Method for producing medical device

Abstract

Provided is a method for producing a medical device 5, wherein the medical device 5 is subjected to cleaning, disinfection, or sterilization using a chemical to enable repeated use thereof. This method for producing a medical device includes a step for changing the orientation of fibrils 120 by subjecting the outer surface, which is formed from a resin material, of the medical device 5 to first blasting.

Description

Medical device manufacturing method

[0001] The present invention relates to a method for manufacturing a medical device.

[0002] Conventionally, there are medical devices that can be repeatedly used by cleaning, disinfecting, or sterilizing them using a chemical solution (see, for example, Patent Documents 1 and 2). The medical devices described in Patent Documents 1 and 2 are transducers for ultrasonic treatment instruments. The ultrasonic treatment instruments treat a target area of ​​biological tissue (hereinafter referred to as a treatment target) by supplying ultrasonic vibrations generated by the transducer in response to supplied power to the target area.

[0003] JP 2013-81776 A JP 2019-521793 A

[0004] FIG. 6 is a diagram illustrating the problems of the related art. Incidentally, resin members made of resin materials are often used in medical devices that are used repeatedly. As shown in FIG. 6(a), crazes 110 generated by the action of stress may exist on the surface of the resin member 100. As shown in FIG. 6(b), these crazes 110 are composed of fibrils 120 oriented in the stress direction (the direction indicated by the arrow in FIG. 6(a) and the vertical direction in FIG. 6(b)) and minute voids 130. Note that in FIG. 6(b), the orientation of the fibrils 120 is represented by straight lines. If the fibrils 120 are aligned in this way, when cleaning, disinfection, or sterilization is performed using a chemical solution, the chemical solution may act to destroy the fibrils 120, causing them to grow into solvent cracks. Even if crazes 110 are not present, if the fibrils 120 are aligned, cleaning, disinfection, or sterilization using a chemical solution may cause the fibrils 120 to break down and grow into solvent cracks. Therefore, there is a demand for technology that can suppress the occurrence of solvent cracks.

[0005] The present invention has been made in view of the above, and aims to provide a method for manufacturing a medical device that can suppress the occurrence of solvent cracks.

[0006] In order to solve the above-mentioned problems and achieve the objectives, the method for manufacturing a medical device of the present invention is a method for manufacturing a medical device that can be repeatedly used by cleaning, disinfecting, or sterilizing it using a chemical solution, and includes a step of changing the orientation of fibrils by performing a first blasting treatment on the outer surface of the medical device made of a resin material.

[0007] According to the method for manufacturing a medical device of the present invention, the occurrence of solvent cracks can be suppressed.

[0008] FIG. 1 is a diagram illustrating an example of a medical device according to an embodiment. FIG. 2 is a flowchart illustrating a method for manufacturing a medical device according to an embodiment. FIG. 3 is a diagram illustrating a method for manufacturing a medical device. FIG. 4 is a diagram illustrating evaluation results of samples of Comparative Example 1 and Examples 1 to 5. FIG. 5 is a diagram illustrating a modified example of an embodiment. FIG. 6 is a diagram illustrating problems with the prior art.

[0009] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below. Furthermore, in the description of the drawings, the same parts are given the same reference numerals.

[0010] [Overall Configuration of Medical Device] Before describing a manufacturing method for a medical device according to this embodiment, a medical device that is the target of this manufacturing method will be described. FIG. 1 is a diagram illustrating an example of a medical device according to this embodiment. Specifically, FIG. 1 is a diagram illustrating a treatment system 1. The treatment system 1 applies treatment energy to a portion of biological tissue that is to be treated (hereinafter referred to as the treatment target) to treat the treatment target. The treatment energy in this embodiment is ultrasonic energy and high-frequency energy. Treatments that can be performed by the treatment system 1 according to this embodiment include coagulation (sealing) of the treatment target or incision of the treatment target. Coagulation and incision may also be performed simultaneously. As shown in FIG. 1, this treatment system 1 includes a treatment tool 2 and a control device 3.

