JPS632012Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a novel device for measuring fracture disease in living bones.

Traditionally, most fractures have been determined based on X-ray images, and when a fracture is determined, the general practice is to immobilize the fractured area with a cast, splint, etc. and wait for it to heal naturally. Judgment of the condition is made based on ○A patient's age, degree of passage of time, ○B degree of agitation when the surgeon moves the affected area, degree of patient's pain and degree of disappearance, ○C X-ray image, etc. However, ○B has large individual differences, ○B is too subjective and intuitive, and ○C can be clearly determined at the time of fracture, but as the healing progresses, due to the characteristics of X-rays, cartilage tissue and bone tissue are separated. It is difficult to distinguish between the two in the photograph, and each has problems that make it difficult to clearly distinguish them.

Due to these circumstances, it has been difficult to measure the disease state of fractures, leading to delays in diagnosis and a high rate of errors, making it difficult to take appropriate measures. When a fracture occurs in the jawbone, the healing process can cause so-called "bone loss," which can lead to a serious secondary condition called facial distortion. Because it is difficult to determine the completion date, the immobilization period is longer than necessary, which means that the appropriate period for subsequent functional recovery training (rehabilitation) is lost, forcing an unnecessarily long training period... etc. The advent of a device that could scientifically determine disease measurements was anticipated. In recent years, one vibrator and one pick-up have been placed on the skin surface around the fracture site, and continuous vibration at a single frequency has been developed.
A device that performs vibration or impulse vibration by sweeping the frequency and diagnoses the condition of the fracture site based on the signal that appears in the pick-up at that time is known from Japanese Utility Model Publications No. 49-5435 and 5436, but it is difficult to diagnose. In order to improve positional accuracy, it is necessary to position the vibrator and pick-up as close as possible to the fracture site; on the other hand, the fracture site is the injured area, and strong excitation, especially continuous The pain caused by vibration or sweep vibration is continuous and extremely severe; with impulse vibration, the pain is momentary, but when a strong impact is applied near the fracture site, the pain is immeasurable. As a practical diagnostic device, it was far from adequate.

The present invention was developed in view of the above, and its general solution is to apply impulse vibration to the living bone including the fracture site, and fix the bone vibration obtained by the vibration to the bone. Electrical signals corresponding to the vibration waveform received by pickup are stored in a memory as data, and various displays are performed based on this data to measure diseases. In the above, at least one set of pick-ups is used, and both of them are fixed directly or indirectly to the bone surface by holding the fracture site, while for impulse vibration, an impulse exciter is also fixed directly or indirectly to the bone surface. The bone vibrations given by this impulse exciter are discarded by the above set of pick-ups, and the fracture is detected from the properties of the vibration waves at positions that do not include the fracture site and at positions that have passed through the fracture site. This is an attempt to measure disease progression. To explain this in more detail, the principle of the present invention is as follows. Immediately after a fracture, the general healing process is that the fracture site is replaced by a continuous, very soft bond of coagulated blood and loose fibrous tissue, which gradually becomes calcified and eventually becomes a healing state with hard bone bonding. However, from a mechanical point of view, a bone containing a fracture is a model in which a fluid or viscoelastic tissue called the fracture site is sandwiched between two hard elastic rods. It is well known that the degree of fracture healing is expressed by the (physical) properties of the above-mentioned fluid or viscoelastic body, and this invention focuses on this point and examines the condition of the fracture before and after the fracture. This method uses mechanical and acoustic vibrations of bones as a detection medium to measure the degree of fracture disease. The above display is basically to display the vibration waveform captured by the two pick-ups, but in addition, the frequency propagation characteristics at the measurement points by the two pick-ups are determined and displayed on the CRT.
The propagation velocity of vibration between both measurement points is displayed on a CRT, or the vibration of a healthy part of the patient (a healthy bone part in a symmetrical position to the fracture site) is displayed in comparison with either... or a combination of both. It is.

