TWI396520B - Soft tissue elasticity measurement method and device - Google Patents

Description

Soft tissue elasticity measuring method and device

The invention relates to a method and device, in particular to a soft tissue elasticity measuring method and device.

According to the literature, the surface soft tissues of the human body (such as muscle tissue, adipose tissue, skin tissue, nerve tissue, and vascular tissue) not only have functional deterioration with age, but also many diseases can cause soft tissue. Producing lesions, leading to the adverse consequences of hardening, ultimately reduces the elastic function of the soft tissue and the loss of the original physiological function. For example, the degree of Hardening of vascular tissue increases with age, and many diseases can also cause vascular tissue sclerosis, such as Cerebral Vessel Disease, Cardiac Disease, Diabetes (Diabetes Mellitus). ), hypertension (Hypertension) and a considerable proportion of kidney disease (Renal Disease), etc., therefore, vascular tissue sclerosis itself can be used as a major predictor of many lesions.

Therefore, how to effectively and accurately measure the characteristics of the surface soft tissue of the human body, so as to understand whether the soft tissue produces lesions as early as possible, and thus achieve the effect of "early diagnosis, early treatment" is a problem worthy of attention.

Many techniques have been used to estimate the composition and characteristics of human soft tissue. One of them is to measure the electrical impedance of soft tissue to obtain the composition and characteristics of the soft tissue. For example, the disclosure of the invention patent No. I278305 (method and device for measuring local fat by bioimpedance technology) reveals that the tissue to be measured inputs a weak alternating current, and the fat and muscle exhibit different resistance values. The bioimpedance characteristic is used to determine the fat content of the tissue to be tested; and as disclosed in the invention patent No. 200642662 (bioelectrical impedance measuring device and body composition measuring device), the predetermined frequency is applied. The alternating current is used to measure the voltage generated in the organism, and the calculation mechanism is used to calculate the bioelectrical impedance parameter value. Although the above two invention patents can be used to evaluate the composition, content, and electrical characteristics of human soft tissue, the accuracy is not high, and the elastic characteristics of the soft tissue cannot be directly obtained.

There is also the use of Ultrasound Echo Tracking, such as the disclosure of the invention patent No. I227665, which is an ultrasonic image scanning device for synchronizing blood pressure and blood vessel diameter measurement measurement system by image The treatment technique obtains the diameter and blood pressure data at the same time, and then establishes the dynamic characteristic parameters of blood pressure, blood vessel diameter and wall tissue strain, such as the stress-strain of the vessel diameter or Intima-Media Thickness. The relationship curve, the dynamic Young's modulus, and the Energy Dissipation Ratio.

However, the accuracy of the ultrasonic image acquisition technology is bound to depend on whether the resolution of the image is high enough, and this also involves the cost of the image capture device, and the measurement and analysis methods are more complicated. In practice, the clinical application is still incomplete; in addition, the patent only uses the stress-strain relationship curve to calculate the dynamic Young's coefficient. Obviously, the vascular tissue is regarded as a single elastic material to calculate the reaction force. Neglecting the effects of resistance such as blood and blood vessel wall quality does not actually reflect the mechanical properties of the vascular tissue itself.

In addition, there are also those who use the technology of magnetic resonance imaging (also known as magnetic resonance imaging, magnetic resonance imaging, magnetic resonance imaging, MRI), for example, the invention patent case of China Publication No. 200801566, Announcement No. I221406, 452488, that is, placing the human body in a magnetic field to wirelessly The electric wave pulse changes the regional magnetic field to excite the resonance of the hydrogen nuclei in the human tissue, and the different tissues of the human body produce different magnetic moment change signals (such as magnetic moment, spin angular momentum, lattice relaxation, pulse and diffusion coefficient, etc. ), after computer processing, can display the cut surface image of human tissue, but the required equipment is not only bulky, the instrument design is quite complicated and expensive, so it is not conducive to popularization and a large number of applications, and in practical operation, Only by technical staff is required to operate.

Furthermore, there are also computerized Tomography (CT) techniques, such as the invention patents No. I272934, I253510, 565437, and 359604, which use different tissues of the human body to have different absorptions for X-rays. The three-dimensional image reconstruction technology obtains the tomographic image of the corresponding organization. The required equipment is not only bulky, complicated, and expensive, but also needs to be operated by specialized personnel, so it cannot achieve the purpose of popularization.

Accordingly, it is an object of the present invention to provide a soft tissue elasticity measurement method that avoids the above-described deficiency and increases efficiency.