[0011] [Configuration of Treatment Instrument] In the following, one side along the central axis Ax1 (FIG. 1) of the outer pipe 10 will be referred to as the distal side Ar1, and the other side will be referred to as the proximal side Ar2. The treatment instrument 2 is an ultrasonic treatment instrument according to the present invention. The treatment instrument 2 applies ultrasonic energy and high-frequency energy to a treatment target, thereby treating the treatment target. As shown in FIG. 1, the treatment instrument 2 includes a handpiece 4 and a transducer 5.

[0012] As shown in FIG. 1, the handpiece 4 includes a fixed handle 6 , an operating handle 7 , a switch 8 , a rotating knob 9 , an outer pipe 10 , a jaw 11 , and an ultrasonic blade 12 .

[0013] The fixed handle 6 supports the entire treatment tool 2 and is a part that is held by an operator (user) such as a surgeon.

[0014] The operating handle 7 is movably attached to the fixed handle 6 and receives opening and closing operations by an operator such as a surgeon.

[0015] The switch 8 is provided in an exposed state on the outside of the fixed handle 6 and receives treatment operations from an operator such as a surgeon.

[0016] The rotation knob 9 has a generally cylindrical shape coaxial with the central axis Ax1 and is provided on the distal end side Ar1 of the fixed handle 6. The rotation knob 9 is rotated by an operator such as a surgeon. This rotation causes the rotation knob 9 to rotate about the central axis Ax1 relative to the fixed handle 6. Furthermore, the rotation of the rotation knob 9 causes the outer pipe 10, the jaw 11, and the ultrasonic blade 12 to rotate about the central axis Ax1.

[0017] The outer pipe 10 has a tubular shape. In this embodiment, the outer pipe 10 is a cylindrical pipe made of a conductive material such as metal.

[0018] In this outer pipe 10, a first pin Pi1 is fixed to the end of the tip side Ar1, which has a cylindrical shape extending in a direction perpendicular to the plane of the paper in Figure 1, and engages with the jaw 11 and supports the jaw 11 so that it can rotate.

[0019] The outer peripheral surface of the outer pipe 10 is covered with an electrically insulating outer tube (not shown). A tubular inner pipe (not shown) that moves back and forth along the longitudinal direction of the outer pipe 10 in response to an opening or closing operation of the operating handle 7 by an operator such as a surgeon is inserted inside the outer pipe 10. A second pin (not shown) that has a cylindrical shape extending in a direction perpendicular to the plane of the paper in Fig. 1 and engages with the jaw 11 is fixed to the end of the tip side Ar1 of the inner pipe.

[0020] The jaw 11 is connected to the outer pipe 10 by the first pin Pi1. The jaw 11 is also connected to the inner pipe by the second pin. The jaw 11 rotates about the first pin Pi1 relative to the outer pipe 10 in conjunction with the forward and backward movement of the inner pipe in response to an opening and closing operation of the operating handle 7 by an operator such as a surgeon. This causes the jaw 11 to open and close relative to a treatment section 121, which is the distal end of the ultrasonic blade 12, and enables the jaw 11 to grasp a treatment target between the treatment section 121 and the jaw 11.

[0021] The treatment tool 2 may be configured as a push-close type or a pull-close type.

[0022] The push-close type has the following configuration: The jaw 11 rotates around the first pin Pi1 in a direction approaching the treatment unit 121 in conjunction with the movement of the inner pipe toward the distal end side Ar1. That is, the jaw 11 closes relative to the treatment unit 121. The jaw 11 also rotates around the first pin Pi1 in a direction away from the treatment unit 121 in conjunction with the movement of the inner pipe toward the proximal end side Ar2. That is, the jaw 11 opens relative to the treatment unit 121.

