KR20180037351A - Apparatus and method for estimating bone structure using ultrasonic nonlinear parameter - Google Patents

Abstract

The present invention provides an apparatus and a method for predicting a bone structure using an ultrasonic nonlinear variable which analyze an ultrasonic signal penetrating a trabecular bone to calculate a nonlinear variable of the trabecular bone, and predict a bone structure of the trabecular bone by a correlation between the calculated nonlinear variable and the bone structure of the trabecular bone. According to the present invention, a nonlinear variable of a trabecular bone measured by using an ultrasonic penetration method allows prediction of a bone structure including a bone capacity ratio and a bony trabecula interval from a high correlation between the nonlinear variable of the trabecular bone and the bone capacity ratio and the bony trabecula interval of the trabecular bone. The ultrasonic nonlinear variable which is a new parameter is provided in addition to a parameter used in a conventional quantitative ultrasonic technique to allow bone structure prediction. The present invention can evaluate bone density and a bone structure together in comparison to a conventional technique of using only a sound speed and a wideband ultrasonic attenuation factor to measure bone density to improve accuracy of osteoporosis diagnosis. A measuring person can be provided with a safe measuring method since the measuring person does not have a risk of being exposed to radiation since the present invention emits an ultrasonic wave to perform osteoporosis diagnosis.

Description

[0001] APPARATUS AND METHOD FOR ESTIMATING BONE STRUCTURE USING ULTRASONIC NONLINEAR PARAMETER [0002]

The present invention relates to an apparatus and method for predicting bone structure using ultrasonic nonlinear parameters.

Osteoporosis is defined as systemic bone disease in which fracture easily occurs even in small impacts due to decrease in bone mass and destruction of bone structure. In the modern society where the elderly population is increasing, osteoporosis is considered as the most serious geriatric disease together with diabetes and cardiovascular disease .

In this regard, osteoporosis is an irreversible disease that can not be reversed to a normal state after the onset of the disease. Prevention by early diagnosis and diagnosis is important, and dual energy X-ray absorptiometry dual energy X-ray absorptiometry (DEXA).

However, since bone mineral density measurement for the diagnosis of osteoporosis requires repetitive measurement for the evaluation of not only osteoporosis but also evaluation of therapeutic response, dual energy X-ray absorptiometry using radiation has a risk of repeated exposure to radiation, Especially, it was difficult to measure the BMD of pregnant women.

Therefore, there are many studies on the diagnosis of osteoporosis which is harmless to the human body, and quantitative ultrasound (QUS) technology for diagnosing osteoporosis using ultrasonic waves has been proposed as a part of this research.

Quantitative ultrasound technology transmits ultrasound to the heel bones of the human body, that is, the calcaneus, and ultrasound characteristics such as the speed of sound (SOS) and normalized broadband ultrasound attenuation (nBUA) of the calcaneus. The method of diagnosing osteoporosis by indirectly predicting the bone mineral density (BMD) of the whole body as a method of diagnosing osteoporosis is as follows. There is no risk of radiation exposure even in repetitive examination, compared with the method of diagnosing osteoporosis using radiation, The cost is relatively inexpensive.

Such a quantitative ultrasonic technique is disclosed in Korean Patent Laid-Open Publication No. 10-2005-0038812 (filed on October 23, 2003, published on Apr. 29, 2005, hereinafter referred to as "prior art").

On the other hand, even if they have the same bone density, the incidence of fracture differs according to the age, the history of fracture, the treatment of steroids, and the difference in the ratio of sponge bone between the sphenoid bone and the bone, As well as changes in bone structure.

However, in the prior art, since only the change of bone density is measured for the diagnosis of osteoporosis, it is difficult to identify and diagnose the cause of osteoporosis caused by the change of the bone structure.

It is an object of the present invention to provide a technique for predicting a bone structure through ultrasound measurement and improving the accuracy of osteoporosis diagnosis from a predicted bone structure.

In order to achieve the above object, an apparatus for predicting a bone structure using an ultrasonic non-linear parameter according to an embodiment of the present invention includes a transmitter for converting an applied electrical signal into an ultrasonic wave, and a receiver for converting the received ultrasonic wave into an electrical signal, A pair of ultrasound transducers for transmitting and receiving ultrasound waves, and a face for transmitting and receiving ultrasound waves around a cavernous bone; A waveform generator for generating an electrical signal for the transmission ultrasonic wave and transmitting the electrical signal to the transmitter; A signal processing unit for detecting an electrical signal of the ultrasonic wave received by the receiving unit; A calculation unit for analyzing the electrical signal detected by the signal processing unit and calculating a nonlinear parameter of the spongy bone; And a bone structure predicting unit for predicting a bone structure of the spongy bone through the correlation between the nonlinear parameter calculated by the calculating unit and the bone structure of the cavernous bone.