The soft tissue elasticity measuring method comprises the steps of: generating a sinusoidal vibration signal having a set frequency and a set maximum displacement amplitude to be transmitted to a soft tissue of a subject; sensing a vibration from the soft tissue reflecting the sine wave Responsive force of the signal to obtain a digital measurement signal related to the reaction force; measuring the signal according to the digital position to find a maximum value related to the reaction force as a maximum reaction force; and setting the maximum displacement amplitude In addition to the maximum reaction force, a soft tissue elasticity corresponding to the set frequency and the set maximum displacement amplitude is obtained.

It is yet another object of the present invention to provide a soft tissue elastic metrology apparatus that avoids the above-described deficiencies and increases efficiency.

The soft tissue elasticity measuring device comprises: a processor for outputting a digital signal having a set frequency and a set maximum displacement amplitude; a vibration generating circuit that touches a soft tissue of a subject and is electrically connected to the processing Receiving the digital signal having the set frequency and the set maximum displacement amplitude, and generating a sine wave vibration signal having the set frequency and the set maximum displacement amplitude to the soft tissue according to the set frequency and the set maximum displacement amplitude And a reactive force sensing circuit electrically connected to the processor and touching the soft tissue to sense a reaction force from the soft tissue reflecting the sine wave vibration signal, and generating a signal at a sampling frequency a digital measurement signal of the sample values of the plurality of reaction forces; and the processor further receives the digital measurement signal of the sampled values of the reaction forces, and finds a maximum value of the sampled values of the reaction forces as a maximum Responsive force; the processor further divides the set maximum displacement amplitude by the maximum reaction force to obtain a corresponding set frequency and the set maximum bit Amplitude of elasticity of soft tissue.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

A preferred embodiment of the soft tissue elastic measuring device of the present invention is adapted to conduct a soft tissue having a set sinusoidal vibration signal with a set maximum displacement amplitude and a set frequency to a subject to measure the reaction force of the soft tissue, Further, a soft tissue elasticity relative to the set frequency and the set maximum displacement amplitude is estimated based on the reaction force and the set maximum displacement amplitude.

Wherein, as shown in FIG. 1 , a mechanical model conforming to the soft tissue characteristics of the present invention is constructed, and an Inertia component M, a Viscosity component η, and an elastic component C are respectively connected in parallel. Wherein, the resistance generated by the damping element M is the acceleration In proportion, the resistance generated by the viscous element η is the speed In proportion, the resistance generated by the elastic element C is proportional to the displacement (X). Therefore, if the mechanical model is subjected to a time-varying displacement X(t), the mechanical model will generate a reaction force. F(t) is the sum of the above three resistances, as in equation (1).

Further, the sinusoidal vibration signal X(t) is applied to a soft tissue of a subject whose mechanical characteristics are equivalent to those achieved by the mechanical model shown in FIG. 1, wherein X(t)=A sin(2π f t), A is the maximum displacement amplitude, and f is the set frequency. Therefore, after deriving X(t) once and differentially, it is possible to obtain equations (2) and (3), respectively.

Substituting the formulas (2) and (3) into the formula (1) gives the formula (4).

Equation (5) can be obtained by dividing each of the left and right sides of the equation (4) by A and merging the right side of the equal sign.

When X(t) has the maximum displacement amplitude, that is, X(t)=A, then sin(2π ft) has a maximum value equal to 1, and cos(2π ft) has a minimum value equal to 0, and is also at X ( t) When there is a maximum displacement amplitude, the soft tissue also produces the maximum reaction force (Fm), and the elasticity is C at that time, so the formula (5) can be reduced to the formula (6).

After the formula (6) is moved, it can be simplified.

Since the experimental results at the set frequency show that the value of the first term on the right side of the upper equal sign is much larger than the value of the second term, the second term can be ignored and the equation (7) can be reduced to the equation (8).

It can be known from the formula (9) that when X(t) has the maximum displacement amplitude, the elasticity C of the soft tissue approximates the ratio of the maximum displacement amplitude A divided by the maximum reaction force Fm (A/Fm).

As shown in FIG. 2, the soft tissue elasticity measuring device comprises: a processor 5, a vibration generating circuit 6, a reaction force sensing circuit 7, and a screen 8.

The processor 5 is electrically connected between the vibration generating circuit 6, the reaction force sensing circuit 7, and the screen 8.