[0023] The pull-close type has the following configuration: The jaw 11 rotates around the first pin Pi1 in a direction approaching the treatment portion 121 in conjunction with the movement of the inner pipe toward the base end side Ar2. That is, the jaw 11 closes relative to the treatment portion 121. Also, the jaw 11 rotates around the first pin Pi1 in a direction away from the treatment portion 121 in conjunction with the movement of the inner pipe toward the tip end side Ar1. That is, the jaw 11 opens relative to the treatment portion 121.

[0024] The detailed configuration of the jaw 11 will be described later in the section "Configuration of the jaw."

[0025] The ultrasonic blade 12 is made of a conductive material and has an elongated shape extending along the central axis Ax1. The ultrasonic blade 12 is inserted into the inner pipe with the treatment portion 121 protruding outward. At this time, the end of the proximal side Ar2 of the ultrasonic blade 12 is mechanically connected to the ultrasonic vibrator 52 constituting the transducer 5, as shown in FIG. 1 . The ultrasonic blade 12 transmits ultrasonic vibrations generated by the transducer 5 from the end of the proximal side Ar2 to the treatment portion 121. The ultrasonic vibrations are longitudinal vibrations that vibrate in a direction along the central axis Ax1. The outer peripheral surface of the ultrasonic blade 12, excluding the treatment portion 121, is covered by an electrically insulating inner tube.

[0026] The transducer 5 corresponds to the medical device according to the present invention. That is, the transducer 5 is a medical device that can be repeatedly used by cleaning, disinfecting, or sterilizing it using a chemical solution. Note that the medical device according to the present invention is not limited to the transducer 5, and other medical devices may also be used. As shown in FIG. 1 , the transducer 5 includes a TD (transducer) case 51 and an ultrasonic vibrator 52.

[0027] The TD case 51 supports the ultrasonic vibrator 52 and is detachably connected to the fixed handle 6. In this embodiment, the TD case 51 is made of a resin material. Examples of the resin material include polyphenylsulfone and polyetheretherketone.

[0028] The ultrasonic vibrator 52 generates ultrasonic vibrations in accordance with the supplied power under the control of the control device 3. In this embodiment, the ultrasonic vibrator 52 is configured by a BLT (bolt-tightened Langevin type vibrator).

[0029] [Configuration of the control device] The control device 3 comprehensively controls the operation of the treatment tool 2 via the electric cable C (Fig. 1). Specifically, the control device 3 detects a treatment operation on the switch 8 by an operator such as a surgeon via the electric cable C. When the control device 3 detects the treatment operation, it applies treatment energy to the treatment target grasped between the jaw 11 and the treatment section 121 via the electric cable C. In other words, the control device 3 treats the treatment target.

[0030] For example, when ultrasonic energy is applied to a treatment target, the control device 3 supplies driving power to the ultrasonic vibrator 52 via the electric cable C. This causes the ultrasonic vibrator 52 to generate longitudinal vibrations (ultrasonic vibrations) that vibrate in a direction along the central axis Ax1. The treatment section 121 also vibrates at a desired amplitude due to the longitudinal vibrations. Then, ultrasonic vibrations are supplied from the treatment section 121 to the treatment target grasped between the jaw 11 and the treatment section 121. Ultrasonic energy is applied from the treatment section 121 to the treatment target.

[0031] Furthermore, for example, when applying high-frequency energy to a treatment target, the control device 3 supplies high-frequency power between the jaw 11 and the ultrasonic blade 12 via the electric cable C or the like. When high-frequency power is supplied between the jaw 11 and the ultrasonic blade 12, a high-frequency current is supplied to the treatment target grasped between the jaw 11 and the treatment section 121. In other words, high-frequency energy is applied to the treatment target.

[0032] [Method for manufacturing a medical device] Next, a method for manufacturing a medical device such as the transducer 5 described above will be described. Note that, hereinafter, only the essential steps of the method for manufacturing a medical device such as the transducer 5 will be described. FIG. 2 is a flowchart showing a method for manufacturing a medical device according to an embodiment. FIG. 3 is a diagram illustrating a method for manufacturing a medical device. Specifically, FIG. 3 shows the outer surface of the TD case 51. Note that in FIG. 3, the orientation of the fibrils 120 is represented by straight lines.

