JP4806561B2 - Fracture risk assessment system - Google Patents

Description

  The present invention relates to a fracture risk evaluation system, and more particularly to a system that comprehensively evaluates the risk or risk (risk) of a fracture from a plurality of viewpoints.

  A bone evaluation apparatus is an apparatus that evaluates bone properties using physical waves such as X-rays and ultrasonic waves. In the case of bone evaluation using X-rays, X-rays are transmitted through the measurement site, and the amount of bone mineral is determined from the attenuation amount of X-rays at that time. In the case of bone evaluation using ultrasonic waves, ultrasonic waves are transmitted to the measurement site, and the mechanical or structural characteristics of the bone are observed by observing the speed of sound and attenuation of the ultrasonic waves that have passed through the measurement site. An evaluation value representing is calculated. Patent Document 1 discloses a bone evaluation apparatus that evaluates bone properties by combining X-ray measurement and ultrasonic measurement. Patent Document 2 discloses that ultrasonic attenuation, in particular, the inclination of attenuation characteristics is used for bone evaluation.

  On the other hand, an apparatus that measures the fluctuation of the center of gravity of a subject is known. By quantitatively evaluating the degree of sway of the center of gravity, it is possible to evaluate the motor ability of the subject. Patent Documents 3, 4, and 5 disclose a center-of-gravity sway measurement device having a load measurement base on which a subject is placed.

  Patent Document 6 describes an apparatus that calculates a motion trajectory for a subject by imaging with a video camera and determines the risk of falling based on the motion trajectory. Patent Document 7 describes an apparatus that comprehensively determines physical ability from a plurality of types of information related to a body condition. Patent Document 8 discloses a system for diagnosing an equilibrium sensory function based on an output signal of a motion sensor mounted on the head or waist of a body.

JP-A-6-22960 JP 7-31612 A JP-A-4-28353 JP 2005-46535 A JP-A-2005-87312 JP 2004-261376 A JP 2003-199728 A JP 2004-344433 A

  However, in the past, combining the assessment of the subject's motor ability (macro assessment) with the assessment of the subject's bone (macro assessment), and combining these assessment results to determine the risk of fracture Not done. Patent Document 7 discloses that a plurality of types of information are referred to, but the properties of the bone itself are not considered.

  One of the ultimate purposes of bone evaluation is to predict fracture risk, but conventionally, such fracture risk has not been comprehensively evaluated. For example, if you compare a person with reduced bone mass as a bone property and a normal person, if the incidence of falls is the same, it can be said that the former has a greater risk of fracture than the latter, If the amount of bone is the same, it can be said that the magnitude of the incidence of falls affects the magnitude of the risk of fracture. In particular, it has been pointed out that when an elderly person falls and fractures a major bone such as the femur, it is highly likely that they will be bedridden. From the viewpoint of preventive medicine, the risk of fracture is comprehensive. Is required to be evaluated.

  An object of the present invention is to enable comprehensive evaluation of fracture risk.

  An object of the present invention is to make it possible to evaluate the risk of fractures by comprehensively considering bone properties and exercise ability.

  The system according to the present invention transmits / receives a physical wave to / from a measurement site of a subject, and obtains a bone property evaluation value representing a bone property of the measurement site based on a reception signal obtained thereby. A property evaluation means, an exercise ability evaluation means for detecting an exercise for the subject, and obtaining an evaluation value of an exercise ability representing a degree of wobbling of the subject based on a detection signal obtained by the exercise; and the bone property Comprehensive evaluation value calculating means for calculating a comprehensive evaluation value representing the degree of fracture risk for the subject based on the evaluation value and the athletic ability evaluation value.

  According to the said structure, a bone property evaluation value is calculated by transmission / reception of physical waves, such as an ultrasonic wave or an X-ray, with respect to the measurement site | part in a subject. That is, the properties of the bone itself (particularly the degree of ease or difficulty of fracture) can be evaluated. On the other hand, the exercise ability of the subject can be evaluated by detecting the exercise of the subject, particularly the degree of wobbling. For example, in the case of an elderly person, in the case of a person with a disability in balance sense or motor function, the fall probability increases, so that it can be evaluated. That is, it is possible to evaluate the probability of occurrence of a phenomenon that directly induces fractures. Then, a comprehensive evaluation value indicating the degree of fracture risk is calculated from the normal bone evaluation value and the exercise ability evaluation value.

