JP6924984B2 - Bone hardness measuring instrument - Google Patents

Description

The present invention relates to a bone hardness measuring device for measuring the hardness of bone such as cancellous bone.

Conventionally, for example, in medical surgery involving sternum incision, a plurality of pairs of connecting holes are formed in the cancellous bone at the cut surface of the sternum and the sternum in order to fix and adhere the sternum and the sternum cut at the time of closing the chest. , A method is used in which a substantially rod-shaped sternum fixing material is inserted into each of the plurality of pairs of connection holes to position the sternum stalk and sternum body and bring them into contact with each other on a cut surface (Patent Document 1).

Here, when the patient is elderly, the bone density of the cancellous bone and bone marrow often decreases and softens due to osteoporosis and the like, and there is a problem that the sternum fixing material as described above cannot firmly support the bone. The present inventors have separately invented and applied for a patent application for a corrugated sternum fixing material that can more reliably close a sternum having a reduced bone density.

Japanese Unexamined Patent Publication No. 63-68155

However, although the above-mentioned corrugated sternum fixing material can fix the sternum more reliably, the cost such as treatment time and medical expenses is high, so it is properly used according to the condition such as the hardness of the cancellous bone and bone marrow of the patient. However, until now, since there was only a substantially rod-shaped sternum fixing material and there was no choice, it was not necessary to evaluate the hardness of bone such as cancellous bone.

On the other hand, since the present inventors have invented a new form of sternum fixing material, it is preferable to select an appropriate sternum fixing material according to the condition of the bone such as cancellous bone of the patient. , The present invention has been completed.

That is, the present invention pays particular attention to the process of sternum fixation, and can measure the hardness of bones such as cancellous bone and bone marrow by a simple operation. The purpose is to provide a measuring instrument.

The present invention
Approximately rod-shaped convex part and
And the convex portion and connected to said stress detection reference portion, the convex portion of said stress detection reference stress detector which Ru stressed in response to the displacement with respect to unit,
Be provided with a, and the stress display unit for displaying the stress in the stress detector,
Provided is a bone hardness measuring instrument for cancellous bone or bone marrow.

In other words, the above-mentioned bone hardness measuring instrument of the present invention is a stress detection standard that supports a convex portion that is directly in contact with a bone such as cancellous bone or bone marrow and a convex portion that can be displaced in the axial direction. A stress detection unit composed of, for example, a spring having a predetermined stress is provided in the stress detection reference unit, and is connected to the convex portion and the stress detection reference unit. ing.

With this configuration, the convex portion and the stress detection reference unit is displaced axially relative to one another, in order to further predetermined stress is given to the displacement, when the protrusion is pressed into the bone, the stress The convex part moves into the stress detection reference part according to the resistance force of the bone against. By displaying the amount of movement on a stress display unit provided with a scale or the like, it is possible to measure the resistance force of the bone.

In bone hardness measuring instrument of the invention described above, the resistance of the bone by detecting the displacement of the convex portion and the stress detection reference unit per stress or constant stress per movable length of the stress detection reference unit It is desirable to have a detection mechanism.

The Hardness measuring apparatus of this invention having such a structure, pressure contact with or in press measuring surface to the bone to be positioned at the front end side of the stress detecting the reference portion, the resistance of the bone at the time of the state (of the protrusion stress "Stress per movable length" that measures the amount of movement into the detection reference part ) and the resistance force of the bone (stress detection of the convex part) in that state by pressing the convex part against the bone while maintaining a constant force measuring the amount of movement) to the reference portion as a "displacement of per stress", it is possible to detect the resistance of the bone by detecting either.

In the above-mentioned bone hardness measuring instrument of the present invention, it is desirable that the range of stress per detectable movable length is 0.05 to 1.50 MPa.

The bone hardness measuring instrument of the present invention having such a configuration, when detecting the "stress per movable length", 0.05 to stress when the measurement surface of the stress detecting the reference portion is brought into contact with the bone by setting the range of 1.50MPa, while preventing the destruction of excessive bone by the measurement, it is possible to detect the stress of sufficient range as the measurement of the resistance of the bone.