Here, the signal processing unit selects an electrical signal for a receiving ultrasonic wave having a frequency that is twice the fundamental frequency (hereinafter, referred to as 'f1 frequency') of the transmission ultrasonic wave (hereinafter, referred to as 'f2 frequency' Can be detected.

The non-linear parameter of the spongy bone can be calculated by the following equation (1).

[Equation 1]

는 한 쌍의 초음파 변환기 사이에 해면질골이 있는 경우에 해면질골을 투과한 f2주파수 성분의 진폭,

는 한 쌍의 초음파 변환기 사이에 해면질골이 없는 경우 물만을 투과한 f2주파수 성분의 진폭, L은 한 쌍의 초음파 변환기 사이의 거리, d는 해면질골의 두께,

은 f1주파수 성분에서 해면질골의 감쇠계수,

는 f2주파수 성분에서 해면질골의 감쇠계수,

는 물/해면질골 사이 경계면에서의 음압투과계수,

는 해면질골/물 사이 경계면에서의 음압투과계수,

는 물의 밀도,

는 물의 음속,

는 해면질골의 밀도,

는 해면질골의 음속, (B/A)w는 물의 비선형 변수, exp는 지수함수)(B / A) s is the nonlinear parameter of the cavernous bone,

The amplitude of the f2 frequency component transmitted through the spongy bone when there is a caudal bone between a pair of ultrasound transducers,

L is the distance between a pair of ultrasound transducers, d is the thickness of the cavernous bone, d is the distance between the ultrasound transducers,

Is the attenuation coefficient of the cavernous bone at frequency f1,

Is the attenuation coefficient of the cavernous bone at the f2 frequency component,

The permeability coefficient at the boundary between water / cavernous bone,

Is the sound pressure transmission coefficient at the interface between the cavernous bone / water,

The density of water,

Is the speed of water,

The density of spongy bone,

(B / A) w is the nonlinear variable of water, exp is the exponential function)

In addition, the bone structure of the cavernous bone may include a bone capacity ratio (BT / TV) and a bone ankle interval (Tb.Sp).

The bone structure predicting unit may include a non-linear parameter of the spongy bone as an independent variable, a bone capacity ratio (BT / TV) of the spongy bone, and a bone span spacing (Tb.Sp) Regression of the variable and each dependent variable, and the correlation between the dependent variable and the dependent variable derived therefrom.

In this case, the correlation between the non-linear parameter of the spongy bone and the bone capacity ratio (BT / TV) of the spongy bone in the bone structure predicting unit is such that the bone capacity ratio (BT / VT) Can have a linearly increasing positive correlation.

In addition, the correlation between the non-linear parameter of the spongy bone and the bone trabecular distance (Tb.Sp) of the spongy bone in the bone structure predicting unit is such that as the nonlinear parameter increases, the bone trabecular distance (Tb.Sp) And can have a negative correlation that decreases with time.

The apparatus for predicting a bone structure using the ultrasonic nonlinear parameter may further include an output unit for outputting the bone structure predicted from the bone structure predicting unit.

According to another aspect of the present invention, there is provided a method of predicting a bone structure using an ultrasonic nonlinear parameter, the method comprising the steps of: receiving a transmission ultrasonic wave from a transmitter, which is one of a pair of ultrasonic transducers, An ultrasonic wave transmitting step of causing the transmitted ultrasonic wave to penetrate the spongy bone; The receiving unit of the pair of ultrasonic transducers receiving the ultrasonic waves transmitted through the sponge bone in the ultrasonic wave transmitting step and the receiving unit converting the received ultrasonic waves into an electric signal; A signal processing step of the signal processing unit detecting the electrical signal converted in the signal receiving step and the calculating unit calculating the nonlinear parameter of the spongy bone by analyzing the electrical signal detected by the signal processing unit; And a bone structure predicting step of predicting a bone structure of the spongy bone through the correlation between the nonlinear parameter calculated in the signal processing step and the bone structure of the spongy bone.

Here, the signal processing step may include selectively filtering an electrical signal for a receiving ultrasonic wave having a frequency that is twice the fundamental frequency (hereinafter, referred to as 'f1 frequency') of the transmitting ultrasonic wave (hereinafter, referred to as f2 frequency) And a detecting step of detecting the detected signal.

The signal processing step may include a calculating step of calculating a non-linear parameter of the spongy bone from the electrical signal detected in the detecting step, using the following equation (1).