  The total evaluation value may be obtained by performing weighted addition on the bone property evaluation value and the motor ability evaluation value. In this case, the weight is variably set according to the subject attributes such as age and sex. desirable. Of course, it is also possible to obtain a comprehensive evaluation value by an arithmetic expression other than weighted addition. In any case, if both the evaluation of the bone itself and the evaluation of the motor function of the subject are taken into consideration, a new index representing fracture risk that cannot be obtained by the conventional one-sided evaluation can be derived.

  Preferably, the physical wave is an ultrasonic wave, and the bone property evaluating means measures the bone property by measuring at least one of sound velocity and attenuation of the ultrasonic wave transmitted through the measurement site based on the received signal. Obtain an evaluation value. If ultrasonic waves are used, the problem of exposure can be avoided. Various bone evaluation methods are known.

  Preferably, the physical wave is an X-ray, and the bone property evaluation unit obtains the bone property evaluation value by measuring an attenuation amount of the X-ray transmitted through the measurement site based on the received signal. . If X-rays are used, the amount of bone mineral in the bone can be obtained with high accuracy from the attenuation. Bone health can be evaluated from the viewpoint of bone mineral content.

  Preferably, the athletic ability evaluation unit obtains the athletic ability evaluation value by detecting the movement of the reference point in the subject. In this case, the subject may stand up on the platform and detect the movement of the reference point in the stationary state, or may cause the subject to perform a predetermined action (for example, stepping movement) The movement of the reference point may be detected in the state.

  Preferably, the athletic ability evaluation means includes a load detection unit for placing both feet of the subject, and a center of gravity motion detection unit that detects the motion of the center of gravity as the motion of the reference point based on an output signal of the load detection unit. And including. For example, the trajectory of the center of gravity movement may be obtained, and the exercise ability may be evaluated from the area, length, etc. Various techniques for evaluating the sway of gravity are known.

  Preferably, the athletic ability evaluation means includes a motion sensor mounted on the subject and an output signal from the motion sensor of a mounting site where the motion sensor is mounted as the motion of the reference point. An attachment site movement detection unit for detecting movement. The motion sensor may be a position sensor, a speed sensor, an acceleration sensor, a direction sensor, or the like. A sensor using geomagnetism can also be used.

  Preferably, the bone property evaluating means is configured to calculate an actual value representing a bone property for the subject based on the received signal, and an actual value calculation unit that calculates the bone property with respect to a standard value registered in advance. A bone property comparison / calculation unit that computes the bone property evaluation value by comparing the measured values to be represented.

  Preferably, the athletic ability evaluation means is configured to calculate an actual value representing an athletic ability for the subject based on the detection signal, and an athletic ability with respect to a standard value registered in advance. And an athletic ability comparison / calculation unit that calculates the athletic ability evaluation value by comparing the measured values to be expressed.

  Desirably, the comprehensive evaluation value calculation means calculates the comprehensive evaluation value while weighting the bone property evaluation value and the exercise ability evaluation value according to attribute information regarding the subject. Desirably, the attribute information regarding the subject includes at least one of age and gender.

  Preferably, a unit for transmitting and receiving a physical wave in the bone property measuring means and a unit for detecting the movement of the subject in the athletic ability evaluating means are structurally integrated to evaluate the bone property. The evaluation of the athletic ability can be performed simultaneously. According to this configuration, measurement can be performed easily and quickly.

  As described above, according to the present invention, the risk of fracture can be comprehensively evaluated. In particular, according to the present invention, the risk of fracture can be evaluated by comprehensively considering bone properties and exercise ability.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows a first embodiment of a fracture risk evaluation system according to the present invention. In the configuration example shown in FIG. 1, the fracture risk evaluation system includes a motion measurement unit 12, a bone measurement unit 14, and a calculation unit 16.

  The motion measurement unit 12 includes a step 13 on which both feet of the subject in an upright state are placed. Further, as will be described later, a plurality of load sensors are provided. With this configuration, the center of gravity of the subject is calculated, and the motion of the center of gravity is calculated.