In the bone hardness measuring instrument of the invention described above, it displacement of the range of the convex portion and the stress detection reference unit per constant stress is 1 to 10 mm, is desirable.

The bone hardness measuring instrument of the present invention having such a configuration, when detecting a "displacement of per stress", while preventing breakage due to invasion of foreign matter into excessive bone by measuring (convex portion), bone it is possible to detect a sufficient displacement of the measurement of the resistance force.

Further, in the bone hardness measuring instrument of the present invention, it is desirable that the radial cross-sectional area of the convex portion is 1 to 13 mm ^2.

In the bone hardness measuring instrument of the present invention having such a configuration, by setting the radial cross-sectional area ^{of the convex portion to 1 to 13 mm 2} , it is possible to more reliably prevent the convex portion from entering the micropores of the cancellous bone. It can be placed within the width of the cancellous bone to avoid invasion of the cortical bone.

Further, it is desirable that the bone hardness measuring instrument of the present invention includes a grip portion.

In the bone hardness measuring device of the present invention having such a configuration, the practitioner operates the bone hardness measuring device using the grip portion to securely fix the bone hardness measuring device and prevent accidental dropping, and easily handle the bone hardness measuring device. be able to.

It is a top view explaining the outline of the bone hardness measuring instrument 1 in this embodiment. 2A and 2B are front views showing the tip end side of the external housing 11, and FIG. 2B is a front view showing only a part of the external housing 11. 2 (c) is a rear view showing the rear end side of the outer housing 11. 3A is a rear view showing the rear end side of the internal housing 13, and FIG. 3B is a side view of the internal housing 13. 3 (c) is a cross-sectional view of the internal housing 13 as viewed from the side surface. 4A is a rear view showing the rear end side of the fitting lid 19, and FIG. 4B is a partial view of the fitting lid 19. It is a side view which looked at only the cross section. 5 (a) is a plan view of the grip portion 9, and FIG. 5 (b) is a side view of the grip portion 9. It is a perspective view which showed the structure of the stress detection reference part 3. It is a schematic diagram which shows the state which presses the convex part 5 against the cancellous bone 101. It is a schematic diagram which shows the state which shows the hardness of the cancellous bone 101 on the stress display part 7. 9A is a diagram illustrating the structure of the bone hardness measuring instrument 61, FIG. 9A is a schematic view showing the configuration of the bone hardness measuring instrument 61, and FIG. 9B is a cross section of the bone hardness measuring instrument 61. It is a figure. It is a schematic diagram which shows the hardness measuring method using the bone hardness measuring instrument 61.

Hereinafter, a typical embodiment of the bone hardness measuring instrument 1 according to the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to those shown in the drawings, and each drawing is for conceptually explaining the present invention. Therefore, the dimensions, ratios or numbers are exaggerated as necessary for easy understanding. Alternatively, it may be abbreviated. Further, in the following description, the same or corresponding parts may be designated by the same reference numerals, and duplicate description may be omitted.

1. 1. Outline of Bone Hardness Measuring Instrument 1 An outline of the bone hardness measuring instrument 1 of the present embodiment will be described with reference to FIG. FIG. 1 is a plan view illustrating an outline of the bone hardness measuring instrument 1 in the present embodiment. The bone hardness measuring device 1 of the present embodiment is a medical instrument that mainly measures the hardness of the cancellous bone 101 in human bones. For example, in an operation involving sternum joining, the hardness of the cancellous bone 101 of the bone to be joined is By measuring, it assists in the selection of the optimal sternum fixation material to be used for joining.

The bone hardness measuring instrument 1 of the present embodiment includes a stress detection reference unit 3 which is a main body, a convex portion 5 which directly contacts the cancellous bone 101, a stress display unit 7 which displays the measured hardness, a doctor, and a doctor. It is composed of a gripping portion 9 for a medical worker or the like to grip the bone hardness measuring instrument 1.
In the present embodiment, the stress display unit 7 is composed of the indicator unit 7A and the scale 7B, but an electronic load cell or the like may be used. In addition, the sternum is used by making a median sternotomy, but if the chest is opened widely, the burden on the living body will increase, so it is preferable to make the chest small. Therefore , the axis of the entire bone hardness measuring device used between the opened bones. The length in the direction is preferably short. Considering the insertion of an intrathoracic measuring device, it is preferably within 10 cm, and when using the method in which the thumb is attached to the rear end of the measuring device, it is preferably within 7 cm.