[0033] First, the worker performs the following step (step S1). Step S1 is a step of performing a blasting treatment using alundum on the outer surface of the TD case 51 made of a resin material. This blasting treatment corresponds to the second blasting treatment according to the present invention. The alundum is a media having corners, and corresponds to the second media according to the present invention. By performing step S1, the outer surface of the TD case 51 is scraped by the collision of the alundum, resulting in an uneven shape, as shown in FIG. 3(a).

[0034] Here, the grain size of the alundum used in the blasting treatment in step S1 is preferably #1000 or more.

[0035] After step S1, the worker performs the following step (step S2). Step S2 is a step of performing a blasting treatment using glass beads 200 on the outer surface of the TD case 51 made of a resin material. This blasting treatment corresponds to the first blasting treatment according to the present invention. By performing step S2, the orientation of the fibrils 120, which were originally vertical in FIG. 3B, changes to horizontal on the outer surface of the TD case 51 as shown in FIG. 3B due to the collision of the glass beads 200, and voids (for example, voids 130 in FIG. 6B) are crushed.

[0036] The particle size of the glass beads 200 used in the blasting treatment in step S2 is preferably #100 or larger. The particle size of the glass beads 200 is preferably larger than the particle size of the alundum used in the blasting treatment in step S1.

[0037] The media used in the blasting process in step S2 is not limited to the glass beads 200, and other media may be used as long as they are media without corners.

[0038] The present embodiment described above provides the following advantages. The method for manufacturing a medical device according to the present embodiment includes a step (step S2) of changing the orientation of the fibrils 120 by performing a first blasting treatment on the outer surface of the medical device made of a resin material. Therefore, the method for manufacturing a medical device according to the present embodiment can suppress the occurrence of solvent cracks in the medical device that are caused by the aligned orientation of the fibrils 120.

[0039] In particular, the first blasting treatment uses glass beads 200, which are media without corners, so that the orientation of the fibrils 120 can be changed efficiently and the voids 130 can be crushed without scraping the outer surface of the medical device.

[0040] The effects of the present invention will now be described based on specific examples. Comparative Example 1 The sample of Comparative Example 1 is a sample in which no treatment was performed on the outer surface of the TD case 51 made of a resin material.

[0041] Example 1 The sample of Example 1 is a sample in which the outer surface of the TD case 51 made of a resin material was subjected to only a treatment of leaving it at 200° C. for 8 hours (hereinafter referred to as heat treatment).

[0042] Example 2 The sample of Example 2 is a sample in which only the blasting treatment of step S2 described above was performed on the outer surface of a TD case 51 made of a resin material.

[0043] Example 3 The sample of Example 3 is a sample in which the outer surface of the TD case 51 made of a resin material is subjected to the above-described heat treatment and then to the blast treatment of step S2.

[0044] [Example 4] The sample of this Example 4 is a sample in which the outer surface of a TD case 51 made of a resin material was subjected to the blasting treatment of the above-mentioned step S1, and then to the blasting treatment of the above-mentioned step S2.

[0045] [Example 5] The sample of this Example 5 is a sample in which the outer surface of a TD case 51 made of a resin material is subjected to the above-mentioned heat treatment, followed by the blast treatment of step S1, and then the blast treatment of step S2.

[0046] [Evaluation Results] Figure 4 shows the evaluation results of the samples of Comparative Example 1 and Examples 1 to 5. The samples of Comparative Example 1 and Examples 1 to 5 were immersed in a chemical solution such as a disinfectant solution, and the samples were removed every predetermined time and evaluated under a microscope for the occurrence of solvent cracking. In Figure 4, samples that exhibited solvent cracking after a short immersion time were rated as "x", and as the immersion time required for solvent cracking to occur became longer than the "x" rating, the evaluation was given in the order of "△" and "◯". Furthermore, samples that did not exhibit solvent cracking even after a long immersion time were rated as "◎".