  In the example shown in FIG. 1, the bone measurement unit 14 is a unit that evaluates bone by transmitting and receiving ultrasonic waves. The subject's foot is placed on the footrest 15, and the footpad is sandwiched between the pair of vibrators 22 and 24. In this state, an ultrasonic wave is transmitted from one vibrator 22, and the ultrasonic wave passes through the foot, particularly the rib, and is received by the other vibrator 24. By analyzing the received signal obtained thereby (for example, by calculating sound speed, attenuation, etc.), the bone is evaluated.

  In the example shown in FIG. 1, the calculation unit 16 is configured by a computer, and the units 12 and 14 are controlled in the calculation unit 16, and based on the signals output from the units 12 and 14. An exercise ability evaluation value and a bone evaluation value are calculated, and a comprehensive evaluation value indicating the degree of fracture risk is calculated from these evaluation values. In the system configuration example shown in FIG. 1, the motion measurement unit 12 and the bone measurement unit 14 are formed separately, but they can be integrated as will be described later with reference to FIG. 3. is there.

  FIG. 2 is a block diagram showing a specific configuration example of the fracture risk evaluation system shown in FIG.

  The motion measurement unit 12 has three sensors 18 provided near the tops of the platform 13 shown in FIG. Each sensor 18 is a load sensor. A signal from each sensor 18 is input to the gravity center calculation unit 20. The center-of-gravity calculation unit 20 calculates the position of the center of gravity of the subject based on the signal from each sensor. The technique is known. A signal representing the position of the center of gravity is output from the motion measurement unit 12 to the arithmetic unit 16.

  On the other hand, the bone measuring unit 14 has a pair of vibrators 22 and 24 as described above. Each transducer 22, 24 is a single transducer or an ultrasonic transducer as an array transducer. A pair of vibrators 22 and 24 sandwich a foot region (see reference numeral 26), and in this state, an ultrasonic wave 23 is transmitted and received. It is desirable to provide a coupling member or the like for acoustic matching on the transmission surface or reception surface of each transducer 22, 24. Alternatively, the feet may be immersed in the water tank, and ultrasonic waves may be transmitted and received in that state. The transmission / reception unit 28 supplies a transmission signal to the vibrator 22 and receives a reception signal output from the vibrator 24. After predetermined processing is performed on the received signal, the processed received signal is output to the arithmetic unit 16.

  The arithmetic unit 16 has a plurality of functions, and each function is realized by a program executed by the CPU. Of course, some functions may be realized by dedicated hardware. Further, it is also possible to configure as a device in which the motion measurement unit 12, the bone measurement unit 14, and the calculation unit 16 are structurally integrated.

  The exercise ability evaluation unit 30 receives a signal output from the exercise measurement unit 12, that is, a detection signal representing the position of the center of gravity, and obtains a motion locus of the position of the center of gravity based on the signal. For example, a process of drawing the locus of the center of gravity position on the two-dimensional coordinate system within a certain time is executed. Then, the athletic ability evaluation unit 30 refers to the area of the figure drawn by the trajectory or the length of the trajectory, and calculates the athletic ability evaluation value E1 representing the degree of wobbling about the subject based on the area. At that time, as will be described in detail later, an athletic ability evaluation value database provided in the storage unit 36 is referred to.

  The bone evaluation unit 32 receives the signal output from the bone measurement unit 14 and calculates the sound velocity or attenuation based on the signal, thereby calculating a property bone evaluation value E2 representing the property of the bone. In that case, as will be described in detail, a bone property evaluation value database provided in the storage unit 36 is referred to.

  The comprehensive evaluation unit 34 calculates a comprehensive evaluation value E representing the degree of fracture risk for the subject based on the motor ability evaluation value E1 and the bone property evaluation value E2. For example, the comprehensive evaluation value E is obtained by weighted addition processing with respect to the athletic ability evaluation value E1 and the bone property evaluation value E2. The comprehensive evaluation value E is displayed on the display unit 38 as a numerical value or a graph.

  The arithmetic unit 16 includes an input unit 40 configured by a keyboard or the like, and data input, condition setting, and the like can be performed using the input unit 40. The control unit 42 controls the overall operation of the fracture risk evaluation system.