2. Configuration of Stress Detection Reference Unit 3 Next, the structure of the stress detection reference unit 3 will be described in detail with reference to FIG. FIG. 6 is a perspective view showing the configuration of the stress detection reference unit 3. The stress detection reference unit 3 is the main body of the bone hardness measuring instrument 1 of the present embodiment, and is configured by assembling a plurality of parts described later as shown in FIG.

The components are the outer housing 11 arranged on the outermost side of the stress detection reference unit 3, the inner housing 13 slidably fitted inside the outer housing 11, and the rear of the outer housing 11. A fitting lid 19 that is screw-fitted to the end, and a spiral spring 15 and a washer 17 that are arranged between the fitting lid 19 and the internal housing 13.

In the present specification, the internal housing 11 and the spring 15 are collectively referred to as a “stress detection unit”, but the type and installation location of the spring 15 may be various aspects as long as the effects of the present invention are not impaired. Can be taken.

Further, the grip portion 9 described later is arranged between the outer housing 11 and the fitting lid 19, and is sandwiched and fixed between the two parts.

3. 3. Structure of External Housing 11 Next, the structure of the external housing 11 will be described in detail with reference to FIGS. 2A, 2B, and 2C. 2 (a), (b), and (c) are views for explaining the structure of the outer housing 11, and FIG. 2 (a) is a front view showing the tip end side of the outer housing 11, and FIG. (B) is a side view in which only a part of the outer housing 11 is viewed in cross section, and FIG. 2 (c) is a rear view showing the rear end side of the outer housing 11.

As shown in FIGS. 2A, 2B, and 2C, the outer housing 11 is a substantially cylindrical part having a hollow layer 21 inside, and has substantially the same dimensions as its own inner diameter on the rear end side. It has an opening 23, and has a convex opening 25 having a size obtained by adding a predetermined clearance to the diameter of the convex 5 at the center on the tip side.

Two grooves 27, which are movable ranges of the indicator portion 7A included in the inner housing 13, are arranged on the side surface, and the two grooves 27 are arranged at an angle θ around the radial center of the outer housing 11. ing. Further, the two grooves 27 have no edge on the rear end side and have a feature that the scale 7B is printed. The angle θ is preferably in the range of 100 degrees to 180 degrees, more preferably 120 degrees.

Further, a housing-side screw 33 spiraling around the radial center is provided in a predetermined range on the side surface of the outer housing 11 on the rear end side. The housing-side screw 33 is used when the outer housing 11 and the fitting lid 19, which will be described later, are screw-fitted.

On the tip side, the central portion is raised to the outer side, and the convex opening 25 is arranged at the center of the raised portion. As a result, the vicinity of the convex portion opening 25 can be easily formed to be thick, and the sliding support range of the convex portion 5 can be made longer. Further, since the hollow layer 21 side of the convex portion opening 25 is provided with a substantially truncated cone-shaped invitation notch 30, the convex portion 5 is easily attracted into the convex portion opening 25 to be a hollow layer. The internal housing 13 can be fitted inside the 21.

The measurement surface 59 is a surface that comes into contact with the bone surface. The diameter is 6 to 10 mm, which is slightly larger than the width of the cancellous bone, and the measurement surface 59 abuts on the cortical bone so that the entire measurement surface 59 is not buried in the cancellous bone. Since the measuring surface 59 is raised, a gap is created between the bone surface and the tip of the outer housing 11 by the amount of the raising, and the field of view can be secured. Therefore, the bone surface and the measuring surface 59 come into contact with the bone surface. It is easier to confirm that it has been completed.

In particular, the edge portion on the tip side may come into contact with each part of the patient during the treatment, so it is preferable to perform chamfering or the like.