The vibration generating circuit 6 is further touched on the soft tissue, and includes a probe 61, a micro vibrator 62, a pusher 63, a sine wave generator 64, and a digital analog converter 65.

The responsiveness sensing circuit 7 also touches the soft tissue and includes a reactive force sensor 71, a high pass filter 75, an amplifier 76, and an analog digital converter 73.

The responsiveness sensor 71 and the probe 61 are disposed above the soft tissue and are electrically connected to the high pass filter 75, but are not shown together in FIG. 2 for convenience of explanation.

Amplifier 76 is electrically coupled between the high pass filter 75 and the analog digital converter 73.

The soft tissue elasticity measuring device performs a soft tissue elasticity measurement method, and as shown in FIG. 3, the following steps are included:

Step 1: The processor 5 controls the vibration generating circuit 6 to generate a sine wave vibration signal having the set frequency and the set maximum displacement amplitude according to a set frequency and a set maximum displacement amplitude. In this embodiment, the set frequency is The optimum range is 0.2~10Hz, and the optimal range for setting the maximum displacement amplitude is 0.1~10mm, and the following substeps are included as shown in Fig. 4:

Step 11: The processor 5 outputs a digital signal having the set frequency and the set maximum displacement amplitude.

Step 12: The vibration generating circuit 6 receives the digital signal from the set frequency and the set maximum displacement amplitude, and generates a sine wave having the set frequency and the set maximum displacement amplitude according to the set frequency and the set maximum displacement amplitude. The vibration signal is transmitted to the soft tissue.

The detailed method of step 12 is as follows:

The digital analog converter 65 is electrically connected to the processor 5 to receive the digital signal having the set frequency and the set maximum displacement amplitude, and generate a signal indicating the set frequency value according to the set frequency and the set maximum displacement amplitude, respectively. A voltage and a second voltage representing the set maximum displacement amplitude value.

The sine wave generator 64 is electrically connected to the digital analog converter 65 to receive the first voltage and the second voltage to generate a sine wave voltage whose frequency is relative to the set frequency and the voltage magnitude is relative to the set maximum displacement amplitude signal.

The pusher 63 is electrically connected to the sine wave generator 64 to receive the sine wave voltage signal, and converts the sine wave voltage signal into a sine wave current signal whose current magnitude is linearly proportional to the magnitude of the voltage of the sine wave voltage signal. .

The micro vibrator 62 is electrically connected to the pusher 63 to receive the sine wave current signal to generate a mechanical force.

The probe 61 is electrically connected to the micro-vibrator 62, and is vertically displaced by the mechanical force to generate a sine wave vibration signal having the set frequency and the set maximum displacement amplitude transmitted to the soft tissue.

Step 2: The reaction sensing circuit 7 senses a reaction force from the soft tissue that reflects the sine wave vibration signal to obtain a digital measurement signal related to the reaction force, and includes the following sub-steps, as shown in FIG. Show:

Step 21: The reaction force sensor 71 senses the reaction force of the soft tissue to generate a measurement signal.

Step 22: The high pass filter 75 receives the measurement signal and filters out the low frequency components to obtain a filtered signal.

Step 23: The amplifier 76 receives the filtered signal and amplifies the amplitude of the filtered signal to obtain a high frequency analog signal.

Step 24: The analog-to-digital converter 65 receives and temporarily stores the high-frequency analog signal, and then separately samples the high-frequency analog signal according to a sampling frequency to obtain sampling values of multiple reaction forces, and further samples according to the reactive forces. The value outputs the digital measurement signal.

Step 3: The processor 5 receives the digital measurement signal having the reaction force, and finds the maximum value of the sampling values of the reaction forces as a maximum reaction force Fm.

Step 4: The processor 5 divides the set maximum displacement amplitude A by the maximum reaction force Fm to obtain a soft tissue elasticity C corresponding to the set frequency and the set maximum displacement amplitude, and displays on the screen 8.

In addition, the measurement process may be repeated with different set frequencies and a fixed set maximum displacement amplitude. After obtaining a plurality of soft tissue elasticity C corresponding to the set frequencies, the processor 5 may display the following on the screen 8. The soft tissue elasticity waveform of the frequency change may be repeated by different setting the maximum displacement amplitude and the fixed set frequency, and the processor 5 obtains the soft tissue elasticity C corresponding to the set maximum displacement amplitude. A soft tissue elasticity waveform that varies with the set maximum displacement amplitude can be displayed on the screen 8.