[Equation 1]

는 한 쌍의 초음파 변환기 사이에 해면질골이 있는 경우에 해면질골을 투과한 f2주파수 성분의 진폭,

는 한 쌍의 초음파 변환기 사이에 해면질골이 없는 경우 물만을 투과한 f2주파수 성분의 진폭, L은 한 쌍의 초음파 변환기 사이의 거리, d는 해면질골의 두께,

은 f1주파수 성분에서 해면질골의 감쇠계수,

는 f2주파수 성분에서 해면질골의 감쇠계수,

는 물/해면질골 사이 경계면에서의 음압투과계수,

는 해면질골/물 사이 경계면에서의 음압투과계수,

는 물의 밀도,

는 물의 음속,

는 해면질골의 밀도,

는 해면질골의 음속, (B/A)w는 물의 비선형 변수, exp는 지수함수)(B / A) s is the nonlinear parameter of the cavernous bone,

The amplitude of the f2 frequency component transmitted through the spongy bone when there is a caudal bone between a pair of ultrasound transducers,

L is the distance between a pair of ultrasound transducers, d is the thickness of the cavernous bone, d is the distance between the ultrasound transducers,

Is the attenuation coefficient of the cavernous bone at frequency f1,

Is the attenuation coefficient of the cavernous bone at the f2 frequency component,

The permeability coefficient at the boundary between water / cavernous bone,

Is the sound pressure transmission coefficient at the interface between the cavernous bone / water,

The density of water,

Is the speed of water,

The density of spongy bone,

(B / A) w is the nonlinear variable of water, exp is the exponential function)

In addition, the bone structure of the cavernous bone may include the bone capacity ratio (BT / TV) and the bone marrow spacing (Tb.Sp) of the cavernous bone.

In the bone structure predicting step, the non-linear parameter of the spongy bone is used as an independent variable, and the bone capacity ratio (BT / TV) of the spongy bone and the bone marrow spacing (Tb.Sp) A regression analysis of independent variables and respective dependent variables, a correlation between the independent variable and the dependent variable is derived, and a bone structure can be predicted from the derived correlation.

In this case, the correlation between the non-linear parameter of the spongy bone and the bone volume ratio (BT / TV) of the spongy bone in the bone structure predicting step is determined by the BT / VT ratio of the spongy bone as the non- Can have a linearly increasing positive correlation.

In addition, the correlation between the nonlinear parameters of the spongy bone and the bone marrow space (Tb.Sp) of the spongy bone in the bone structure predicting step is such that as the nonlinear parameter increases, the bone marrow space (Tb.Sp) As shown in FIG.

The method of predicting a bone structure using the ultrasonic nonlinear parameter may further include outputting a result predicted by the bone structure prediction step to an output unit.

As described above, the present invention has the following effects.

First, even if they have the same bone density, they have different fracture incidence rates depending on the bone structure including the bone marrow aspiration interval and the bone volume ratio, so that the accuracy of diagnosis of osteoporosis can be improved by predicting the bone structure using ultrasonic nonlinear parameters.

Second, the nonlinear parameters of spongiform bone measured by ultrasonography include the ratio of bone capacity and bone space from the high correlation between the nonlinear variables of spongiform bone, the bone volume ratio of sponge bone, and the bone marrow space of spongy bone. Prediction of the bone structure may be possible.

Third, compared to a method of predicting bone structure by providing ultrasonic nonlinear parameters, which are new parameters in addition to the parameters used in existing quantitative ultrasonic techniques, and comparing bone density by using only conventional sonic velocity and wide-band ultrasound attenuation, In addition, the bone structure can be evaluated together, and the accuracy of diagnosis of osteoporosis can be improved.

Fourth, since the diagnosis of osteoporosis is made by irradiating ultrasonic waves, the present invention can provide a safe measurement method to a measurer since there is no risk that a measurer is exposed to radiation.

1 is a schematic view showing an apparatus for predicting a bone structure using an ultrasonic non-linear parameter according to an embodiment of the present invention.
2 is a graph showing a correlation between a nonlinear parameter and a bone structure of a spongy bone phantom according to an embodiment of the present invention.
3 is a flowchart illustrating a bone structure predicting method using an ultrasonic non-linear parameter according to an embodiment of the present invention.

The preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings, in which the technical parts already known will be omitted or compressed for simplicity of explanation.

<Using ultrasonic nonlinear variables Bone structure  About predictors>

1 is a schematic view showing an apparatus for predicting a bone structure using an ultrasonic non-linear parameter according to an embodiment of the present invention.

An apparatus 100 for predicting a bone structure using an ultrasonic nonlinear parameter according to an embodiment of the present invention includes a pair of ultrasonic transducers 110, a waveform generator 120, a signal processor 130, a calculator 140, A structure predicting unit 150, and an output unit 160.

The pair of ultrasound transducers 110 can convert the applied electrical signals into ultrasound waves or convert the received ultrasound waves into electrical signals.

At this time, any one of the pair of the ultrasonic transducers 110 operates as a transmission unit 111 that converts an electric signal into an ultrasonic wave and transmits the transmission ultrasonic wave, and the other of the pair of the ultrasonic transducers 110 converts the reception ultrasonic wave into electric And converts it into a signal.

Here, the pair of ultrasonic transducers 110 are positioned such that one side of the ultrasonic transducer 110 is opposite to the one transmitting and receiving ultrasonic waves, and the distance between the pair of ultrasonic transducers 110 is spaced apart by a predetermined distance.

At this time, a trabecular bone may be positioned between the pair of ultrasonic transducers 110.