4. Structure of Internal Housing 13 Next, the structure of the internal housing 13 will be described in detail with reference to FIGS. 3A, 3B, and 3C. 3 (a), (b), and (c) are views for explaining the structure of the internal housing 13, and FIG. 3 (a) is a rear view showing the rear end side of the internal housing 13. 3 (b) is a side view of the inner housing 13, and FIG. 3 (c) is a cross-sectional view of the inner housing 13 as viewed from the side direction.

As shown in FIGS. 3A, 3B, and 3C, the internal housing 13 is a substantially cylindrical part that supports the convex portion 5, and includes a hollow layer 29 inside. Further, the rear end side is provided with an opening 31 having substantially the same dimensions as the inner diameter of the inner housing 13, and the front end side is provided with a columnar protrusion having a predetermined outer diameter, and a convex portion is provided at the center of the protrusion. The end of 5 is fixed. It is desirable that the convex portion 5 is fixed in parallel with the axial direction of the inner housing 13.

When the inner housing 13 is inserted into the hollow layer 21 of the outer housing 11, it is preferable that the inner housing 13 can slide smoothly in the axial direction without rattling. Therefore, it is desirable that the outer diameter of the inner housing 13 is slightly smaller than the inner diameter of the outer housing 11 to provide a predetermined clearance. The clearance is preferably in the range of, for example, 0.01 mm to 0.5 mm for reasons such as slidability and manufacturing.

Two substantially elongated columnar indicating portions 7A are arranged on the side surface of the inner housing 13, and the two indicating portions 7A are arranged at an angle θ with respect to the radial center of the inner housing 13. There is. The angle θ is preferably in the range of 100 degrees to 180 degrees, more preferably 120 degrees, as in the groove 27 of the outer housing 11. The arrangement angle θ of the two grooves 27 in the outer housing 11 and the arrangement angle θ of the two support portions 7A in the inner housing 13 are always the same.

The convex portion 5 is formed in a substantially rod shape and having a predetermined length. If the cross-sectional area in the radial direction is too small, it will pass through the fine pore diameter of the cancellous bone 101, and if it is too large, it will exceed the width of the cancellous bone 101. Therefore, it is preferably 1 mm to 13 mm 2. When the convex portion 5 has a rod shape, the diameter is preferably 1 mm to 4 mm. The protruding length of the convex portion 5 after assembly is preferably 1 to 10 mm. If it is too short, an error will be large during measurement detection, and if it is too long, it will penetrate the cancellous bone and reach the cortical bone, making accurate measurement impossible.

5. Structure of Fitting Cover 19 Next, the structure of fitting lid 19 will be described in detail with reference to FIGS. 4A and 4B. 4 (a) and 4 (b) are views for explaining the structure of the fitting lid 19, and FIG. 4 (a) is a rear view showing the rear end side of the fitting lid 19, which is shown in FIG. 4 (a). b) is a side view of only a part of the fitting lid 19 as a cross-sectional view.

As shown in FIGS. 4A and 4B, the fitting lid 19 is a substantially cylindrical part, which has an opening 35 on the front end side and a diameter smaller than that of the opening 35 on the rear end side. Hole 37 is provided. Further, the inner surface on the tip end side of the side surface is provided with a lid-side screw 39 that fits with the housing-side screw 33 included in the outer housing 11.

Further, uneven patterns 41 composed of protrusions and the like having various shapes are regularly or irregularly arranged on the side surface, so that the outer housing 11 and the fitting lid 19 can be easily screw-fitted. ..

6. Structure of the grip portion 9 Next, the structure of the grip portion 9 will be described in detail with reference to FIGS. 5 (a) and 5 (b). 5 (a) and 5 (b) are views for explaining the structure of the grip portion 9, FIG. 5 (a) is a plan view of the grip portion 9, and FIG. 5 (b) is a view of the grip portion 9. It is a side view of.

As shown in FIGS. 5A and 5B, the grip portion 9 is a substantially spatula-shaped part, and when the practitioner grips the bone hardness measuring instrument 1 of the present embodiment, the bone hardness measuring device 1 of the present embodiment is reliably held in the palm. It has a shape that can be fixed and easily handled. First, as a planar feature, the wide waist portion 43, the narrow neck portions 45 and tail portions 47 arranged in front of and behind the waist portion 43, and the stress detection reference portion 3 arranged via the neck portion 45 are fitted. The part is separated from the head 49.

