JPH03297462A - Microsurgery cannula - Google Patents

Abstract

PURPOSE: To decrease injuries inflicted on the eye to be operated for increased safety, guarantee high suction efficiency by means of low water pressure, and reduce suction time by forming a microsurgery cannula from a suction tube which communicates to a hollow adapter head at one end and has a suction opening over the side face of the other end and whose flow passage cross-section area increases monotonously from the other end to the hollow adapter head throughout its length. CONSTITUTION: A microsurgery cannula comprises a hollow adapter head 1 designed to communicate to a syringe or an aspirator and a suction tube 2 connected to the head 1 via one end. The inner passage 3 of the suction tube 2 communicates to the tapered inlet opening 4 of the hollow adapter head 1. A suction opening 6 is provided over the side face of the other space end 5 of the suction tube 2. The flow passage cross-section of the inner passage 3 of the suction tube 2 increases monotonously from the space end 5 to the hollow adapter head 1 over the entire suction tube length. Thereby water pressure resistance is decreased, the extraction time of crystalline lumps is reduced, and the contact time between ocular tissue and a surgical instrument is reduced, whereby injuries to the tissue can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates generally to medical engineering, and more particularly to microsurgical cannulae.

The present invention is applicable to cataract treatment, that is, crystalline masses (crystalline lumps)
It is most practical in eye surgery for the purpose of enucleating and removing talline w+asses.

[Conventional technology]

Microsurgery cannulae (Gan5 Gen, Federal Republic of Germany) currently known in the art
Catalog by der Co, Catalog No.

G-15280, No. G-15285) consists of a suction tube connected at one end to a hollow adapter head and having a suction opening on the side of the open other end. The suction tube is characterized in that the entire length from the open end toward the hollow adapter head has a constant cross-sectional area, and the cross-sectional area is circular.

The microsurgery cannula can be connected via a tapered inlet in the hollow adapter head to a pipe connection or to a suction system, either of which is used for aspiration of the crystalline mass from the lens color and subsequent removal of the lens nucleus. Rarefaction in the suction tube
form. However, this known microsurgery cannula has a crystalline mass (with a considerable density that falls within the range of 15.7 to 32P, which is the structural parameter of the suction tube).
cortical layer), and is characterized by a relatively low suction efficiency due to the structure and total area of the crystalline mass.

The structural parameters of this suction tube have the following correlation with suction efficiency. The inner diameter of the suction tube including the limited outer diameter of the suction tube 7 (0.4 to 1.0 mm) is 0.1
6 to 0.8 mm, while the internal cross-sectional area of the suction tube is in the range 0.08 to 2.0 mm''.

The outer diameter of this or other suction tubes depends on the surgical technique used in the ophthalmic surgery and the physiology of the operated eye.

Thus, for example, a dense crystalline mass can be aspirated by a microsurgery cannula with a large flow area. However, the large internal cross-sectional area results in a large external diameter and the large external surface area of the suction tube of known microsurgical cannulae contacts the patient's tissue, causing additional damage. On the other hand, the use of microsurgery cannulae with small external diameters on dense crystalline masses leads to surgical complications with increased aspiration time due to high hydraulic resistance. The hydraulic resistance is greatly influenced by the area of the suction opening.

In the known microsurgery cannula, the side suction opening is circular, the diameter of which does not exceed the internal diameter of the suction tube and does not reduce the water pressure at the inlet of the suction tube.

(Problems to be Solved by the Invention) The basic and essential purpose of the present invention is to reduce trauma to the operated eye by the configuration of the suction tube 7, increase safety in actual use, and provide high suction with low water pressure. An object of the present invention is to provide a microsurgery cannula that can guarantee efficiency and shorten suction time.

[Means and effects for achieving the object] The above object is to have one end communicating with the hollow adapter head and a suction opening on the side surface of the other end, the cross-sectional area of the flow path being connected to the other end. This is achieved by a microsurgery cannula consisting of a suction tube that increases monotonically over its entire length from the top to the top of the hollow adapter.

Providing a suction tube characterized by a monotonically increasing flow cross-sectional area reduces hydraulic resistance, thereby shortening the extraction time of the crystalline mass and reducing the contact time of surgical instruments with ocular tissue, reducing the It has a structural advantage over previously known microsurgical cannulae having a constant cross-section flow path area in reducing tissue trauma. Furthermore, since the size (effective) of the other end of the opening of the microsurgery cannula of the present invention can be reduced without affecting the hydraulic resistance value, the device can be made more compact. This also reduces damage to the involved tissues. Providing a suction tube with the above characteristics is furthermore convenient for cleaning and pre-sterilization cleaning.

