JPS6451B2 - - Google Patents

Description

Detailed Description of the Invention The present invention provides an endoscope that allows the insertion part of the endoscope to be smoothly inserted into a body cavity when using the endoscope to observe or treat the inside of a body cavity. This invention relates to improvements in insertion guide tubes.

This type of insertion guide tube includes an insertion section for insertion into a body cavity through which an insertion section of an endoscope can be inserted. In use, the insertion section for insertion into a body cavity is inserted into the oral cavity, and then the insertion section of the endoscope is inserted into this insertion section. Using the insertion portion as a guide, the device can be easily and smoothly inserted into the body cavity.

However, when inserting the insertion part for insertion into a body cavity, the diameter of the insertion part for insertion into a body cavity is larger than that of an endoscope.
Insertion into a body cavity is difficult and causes great pain to the patient.

Therefore, an insertion guide tube has been developed in which the radial cross-sectional area of the insertion portion for insertion into a body cavity is changed during insertion to facilitate insertion and reduce patient pain. Most conventionally known devices are designed to change the radial cross-sectional area of an insertion portion for insertion into a body cavity by mechanical or fluid manipulation. As a typical example, first, a plurality of pieces formed by rotatably supporting a pair of semicircular rings are fixed in a line in a flexible tube, and the pivots of each piece are fixed in a flexible tube. They are connected by a side stay to form an insertion section for insertion into a body cavity, and the diameter of the insertion section is changed in the radial direction by relative movement of the side stay and the flexible tube along the axial direction. There is something. Second, a plurality of cylindrical balloons are arranged in series in the axial direction through a fluid flow path to constitute an insertion section for insertion into a body cavity, and the fluid can be injected and discharged from each balloon in the same manner. There are some that change in the radial direction. Third, a cylindrical coil formed by winding a coil piece constitutes an insertion section for insertion into a body cavity, and a part of this coil is moved forward and backward in the axial direction with an operating wire, etc. There is also one that similarly changes in the radial direction by flattening.

However, all of these insertion guide tube structures have problems in practical use because they are structurally complex and the handling operations involved in changing the radial cross-sectional area are complicated.

This invention was made in view of the above circumstances, and its purpose is to construct an insertion section for insertion into a body cavity using a shape memory alloy, and to reverse the shape memory alloy of the insertion section by heating means. With a structure that causes transformation and changes the radial cross-sectional area of the insertion part,
An endoscope insertion guide tube with a simple structure that facilitates insertion into a body cavity, reduces pain to the patient due to insertion, and facilitates handling operations. This is what we are trying to provide.

A first embodiment of the present invention will be described below with reference to the drawings. Figure 1 shows the insertion guide tube.
is an insertion portion for insertion into a body cavity. The insertion section 1 is basically constructed by covering a tubular member 2 with an outer sheath 3. A cylindrical mouthpiece 4 is connected to the end of the insertion portion 1, forming an insertion guide tube structure for insertion into the oral cavity.

To explain the structure of the insertion portion 1 in detail, the tubular member 2 is insulated with a wire material 2a made of a so-called shape memory alloy such as a Cu-Zn-Al alloy or a Ti-Ni alloy. The elastic spiral tube 5 has a double-wound structure in which a heating wire 2b, which is an electric heating element, is wound in two spiral tubes. The inner and outer circumferential surfaces of the elastic spiral tube 5 are closely covered with an elastic member 6 made of silicone resin, urethane resin, rubber, etc., except for the end portion used for connection with the mouthpiece 4. In addition to constituting the third part,
It constitutes an insertion section 1 having a small diameter. That is, the elastic helical tube 5 is first in a high-temperature phase, the so-called matrix phase, so that the insertion portion 8 of the endoscope 7 can be fully inserted through it, including the outer sheath 3a, as shown in FIGS. 3 and 4. An elastic helical tube 5 having an outer dimension and shape including an inner diameter, that is, a circular radial cross-sectional shape with an outer dimension D is formed. Next, this elastic helical tube 5 is transformed into martensitic material, and as shown in FIG.
And the uneven waveform 9 along the radial direction on the heating wire 2b...
is plastically deformed into a ring shape, and its external dimension d in its normal state is smaller than the external dimension D in the parent phase (high temperature phase), that is, it has a small diameter that makes it impossible for the endoscope 7 to pass through. The relationship D>d is maintained. In other words, the elastic helical tube 5 has a shape memory effect in which the circular cross-sectional shape of the parent phase (high temperature phase) is memorized in the state of fine grains having normal uneven waveforms 9 . Further, the temperature at which reverse transformation starts, which is caused by the heating that causes so-called reverse transformation to form the shape of the parent phase (high-temperature phase), is set to be higher than room temperature, for example, near body temperature.