The present invention will be explained in detail below using preferred embodiments. Fig. 1 is a schematic explanatory diagram showing an example of measuring a mandibular fracture using the device of the present invention, and Fig. 2 shows a vibration pickup in the device of the present invention. Figure 3 is a similar view of the same impulse exciter;
Fig. 4A is a vertical sectional view of the main part showing the fixing relationship between the vibration pickup and the bone, Fig. 4B is a similar view of Fig. 4 in another embodiment, Fig. 5 is a block diagram of the device of the present invention, and Fig. 6I. , B, C, and D respectively show front views showing aspects of the diagnostic display of the present invention.

As shown in the figure, in the device of the present invention, a permanent magnet 13 is fixed in a hollow cylindrical case 12, a cylindrical vibrator 14 is connected concentrically with the magnet 13, and a magnetic core 15 and a drive coil 16 are connected to the vibrator 14. Further, plate springs 17 and 18 for restoring are provided close to the
is attached to the vibrator 14 and excites mechanical impulse vibration as a bending wave from the surface of the living bone B including the fracture site 6, and a base 23 having a bolt part 22 on the upper part. bolt part 2
Piezoelectric elements 24, 25 with an electrode 26 sandwiched therebetween and a mass body 27 are mounted on the casing 29, and these are coaxially tightly pressed and held by a nut 28 and housed in a case 29. Bone vibration above human bone B
Two or more vibration pickups 2, 3 received from
, a memory means 4 for storing the vibration waveforms captured by the pick-ups 2 and 3 as electrical signals, and a display means 5 for displaying the vibration waveforms captured by the pick-ups 2 and 3 as voltage waveforms on a CRT. , For more details, see Figures 1 and 5.
As shown in the figure, the impulse exciter 1 is connected to an impulse excitation source 502 and an impulse excitation amplifier 11 to form an impulse excitation system, and a set of vibration pickups 2 and 3 are connected to a set of charge amplifiers 21 ，
31 to constitute a bone vibration pickup system PU, and as shown in Fig. 5, display means 5, display selection button group 6... electronic circuits such as RAM, ROM, CPU, and CRT constitute an analysis display system A. are doing. As shown in FIG. 3, the impulse exciter 1 has a permanent magnet 13 fixed in a hollow cylindrical case 12 with a bottom, a cylindrical vibrator 14 concentrically connected to the magnet 13, and a magnetic core 15. A drive coil 16 is provided close to the vibrator 14, and restoring plate springs 17 and 18 are attached in relation to the vibrator 14. With this configuration, when a current is passed through the coil 16, the vibrator 14 makes a reciprocating linear motion according to the magnitude and direction of the current, based on the same principle as in an acoustic speaker. In order to directly fix the vibration of the vibrator 14 to the living bone B, a needle member 19 is attached to the lower end of the vibrator 14. For this purpose, permanent magnets 140, 190 are attached to the lower end of the vibrator 14 and the upper end of the needle member 19. are provided, and attachment and detachment are performed by magnetic coupling between the two. As an example, in the case of the mandible, the impulse excitation force is preferably between 0.1 and 1N in peak excitation force.

