KR102023340B1 - Method of informing tensile force of medical suture utilizing highly sensitive strain sensors - Google Patents

Abstract

The present invention, measuring the strain of the medical knot mechanism caused by pulling the knot thread with the medical knot mechanism, matching the measured strain with data including the strain of the knot mechanism according to the tension and tension of the medical knot thread Comprising the step of calculating the tension of the knot thread, and relates to the tension display method of the medical knot thread comprising the step of displaying the calculated tension of the knot thread.
The tension display method of the medical knot thread using the high-sensitivity strain measurement sensor according to the present invention can provide information on the tension acting when using the knot thread, thereby improving the surgical stability and accuracy.

Description

Tension display method of medical knot thread using high-sensitivity strain sensor {METHOD OF INFORMING TENSILE FORCE OF MEDICAL SUTURE UTILIZING HIGHLY SENSITIVE STRAIN SENSORS}

The present invention relates to a method for displaying the tension of medical knot thread using a high-sensitivity strain measurement sensor, and more particularly, to a method for easily measuring the tension acting on the knot thread when sutured and inform the user.

Knot thread requires accurate suture and knot process for normal recovery from medical and aesthetic point of view. The suture process depends on the experienced surgical ability of the operator. On the other hand, the knot thread is composed of different thicknesses and materials, depending on the purpose of use and the target tissue, each has its own breaking strength may be configured differently.

In particular, in the case of knot thread used in precision suture surgery such as corneal transplantation surgery, the knot thread is broken when a force exceeding the breaking strength and a tension of about 0.3 N is applied. In this regard, 'Guide Insert Apparatus and Method' is disclosed in Korean Unexamined Patent Publication No. 2014-0061520. However, there is a limit to rely on the sense of the hand of the doctor in order to prevent the fracture of the aforementioned knot thread.

Republic of Korea Patent Publication No. 2014-0061520 (2014.05.21.)

It is an object of the present invention to provide a tension display method of medical knot thread using a high-sensitivity strain measurement sensor that can prevent the problem that the breaking strength is transmitted by breaking when sutured using a conventional knot thread.

As a means for solving the problem, the step of measuring the strain of the medical knot mechanism generated by pulling the knot thread with the medical knot mechanism, the data including the strain of the knot mechanism according to the tension and tension of the medical knot thread and measured According to the present invention, a method for displaying tension of a medical knot thread may be provided. The method may include calculating a tension of a knot thread by matching strains, and displaying the calculated tension of the knot thread.

Here, the step of measuring the strain may be performed using a strain measurement sensor using nanocracks configured to increase the resistance as the length is extended.

In addition, the medical knot mechanism may be configured to be used by the user gripping.

In the measuring of the strain, the strain may be measured at at least three points to measure the change generated by pulling in the three-dimensional direction, and the calculating of the tension of the knot thread may be performed by combining the strains measured at the three points. The tension can be calculated by matching with the stored strain combination.

Meanwhile, the strain measuring sensor is attached to the surface of the knot mechanism at the initial length before stretching, and the step of calculating the tension of the knot thread may be calculated based on the elongation rate of the surface on which the strain measuring sensor is attached in the medical knot apparatus.

In addition, the strain measuring sensor is attached to the surface of the knot mechanism in a state of being elongated by a predetermined length, and calculating the tension of the knot thread may be calculated based on the shrinkage rate or the elongation rate of the surface on which the strain measuring sensor is attached in the medical knot apparatus. Can be.

On the other hand, the data includes a threshold strain value corresponding to a threshold tension value at which break occurs according to the type of knot thread, the threshold exceeding determination step of determining whether the measured strain is within a predetermined range of the threshold strain value and In the determination of whether the threshold is exceeded, the method may further include a warning step of alerting the user when the strain measurement value exceeds the threshold strain value.

The determination of whether the threshold is exceeded may determine that the threshold value is exceeded when any one of the measured values measured by the plurality of strain measurement sensors exceeds the threshold strain value.

On the other hand, the warning step may be displayed by changing the color so as to be visually recognized.

In addition, one of a plurality of knot yarns having different use strengths may be selected, and the medical knot appliance may be configured to have different strengths, and may be selected according to the use strength of the selected knot yarn, and the information of the selected knot yarn and medical knot appliance It may be configured to further include an input step of inputting.