The heating structure for causing the reverse transformation of the insertion portion 1 configured as described above includes the elastic spiral tube 5,
In other words, one end of the heating wire 2b provided in the tubular member 2 on the mouthpiece 4 side is connected to the mouthpiece 4.
Similarly, the other end on the distal side of the insertion section 1 is once exposed to the outer sheath 3 of the insertion section 1, and the mouthpiece 4 is inserted through the side wall 4a of the Similarly, the contact point 11 is formed by passing through the side wall 4a of the mouthpiece 4 and exposing it to the end surface of the mouthpiece 4. This contact point 11 is configured by connecting a power source 12 detachably, and by supplying electricity to the heating wire 2b side by turning the power source 12 ON and OFF,
The insertion portion 1, which has a small radial cross-sectional shape under normal conditions, that is, at room temperature (before and after 25°C), is replaced by the heating element 2b.
By being heated, the radial cross-sectional shape can maintain a required inner diameter sufficient for insertion of the insertion portion 8 of the endoscope 7. That is, the heating means 13 is configured by the heating wire 2b and the power source 12 configuration. In addition, when covering the outer sheath 3, as shown in FIG. Elastic spiral tube 5 except for (close contact)
It may be configured so that it does not come into close contact with the
According to such a jacket structure, the space between the outer surface of the elastic spiral tube 5 and the inner surface of the jacket 3 on the outer peripheral side is used to
The end of the heating wire 2b exposed in this space can be inserted, and the outer peripheral surface of the insertion portion 1 can be made circular in the normal state, contributing to smoothing the outer surface of the insertion portion 1. The smoothness of insertion of the insertion portion 1 can be improved.

In the figure, reference numeral 14 denotes a sponge-like gasket, which is provided on the inner circumferential surface of the mouthpiece 4 connected to the insertion section 1 and is used to elastically bring the outer circumferential surface of the insertion section 8 of the endoscope 7 into close contact.

When observing from the oral cavity with the endoscope 7 or performing a treatment using the insertion guide tube configured as described above, the outer diameter of the insertion portion 1 is first kept at room temperature (around 25°C). Outer diameter with reduced dimensions
Prepare an insertion guide tube having a diameter d′. Then, the insertion part 1 of the insertion guide tube is inserted into the gourmand through the oral cavity of the patient who is being examined, and when it is inserted into the predetermined insertion position, the mouthpiece 4 is bitten lightly with the teeth. , to securely hold the insertion guide tube.
Then, the power source 12 is connected to the contact 11 of the heating wire 2b, and electricity is supplied to the heating wire 2b to cause the heating wire 2b to generate heat. Thereafter, when the insertion part 1 rises to a preset reverse transformation temperature near body temperature by heating, the elastic helical tube 5 undergoes reverse transformation (martensitic phase → parent phase) and is set in the parent phase (high temperature phase). The cross-sectional shape changes to a circular cross-sectional shape (as shown in FIG. 4), and at the same time, the outer cover 3 also changes to follow the change. After this change, the inner diameter A of the insertion hole 1a of the insertion portion 1 is the same as that of the insertion portion 8 of the endoscope 7, as shown in FIG.
The insertion section 8 of the endoscope 7 can be inserted into the insertion section 1 at a point where the outer diameter A' becomes sufficiently larger than the outer diameter A'.