The neck portion 45, the waist portion 43, and the tail portion 47 are connected to each other by a smooth curve along the width, the head portion 49 is substantially circular, and a fitting hole for fitting with the stress detection reference portion 3 in the center. 51 is equipped.

Further, on the inner side of the fitting hole 51, two protrusions 53 that fit into the two grooves 27 of the outer housing 11 are arranged, and the two protrusions 53 are the center of the fitting hole 51. Is arranged at an angle θ around the axis (arranged symmetrically toward the neck 45 side).

The angle θ is preferably in the range of 100 degrees to 180 degrees, more preferably 120 degrees, as in the groove 27 of the outer housing 11. The arrangement angle θ of the two grooves 27 in the outer housing 11 and the arrangement angle θ of the two protrusions 53 in the grip portion 9 are always the same.

As a lateral feature, the waist 43, the neck 45, and the tail 47 are composed of a smooth portion 55 and a distorted portion 57 within a predetermined range, and the rearmost end of the tail 47 and the tip of the neck 43. Is distorted in the same direction. Although the head 49 is connected to the neck 43, it is configured to be substantially parallel to the smooth portion 55 and is not distorted.

Since the grip portion 9 has the above-mentioned characteristics, the practitioner grips the tail portion 47 in a narrow space around the palm bottom and the little finger while grasping the lumbar region 43, and further easily grips the neck portion 45 with the thumb and index finger. be able to. Further, due to the side shape composed of the smooth portion 55 and the distorted portion 57, the rearmost end of the tail portion 47 and the tip end of the neck portion 43 can be caught in the hands of the practitioner, and more securely gripped to prevent falling off. Is possible.

The outer housing 11, the inner housing 13, the spring 15, the washer 17, the fitting lid 19, and the grip portion 9 are preferably made of a material having corrosion resistance.

7. Structure of Spring 15 and Washer 17 Next, the structure of the spring 15 and washer 17 will be described. The spring 15 is a general cylindrical compression coil spring having a predetermined stress, and it is preferable to determine the material, wire diameter, number of turns, pitch, and the like. Since the spring 15 is inserted into the hollow layer 29 of the inner housing 13, the outer diameter is set to be smaller than the inner diameter of the inner housing 13.

The washer 17 is a component arranged between the spring 15 and the fitting lid 19, and is for forcing the spring 15 to expand and contract in the axial direction. The washer 17 is a thick flat washer having an outer diameter substantially the same as the outer diameter of the spring 15, and one surface of the washer 17 has a predetermined taper from the outer diameter to the inner diameter.

Since such a configuration is provided, when the surface having the taper is arranged toward the spring 15, the surface having the taper enters the inner diameter of the spring 15, and the washer 17 and the spring 17 are fitted and fixed. NS.

In the above uses the washers 1 7 describes a manner of reducing the frictional resistance between the spring 15 and the Hamagofuta 19. Incidentally, it omitted the washers 1 7, can be used to adjust the initial length of the spring. In this case, it is preferable to reduce the number of parts and facilitate cleaning and assembly.

8. Assembly of Bone Hardness Measuring Instrument 1 Subsequently, the method of assembling the bone hardness measuring instrument 1 of the present embodiment will be described with reference to FIG. 6 again. First, the shaft of the outer housing 11 and the shaft of the inner housing 13 are aligned, and the inner housing 13 is inserted into the hollow layer 21 of the outer housing 11 from the convex portion 5 side. More specifically, by inserting the protruding portion 5 in the protrusion opening 25 of the outer housing 11, the housing 1 3 to the housing 13 is completely housed in the hollow layer 21 of the outer housing 11 The rear end side is pressed toward the outer housing 11. At this time, it is necessary to insert the two indicating portions 7A of the inner housing 13 into the two grooves 27 of the outer housing 11 at the same time.