On the other hand, the vibrating pickups 2 and 3 (only 2 will be explained) are made of aluminum-based light alloy material or stainless steel material, as shown in FIG. Annular piezoelectric elements 24 and 25 made of PZT or barium titanate are mounted on the part 22 with an electrode 26 sandwiched between them, and a mass body made of brass material which is an acceleration-to-force conversion member is mounted on the element 24. 27 are mounted on a shaft, and these are coaxially and tightly pressed and held by a nut 28, and the base 23 has the above-mentioned elements 24, 25,
The electrode 26 and the nut 28 are housed in a case 29 made of the same material as the base 23 to prevent foreign nozzles. In order to directly fix this base 23 to the living bone B, a needle member 2 is attached to the lower end of the base 23 as described above.
0 (as an example, a needle member with a diameter of 1.5 to 2 mm) is attached, and permanent magnets 230 and 200 are provided between the two, and their magnetic coupling allows attachment and detachment. In the above embodiment, the piezoelectric elements 24 and 25 are preferably polarized in the thickness direction, and are arranged in an opposing relationship such that when the nut 28 is tightened, a positive output is generated in the electrode 26 in the same phase. The mass body 27 should be light when measuring the pick-up frequency up to a high frequency range (about 20KHz), and should be made light to the minimum required frequency range (up to 5KHz).
When focusing on sensitivity by ensuring
Around 10g is sufficient for the purpose of this invention. Note that the symbols 101, 201, and 301 in FIGS. 2 and 3 indicate lead wires. Also, since the pickup 3 is exactly the same as the pickup 2, illustration thereof is omitted, and only the corresponding reference numerals are given in FIG. As mentioned above, the impulse exciter 1 and the vibration pickup 2,
In the direct bone conduction mode in which the fourth bone B is directly fixed to the living bone B, the fourth
The transducer 14 and the bases 23, 33 are placed directly on the skin S as shown in Figure A, but if non-invasive diagnosis is desired, the transducer 14 and the bases 23, 33 are placed directly on the skin S without using the needle members 19, 20, 30. It is also possible to adopt a skin conduction mode in which the device is pressed and fixed. At this time, the skin S is a soft tissue and has large viscoelasticity, and it is known that these parameters exhibit ^nonlinearity . When measured by applying a pressure of ² or more,
It was demonstrated that the viscoelastic parameters of the skin S showed a constant value, and the reproducibility of the measured values was good. The instructions for using the impulse exciter 1 and the vibration pickups 2 and 3 are as follows: In both the direct bone vibration mode and the skin conduction mode, the pickups 2 and 3 are placed on either side of the fracture site b, as shown in Figure 4. Specifically, in the case of a jaw fracture, it is desirable to keep the distance d ₂ at a distance of 2 mm to several mm in the case of direct bone vibration mode, and several cm in the skin conduction mode, near one of the pick-ups 2 and 3. Then, the vibrator ₁ is placed at a position d1 that is farther away from the pickups 2 and 3. The vibrations propagated from the vibrator 1 to the pick-ups 2 and 3 are vibrations perpendicular to the longitudinal direction (axis) of the bone, and are mechanically given as bending waves (transverse waves). The shaker 1 and the pick-ups 2 and 3 are fixed to the skin S in the normal direction. The impulse excitation system and bone vibration pickup system are
The details of PU may be understood.

Next, talking about the analysis display system A, which is the core of this device, this system A is roughly composed of a display section 4, an electronic circuit 5, and a group of display selection buttons 6.
This display section 4 includes a CRT display, an oscillograph display, and other displays by a printer (not shown), and a display selection button group 6... is a button for driving an electronic circuit to select and display various displays as described later. It is. A block diagram of the electronic circuit is shown in FIG.
As shown in the figure, a clock pulse from a clock oscillation circuit 501 is converted to an impulse excitation source (conversion unit) 502.
The frequency is divided and converted to form an impulse signal, and this signal is amplified by the impulse excitation amplifier 11 shown in FIG. 1 to drive the vibrator 1 shown in FIG. 1 to apply an impulse to the living bone B. Make a shake. After the bone vibrations thus obtained are received by the pick-ups 2 and 3, an amount of electricity (charge) proportional to the speed of the bone vibrations is transferred to the charge amplifiers 21 and 31 (the fifth
(corresponding to FIGS. 503 and 504), is further amplified to an appropriate level by amplifiers 505 and 506, and is converted to a digital signal at a predetermined clock frequency by A/D converters 507 and 513.
It is stored in RAM1 memory 509 via PIO (Parallel I/O Circuit) 508. An FFT program (described later) is stored in the ROM memory 510 in advance. In addition to RAM 1 memory 509
A RAM 2 memory 511 is also provided, and a group of display selection buttons 6 are provided on the surface of the main body 10, one of which can be selectively pressed.
In addition, CTC (Counter Timer Circuit) in Figure 5
512 is a counter timer circuit that generates time counts and A/D conversion timing signals.

Display selections and their contents during measurement are as follows.