Then, the insertion section 8 of the endoscope 7 is inserted into the insertion section 1.
By inserting the endoscope 7, the distal end of the endoscope 7 is guided into the body cavity, and endoscopic examination such as observation or treatment using the endoscope 7 is performed. In addition,
During this examination, the endoscope 7 can be freely withdrawn or inserted through the insertion guide tube.

When the insertion guide tube is removed from the oral cavity after the examination, the temperature of the insertion section 1 is gradually lowered by turning off the power supply 12, and the elastic helical tube 5 undergoes transformation and the outer diameter of the insertion section 1 increases again. The insertion portion 1 becomes thinner, and can be easily removed by removing the insertion portion 1 in this reduced diameter state from the oral cavity.

Therefore, as described above, the insertion part 1 of the insertion guide tube is constructed using a shape memory alloy, and the cross-sectional area of the insertion part 1 is changed by reverse transformation by heating the shape memory alloy by the heating means 13. As a result, handling operations associated with changes in the insertion guide tube can be made simply by turning the power on and off. Furthermore, the structure is simple because the radial cross-sectional area of the insertion portion 1 is reversibly changed by utilizing the characteristics of the shape memory alloy. In addition, since the insertion portion 1 of the insertion guide tube maintains a small outer diameter at room temperature, that is, under normal conditions, it can be easily inserted into a body cavity, causing extremely little pain to the patient being examined. It is something that can be made into something.

In addition, in the above-mentioned embodiment, a tubular member made of a shape memory alloy is made of a wire material and a heat generating wire.
Although the insertion portion has been constructed from an elastic spiral tube wound into strips, it is not limited thereto. Embodiments that take this point into consideration are shown in FIG. 6 as the second embodiment, FIGS. 7, 8, 9, and 10 as the third embodiment, and 11 as the fourth embodiment. Each is shown as an example.

That is, in the second embodiment, the tubular member 2 is
The material is a thin strip member 20 made of a shape memory alloy such as a Cu-Zn-Al alloy or a Ti-Ni alloy, and a strip-shaped heating element 21 coated with insulation is tightly attached to the outer surface of the strip member 20. It is constructed from an elastic spiral tube 22 which is wound into a spiral tube shape. Note that the shape memory effect due to changes in the parent phase and martensitic phase in the elastic spiral tube 22 is the same as in the first embodiment described above. However, 23 is a lead wire connected to the heating element 21.

Further, the third embodiment is a band-shaped heating element 24 whose outer surface is coated with insulation and is made of a shape memory alloy such as a Cu-Zn-Al alloy or a Ti-Ni alloy.
The elastic helical tube 16 is formed by winding the thin band-shaped member 25, which is in close contact with the thin band member 25, into a spiral tube shape so as to have an inner diameter that allows the endoscope insertion portion to be inserted sufficiently in the parent phase (high temperature phase) state.
This is transformed into martensitic material, and this elastic helical tube 26 is further twisted in the winding direction at room temperature so that the cross-sectional shape becomes an outer diameter d'' smaller than the outer diameter D'' of the circular cross-sectional shape of the matrix. The outer circumferential surface of the elastic helical tube 26 in its normal state is covered with an elastic sheath 3 so as to be in close contact with the circumferential surface, and only both ends of this sheath 3 are covered. are fixed to both ends of the elastic spiral tube 26 to form the insertion portion 1.
It is designed to compose the following. However, even if the insertion portion 1 is configured in this way, when heated to a preset reverse transformation starting temperature,
Based on the reverse transformation, the elastic spiral tube 26 twists in the direction opposite to the winding direction, that is, in the direction of returning
The shape memory effect appears in the same manner as in the embodiment. 7 shows the state of the martensitic phase, FIG. 8 shows the cross-sectional shape at that time, FIG. 9 shows the state of the parent phase, and FIG. 10 shows the cross-sectional shape at that time.

The fourth embodiment replaces the tubular member 2 of the first embodiment with Cu-Zn-Al alloy or Ti-
A plurality of rings 27 made of a shape alloy such as a Ni-based alloy are arranged in parallel along the axial direction, and each ring 27 is connected to an insulated heating wire 28 which is a continuous wire member. This is what I did. Note that FIG. 11 shows the memorized shape state in the parent phase state, and the shape in the martensitic phase state is the same as in the first embodiment described above.