On the other hand, the strain measuring sensor is composed of a first layer and a conductive material consisting of a non-conductive material, is formed on the first layer, the second configured to vary the size of the resistance as the width of the plurality of nanocracks change The layer may include a layer, and the second layer may be formed to have a thickness of 2 μm or less so that a plurality of cracks may be formed uniformly and densely in the entire area of the second layer.

In addition, the second layer may be configured to increase resistance by subtracting the width of the plurality of cracks formed in the second layer in the extending direction.

In addition, the first layer may be formed of an elastic member so that cracks do not occur within an extension range for measuring the strain.

The tension display method of the medical knot thread using the high-sensitivity strain measurement sensor according to the present invention can provide information on the tension acting when using the knot thread, thereby improving the surgical stability and accuracy.

1 is a perspective view of a medical knot instrument.
2 is a view showing the concept of the tension acting on the knot thread when using a medical knot mechanism.
3 is a view showing a state of the knot mechanism that is deformed according to the direction to pull the knot thread.
4 is a diagram illustrating a resistance value measured from a strain measuring sensor when pulled in the triaxial direction.
5 is a partially enlarged view illustrating a display unit.
6 is a diagram illustrating the concept of a medical knot instrument set.
Figure 7 is a flow chart of the tension display method of the medical knot thread according to the present invention.
8 is another flow chart of the tension display method of the medical knot thread according to the present invention.
9 is a flow chart showing whether the threshold exceeded and the warning step of the tension display method of the medical knot thread according to the present invention.
10 is a perspective view of a strain measuring sensor.
11 is a photograph taken by enlarging a crack generated in the second layer of the strain measurement sensor.
12 is a photograph comparing cracks generated in the second layer of the strain sensor.
13 is a diagram showing the strain-stress of the strain measuring sensor.
14 is a view showing a resistance change during repeated extension of the strain measurement sensor.
15 shows the resistance change according to the deformation of the strain measurement sensor.
16 is a flowchart of a manufacturing method of a strain measuring sensor.
17 is a cross-sectional view schematically showing how the strain measuring sensor is manufactured.

Hereinafter, the tension display method of the medical knot thread using the high sensitivity strain sensor in the embodiment of the present invention will be described in detail with reference to the accompanying drawings. And the names of each component in the description of the following embodiments may be called other names in the art. However, if their functional similarity and identity, even if the modified embodiment can be seen as an equivalent configuration. In addition, the symbols added to each component is described for convenience of description. However, the contents shown in the drawings in which these symbols are described do not limit each component to the ranges in the drawings. Similarly, even if an embodiment in which the configuration on the drawings is partially modified is employed, it can be regarded as an equivalent configuration if there is functional similarity and identity. In addition, in view of the general level of those skilled in the art, if it is recognized as a component to be included naturally, the description thereof will be omitted.

1 is a perspective view of the medical knot mechanism 10, Figure 2 is a view showing the concept of the tension acting on the knot thread 2 when using the medical knot mechanism (10). As shown, the medical knot instrument 10 using the high sensitivity strain measurement sensor 400 is configured to allow the user to grasp or loosen the knot thread 2 or the needle 3 selectively, and in a gripped state. It may be configured so that the knot thread (2) or the needle (3) does not escape from the gripped position during operation. Meanwhile, hereinafter, the knot mechanism 10 may grab the knot thread 2 or the needle 3, but for convenience of explanation, the knot mechanism 10 will be described as a single expression for grasping the knot thread 2.

The medical knot instrument 10 may be configured to include a gripping part, a fixing part 40, a body part 10, a strain measuring sensor 400, a calculating part, and a display part 60.

The gripping portion is configured to allow the user to gripping by hand. The gripping portion may be configured to include a fingering 20 so that a user can insert and fix a finger. The gripping portion may be configured as one side or both sides of the body portion 10.

The fixing part 40 is comprised of a pair of fixing pieces, and is comprised so that the needle 3 or the knotted thread 2 may be grasped by a hinge operation. The operation of the fixing part 40 will be described in detail below.

Body portion 10 may be composed of two parts so that the knot mechanism 10 is configured in the shape of scissors to grab and release by the scissors operation, the hinge is connected in the center portion relatively rotatable It can be configured to. The body portion 10 may include a first member and a second member.