Next, the spring 15 is inserted into the hollow layer 29 of the inner housing 13, the washer 17 is brought into contact with the tapered surface toward the rear end side of the spring 15, and the grip portion 9 is further attached to the tail portion 47 of the tail portion 47. The fitting hole 51 of the grip portion 9 is put on the rear end side of the outer housing 11 and fitted with the distorted end end facing the tip side of the outer housing 11. When fitting the grip portion 9 and the outer housing 11, the two protrusions 53 included in the fitting hole 51 are surely inserted into the two grooves 27 provided in the outer housing 11. warn.

Subsequently, the opening 35 of the fitting lid 19 is made to face the outer housing 11 side while aligning the radial axes of the outer housing 11 and the fitting lid 19. The housing side screw 33 arranged on the rear end side of the outer housing 11 and the lid side screw 39 arranged on the opening 35 of the fitting lid 19 are screw-fitted and the rear end side of the outer housing 11 is fitted. The fitting lid 19 is fixed to.

After completing the above procedure, it is confirmed that there is no rattling in the fitting of each part, and the assembly of the bone hardness measuring instrument 1 of the present embodiment is completed.

9. Method of Measuring Hardness Using Bone Hardness Measuring Instrument 1 Next, a method of measuring hardness of the bone hardness measuring instrument 1 in the present embodiment will be briefly described with reference to FIGS. 7 and 8. FIG. 7 is a schematic view showing a state in which the convex portion 5 of the bone hardness measuring instrument 1 is pressed against the cancellous bone 101, and FIG. 8 shows a state in which the hardness of the cancellous bone 101 is displayed on the stress display unit 7. It is a schematic diagram.

First, the practitioner grips the bone hardness measuring device 1 of the present embodiment while gripping the grip portion 9 with the thumb of the gripper attached to the rear end portion of the fitting lid 19. At this time, the thumb of the gripper is placed on the extension of the substantially center of the convex portion 5 on the rear side in the axial direction so that the force of the thumb can be linearly transmitted to the convex portion 5 in a gripping state. ..

Next, the tip of the convex portion 5 is brought into contact with the surface of the cancellous bone 101 substantially perpendicularly, and stress is detected on the cancellous bone 101 side until the measurement surface 59 of the outer housing 11 comes into contact with the surface of the cancellous bone 101. Press the reference portion 3. As a result, the cancellous bone 101 generates a reaction force (resistance force) against the pressing of the convex portion 5 according to its own hardness and state, and resists the pressing of the convex portion 5.

When the force pressing the stress detection reference portion 3 of the practitioner and the reaction force of the cancellous bone 101 exceed the stress of the spring 15, the spring 15 is compressed in the axial direction, and the stress detection reference while accommodating the convex portion 5 inside. Part 3 approaches the cancellous bone 101 side. At this time, the inner housing 13 slides and moves to the rear end side in the axial direction inside the outer housing 11 together with the convex portion 5, and the instruction portion 7A provided in the inner housing 13 is accompanied by the sliding movement of the outer housing 11 to the rear end side in the axial direction. The groove 27 is moved (the position of the scale 7B pointed to by the indicator 7A changes).

By continuing to press the stress detection reference unit 3, the measurement surface 59 arranged at the tip of the outer housing 11 comes into contact with the cancellous bone 101, and the stress display unit 7 (scale 7B pointed to by the indicator unit 7A) in that state. By reading the position), the hardness measurement of the cancellous bone 101 is completed. If the hardness of the cancellous bone 101 is high, the amount of insertion of the convex portion 5 into the cancellous bone 101 is small, and if the hardness is low, the amount of insertion is large. Therefore, the display of the stress display portion 7 changes depending on the hardness of the cancellous bone 101.

The hardness measurement using the bone hardness measuring device 1 of the present embodiment provides a hole in the cancellous bone 101 into which the convex portion 5 is inserted. However, by aligning the measurement position with the planned insertion position of the joining pin, It can also be used as a pilot hole for the joining pin.

As described above, a typical embodiment of the present invention (a mode in which the stress detection unit detects the stress per movable length of the stress detection reference unit ) has been described with reference to the drawings, but the present invention describes these embodiments. There are other improvements and modifications as long as they do not deviate from the spirit and teachings of the claims. It is easily understood by those skilled in the art that all such improvements and modifications are included in the technical scope of the present invention.