() When the FFT button is pressed, the data in the RAM1 memory 509 is subjected to FFT (fast Fourier transform) according to the FFT program stored in the ROM memory 510 to obtain each frequency spectrum.
Calculated by the CPU, the quotient is the frequency spectrum obtained from the pick-up 2 near the vibrator 1 as the denominator and the frequency spectrum obtained from the pick-up 3 far from the vibrator 1 as the numerator, that is, the propagation characteristics due to the fracture site b. After calculating by CPU and storing the result in RAM2 memory 511, SIO (Serial I/O
circuit) 512 to the video signal conversion and character generator circuit 513.
The image shown in FIG. 6A is displayed on the CRT display device 515, that is,
For diagnosing mandibular fractures in humans, the horizontal axis frequency ranges from 2 to 2.
The frequency is 2.5KHz, and the vertical axis is usually displayed as a decibel scale (a value proportional to the logarithm of the amplitude ratio). As an example, in the case of mandibular fracture and skin conduction mode, a high-frequency inflection point (cut-off point) of the propagation characteristic appeared at 500 to 700 Hz immediately after the fracture, but 4 to 700 Hz.
After 6 weeks have passed and fracture site B has completely healed,
The inflection point moved from 1500 to 1800Hz.

() When the WAVE button is pressed, a voltage proportional to the vibration of the RAM1 memory 509 is displayed as shown in FIG. 6B. That is, the horizontal axis represents time and the vertical axis represents amplitude (voltage). In this case, the display start point (trigger point) is the impulse drive source 5 in Figure 5.
It is preferable to display the time axis based on the impulse voltage generated by 02, and the time axis should be 400 to 500 μs at full scale in direct bone conduction mode, and several ms at full scale in skin conduction mode. Dot one of the input voltage waveforms proportional to the vibrations in 2 and 3.
When displayed, the two waveforms can be clearly contrasted.

() When the RESULT button is pressed, the three calculated values as shown in Figure 6C, that is, the above-mentioned
The waveform amplitude ratio (AB/AA), slope ratio (SB/SA), and waveform rise time difference t in the waveform obtained using the WAVE button are stored in RAM1 memory 50.
The CPU calculates the distance between the vibration pickups 2 and 3 from the data in step 9 (d ₂ in Figure 4).
The quotient obtained by dividing t by t is expressed as VEL, and these are displayed as shown in Figure 6 (c). According to clinical experiments, these values gradually increase in proportion to the progress of fracture healing, and are characterized by a constant value when the fracture is completely healed. As an example, in direct fracture conduction mode _d2 is approximately 5 cm
In the case of , AB/AA≒0.2 at 1 week after fracture,
Although SB/SA≒0.25 and VEL=d ₂ /t≒1900 m/s, 6 weeks after reaching a complete cure state,
AB/AA≒0.4, SB/SA≒0.55, VEL= _d2 /
It showed a value of t≒2300m/s.

() When the RESULT REF button is pressed together with the STORE 1 and 2 buttons, the previous
RESULT (POST) and this RESULT (NEW)
are displayed simultaneously in contrast. similarly
When the FFT REF button is pressed together with STORE1 and STORE2 buttons, the previous amplitude propagation characteristics and the current one are
The waveforms appear as shown in the solid line and broken line waveforms in FIG. In this case, the broken line indicates that the cure is more advanced.

In FIG. 6, CH1 and 2 represent the plugs of the pickups 2 and 3, IMPULSE represents the plug of the vibrator 1, and POWER represents the power button.

I think you have understood the instructions for using the device of this invention from the above explanation, but to summarize and restate using a mandibular fracture as an example, in the afternoon when a patient with a mandibular fracture comes to the oral surgery department, the surgeon , Palpation and X-ray photography are performed to determine the extent of the fracture, and the upper and lower teeth are fixed using wire, sheen, etc. between the lower jaw and the parietal region to prevent the fracture site from moving. Using the device of this invention, impulses are applied to the mandible, including the fracture site, and the propagation characteristics and waveform of the impulse vibrations are displayed and measured.If necessary, healthy symmetrical parts of the patient without fractures are measured for comparison. and press the STORE 1 and 2 buttons for each data.
Store it in RAM1 memory. The fracture site heals naturally over time, but as a periodic diagnosis, use this device to measure the propagation characteristics, waveforms, etc., and compare them with the propagation characteristics, waveforms, etc. of the healthy symmetric site immediately after the fracture. Is the inflection point shifting to the higher range?
By observing whether the amplitude ratio, slope ratio, and velocity are increasing, or whether the inflection point is lower and farther away than in the healthy region, and whether the amplitude ratio, slope ratio, and velocity are small. It is possible to measure the state and extent of fracture healing. When the cure is completed, the inflection point of the propagation characteristics no longer shows a high-frequency shift, and the values of the amplitude ratio, slope ratio, and velocity are saturated, and the propagation characteristics and propagation at the healthy symmetric site are no longer observed. It remains at the same level as the waveform curve and value, and this is used as the criterion for determining the completion of treatment.