The first member may include a first finger ring 20, a link 30, and a first fixing piece 41. The first fingering 20 is hingedly connected to the second member and configured to be relatively rotatable. The first fixing piece 41 is hinged at a point adjacent to the second fixing piece 42 and is configured to be relatively rotatable. The link 30 is formed to have a predetermined length and is configured to be hinged to the first fingering 20 and the first fixing piece 41, respectively. Therefore, the relative rotational movement of the first finger ring 20 and the second finger ring 20 is mechanically connected to allow the relative rotation of the first fixing piece 41 and the second fixing piece 42. Meanwhile, the rotation radius of the fixing part 40 may be configured to be smaller than the rotation radius of the fingering 20 for the minute manipulation of the fixing part 40.

Body portion 10 may be made of a material of strength that can be deformed when pulled to the extent that the tension occurs in the knot thread (2) in the state of holding the knot thread (2). That is, the amount of deformation varies depending on the pulling force of the knot thread 2, and in particular, the cross section of which the secondary moment value is smaller than that of the other parts of the body portion 10 is formed so that the deformation concentration portion 50, which is the portion where the deformation is concentrated, is formed. It may be configured to include at least one portion having a shape. It may also be configured to include at least two sides to measure the deformation in the biaxial direction.

Strain measurement sensor 400 is attached to the deformation concentration portion 50 of the body portion 10 is configured to measure the amount of deformation of the body portion 10. The strain measurement sensor 400 may be a thin film type sensor that can be changed in resistance as the length is extended. As the length is extended, the width of the crack on the surface of the conductive layer is widened, so that the resistance value is increased. Strain measurement sensor 400 is provided on at least two or more surfaces to measure the strain on two or more axes is configured to measure the strain. On the other hand, the configuration of such a sensor will be described in detail later with reference to FIGS. 10 to 17.

The calculation unit (not shown) is configured to measure the resistance change generated from the strain measurement sensor 400, calculate the amount of deformation of the body portion 10 from the resistance change, and calculate the tension acting on the knot thread (2). The calculating part may be provided inside the body part 10, and may include a microprocessor, and may include information about mechanical values of the knot mechanism 10, information related to strains such as secondary moments, and thresholds for the knot thread 2. It can be configured to include a memory that contains information about the tension. The calculator may generate a signal that can be output from the display unit 60 by calculating a tension currently applied within a range of tension of the knot thread 2. The calculating unit may generate a signal indicating in visually recognizable color or scale bar whether the current tension is within the use tension of the knot thread 2. It may also be configured to generate a signal for simple visual recognition such as lighting so that the notification can be performed only when the critical tension is reached.

The display unit 60 may be configured to receive a signal from the calculating unit and to display the tension currently acting on the knot thread 2 within the use tension of the knot thread 2. It may be configured as an LCD or LED so as to receive a signal from the operation unit to be displayed visually.

However, although not displayed, it may include a separate power supply unit for driving the operation unit and the display unit 60.

Hereinafter, the operation of the medical knot instrument 10 will be described in detail with reference to FIGS. 3 to 5.

3 is a view showing a state of the knot mechanism 10 is deformed according to the direction to pull the knot thread (2), Figure 4 is a resistance value measured from the strain measuring sensor 400 when pulled in the three-axis direction 5 is a partially enlarged view showing the display unit 60.

As shown, the medical knot mechanism 10 is configured to calculate the tension by measuring the strain when the knot thread (2) is fixed and pulled from the fixing portion 40 provided at the end. On the other hand, in the actual clinical practice it is not often pulled the knot thread (2) in the longitudinal direction of the knot mechanism 10 to be described in detail only in the representative two directions in which the tension direction and the longitudinal direction of the knot thread (2) is vertical do.

Referring to Figure 3 (a), the change that appears when the knot thread (2) is pulled in the Y direction in the fixed state 40 is shown. The end of the knot mechanism 10 is bent in the -y direction by the tension of the knot thread, and the deformation is made in the deformation concentration portion 50. In addition, as shown in Fig. 3 (b), when the knot mechanism 10 is pulled in the -x direction, deformation is bent in the x direction by the tension of the knot thread. Even in this case, deformation occurs intensively in the deformation concentration part 50. Each surface of the strain concentration part is provided with a strain measurement sensor 400 to measure the resistance change according to the deformation, respectively. Although not shown, even when the strain is made by pulling in the z direction, the tension of the knot thread can be calculated from the resistance measurement values of the plurality of strain measuring sensors.