For example, it may be a mode for detecting the resistance of the bone by the stress detecting section detects displacement of the convex portion and the stress detection reference unit per constant stress. The bone height measuring device of the present invention in that case will be described later as a bone hardness measuring device 61 according to a modified example in which the third housing 63 is provided on the outermost side.

10. Bone hardness measuring instrument 61
The structure of the bone hardness measuring instrument 61 according to the modified example will be described in detail with reference to FIGS. 9A and 9B. 9 (a) and 9 (b) are views for explaining the structure of the bone hardness measuring device 61, and FIG. 9 (a) is a schematic view showing the configuration of the bone hardness measuring device 61, which is a schematic view showing the configuration of the bone hardness measuring device 61. b) is a cross-sectional view of the bone hardness measuring instrument 61.

As shown in FIG. 9A, the bone hardness measuring instrument 61 includes a cylinder 63A, a lid 63B, and a reference portion 65 having substantially the same configuration as the bone hardness measuring instrument 1 described in detail above. Has been done. The cylinder 63A is a substantially cylindrical part, and is provided with a hollow layer 67 inside, and a convex portion opening 71 for inserting a convex portion 69 included in the reference portion 65 is provided on the tip side thereof. An opening 73 for inserting the reference portion 65 is provided on the end side. Since the measurement reference surface 75 provided with the convex opening 71 is in direct contact with the cancellous bone 101, it is desirable that the measurement reference surface 75 be formed smoothly without unevenness.

Around the inside of the opening 73, a cylinder-side screw 77 for screw fitting with a lid 63B, which will be described later.
It has. Further, the hollow layer 67 is provided with a tapered portion 79 that is inclined from the rear end side to the front end side, and has a structure in which the reference portion 65 is guided to the hollow layer 67 at the time of assembly and can be easily inserted.

A slit 89 is provided on the side surface of the cylinder 63A with a predetermined length in the axial direction from the rear end side, and a movement amount display unit 91 on which a scale or the like is printed is provided in the vicinity of the slit 89.

The lid 63B is generally composed of a flange portion 81 and a fitting portion 83 to be inserted into the cylinder 63A. The collar portion 81 is an annular plate part having a circular opening 87 inside, and is a fitting portion. Reference numeral 83 denotes a cylindrical part. The flange portion 81 and the fitting portion 83 are arranged in parallel and concentrically in the radial direction of both, and are in contact with each other and are joined. The diameter of the opening 87 has a predetermined dimensional difference with respect to the inner diameter of the fitting portion 83, and the diameter of the opening 87 is smaller than the inner diameter of the fitting portion 83. Further, a lid side screw 85 for fitting with the cylinder 63A is provided on the side surface of the fitting portion 83.

The reference portion 65 has substantially the same configuration as the bone hardness measuring instrument 1 according to the above-described embodiment, and includes a collar portion 93 without a grip portion 9. The collar portion 93 is an annular plate-shaped protrusion provided on the side surface of the reference portion 65, and the outer diameter dimension is smaller than the inner diameter of the fitting portion 83 included in the lid 63B, and the opening 87 provided in the collar portion 81. It is desirable to have a size larger than the diameter.

11. Assembling the Bone Hardness Measuring Instrument 61 Assembling the bone hardness measuring instrument 61, as shown in FIG. 9B, inserts the reference portion 65 into the cylinder 63A and fixes it with the lid 63B. More specifically, the cylinder 63A, the reference portion 65, and the lid 63B are arranged so that their respective axial centers are linear, and the reference portion 65 is arranged from the convex portion 69 side to the opening 73 of the cylinder 63A. The convex portion 69 is inserted into the convex portion opening 71 while being housed inside the hollow layer 67 to be exposed to the outside.

With the reference portion 65 housed in the cylinder 63A, the fitting portion 83 of the lid 63B is inserted through the opening 73 of the cylinder 63A, and while rotating around the axial direction, the cylinder side screw 77 and the lid side screw 85 and 85 are screw-fitted.

After completing the above procedure, it is confirmed that there is no rattling in the fitting of each part, and the assembly of the bone hardness measuring instrument 61 is completed.