In addition, in the above-mentioned 2nd Example - 4th Example, the same component as the above-mentioned 1st Example was given the same number, and the description was abbreviate|omitted.

Further, in all of the embodiments described above, the present invention is applied to an insertion guide tube for insertion into the oral cavity, but it is of course applicable to an insertion guide tube for an endoscope for other purposes.

As explained above, according to the present invention, the insertion section for insertion into a body cavity is constructed of a tubular member made of a shape memory alloy and an elastic outer sheath that covers the tubular member and has a small diameter. Since the tubular member is provided with a heating means that heats the tubular member and changes the inner diameter of the insertion portion to a diameter through which the insertion portion of the endoscope can be inserted through reverse transformation, insertion of the insertion guide tube into the body cavity is facilitated. In this case, the tube can be inserted with a reduced diameter, making the insertion easy and reducing the pain caused to the subject during the insertion. In addition, the handling operation for changing the radial cross-sectional area of the insertion portion only requires turning on and off the power supply for heating the tubular member, and handling is easy and can be performed quickly. Furthermore, the structure is simple because the radial cross-sectional area of the insertion portion is reversibly changed using the characteristics of the shape memory alloy.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing the structure of the insertion guide tube in the normal state (martensitic phase) of the first embodiment of the present invention, FIG. 2 is a side sectional view of the insertion part at that time, and FIG. 3 is the same. FIG. 4 is a front sectional view showing the state configuration of the insertion guide tube when it is heated (mother phase); FIG. 4 is a side sectional view of the insertion portion at that time; FIG. FIG. 6 is a front cross-sectional view of the second embodiment of the present invention in normal state (martensitic phase), FIG. 7 is a front cross-sectional view of the third embodiment in normal state (martensite phase), and FIG. Figure 8 is a side sectional view of the insertion part at that time, Figure 9 is a front sectional view showing the state when heated (mother phase), Figure 10 is a side sectional view of the insertion part at that time, and Figure 11. FIG. 3 is a perspective view showing the structure of a tubular member according to a fourth embodiment. DESCRIPTION OF SYMBOLS 1...Insertion part, 2...Tubular member, 2b...Heating wire (electric heating element), 3...Outer cover, 8...Insertion part of endoscope, 12...Power source, 13...Heating means .

Claims (1)

[Scope of Claims] 1. An endoscope that is configured to include a freely insertable insertion section for insertion into a body cavity, and that guides the insertion section of the endoscope into the body cavity through this insertion section. In the insertion guide tube, the insertion portion for insertion into the body cavity is configured with a small diameter from a tubular member made of a shape memory alloy and an outer cover made of an elastic member covering the tubular member, An insertion endoscope characterized in that the tubular member is provided with a heating means for heating the tubular member and changing the diameter of the inner lumen of the insertion portion to a diameter through which the insertion portion of the endoscope can be inserted through reverse transformation. Guide tube. 2. The tubular member maintains the insertion part lumen at a small diameter that the insertion part of the endoscope cannot pass through below the reverse metamorphosis starting temperature, and keeps the insertion part lumen small enough to prevent the insertion part of the endoscope from passing through the insertion part lumen when the temperature exceeds the reverse transformation starting temperature. The insertion guide tube for an endoscope according to claim 1, characterized in that the endoscope insertion guide tube has a shape memory effect that changes the diameter to a large diameter through which the endoscope can be inserted. 3. The insertion guide tube for an endoscope according to claim 2, wherein the reverse transformation starting temperature is close to body temperature. 4. The insertion guide tube for an endoscope according to claim 1, wherein the tubular member is an elastic spiral tube formed by spirally winding a shape memory alloy material. 5. Claim 1, wherein the tubular member is constructed by arranging a plurality of rings made of a shape memory alloy in parallel along the axial direction, and connecting these rings with a wire member. The insertion guide tube for the endoscope described in Section 1. 6. The endoscope according to claim 1, wherein the heating means includes an electric heating element provided in a tubular member and a power source that supplies electricity to the electric heating element. insertion guide tube.