Referring to FIG. 4, the resistance change measured by the strain measurement sensor 400 when the tension acts in each axial direction is shown. In this case, the strain measuring sensor 400 may be attached to the strain concentration part 50 in a state in which the strain is elongated to a predetermined length so that the strain in one axial direction and the negative direction may be measured. In this case, since the state extended to the predetermined length becomes the initial state, it is possible to measure the resistance change according to shrinkage and extension.

On the other hand, it is a general case that tension having a size and a direction in which three components are combined is applied rather than a substantially independent three directions of deformation. In this case, the tension may be calculated based on information on physical properties such as usage tension according to the type of the knot thread 2, mechanical values of the knot mechanism 10, and young's modulus. That is, a combination of resistance change values measured by the plurality of strain measurement sensors 400 may be uniquely matched according to the pre-input information and the magnitude and direction of the tension. Therefore, the calculation unit may calculate the tension currently acting on the knotted yarn 2 by the combination of the resistance values measured by the plurality of strain measurement sensors 400.

Referring to FIG. 5, a concept of a method of transmitting visual information on the display unit 60 is illustrated. The strain of the current relative resistance value is measured, from which the tension of the knot thread 2 is calculated. At this time, if the tension is increased until there is a risk that the knot thread 2 is broken, it may be determined and a warning may be performed to the user. The display unit 60 may be configured as, for example, an LED or an LCE so as to be visually recognizable, and performs a warning through blinking or changing of color. Therefore, the user can sense the risk and lower the external force to perform the suture.

6 illustrates the concept of a set of medical knot instruments 10. The medical knot thread 2 may be configured in various types and thicknesses, and thus may include various types of knot mechanisms 10 so that tension can be measured. The medical knot instrument 10 can measure the strain and calculate the tension of the knot thread 2 only when an appropriate amount of deformation occurs according to the tension of the knot thread 2. However, if the deformation of the knot mechanism 10 is too small within the use tension of the knot thread 2, the user's feeling of operation is degraded and the reactivity is low, which is undesirable. On the contrary, if the deformation of the knot mechanism 10 is too great and the deformation of the knot thread 2 is too small within the use tension of the knot thread 2, even if excessive operating force is applied from the user, the tension measurement may not be performed smoothly. It is not preferable because there is concern. Therefore, operation mechanisms having an appropriate deformation amount according to the tension of the knot thread 2 can be matched. This matching can be determined experimentally.

Hereinafter, the tension display method of the medical knot thread according to the present invention will be described in detail with reference to FIGS. 7 to 9.

Figure 7 is a flow chart of the tension display method of the medical knot thread according to the present invention.

As shown, the method of displaying the tension of the medical knot thread according to the invention step of measuring the resistance change of the strain measuring sensor (S1000), the strain calculation step (S2000) of the medical knot instrument, the step of calculating the tension of the knot thread It may be configured to include (S3000) and the step of displaying the tension (S4000).

Measuring the resistance change of the strain measuring sensor (S1000) is carried out by using a knot mechanism consisting of a structure that can be gripped by the user, and selectively grasping the knot thread. Explaining that one end of the knot thread is fixed to the tissue, when pulling the knot thread while holding the other end with the knot mechanism, tension is generated in the knot thread. At this time, the strain generated in the knot mechanism is measured. do. Strain is performed by using a strain measurement sensor, the strain sensor is extended as the width of the crack of the conductive layer can be used to increase the resistance of the sensor. A plurality of resistance values can be measured from the strain measurement sensor attached to the surface of the three directions of the knot mechanism so that the strain in the three axis direction can be measured respectively.

Strain calculation step (S2000) of the medical knot instrument matching the strain of the knot instrument according to the combination of the current resistance change from the deformation information of the appearance of the medical knot instrument according to the combination of resistance changes measured from a plurality of pre-stored strain measurement sensors Corresponds to the steps to do. In this case, the resistance value measured from the strain measurement sensor is used, or the change of the resistance value measured from the strain measurement sensor is configured to match the strain of the knot mechanism.

Calculating the tension of the knot thread (S3000) corresponds to the step of calculating the external force at the portion where the knot thread is fixed by using the knot mechanism strain, the knot mechanism geometry, and the property information calculated in the previous step. At this time, the calculation process using the deformation theory of the object according to the external force is performed to calculate the external force.