Here, the spongy bone is a bone tissue that constitutes the bones of the human body together with a cortical bone having a very dense structure, and has a larger surface area than that of the cortical bone. Therefore, most of the bone tissue metabolism occurs in the caustic bone, The bone mineral density of spongiform bone is measured as an index for the diagnosis.

Therefore, in one embodiment of the present invention, the spongy bone phantom P made of aluminum foam, which is one of the foamed metals having the bone structure similar to the spongy bone, is placed.

Here, a plurality of spongy bone phantom P are used to be included in the bone structure predicting unit 150 to be described later as a bone structure predicting index, and the spongy bone phantom P is similar to the spongy bone formed of a three- , Each having a different porous structure.

In addition, the spongy bone phantom (P) was used in an embodiment of the present invention since the sound velocity of aluminum (about 5000 m / s) does not show a comparatively large difference from the sonic velocity of the mineral bone (about 2520-4290 m / s).

The pair of ultrasound transducers 110 of the apparatus 100 for predicting a bone structure using ultrasound nonlinear parameters according to an embodiment of the present invention is installed in water and has water characteristics similar to the soft tissues of the human body, And is used as an ultrasonic wave propagation medium.

At this time, distilled water can be used as water.

The waveform generating unit 120 drives the ultrasonic transducer 110 and generates an electrical signal for the transmitting ultrasonic wave and transmits the electrical signal to the transmitting unit 111.

At this time, the electrical signal generated by the waveform generating unit 120 may be in the form of a pulse or a continuous wave.

Herein, in one embodiment of the present invention, an electrical signal for generating a transmission ultrasonic wave in the form of a pulse is generated.

The signal processing unit 130 detects an electric signal of the ultrasonic wave received by the receiving unit 112.

At this time, amplification and filtering of the detected electrical signal can be performed.

The signal processing unit 130 selects an electric signal for a receiving ultrasonic wave having a frequency that is twice the fundamental frequency (hereinafter, referred to as 'f1 frequency') of the transmitting ultrasonic wave .

The calculation unit 140 analyzes the electrical signal detected by the signal processing unit 130 and calculates a non-linear parameter B / A of the spongy bone.

At this time, the nonlinear parameter (B / A) of the caudal bone is calculated by the following equation (1).

[Equation 1]

는 한 쌍의 초음파 변환기 사이에 해면질골이 있는 경우에 해면질골을 투과한 f2주파수 성분의 진폭,

는 한 쌍의 초음파 변환기 사이에 해면질골이 없는 경우 물만을 투과한 f2주파수 성분의 진폭, L은 한 쌍의 초음파 변환기 사이의 거리, d는 해면질골의 두께,

은 f1주파수 성분에서 해면질골의 감쇠계수,

는 f2주파수 성분에서 해면질골의 감쇠계수,

는 물/해면질골 사이 경계면에서의 음압투과계수,

는 해면질골/물 사이 경계면에서의 음압투과계수,

는 물의 밀도,

는 물의 음속,

는 해면질골의 밀도,

는 해면질골의 음속, (B/A)w는 물의 비선형 변수, exp는 지수함수)(B / A) s is the nonlinear parameter of the cavernous bone,

The amplitude of the f2 frequency component transmitted through the spongy bone when there is a caudal bone between a pair of ultrasound transducers,

L is the distance between a pair of ultrasound transducers, d is the thickness of the cavernous bone, d is the distance between the ultrasound transducers,

Is the attenuation coefficient of the cavernous bone at frequency f1,

Is the attenuation coefficient of the cavernous bone at the f2 frequency component,

The permeability coefficient at the boundary between water / cavernous bone,

Is the sound pressure transmission coefficient at the interface between the cavernous bone / water,

The density of water,

Is the speed of water,

The density of spongy bone,

(B / A) w is the nonlinear variable of water, exp is the exponential function)

)는 1000 kg/m³을 이용하였으며, 물의 음속(

)은 하기 수학식2에 의해 계산되었다.Here, the density of water (

) Was used at 1000 kg / m³ and the sound velocity of water

) Was calculated by the following equation (2).

&Quot; (2) &quot;

는 온도에 의존하는 수중에서의 음속(m/s), T는 수중 섭씨온도)(here,

(M / s) in water dependent on the temperature, T is the water temperature in water)

)은 하기 수학식 3에 의해 계산되었다.In addition, the sonic velocity of cavernous bone

) Was calculated by the following equation (3).

&Quot; (3) &quot;

는 수중에서의 음속(m/s),

는 초한 쌍의 초음파 변환기 사이에 해면질골이 없는 경우 수신된 기준신호와 한 쌍의 초음파 변환기 사이에 해면질골이 있는 경우 수신된 수신신호간의 수신시간 차이, d는 해면질골의 두께)(Where SOS is the sound velocity of the cavernous bone, m / s)

(M / s) in water,

Is the difference in reception time between the received reference signal and the received signal when there is a sponge bone between a pair of ultrasonic transducers, d is the thickness of the cavernous bone,

)는 하기 수학식 4에 의해 계산되었다.The permeability coefficient at the interface between water / cavernous bone (

) Was calculated by the following equation (4).