Although the description has been given using the mandible as an example, it goes without saying that the present invention can be broadly applied to measuring the progression of disease in fractures of human bones other than the mandible.

In this way, the device of this invention regards the human bone, including the fracture site, as a mechanical model, and the impulse vibration applied to the bone propagates as a bending wave. It is possible to quantitatively diagnose the status and degree of fracture healing by observing its characteristics, so (a) it is possible to immediately determine whether fracture healing is going well or poorly, and (b) it can be used to measure a wide range of fracture diseases. In particular, when iliac bone is transplanted for prosthesis of jaw fractures, it can be used not only to diagnose the degree of integration with the transplanted bone, but also to diagnose bone abnormalities other than fractures, such as bone tumors such as osteosarcoma and rheumatoid arthritis. (c) X-ray photography can also be used to diagnose fracture sites when it is not possible to clearly determine whether or not there is a fracture due to shadows from multiple images; (d) Skin The conduction mode allows for non-invasive and moderate judgments, while the direct bone conduction mode allows precise diagnosis of small fractures such as cracks and cracks, incomplete fracture sites, and bone abnormalities. Because of the impulse vibration, there is no harm to living organisms... According to the present invention, excellent effects can be obtained that can eliminate the conventional problems.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram showing an example of diagnosing mandibular fracture using the device of the present invention, Fig. 2 is a partial longitudinal exploded view of the vibration pickup in the device of the present invention, and Fig. 3 is the same impulse exciter. Similar figure, 4th
Figure A is a vertical sectional view of the main part showing the fixing relationship between the vibrating pickup and the bone, Figure 4B is a similar view of Figure 4 in another embodiment, Figure 5 is a block diagram of the device of the present invention, Figure 6A, B, C, and D respectively show front views showing aspects of the measurement display of the present invention. Explanation of symbols, 1... Impulse exciter, 2, 3
... Vibration pickup, 4... Memory means, 5
...Display means, 6...Display selection button group, 19,2
0, 30...Needle member, B...Living bone, b...Fracture site, _d2 ...Distance, S...Skin.

Claims (1)

[Claims for Utility Model Registration] 1. A permanent magnet 13 is fixed in a hollow cylindrical case 12, and a cylindrical vibrator 14 is connected concentrically with this magnet 13, and a magnetic core 15 and a drive coil 16 vibrate. Located close to child 14,
Further, plate springs 17 and 18 for restoration are attached to the vibrator 14, and the living bone B including the fracture site 6 is
an impulse exciter 1 that excites mechanical impulse vibrations as bending waves from the surface of
Piezoelectric elements 24, 25 with an electrode 26 sandwiched therebetween and a mass body 27 are mounted on the casing 29, and these are coaxially tightly pressed and held by a nut 28 and housed in a case 29. Two or more vibration pickups 2 and 3 that receive bone vibrations from the human bone B, a memory means 4 that stores vibration waveforms caught by the pickups 2 and 3 as electrical signals, and vibrations caught by the pickups 2 and 3. A fracture measuring device comprising display means 5 for displaying a waveform as a voltage waveform on a CRT. 2. The device according to claim 1, wherein the impulse vibrator 1 and the vibration pickups 2 and 3 are directly fixed in contact with the living bone B via the needle members 19, 20, and 30, respectively. 3. The device according to claim 1, wherein the impulse vibrator 1 and the vibration pickups 2 and 3 are pressed against and fixed on the skin S on the bone. 4 Utility model registration claim 1 further including display selection button group 6 for selecting display means 5...
Apparatus described in section.