Displaying the tension (S4000) corresponds to the step of displaying the external force calculated in the previous step as the tension. Displaying the tension (S4000) is configured to use the display unit provided in the knot mechanism so that the user can visually recognize, or to recognize the tension using the display unit provided separately. In the step of displaying the tension (S4000), the calculated tension is displayed as a numerical value, a scale bar form is displayed so as to check how much tension is currently operating in the used tension, or a method of displaying the color change. This can be done in a variety of visually recognizable ways.

Hereinafter, another flowchart of the method for displaying the tension of the medical knot thread according to the present invention will be described. For the same embodiment as the above-described embodiment, the description will be omitted to avoid overlapping materials, and only the differences will be described. Shall be.

8 is another flowchart of the method for displaying the tension of the medical knot thread. As shown, the matching step (S2500) corresponds to the step of matching and calculating the tension DB acting on the current knot thread according to the geometry and type of the knot mechanism currently used, using a combination of the measured resistance values. The DB stores the combined values of the resistance changes generated by the plurality of strain measuring sensors according to the magnitude and direction of the tension acting on the knot thread for each knot mechanism. Therefore, when the knot mechanism is selected and the resistance value is measured and combined in the strain measuring sensor, tension can be easily derived from the DB. In this case, setting up a DB can minimize processor resource waste.

9 is a flow chart showing whether the threshold exceeded and the warning step of the tension display method of the medical knot thread according to the present invention.

As shown, the present embodiment may include a threshold exceedance determination step (S2600), a warning step (S2700).

The threshold exceeding determination step (S2600) is a step of deriving the current tension using the measured resistance value and determining whether the current tension is a dangerous level. The breaking strength value of the knot thread may be used to determine whether the threshold is exceeded. The breaking strength will vary depending on the type of knot thread, and the tension at which the break can be determined can be determined using the breaking strength value and the cross-sectional area of the knot thread. The tension and the strain data of the knot mechanism according to the tension can be stored, and it is possible to determine whether the strain of the knot mechanism according to the resistance value measured by the strain measuring sensor exceeds the critical strain. If it is determined that the critical strain is exceeded, a warning step (S2700) may be performed. If it is not exceeded, the current tension may be displayed and the critical strain excess determination step (S2600) may be performed again. On the other hand, the step of determining whether the critical strain is exceeded (S2600) may be performed repeatedly by measuring the resistance change at a constant sampling time.

The warning step S2700 corresponds to a step of warning the user that there is a risk that the knot thread is broken when it is determined that the strain of the knot mechanism exceeds the critical strain. It may be performed in an audiovisual manner to the user, and it is preferable that the warning is performed in a visual manner so as to minimize the influence on the suture operation. It is desirable that the warning be performed in a visual manner so that it can be done.

Hereinafter, the strain measuring sensor applied to the present invention will be described in detail with reference to FIGS. 10 to 17.

10 is a perspective view of a strain measuring sensor according to the present invention.

As shown, the strain measurement sensor 400 according to the present invention may be configured to include a first layer 410, a second layer 420.

The first layer 410 and the second layer 420 are attached to each other, it is configured to extend together when measuring the strain.

The first layer 410 is composed of a stretchable member so as to be stretched by receiving an external force from the measurement target, and may be formed of a non-conductive member so as not to affect the resistance change of the second layer 420 to be described later. .

The first layer 410 may be configured so that the crack 430 does not occur within the strain measurement range. When the crack 430 of the first layer 410 is generated, the crack 430 generated in the second layer 420 may become uneven. In this embodiment, the example has a strain of 60% as a limit. Accordingly, when it is extended within 60% of the length of the first layer 410, the crack 430 is not generated in the first layer 410. It is. Specifically, the material constituting the first layer 410 may include polyurethane (Polyurechane), the thickness of the first layer 410 is preferably composed of 200μm or less. However, these thicknesses and materials can be configured in various ways depending on the measurement range.

The second layer 420 is made of a conductive material and is configured to increase its resistance as the width of the plurality of cracks 430 increases as the length thereof is extended. In this case, the plurality of cracks 430 may be formed by attaching and extending the second layer 420 to the first layer 410.