&Quot; (4) &quot;

는 물/해면질골 사이 경계면에서의 음압투과계수,

는 물의 밀도,

는 물의 음속,

는 해면질골의 밀도,

는 해면질골의 음속)(here,

The permeability coefficient at the boundary between water / cavernous bone,

The density of water,

Is the speed of water,

The density of spongy bone,

The sonic velocity of the cavernous bone)

)는 하기 수학식 5에 의해 계산되었다.In addition, the sound pressure transmission coefficient at the interface between cavernous bone / water (

) Was calculated by the following equation (5).

&Quot; (5) &quot;

는 물/해면질골 사이 경계면에서의 음압투과계수,

는 물의 밀도,

는 물의 음속,

는 해면질골의 밀도,

는 해면질골의 음속)(here,

The permeability coefficient at the boundary between water / cavernous bone,

The density of water,

Is the speed of water,

The density of spongy bone,

The sonic velocity of the cavernous bone)

)는 하기 수학식 6에 의해 계산되었다.The spontaneous bone damping coefficient of the frequency component f1 (

) Was calculated by the following equation (6).

&Quot; (6) &quot;

은 f1 주파수 성분의 해면질골 감쇠계수(dB/cm), d는 해면질골의 두께,

는 해면질골이 없는 경우에 수신된 f1 주파수 신호의 파워스펙트럼레벨 ,

는 해면질골이 있는 경우에 수신된 f1 주파수 신호의 파워스펙트럼레벨,

는 물과 해면질골 사이의 경계면에서 파워투과계수, ln은 자연로그)(here,

Is the spongy bone damping coefficient (dB / cm) of the frequency component f1, d is the thickness of the cavernous bone,

Is the power spectral level of the received f1 frequency signal in the absence of spongy bone,

Is the power spectral level of the received f1 frequency signal in the presence of spongy bone,

Is the power transmission coefficient at the interface between water and cavernous bone, and ln is the natural logarithm)

)는 하기 수학식 7에 의해 계산되었다.Also, the sponge bone damping coefficient of the frequency component f2 (

) Was calculated by the following equation (7).

&Quot; (7) &quot;

은 f2 주파수 성분의 해면질골 감쇠계수(dB/cm), d는 해면질골의 두께,

는 해면질골이 없는 경우에 수신된 f2 주파수 신호의 파워스펙트럼레벨 ,

는 해면질골이 있는 경우에 수신된 f2 주파수 신호의 파워스펙트럼레벨,

는 물과 해면질골 사이의 경계면에서 파워투과계수, ln은 자연로그)(here,

(DB / cm) of the sponge bone damping coefficient of the frequency component f2, d is the thickness of the cavernous bone,

Is the power spectrum level of the received f2 frequency signal in the absence of spongy bone,

Is the power spectral level of the received f2 frequency signal in the presence of spongy bone,

Is the power transmission coefficient at the interface between water and cavernous bone, and ln is the natural logarithm)

The bone structure predicting unit 150 predicts the bone structure of the cavernous bone through the correlation between the nonlinear parameter (B / A) calculated by the calculator 140 and the bone structure of the cavernous bone.

At this time, the bone structure of the cavernous bone is represented by the ratio of the bone volume (BT / TV) represented by the bone volume occupied by the bone mineral in the tissue volume including the columnar bone trabecula and the trabecular spacing ; Tb.Sp).

Herein, the bone structure predicting unit 150 determines the spontaneous bone volume ratio (BT / TV) of the spongy bone and the bone marrow spacing (Tb.Sp) of the spongy bone as dependent variables, The independent variable and each dependent variable are regressed, and the independent variable derived from this and the correlation between each dependent variable are included.

The correlation between the nonlinear parameter B / A of the spongy bone phantom P and the bone capacity ratio BT / TV of the spongy bone phantom P as shown in FIG. 2 (a) / A), the bone capacity ratio (BT / TV) of the spongy bone phantom (P) increases linearly.

2B, the correlation between the nonlinear parameter B / A of the spongy bone phantom P and the pitch distance Tb.Sp of the spongy bone phantom P is represented by a nonlinear parameter B / A) of the spongy bone phantom (P) increases linearly with the bone pitch interval (Tb.Sp) of the spongy bone phantom (P).

Although the embodiment of the present invention includes the correlation between the nonlinear parameter B / A of the spongy bone phantom P and the bone structure of the spongy bone phantom P, the spongy bone phantom P and the spongy body of the human body Since the bone has similar structure and acoustical characteristics, it is also possible to measure the human bone structure through the above-described correlation. In this case, the correlation included in the bone structure predicting unit 150 is a correlation between the clinically measured human spongy bone Nonlinear variables (B / A) can be correlated with bone structure.

