed. The rank of intensity H is determined. When the rank of the strength H is determined in this way, the result is printed or displayed on the printer 10e or the display 10f.

According to the bone strength measuring device configured as described above, since the bone strength measured and calculated can be shown by rank, for example, in a medical examination at a fitness club or school, a large number of people can be examined in a short time. Can be measured and used as a measure of bone strength.

Further, in the bone strength measuring apparatus of this embodiment, the impact exciter 18 constantly applies an impact of a constant force, and the frequency spectrum of this impact becomes constant. Therefore, the spectrum of the excitation force and the response spectrum are And the transfer function need not be calculated to calculate the transfer function, the calculation process is simplified, and the force sensor does not need to be arranged on the impact shaker 18 side, which may simplify the configuration. Therefore, the high cost of the device can be avoided.

Further, in the bone strength measuring apparatus of this embodiment, the acceleration sensor 14b is fixed to the washing scissor-like holder body 14a, and the acceleration sensor 14b is pressed against the humerus via the holder body 14a. With this configuration, the mounting of the sensor is very easy and the measurement speed is also ensured.

[0027]

As described above in detail in the embodiments,
According to the bone strength measuring device of the present invention, it is possible to easily display the estimated strength value, which is a measure of the bone strength, in a ranked state.

[Brief description of drawings]

FIG. 1 is a functional configuration block diagram of a bone strength measuring device according to the present invention.

FIG. 2 is an explanatory diagram showing a hardware configuration of a bone strength measuring device according to the present invention.

FIG. 3 is an explanatory diagram showing an example of ranking of the strength measuring device.

[Explanation of symbols]

 10 Device Main Body 10a Amplifier 10b A / D Converter 10c CPU 10e Printer 10f Display 10h RAM (Memory Means) 12 Excitation Table 14 Sensor Holder 14a Main Body 14b Acceleration Sensor 16 Housing 18 Impact Vibration Machine 18a Arm 18b Hammer 18c Electromagnetic solenoid 20 pads

Claims (2)

[Claims] 1. An acceleration sensor attached to one end of a humerus, an impact shaker for applying a constant force impact to the other end of the humer, and a frequency analysis for obtaining a response spectrum based on an output signal of the acceleration sensor. Bone strength measurement comprising means and means for calculating the natural frequency of the humerus based on the output of the frequency analysis means and estimating and calculating the bone strength by multiplying the natural frequency by the length of the humerus In the device, a storage unit that stores the bone strength index data obtained by multiplying the natural frequency by the length of the humer in a plurality of ranks, and a rank corresponding to the bone strength calculated by the calculation unit from the plurality of ranks. A bone strength measuring device comprising: a rank selecting means for selecting; and a displaying means for displaying the rank selected by the rank selecting means. 2. The bone strength measuring device according to claim 1, wherein the acceleration sensor is fixed to a clothespin-shaped holder and is pressed against the arm bone through the holder.