The second layer 420 is configured not to completely block the flow of current even though it is stretched within the strain measurement range. That is, the plurality of cracks 430 are configured to be densely packed so as not to be excessively extended at one portion and electrically disconnected. On the other hand, it is possible to select a suitable material to have such a feature, it may be configured to include a material having excellent conductivity and ductility, such as gold, silver, platinum. In this embodiment, platinum is included.

The plurality of cracks 430 are formed to have a direction approximately perpendicular to a direction in which the length of the second layer 420 extends. Therefore, as the width of the crack 430 increases when the second layer 420 is stretched, the contact area decreases, and the effective area for determining the size of the resistance decreases, thereby increasing its own resistance. On the contrary, when returning to the original length, the width of the crack 430 decreases, so that the contact area becomes wider, so that the effective cross-sectional area increases, thereby reducing its own resistance.

The operation, function and formation process of the crack 430 will be described in detail later.

The first layer 410 may be fixed to the strain measurement object. As the length of the measurement target is extended, the first layer 410 is extended. At this time, as the second layer 420 attached to the first layer 410 is extended together, the resistance value is changed, and external devices are connected to both sides of the second layer 420 to be configured to measure resistance change. .

Referring back to FIG. 10, the second layer 420 may be attached to the first layer 410 spaced apart from a point at which an external force acts. Therefore, stress concentration, partial breakage, and the like, which may occur in the second layer 420 by the action of an external force, may be prevented.

In addition, the second layer 420 may be attached at a predetermined distance from the edge of the first layer 410. When the first layer 410 is cut, the cut surface may be rough, and when the second layer 420 is attached to the rough edge, it is to prevent a problem in which proper performance may be exhibited due to stress concentration.

Hereinafter, the function and operation of the strain measurement sensor 400 will be described in detail with reference to FIGS. 11 to 14.

11 is an enlarged photograph of a crack 430 generated in the second layer 420 according to the present invention.

11 (a) shows a state when the length of the strain measuring sensor 400 is 20% elongated, and FIG. 11 (b) shows a state when the length of the strain measuring sensor 400 is 50% elongated. The scale bar shown on the upper right side is 5 m in length.

The plurality of cracks 430 as illustrated in the second layer 420 are uniformly distributed. The crack 430 is formed in a direction substantially perpendicular to the direction in which the second layer 420 extends. As described above, the crack 430 is configured to increase the resistance by increasing the width in the direction in which the second layer 420 is extended so that the contact area decreases. Can be configured.

The crack 430 is formed in a direction crossing the other side from one side of the second layer 420, but is formed so that the second layer 420 is not broken. Therefore, even if the width of the crack 430 is wide, the current flowing in the second layer 420 is not completely blocked by any one crack 430. That is, a plurality of cracks 430 are formed to have a length shorter than the width of the second layer 420 so that a current can pass to a portion where the crack 430 is not formed even when the second layer 420 is extended.

12 is a photograph comparing the cracks 430 generated in the second layer 420 according to the present invention, and is shown when the length is 20% elongated.

FIG. 12A illustrates an inadequately wide width of the crack 430 formed on the second layer 420. FIG. 12B illustrates a width of the crack 430 formed on the second layer 420. This suitably constructed, uniformly and densely formed figure is shown.

If the width of the crack 430 is inappropriately large, as shown in Figure 12 (a) will be partially broken by any one crack 430. Partial rupture interrupts the flow of current in that portion, resulting in a dramatic increase in the resistance of the second layer 420 that is measured despite small deformations of less than 5% overall. This means that if the measuring range is 5% or more of strain, the measurement becomes impossible.

On the other hand, in the case where the crack 430 is denser than FIG. 12 (a) as shown in FIG. 12 (b), the width of the larger number of cracks 430 is increased uniformly despite the same elongation (20%). Since various paths through which the current can flow can be formed between the crack 430 and the crack 430 on the two layers 420, the current can stably flow.

The width and density of the crack 430 as described above may be variously configured according to the elongation rate of the measurement target. For example, when the width of the crack 430 is formed at 5 nm or more in the state where the width of the crack 430 is elongated at the maximum strain when the measurement range of the maximum elongation is 60%, a rapid resistance change occurs in the strain measurement range, making accurate measurement difficult. . Therefore, in this case, the width of the crack 430 is preferably composed of 5nm or less.

13 is a diagram showing a strain-stress graph of the strain measuring sensor 400 according to the present invention. The strain measurement sensor 400 repeatedly shows data that is repeatedly stretched at 60% strain, and is displayed in different colors according to the number of stretches.