In addition, the correlation included in the bone structure predicting unit 150 may include measurement results of not only spongy bone but also cortical bone and soft tissue.

The non-linear parameter (B / A) of the cavernous bone calculated through the ultrasonic measurement is determined by the correlation between the nonlinear parameter (B / A) of the cavernous bone included in the bone structure predicting unit 150 and the bone structure of the cavernous bone The bone structure corresponding to the nonlinear parameter (B / A) can be derived, and the predicted osteoporosis diagnosis result can be predicted therefrom.

For example, if the nonlinear parameter (B / A) has a small value, it means that there is a small amount of bone trabeculae (T) because the interval between bone marrow traces (Tb.Sp) BV / TV) has a small value.

If the nonlinear parameter (B / A) has a large value, it means that there is a large number of bone trabeculae since the bone trabecular distance (Tb.Sp) has a narrow value, and the bone volume ratio (BV / TV) .

Here, the presence of a small amount of bone marrow means that the risk of osteoporosis is high.

The output unit 160 can output the osteoporosis diagnosis result predicted from the bone structure together with the bone structure including the bone volume ratio BV / TV and the bone marrow space Tb.Sp from the bone structure predicting unit 150 have.

At this time, the output unit 160 may include a speaker, a display monitor, and the like capable of outputting a voice signal or a video signal.

<Using ultrasonic nonlinear variables Bone structure  About prediction method>

3 is a flowchart illustrating a bone structure predicting method using an ultrasonic non-linear parameter according to an embodiment of the present invention.

The method of predicting a bone structure using an ultrasonic nonlinear parameter according to an embodiment of the present invention includes the steps of transmitting an ultrasonic wave (S100), receiving a signal (S200), processing a signal (S300), estimating a bone structure (S400) S500).

The ultrasound transmission step S100 is a step of transmitting ultrasonic waves to be transmitted to the cavernous bone by transmitting ultrasound waves transmitted from the transmitter 111 of the pair of ultrasound transducers 110 to the cavernosal bone.

In this case, the transmission ultrasonic wave may be provided in the form of a pulse. When the waveform generator 120 transmits an electric signal to the pulse transmitter to the transmitter 111, the transmitter 111 converts the electric signal into an ultrasonic signal, Type ultrasonic waves, and the generated ultrasonic waves in the form of pulses are transmitted through the spongy bone.

Here, a non-focusing type transducer having a center frequency of 0.5 MHz may be used as the transmitting unit 111. [

In the signal receiving step S200, the receiving unit 112 of the pair of ultrasonic transducers receives ultrasound transmitted through the spongy bone in the ultrasound transmitting step S100 (hereinafter referred to as 'receiving ultrasound'), Is a step of converting received ultrasound waves into electrical signals.

Here, a non-focusing type transducer having a center frequency of 1 MHz may be used as the receiving unit 112. [

At this time, the transmitting unit 111 and the receiving unit 112 are positioned to face each other, and the distance between the transmitting unit 111 and the receiving unit 112 may be about 60 mm.

The distance between the transmitting unit 111 and the receiving unit 112 may be determined by the near field length (NFL) of the ultrasonic transducer 100.

At this time, the near-field sound field is a point where the beam width of the ultrasonic wave is narrowest when ultrasonic waves are generated through the non-focusing transducer, and the sponge bone is located at a position where the center thereof coincides with the near- can do.

The signal processing step S300 is a step of calculating the nonlinear parameter B / A of the spongy bone by detecting the electrical signal converted in the signal reception step S200 and analyzing the detected electrical signal.

At this time, the signal processing step S300 includes a signal detecting step S310 and a calculating step S320.

Here, the signal processing step S300 is a step of selectively detecting an electrical signal for a receiving ultrasonic wave having a frequency f2 frequency which is twice the frequency f1 of the transmitting ultrasonic wave, which is performed in the signal processing unit 130. [

The calculation step S320 is performed by the calculation unit 140 and is a step of calculating the nonlinear parameter B / A of the spongy bone from the electrical signal detected in the detection step S310 .

At this time, calculation of the values of the parameters for calculating the nonlinear variable B / A is also performed and can be calculated through the above-described Equations (2) to (7).

The bone structure predicting step S400 is performed in the bone structure predicting unit 150. The correlation between the nonlinear parameter B / A calculated in the signal processing step S300 and the bone structure of the cavernous bone, It is a step to predict the structure.

Here, the bone structure of the cavernous bone includes the bone capacity ratio (BT / TV) of the cavernous bone and the bone marrow interval (Tb.Sp).

At this time, the bone structure predicting step (S400) determines the bone volume ratio (BT / VT) of the spongy bone and the bone marrow spacing (Tb.Sp) of the spongy bone as the dependent variable as the independent variable, The independent variable and each dependent variable are regressed and the correlation between the independent variable and the dependent variable is derived and the bone structure is predicted from the derived correlation.