  Here, a preferred example of the method for calculating the comprehensive evaluation value will be described below. In the present embodiment, as described above, the athletic ability evaluation value database and the bone property evaluation value database are provided on the storage unit 36. The athletic ability evaluation value database has an average value (standard value) and a standard deviation value (SD value) of athletic ability evaluation values registered for each combination of sex and age. Similarly, the bone property evaluation value database has an average value (standard value) and a standard deviation value (SD value) of bone evaluation values registered for each combination of sex and age.

  As described above, the athletic ability evaluation unit 30 analyzes the center of gravity and obtains the athletic ability evaluation value as the analysis result. However, the analysis result, that is, the actual measurement value itself is not used as the athletic ability evaluation value E1. The actual measurement value is compared with the average value of the same gender and the same age, and the result is set as the athletic ability evaluation value E1. In that case, the difference between the positive direction and the negative direction from the average value is expressed in terms of the SD value. In this case, in this example, the more difficult to wobble, that is, the one with a lower probability of falling is the positive side, and the more easy to wobble, that is, the one with a higher probability of falling is the negative side. These relationships may be reversed, but it is desirable to perform a sign operation so that an appropriate result can be obtained by subsequent weighted addition.

  For example, the actual measurement value related to the sway of gravity is expressed as −1.7SD as a difference from the average value under the same condition, and this is set as the motion evaluation value E1.

  On the other hand, in the bone evaluation unit 32, the same calculation as that of the athletic ability evaluation unit 30 is performed. That is, when a certain actual measurement value is obtained as a bone property evaluation result, an average value of the same sex and the same age is read from the bone evaluation value database, and the average value and the actual measurement value are compared. As a result of the comparison, that is, a value having a standard deviation (SD value) as a unit is obtained as a difference amount. For example, the bone evaluation value E2 is expressed as + 1.2SD. In addition, when E1 is -1.7 SD and E2 is +1.2 SD, the amount of bone is slightly larger than the standard, but it is inferred that it is inferior to the standard in terms of exercise ability.

  The comprehensive evaluation unit 34 obtains the comprehensive evaluation value E, for example, by executing the following calculation. Α is a weight value.

      E = α · E1 + (1−α) · E2 (1)

  That is, the comprehensive evaluation value E is obtained by weighted addition for each evaluation value.

  The weight α is desirably variably set according to, for example, age. In that case, a function of α = f (gender, age) may be registered in the storage unit 36. In the above example, when α = 0.5, the arithmetic average is obtained, and 0.5 {(− 1.7) + (+ 1.2)} = (− 0.25). In the present embodiment, the positive side indicates that the risk of fracture is small, and the negative side indicates that the risk of fracture is high. Therefore, in this example, it is evaluated that there is a risk of fracture.

  According to the above calculation, the fracture risk as a whole considering the risk of fracture as seen from the nature or structure of the bone itself and the fracture risk as the risk of falls as seen from the exercise ability of the subject. There is an advantage that the risk can be evaluated. Therefore, there is an advantage that it is possible to provide useful information particularly in a group medical examination in an older age group. Of course, the above arithmetic expression is an example, and various arithmetic expressions can be adopted as long as the fracture risk can be evaluated in consideration of both the bone itself and the exercise ability of the subject. In the above embodiment, since the evaluation value is obtained by comparison with the standard value registered in the database, there is an advantage that a more objective relative evaluation can be performed. Of course, an absolute evaluation value may be obtained without considering age and gender.

  Next, a second embodiment will be described with reference to FIGS. 3 and 4. In addition, the same code | symbol is attached | subjected to the structure similar to the structure shown in FIG. 1, and the description is abbreviate | omitted.

  In the fracture risk evaluation system shown in FIG. 3, the movement measurement unit 12 and the bone measurement unit 45 are structurally integrated to constitute a measurement unit 44. Reference numeral 16A denotes an arithmetic unit similar to that of the embodiment shown in FIG.

  Similar to the embodiment shown in FIG. 1, the motion measurement unit 12 includes a step 13 and a plurality of sensors (not shown), and the position of the center of gravity and the motion trajectory thereof are calculated by their configuration. In this embodiment, the bone measuring unit 45 measures the amount of bone mineral using X-rays. Boxes 50 and 52 are provided above the two columns 46 and 48, respectively, and an X-ray generator and an X-ray detector are provided inside the boxes 50 and 52, respectively.