12. Method of Measuring Hardness Using Bone Hardness Measuring Instrument 61 Next, a method of measuring hardness of the bone hardness measuring instrument 61 will be briefly described with reference to FIG. FIG. 10 is a schematic view showing a hardness measuring method using the bone hardness measuring device 61. First, the practitioner grips the third housing 63 with the convex portion 69 facing the cancellous bone 101 side, brings the measurement reference surface 75 of the cylinder 63A into contact with the surface of the cancellous bone 101, and the third housing. The state is maintained so that 63 is perpendicular to the cancellous bone 101.

Subsequently, the reference portion 65 exposed from the rear end side of the third housing 63 is constantly pressed against the axial cancellous bone 101 side with a predetermined force. As a result, the cancellous bone 101 generates a reaction force (resistance force) against the pressing of the convex portion 69 according to its own hardness and state, and resists the pressing of the convex portion 69. Although it varies depending on the hardness and condition of the cancellous bone 101, the resistance force compresses the spring by resisting the force pressing the reference portion 65 of the practitioner and the stress of the spring inside the reference portion 65. push the protrusions 6 9 inside the reference 6 5 Te, also destroyed by the pressing of the convex portion 6 9 some of the protrusions 6 9 is inserted into the cancellous bone 101.

After the movement of the convex portion 6 9 calm, check the position of the collar 93 of the reference portion 65 from the slit 89 of the third housing 63, confirm the movement amount of the reference portion 65 from the scale of the movement amount display unit 91 do. Further, as described above, the reference portion 65 has substantially the same configuration as the bone hardness measuring instrument 1, and the stress of the spring inside the reference portion 65 at that time can also be read from the stress display portion of the reference portion 65. The hardness and state of the cancellous bone 101 can be measured from the amount of movement of the reference portion 65 thus obtained and the stress of the spring at that time.

When measured with an osteoporosis patient using a bone hardness measuring device 61 at a specific amount of movement , a scale of 1 (0.4 MPa) was shown, and when measured with a young healthy person, a scale of 5 (1.1 MPa) was shown. , Both could be evaluated appropriately by the bone hardness measuring instrument.

The bone hardness measuring instrument 1 of the present invention is a medical instrument that mainly measures the hardness of cancellous bone 101 in human bone. By measuring, it assists in the selection of the optimum joining pin to be used for joining.

1 Bone hardness measuring instrument 3 Stress detection reference part 5 Convex part 7 Stress display part 7A Indicator 7B Scale 9 Grip part 11 External housing 13 Internal housing 15 Spring 17 Washer 19 Fitting lid 21 Hollow layer 23 Opening 25 For convex parts Opening 27 Groove 29 Hollow layer 30 Invited citation Notch 31 Opening 33 Housing side screw 35 Opening 37 Hole 39 Lid side screw 41 Concavo-convex pattern 43 Waist 45 Neck 47 Tail 49 Head 51 Fitting hole 53 Protrusion 55 Smoothing part 57 Distorted part 59 Measuring surface 61 Bone hardness measuring instrument 63 Third housing
63A cylinder
63B Lid 65 Reference part 67 Hollow layer 69 Convex part 71 Convex part opening 73 Opening 75 Measurement reference surface 77 Cylinder side screw 79 Tapered part 81 Flange part 83 Fitting part 85 Lid side screw 87 Opening 89 Slit 91 Movement amount display part 93 Collar 101 cancellous bone θ angle

Claims (4)

Approximately rod-shaped convex part and
And the convex portion and connected to said stress detection reference portion, the convex portion of said stress detection reference stress detector which Ru stressed in response to the displacement with respect to unit,
Be provided with a, and the stress display unit for displaying the stress in the stress detector,
A bone hardness measuring instrument for cancellous bone or bone marrow. Range 0.05~1.50MPa der Rukoto of the stress,
The bone hardness measuring instrument according to claim 1. The radial cross-sectional area of the convex portion is 1 to 13 mm ² .
The bone hardness measuring instrument according to claim 1 or 2. Further Rukoto be provided with a grip portion,
The bone hardness measuring instrument according to any one of claims 1 to 3.

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