As shown in FIG. 2 (a), the correlation between the non-linear parameter (B / A) of the spongy bone and the bone capacity ratio (BT / TV) And the bone-to-bone ratio (BT / TV) ratio of the bone linearly increases.

As shown in FIG. 2 (b), the correlation between the non-linear parameter (B / A) of the cavernous bone and the bone trabecular distance (Tb.Sp) (Tb.Sp) of the lower limb has a linearly decreasing negative correlation.

2 (a) and 2 (b) show the ultrasonic nonlinear parameters (B) of 18 cavernous bone phantoms (P) made of aluminum foam, which is one of the foamed metals having a similar bone structure to the caustic bone, (B / A) of the spongy bone phantom (P) and the bone volume ratio (BT / VT) of the spongy bone phantom (P) were positively correlated (B / A) and bone capacity ratio (BT / VT) through the Pearson correlation coefficient R value of 0.71 obtained by linear regression .

In addition, it can be confirmed that the nonlinear parameter (B / A) of the spongy bone phantom (P) has a negative correlation with the interval between the bone traces (Tb.Sp) of the spongy bone phantom (P), and the Pearson correlation The coefficient R value is -0.75. It can be seen that the nonlinear parameter (B / A) has a high correlation with the gap length (Tp.Sp).

At this time, the bone structure can be derived from the correlation between the nonlinear parameter (B / A) of the caustic bone and the sponge bone structure by measuring the ultrasonic characteristics of the measurer, calculating the nonlinear parameter (B / A) It may be possible to predict the diagnosis of osteoporosis.

For example, if the nonlinear parameter (B / A) has a small value, it means that there is a small amount of bone trabeculae because the interval between the trabecular bone is large (Tb.Sp) ) Has a small value.

Here, the presence of a small amount of bone marrow means that the risk of osteoporosis is high.

The output step S500 is a step of outputting a result predicted in the bone structure predicting step S400 to the output unit 160. [

Here, the predicted bone structure can be output as a video signal, a voice signal, or the like.

At this time, the predicted results can be output together with the bone structure including the bone capacity ratio (BV / TV) and the bone marrow interval (Tb.Sp) together with the osteoporosis diagnosis result predicted from the bone structure.

As a result, in the present invention, the nonlinear parameters of the cavernous bone measured by the ultrasonic transmission method are determined from the high correlation between the non-linear parameter of the cavernous bone, the bone volume ratio of the cavernous bone, and the bone marrow space of the cavernous bone, It is possible to predict the bone structure including the interval and to predict the bone structure by providing the ultrasonic nonlinear parameter which is a new parameter in addition to the parameters used in the existing quantitative ultrasonic technique. Thus, the bone structure can be predicted using only the conventional sonic velocity and wide- The present invention can improve the accuracy of diagnosis of osteoporosis and can improve the accuracy of diagnosis of osteoporosis. In addition, since the present invention diagnoses osteoporosis by irradiating ultrasonic waves, A method of predicting bone structure using non-linear ultrasonic parameters The.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. And the scope of the present invention should be understood as the following claims and their equivalents.

100: Bone structure prediction device using ultrasonic nonlinear variables
110: Ultrasonic transducer
111:
112:
120: Waveform generator
130: Signal processor
140:
150: Bone structure prediction unit
160: Output section
P: spongy bone phantom

Claims (16)

A pair of ultrasound transducers for transmitting and receiving ultrasonic waves, the ultrasound transducer including a transmitting unit for converting an applied electrical signal into an ultrasonic wave and a receiving unit for converting the received ultrasonic wave into an electrical signal;
A waveform generator for generating an electrical signal for the transmission ultrasonic wave and transmitting the electrical signal to the transmitter;
A signal processing unit for detecting an electrical signal of the ultrasonic wave received by the receiving unit;
A calculation unit for analyzing the electrical signal detected by the signal processing unit and calculating a nonlinear parameter of the spongy bone; And
And a bone structure predicting unit for predicting a bone structure of the spongy bone through the correlation between the nonlinear parameter calculated by the calculating unit and the bone structure of the cavernous bone,
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
The method according to claim 1,
The signal processing unit selectively detects an electric signal for a receiving ultrasonic wave having a frequency that is twice the fundamental frequency (hereinafter, referred to as 'f1 frequency') of the transmitted ultrasonic wave (hereinafter, referred to as 'f2 frequency') Characterized in that
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
3. The method of claim 2,
Characterized in that the non-linear parameter of the spongy bone is calculated by the following equation
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
[Equation 1]

(B / A) s is the nonlinear parameter of the cavernous bone,

The amplitude of the f2 frequency component transmitted through the spongy bone when there is a caudal bone between a pair of ultrasound transducers,

L is the distance between a pair of ultrasound transducers, d is the thickness of the cavernous bone, d is the distance between the ultrasound transducers,

Is the attenuation coefficient of the cavernous bone at frequency f1,

Is the attenuation coefficient of the cavernous bone at the f2 frequency component,