As shown, the data at the first stretch is somewhat different from the following data. In this case, the first stretch is data that is stretched in a state before the crack 430 is formed in the second layer 420, and the second layer 420 is applied according to a stress applied to a higher level during the first stretch. ), The plurality of cracks 430 described above are generated, and the first layer 410 generates micro deformation.

However, in the subsequent repeated use, a constant stress is applied according to the deformation as shown, and the repeated use shows that the data converges.

As such, when the strain measurement sensor 400 according to the present invention is used, the uniform crack 430 should be generated by firstly extending it to improve reliability. However, the crack 430 may not be formed and may be extended to generate the crack 430 immediately before use in the state where the first layer 410 and the second layer 420 are attached.

14 is a view showing a resistance change during repeated extension of the strain measurement sensor 400 according to the present invention.

As shown, when the strain measurement sensor 400 is repeated at an elongation of 50%, a change in resistance may occur by about 15 times. In other words, even if 10% deformation occurs, the resistance can be operated very sensitively because the difference is more than three times.

On the other hand, the most representative factor indicating the sensitivity of the stretchable strain measurement sensor 400 may be a gauge factor (GF = (resistance change / initial resistance) / strain), the GF value of this embodiment is a value of 20 to 40 When the conventional metal gauge measures strain within 5%, the GF may have a GF value of about 2 times higher than that of the conventional stretchable strain sensor 400 about 0.8. Therefore, it is possible to measure the strain very sensitively, it is possible to measure the deformation by the external force that changes in 0.01 N units.

In addition, even if repeated use, the resistance value of the strain measurement sensor 400 according to the strain is constantly changed, thereby ensuring the reliability.

15 shows the resistance change according to the deformation of the strain measuring sensor 400 according to the present invention.

As shown, the resistance is increased as the strain measuring sensor 400 is stretched within 30% of the strain, and the resistance value of the strain measuring sensor 400 is linearly increasing as the length is linearly increased to 30%. Increasing experimental data is shown.

Since the plurality of cracks 430 formed in the second layer 420 are densely packed to prevent a sudden change in resistance and the resistance varies linearly according to the extension of the length, the strain may be calculated using an absolute value using a measured value or It is easy to calculate the strain according to the relative change in resistance. In addition, the resistance changes rapidly due to deformation, and a small overshoot and a small recovery time in return are shown.

16 is a flow chart of the manufacturing method of the strain measurement sensor 400 according to the present invention.

As shown, the strain measurement sensor 400 according to the present invention includes generating a first layer (S100), generating a second layer (S200), and generating a crack 430 (S300). Can be configured.

In addition, a process of attaching and removing a mask for determining a region to which the second layer 420 is attached when the second layer 420 is generated may be included.

In the generating of the first layer (S100), the nonconductive and stretchable member may be generated by a spin coating method. The polyurethane solution is dropped on the upper side of the rotating slide glass to form a thin film first layer 410 by rotation. In this case, the first layer may be generated to 200 μm or less.

Subsequently, in order to prevent stress concentration of the second layer 420, a mask for determining a generation area may be attached so that the second layer 420 may be attached at a predetermined interval apart from the edge of the first layer 410. The mask penetrates only the area attaching the second layer 420 to selectively generate the second layer 420 on the first layer 410.

The generating of the second layer (S200) attaches the conductive second layer 420 to one surface of the first layer 410. As an example, the second layer 420 is generated by using a sputtering process, wherein sputtering may be performed using a platinum target and performed for 10 to 20 mA for 200 to 300 seconds. When sputtering is performed at 15 mA for 240 seconds, it is preferable to manufacture a strain measurement sensor 400 that can be measured within 60% of elongation. Meanwhile, such sputtering is an example, and various processes may be adopted according to a measurement range to be measured, and a time and a current applied to sputtering may be variously applied. In this case, the thickness of the second layer 420 may be formed to be 2 μm or less.

After the second layer 420 is generated, the mask is removed.

In the generating of the crack (S300), the plurality of cracks 430 are generated with a uniform distribution by applying a uniform tensile force to the entire area of the second layer 420 by stretching the first layer 410.