In summary, the present invention has the following advantages:

(1) The soft tissue elasticity can be calculated by using the set maximum displacement amplitude and the set frequency, and the measured maximum reaction force, which can reduce the complexity of the calculation.

(2) Simultaneously displaying the soft tissue elasticity waveform on the screen 8 to let the user know which frequency corresponds to the soft tissue elasticity.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

1. . . Vibration step

11. . . Provided steps

12. . . Steps generated

2. . . Measuring step

twenty one. . . Sensing step

twenty two. . . Filtering step

twenty three. . . Step of zooming in

twenty four. . . Sampling step

3. . . Reaction step

4. . . Calculation step

5. . . processor

6. . . Vibration generating circuit

61. . . Probe

62. . . Micro vibrator

63. . . Pusher

64. . . Sine wave generator

65. . . Digital analog converter

7. . . Responsive sensing circuit

71. . . Responsive sensor

73. . . Analog digital converter

75. . . High pass filter

76. . . Amplifier

8. . . Screen

Figure 1 is a mechanical model diagram of the characteristics of the soft tissue constructed in accordance with the present invention;

Figure 2 is a functional block diagram of a preferred embodiment of the present invention;

Figure 3 is a flow chart of the preferred embodiment;

Figure 4 is a flow chart of the first step; and

Figure 5 is a flow chart of the second step.

5. . . processor

6. . . Vibration generating circuit

61. . . Probe

62. . . Micro vibrator

63. . . Pusher

64. . . Sine wave generator

65. . . Digital analog converter

7. . . Responsive sensing circuit

71. . . Responsive sensor

73. . . Analog digital converter

75. . . High pass filter

76. . . Amplifier

8. . . Screen

Claims (12)