The permeability coefficient at the boundary between water / cavernous bone,

Is the sound pressure transmission coefficient at the interface between the cavernous bone / water,

The density of water,

Is the speed of water,

The density of spongy bone,

(B / A) w is the nonlinear variable of water, exp is the exponential function)
The method of claim 3,
Wherein the bone structure of the spongiform bone includes a bone-to-bone ratio (BT / TV) and a bone marrow interval (Tb.Sp)
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
5. The method of claim 4,
The bone structure predicting unit may include a non-linear parameter of the spongy bone as an independent variable, a bone capacity ratio (BT / TV) of the spongy bone, and a bone span interval (Tb.Sp) And a correlation between the dependent variable and the dependent variable derived from the regression analysis of each dependent variable.
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
6. The method of claim 5,
The correlation between the non-linear parameter of the spongy bone and the bone capacity ratio (BT / TV) of the spongy bone in the bone structure predicting unit is such that the bone capacity ratio (BT / VT) And a positive correlation value
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
6. The method of claim 5,
The correlation between the non-linear parameter of the spongy bone and the bone marrow gap (Tb.Sp) of the spongy bone in the bone structure predicting unit is such that the bone marrow gap (Tb.Sp) of the spongy bone is linearly And a negative correlation of decreasing
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
The method according to claim 1,
And an output unit for outputting the predicted bone structure from the bone structure predicting unit, wherein the bone structure predicting apparatus using the ultrasonic non-
An apparatus for predicting bone structure using ultrasonic nonlinear variables.
An ultrasonic wave transmitting step of causing a transmitted ultrasonic wave transmitted from a transmitting unit of a pair of ultrasonic transducers arranged to face and transmit ultrasonic waves to the cavernous bone and transmitting the transmitted ultrasonic wave through the cavernous bone;
The receiving unit of the pair of ultrasonic transducers receiving the ultrasonic waves transmitted through the sponge bone in the ultrasonic wave transmitting step and the receiving unit converting the received ultrasonic waves into an electric signal;
A signal processing step of the signal processing unit detecting the electrical signal converted in the signal receiving step and the calculating unit calculating the nonlinear parameter of the spongy bone by analyzing the electrical signal detected by the signal processing unit; And
And a bone structure predicting step of predicting a bone structure of the spongy bone by the correlation between the nonlinear parameter calculated in the signal processing step and the bone structure of the spongy bone,
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
10. The method of claim 9,
The signal processing step selectively detects an electrical signal for a receiving ultrasonic wave having a frequency which is twice the fundamental frequency (hereinafter, referred to as 'f1 frequency') of the transmitting ultrasonic wave (hereinafter, referred to as f2 frequency) Characterized by comprising a detecting step
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
11. The method of claim 10,
Wherein the signal processing step includes a calculating step of calculating a non-linear parameter of the spongy bone from the electrical signal detected in the detecting step, using the following equation
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
[Equation 1]

(B / A) s is the nonlinear parameter of the cavernous bone,

The amplitude of the f2 frequency component transmitted through the spongy bone when there is a caudal bone between a pair of ultrasound transducers,

L is the distance between a pair of ultrasound transducers, d is the thickness of the cavernous bone, d is the distance between the ultrasound transducers,

Is the attenuation coefficient of the cavernous bone at frequency f1,

Is the attenuation coefficient of the cavernous bone at the f2 frequency component,

The permeability coefficient at the boundary between water / cavernous bone,

Is the sound pressure transmission coefficient at the interface between the cavernous bone / water,

The density of water,

Is the speed of water,

The density of spongy bone,

(B / A) w is the nonlinear variable of water, exp is the exponential function)
12. The method of claim 11,
Wherein the bone structure of the spongy bone includes the bone capacity ratio (BT / TV) and the bone ankle spacing (Tb.Sp) of the cavernous bone
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
13. The method of claim 12,
The bone structure predicting step may be performed by using the non-linear parameter of the spongy bone as an independent variable, taking the bone capacity ratio (BT / TV) of the spongy bone as the dependent variable and the bone span interval (Tb.Sp) And regression analysis of each dependent variable, deriving a correlation between the independent variable and the dependent variable, and predicting the bone structure from the derived correlation
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
14. The method of claim 13,
The correlation between the non-linear parameter of the spongy bone and the bone capacity ratio (BT / TV) of the spongy bone in the bone structure predicting step is such that the bone capacity ratio (BT / VT) And a positive correlation value
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
14. The method of claim 13,
In the bone structure predicting step, the correlation between the non-linear parameter of the spongy bone and the bone marrow interval (Tb.Sp) of the spongy bone decreases as the non-linear parameter increases, the bone marrow interval (Tb.Sp) of the spongy bone decreases linearly And a negative correlation with
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.
10. The method of claim 9,
The method of predicting a bone structure using the ultrasonic nonlinear parameter may further include outputting a result predicted by the bone structure predicting step to an output unit
Estimation of Bone Structure Using Ultrasonic Nonlinear Parameters.

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