  FIG. 4 is a block diagram showing the configuration of the embodiment shown in FIG. As described above, the bone measuring unit 45 has the X-ray generator 54 and the X-ray detector 56 arranged on both sides of the subject indicated by the reference numeral 58. Here, various types of measurement sites in the subject 58 can be mentioned, but in the present embodiment, X-ray measurement is performed on the thigh. The X-ray controller 60 functions as a unit that controls generation and detection of X-rays. The X-ray detection signal is output from the X-ray controller 60 to the bone evaluation unit 32A in the arithmetic unit 16A. The bone evaluation unit 32A has a function of calculating a bone mineral content or a bone mineral density (BMD) based on a known DXA method in this configuration example. That is, it is obtained as an actual measurement value, and the bone evaluation value E2 is calculated by comparing the actual measurement value with the average value on the database as described above. Other configurations are the same as those in the embodiment shown in FIG.

  According to the configuration example shown in FIG. 3 and FIG. 4, the measurement of the bone property and the measurement of the center of gravity can be performed at the same time, so that there is an advantage that the measurement time can be shortened. That is, in the embodiment shown in FIG. 1 and the like, it was necessary to separately perform the measurement of the center of gravity and the measurement of the bone property, but in the embodiment shown in FIG. 3 and FIG. Is possible. Of course, these measurements may be performed sequentially as necessary.

  Next, a third embodiment will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the structure similar to each embodiment mentioned above, and the description is abbreviate | omitted.

  In the third embodiment, the motion measurement unit 62 includes an attachment unit (portable unit) 64 attached to the subject 63 and a fixed unit 66 that communicates with the attachment unit 64. ing. Incidentally, the mounting unit 64 is fixed to the subject 63 by a member such as a belt 65, for example. The fixing part is preferably the waist or the like, but may be other parts.

  FIG. 6 is a block diagram showing the overall configuration of the fracture risk evaluation system shown in FIG.

  As described above, the motion measurement unit 62 includes the mounting unit 64 and the fixed unit 66. The mounting unit 64 includes a motion sensor 68 and a communication unit 70. On the other hand, the fixed unit 66 includes a communication unit 72 and a motion calculation unit 74.

  The motion sensor 68 is configured by a sensor capable of measuring the motion of the subject such as a geomagnetic sensor or an acceleration sensor. When a geomagnetic sensor is used, it is desirable to use, for example, a 2-axis type or 3-axis type sensor. Data transmission / reception is performed between the communication unit 70 and the communication unit 72 by a method such as infrared rays or radio waves. The fixed unit 66 is configured as a unit connected to a computer as the arithmetic unit 16 via a cable, or is configured as a card inserted into a slot in the computer. The motion calculation unit 74 detects the motion of the part to which the mounting unit 64 is mounted based on the signal output from the motion sensor 68, and executes a process of drawing the trajectory of the motion on two-dimensional coordinates. Of course, such processing may be performed on the arithmetic unit 16 side.

  The athletic ability evaluation unit 30A calculates an area or length of the movement locus of the wearing part to obtain an evaluation result as an actual measurement value. And the athletic ability evaluation value E1 is calculated like the above by comparing the measured value with the average value registered on the database. Other configurations are the same as those in the embodiment shown in FIG.

  According to the embodiment shown in FIGS. 5 and 6, there is an advantage that the degree of wobbling or the probability of falling about the subject can be easily measured. When measuring bone properties, for example, the subject is seated on a chair and bone evaluation is performed with the heel as a measurement target. Before or after that, the mounting unit is attached to a predetermined part of the subject to stand up. By maintaining the stationary state or performing a predetermined exercise and evaluating the movement of the wearing site at that time, the degree of wobbling of the subject, that is, the exercise ability can be evaluated. For example, when it is desired to evaluate athletic ability over a long period of time, it is desirable to adopt the embodiment shown in FIGS. A function for storing data may be mounted in the mounting unit, and the stored data may be transferred when a state in which the fixed unit and the mounting unit are close to each other is formed.