At this time, the length that is elongated when the crack 430 is generated may be extended by applying the maximum value of the strain to be measured by the strain measurement sensor 400. For example, when a strain measurement sensor 400 having a measurement range is within 60%, a plurality of cracks 430 are generated on the second layer 420 by extending the first layer 410 by 60%. Afterwards, the data on the strain due to repeated use may be shown in FIG. 13.

17 is a cross-sectional view schematically showing how the strain measuring sensor 400 according to the present invention is manufactured.

As shown, a first layer is generated (a), a mask is attached to the generated first layer (b), and a portion of the second layer 420 is generated by sputtering (c). Thereafter, the mask is removed (d) and the first layer 410 is extended to generate a uniform crack 430 in the second layer 420 (e).

As described above, the method for displaying the tension of the medical knot thread according to the present invention can be transferred to the user can recognize the tension of the knot thread used for precise closure can prevent the knot thread break It has the effect of improving the accuracy and stability of the surgery.

1: knot utensil
2: knot thread
3: needle
10: body part
20: fingering
30: Link
40: fixed part
41: first fixing piece
42: second fixing piece
50: strain concentration
60: display unit
400: strain measurement sensor
S1000: Strain measurement sensor resistance change measurement step
S2000: Strain calculation step of medical knot instrument
S3000: Calculation of knot thread tension
S2500: resistance change-tension DB matching step
S2600: Determining whether the threshold is exceeded
S2700: warning steps
S4000: Display step

Claims (13)

One side is configured to be held by the user, the other side is carried out in a medical knot mechanism is configured to secure the knot thread,
Measuring a strain generated in the medical knot instrument due to the gripping force of the user and the tension of the knot thread;
Calculating the tension of the knot thread by matching the measured strain with data including the tension of the medical knot thread and the strain of the knot mechanism according to the tension;
And displaying the calculated tension of the knot thread. According to claim 1,
Measuring the strain is a tension display method of the medical knot thread, characterized in that performed using a strain measuring sensor using a nanocracks configured to increase the resistance as the length is extended. delete The method of claim 2,
Measuring the strain, the strain is measured at at least three points to measure the change that occurs as the pull in the three-dimensional direction,
The calculating of the tension of the knot thread may include calculating the tension by matching the strain combinations measured at the three points with the stored strain combinations. The method of claim 2,
The strain measuring sensor is attached to the surface of the knot mechanism in the initial length before stretching,
Calculating the tension of the knot thread,
And displaying the tension of the medical knot device based on the elongation rate of the surface on which the strain measuring sensor is attached. The method of claim 2,
The strain measuring sensor is attached to the surface of the knot mechanism in a state extending to a predetermined length,
Calculating the tension of the knot thread,
The method of displaying the tension of the medical knot thread, characterized in that calculated based on the shrinkage or elongation rate of the surface attached to the strain measuring sensor of the medical knot mechanism. The method of claim 2,
The data includes a threshold strain value corresponding to a threshold tension value at which break occurs according to the type of the knot thread.
A threshold exceedance determining step of determining whether the measured strain rate falls within a predetermined range within the threshold strain value; And
And a warning step of warning the user when the strain measurement value exceeds the threshold strain value in the determining whether the threshold is exceeded. The method of claim 7, wherein
The determining whether the threshold is exceeded,
And if any one of the measured values measured by the strain measuring sensor exceeds the threshold strain value, determines that the threshold value of the medical knot thread is exceeded. The method of claim 8,
The warning step is a tension display method of the medical knot thread, characterized in that the display by changing the color so as to be visually recognized. The method of claim 4, wherein
The knot thread is selected from a plurality of each having a different use strength,
The medical knot instrument is composed of different strengths, each selected according to the strength of use of the selected knot thread,
And an input step of inputting information of the selected knot thread and medical knot instrument. The method of claim 2,
The strain measuring sensor,
A first layer composed of a non-conductive material; And
A second layer formed of a conductive material and formed on the first layer, the second layer being configured to vary in size as resistances of the plurality of nanocracks vary.
And the second layer is formed to have a thickness of 2 μm or less so that the plurality of cracks can be formed uniformly and densely in the entire area of the second layer. The method of claim 11, wherein
And the second layer is configured to increase resistance by deflecting in a direction in which the widths of the plurality of cracks formed in the second layer are extended during stretching. The method of claim 12,
The first layer,
Tension display method of the medical knot thread characterized in that it is composed of an elastic member so that no crack is generated within the stretch range for measuring the strain.

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