A soft tissue elasticity measurement method includes the steps of: generating a sinusoidal vibration signal having a set frequency and a set maximum displacement amplitude to be transmitted to a soft tissue of a subject, and the optimal range of the set frequency is 0.2 to 10 Hz. Sensing a reaction force from the soft tissue reflecting the sine wave vibration signal to obtain a digital measurement signal related to the reaction force; and measuring the signal according to the digital position to find a maximum value related to the reaction force As a maximum reaction force; and dividing the set maximum displacement amplitude by the maximum reaction force to obtain a soft tissue elasticity corresponding to the set frequency and the set maximum displacement amplitude. According to the soft tissue elasticity measurement method of claim 1, wherein the step of generating the sine wave vibration signal comprises: outputting a digital signal having the set frequency and the set maximum displacement amplitude; receiving the digital signal, And generating, according to the set frequency and the set maximum displacement amplitude, a first voltage indicating the set frequency and a second voltage indicating the set maximum displacement amplitude; receiving the first voltage and the second voltage to generate a frequency is Relative to the set frequency and a voltage magnitude is a sine wave voltage signal relative to the set maximum displacement amplitude; converting the sine wave voltage signal into a sine wave whose current magnitude is linearly proportional to the magnitude of the voltage of the sine wave voltage signal Current signal Receiving the sine wave current signal to generate a mechanical force; and controlling the probe to perform up and down displacement by the mechanical force to generate a sine wave vibration signal having the set frequency and the set maximum displacement amplitude. The soft tissue elasticity measurement method according to claim 1, wherein the step of generating the digital measurement signal comprises: sensing a reaction force of the soft tissue to generate a measurement signal; filtering the measurement signal The low frequency component is obtained to obtain a filtered signal; the amplitude of the filtered signal is amplified to obtain a high frequency analog signal; and the high frequency analog signal is separately sampled according to a sampling frequency to obtain a reactive power sampling value, and then according to The reaction force sample value outputs the digital measurement signal. According to the soft tissue elasticity measurement method according to the first aspect of the patent application, the repeated setting is performed according to different set frequencies and a fixed set maximum displacement amplitude to obtain a plurality of soft tissue elastic degrees corresponding to the set frequency, and further Obtaining a soft tissue elasticity waveform according to the frequency, and repeatedly performing according to different set maximum displacement amplitudes and a fixed set frequency to obtain a plurality of soft tissue elasticity corresponding to the set maximum displacement amplitude, thereby obtaining the setting A soft tissue elasticity waveform with a change in maximum displacement amplitude. According to the soft tissue elasticity measurement method described in claim 1, wherein the optimum range of the maximum displacement amplitude is 0.1 to 10 mm. A soft tissue elastic measuring device comprising: a processor, outputting a digital signal having a set frequency and a set maximum displacement amplitude, the optimal range of the set frequency is 0.2~10 Hz; a vibration generating circuit that touches a soft tissue of a subject and electricity Connected to the processor to receive the digital signal having the set frequency and the set maximum displacement amplitude, and generate a sine wave vibration signal having the set frequency and the set maximum displacement amplitude according to the set frequency and the set maximum displacement amplitude Conducting to the soft tissue; and a reactive force sensing circuit electrically coupled to the processor and touching the soft tissue to sense a reaction force from the soft tissue reflecting the sine wave vibration signal, and at a sampling frequency Generating a digital measurement signal having a plurality of reaction force sampling values; and further, the processor receives the digital measurement signal having the sampling values of the reaction forces, and finds a maximum of the sampling values of the reaction forces The value is used as a maximum reaction force; the processor further divides the set maximum displacement amplitude by the maximum reaction force to obtain a corresponding corresponding to the set frequency and the setting Soft tissue displacement amplitude of elasticity. The soft tissue elasticity measuring device according to claim 6, wherein the reaction force sensing circuit comprises: a reaction force sensor disposed above the soft tissue to sense the reaction force of the soft tissue to generate a Measuring a signal; a high-pass filter electrically connected to the reaction force sensor to receive the measurement signal and filtering out low frequency components to obtain a filtered signal; An amplifier electrically coupled to the high pass filter to receive the filtered signal and amplify the amplitude of the filtered signal to obtain a high frequency analog signal; and an analog to digital converter electrically coupled to the amplifier for receiving and temporarily storing The high frequency analog signal is further sampled according to the sampling frequency to obtain sampling values of the reactive forces, and the digital measuring signal is output according to the sampling values of the reactive forces. The soft tissue elasticity measuring device according to claim 6, further comprising a screen electrically connected to the processor, wherein the screen is used to display the soft tissue elasticity. The soft tissue elasticity measuring device according to claim 6 is repeatedly executed according to different set frequencies to obtain a plurality of soft tissue elastic degrees corresponding to the set frequency, thereby obtaining a soft tissue that changes with frequency. The elasticity degree waveform is repeatedly executed according to different set frequencies and a fixed set maximum displacement amplitude to obtain a plurality of soft tissue elasticity degrees corresponding to the set frequency, thereby obtaining a soft tissue elasticity degree waveform which changes with frequency, and according to The different set maximum displacement amplitudes and the fixed set frequencies are repeatedly executed to obtain the soft tissue elasticity corresponding to the set maximum displacement amplitudes, and then a soft tissue elasticity waveform corresponding to the set maximum displacement amplitude is obtained. According to the soft tissue elasticity measuring device of the eighth aspect of the patent application, the soft tissue is repeatedly measured according to different set frequencies and a fixed set maximum displacement amplitude, so that the processor obtains the plurality of the set frequencies corresponding to the soft tissue. Soft tissue elasticity, showing changes with frequency on the screen a soft tissue elasticity waveform, and repeatedly measuring the soft tissue according to different set maximum displacement amplitudes and a fixed set frequency, so that the processor obtains the soft tissue elasticity corresponding to the set maximum displacement amplitude, and then on the screen A soft tissue elasticity waveform that varies with the set maximum displacement amplitude is displayed. The soft tissue elasticity measuring device according to claim 6, wherein the vibration generating circuit comprises: a digital analog converter electrically connected to the processor to receive the set frequency and the set maximum displacement amplitude a digital signal, and respectively generating a first voltage indicating the set frequency value and a second voltage indicating the set maximum displacement amplitude value according to the set frequency and the set maximum displacement amplitude; a sine wave generator electrically connected to the The digital analog converter receives the first voltage and the second voltage to generate a sine wave voltage signal with respect to the set frequency and the voltage magnitude relative to the set maximum displacement amplitude; a pusher electrically connected to the The sine wave generator receives the sine wave voltage signal, and converts the sine wave voltage signal into a sine wave current signal whose current magnitude is linearly proportional to the voltage magnitude of the sine wave voltage signal; a micro vibrator, electrical connection The pusher generates a mechanical force to receive the sine wave current signal; and a probe electrically connected to the micro-vibrator and subjected to the mechanical force Controlling up and down displacement produces the set frequency and the set maximum displacement vibration The amplitude of the sinusoidal vibration signal is transmitted to the soft tissue. The soft tissue elasticity measuring device according to claim 7, wherein the optimum range of the maximum displacement amplitude is 0.1 to 10 mm.