  According to each embodiment shown above, as already explained, the evaluation result of the property of the bone itself in the subject and the evaluation result in terms of the probability of the fall from the subject's motor ability are comprehensive. There is an advantage that the risk of fracture can be evaluated. Therefore, even when the risk of fracture cannot be properly evaluated by the single evaluation results, there is an advantage that the risk of fracture can be appropriately evaluated by performing multifaceted or compound eye evaluation.

1 is a perspective view of a first embodiment according to the present invention. It is a block diagram of a 1st embodiment. It is a perspective view of 2nd Embodiment. It is a block diagram of 2nd Embodiment. It is a perspective view of 3rd Embodiment. It is a block diagram of a 3rd embodiment.

Explanation of symbols

  12 motion measurement units, 14 bone measurement units, 16 computation units, 30 motor ability evaluation units, 32 bone evaluation units, 34 comprehensive evaluation units.

Claims (8)

Bone property evaluation means for obtaining a bone property evaluation value representing the bone property of the measurement site, based on the received signal obtained by transmitting and receiving a physical wave to the measurement site of the subject,
An athletic ability evaluation means for detecting an exercise for the subject and obtaining an athletic ability evaluation value representing the degree of wobbling of the subject based on a detection signal obtained thereby;
Based on the bone property evaluation value and the athletic ability evaluation value, a comprehensive evaluation value calculating means for calculating a comprehensive evaluation value representing the degree of fracture risk for the subject;
Including
The comprehensive evaluation value calculating means includes a function that variably sets a weight according to the sex and age of the subject, and uses a weight that is variably set according to the sex and age of the subject according to the function. Calculating the overall evaluation value while weighting the bone property evaluation value and the athletic ability evaluation value,
Fracture risk assessment system characterized by that. The system of claim 1, wherein
The physical wave is an ultrasonic wave,
The bone property evaluation means obtains the bone property evaluation value by measuring at least one of sound velocity and attenuation of the ultrasonic wave transmitted through the measurement site based on the received signal. system. The system of claim 1, wherein
The physical wave is an X-ray;
The fracture property evaluation system, wherein the bone property evaluation unit obtains the bone property evaluation value by measuring an attenuation amount of X-rays transmitted through the measurement site based on the received signal. The system of claim 1, wherein
The fracture ability evaluation system, wherein the exercise ability evaluation means obtains the exercise ability evaluation value by detecting movement of a reference point in the subject. The system of claim 4, wherein
The athletic ability evaluation means includes
A load detection unit for placing both feet of the subject;
Based on the output signal of the load detection unit, a gravity center motion detection unit that detects the motion of the center of gravity as the motion of the reference point;
The fracture risk evaluation system characterized by including. The system of claim 4, wherein
The athletic ability evaluation means includes
A motion sensor attached to the subject;
A wearing part movement detection unit that detects movement of a wearing part to which the movement sensor is attached as a movement of the reference point based on an output signal from the movement sensor;
The fracture risk evaluation system characterized by including. The system of claim 1, wherein
The bone property evaluation means includes
Based on the received signal, an actual value calculation unit that calculates an actual value representing bone properties for the subject;
The bone property evaluation value is calculated as a numerical value having a positive or negative sign by comparing an actual measurement value representing the bone property against a pre-registered bone property standard value corresponding to the sex and age of the subject. A bone property comparison operation unit,
Including
The athletic ability evaluation means includes
Based on the detection signal, an actual value calculation unit that calculates an actual value representing athletic ability for the subject;
The athletic ability evaluation value is calculated as a numerical value having a positive or negative sign by comparing an actual measurement value representing the athletic ability against a pre-registered athletic ability standard value corresponding to the sex and age of the subject. An athletic ability comparison operation unit,
Including
The comprehensive evaluation value calculating means calculates the comprehensive evaluation value as a numerical value having a positive or negative sign by weighted addition of the bone property evaluation value and the athletic ability evaluation value.
Fracture risk assessment system characterized by that. The system of claim 1, wherein
The unit for transmitting and receiving physical waves in the bone property evaluation means and the unit for detecting the movement of the subject in the exercise ability evaluation means are structurally integrated,
The fracture risk evaluation system characterized in that the evaluation of the bone property and the evaluation of the exercise ability can be performed simultaneously.

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