[0047] As a result, as can be seen from the evaluation results of the samples of Examples 2, 4, and 5, it was found that the occurrence of solvent cracks can be suppressed by performing a blasting treatment using glass beads 200. Furthermore, as can be seen from the evaluation results of the sample of Example 4, it was found that the most effective way to suppress the occurrence of solvent cracks is to perform a blasting treatment using alundum followed by a blasting treatment using glass beads 200.

[0048] (Other Embodiments) Up to this point, the embodiments for carrying out the present invention have been described, but the present invention should not be limited to only the above-described embodiments. Fig. 5 is a diagram illustrating a modified embodiment. Specifically, Fig. 5 is a flowchart showing a modified method for manufacturing a medical device. In order to suppress the occurrence of solvent cracks, the method for manufacturing a medical device shown in Fig. 5 may be adopted.

[0049] First, an operator performs the following step (step S100). Step S100 is a step of placing a coating agent and a medical device such as a transducer 5 whose outer surface is made of a resin material in a predetermined container. An example of the coating agent is a fluorine-based monomolecular water repellent agent.

[0050] After step S100, the operator performs the following step (step S200): Step S200 is a step of reducing the pressure inside the container described above.

[0051] After step S200, the worker performs the following step (step S300): Step S300 is a step of applying vibration to the container described above.

[0052] By performing step S200, the volume of air in the voids (e.g., void 130 in FIG. 6(b)) contained in the medical device stored in the container described above increases. Then, by performing step S300 once the air has escaped from the outer surface of the medical device to the outside, the coating agent is allowed to penetrate into the interior of the medical device. This makes it possible to suppress the occurrence of solvent cracking.

[0053] REFERENCE SIGNS LIST 1 treatment system 2 treatment tool 3 control device 4 handpiece 5 transducer 6 fixed handle 7 operating handle 8 switch 9 rotation knob 10 outer pipe 11 jaw 12 ultrasonic blade 51 TD case 52 ultrasonic vibrator 100 resin member 110 craze 120 fibril 121 treatment portion 130 void 200 glass beads Ar1 distal end side Ar2 proximal end side Ax1 central axis C electric cable Pi1 first pin

Claims

1. A method for manufacturing a medical device that can be repeatedly used by cleaning, disinfecting, or sterilizing it using a chemical solution, the method including a step of changing the orientation of fibrils by performing a first blasting treatment on the outer surface of the medical device, which is made of a resin material.

2. The method for manufacturing a medical device according to claim 1, wherein the first blasting treatment uses media with no corners.

3. The method for manufacturing a medical device according to claim 2, wherein the media is glass beads.

4. The method for manufacturing a medical device according to claim 3, wherein the particle size of the glass beads is #100 or larger.

5. A method for manufacturing a medical device according to claim 1, wherein the first blasting treatment changes the orientation of the fibrils and collapses voids.

6. A method for manufacturing a medical device as described in claim 1, which includes a step of performing a second blasting treatment on the outer surface using a second media different from the media used in the first blasting treatment before the first blasting treatment.

7. The method for manufacturing a medical device according to claim 6, wherein the second blasting treatment uses the second media having corners.

8. The method for manufacturing a medical device according to claim 6, wherein the second medium is alundum.

9. A method for manufacturing a medical device according to claim 6, wherein the particle size of the second media is smaller than the particle size of the media used in the first blasting treatment.

10. A method for manufacturing a medical device according to claim 6, wherein the particle size of the second media is #1000 or greater.

11. The method for manufacturing a medical device according to claim 1, wherein the resin material is polyphenylsulfone or polyetheretherketone.

12. The method for manufacturing a medical device according to claim 1, wherein the medical device is a transducer used in an ultrasonic treatment tool that generates ultrasonic vibrations in response to supplied power.

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