The suction opening on the side surface of the suction tube is elliptical, the area of which exceeds the cross-sectional area of the suction tube in the area of the opening, and the main axis of the opening is elliptical. Preferably, it is set along the long axis.

The microsurgery cannula configured as described above reduces the input resistance of the internal passageway of the microsurgery cannula. The oval suction opening is one of the best shapes for the inflow of crystalline mass at the inlet of the suction tube, with a linear flow extending along the long axis of the suction tube. Furthermore, rupture in the crystalline block method does not occur in the case of dense blocks. The risk of sharp pressure oscillations at the inlet of the suction tube and the entire interior of the biconvex microsurgery cannula is reduced. This surgery is performed in a closed room,
This is particularly important when the surgery requires minimal corneal ablation and the provision of irrigation fluid. In such a case, a constant pressure must be applied to the chamber so that the fluid enters the chamber at the same speed as the fluid exits. Additionally, high pressure fluctuations can cause damage to ocular tissue.

Preferably, the suction tube of the present invention has a circular cross-sectional flow region.

Such a shape allows the cannula to provide better closure for surgical wound sealing when used in closed chamber surgery compared to the prototype circular suction tube.Furthermore, the circular cross-sectional flow path of the suction tube The incision (i.e., surgical wound) is made smaller to avoid surgical trauma.The suction tube with a circular cross-sectional flow path according to the present invention has a smaller diameter at the effective end of the suction tube than the prototype, thereby reducing the surgical trauma. Coverage can be minimized.

It is practical for the suction tube of the present invention to have a flow path area with an elliptical cross section.

A suction tube with such a structure closes the cannula with "closure 1".
When used indoors, it is ideal for sealing surgical wounds. This is because the oval cross-section of the suction tube reduces the concentration of tissue stress to the greatest extent at the corners (edges) of the surgical wound. Compared to a suction tube with a circular cross section, a suction tube with an oval cross section is suitable for introducing the microsurgery cannula into a surgical wound because the shape of the microsurgery cannula almost resembles a surgical wound.

The cross-section of the flow path region of the suction tube according to the invention may be biconvex.

Such a biconvex cross-sectional flow region reduces the occlusion of the inlet suction opening during "closed" chamber procedures since the anterior chamber does not close the inlet opening.

The irrigation tube is located outside the coaxial suction tube, has an air gap therebetween, and has a flow path with an elliptical cross section that increases monotonically from the spatial end of the suction tube, and has an air gap between the suction tube and the suction tube. the suction tube has a section, while the spatial end of the suction tube extends from the irrigation tube.

Irrigation tube placement reduces the amount of trauma when performing surgery by requiring only one incision and reducing its length. Furthermore, it best seals the surgical wound. The installation of the irrigation tube according to the invention allows for the best circulation of the irrigation fluid and thus improves the cleaning of the crystalline mass.

In order to reduce tissue stress when introducing the microsurgery cannula into the surgical wound, the region of the end of the irrigation tube must have a symmetrical slope. This gradient is inclined to the long axis of the irrigation tube at an obtuse angle to the main axis of the oval suction opening and is connected to the suction tube at least in the region of the end.

Such a configuration reduces the risk of tissue destruction when introducing the microsurgery cannula, and a structure with an appropriate slope angle prevents tissue damage when introducing the microsurgery cannula into a surgical wound and improves the effectiveness of the flow path. The increased area provides laminar flow.

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[Examples and effects]

The microsurgery cannula according to the invention includes a hollow adapter head 1 (FIG. 1) configured to communicate with a syringe (not shown) or a suction device (not shown), and one end in the head 1. It consists of a suction tube 2 connected through a section. The inner passage 3 of the suction tube 2 communicates with the tapered inlet hole 4 of the hollow adapter head 1. A suction opening 6 is provided on the side surface of the other spatial end 5 of the suction tube 2 .

The cross section of the flow path area of the inner passage 3 of the suction tube 2 is the space end 5
from the hollow adapter head 1 over the entire suction tube length.

Suction opening 6 of the space end 5 of the suction tube 2 (
(Fig. 2) is oval in shape, the area of which is larger in the area of the suction opening 6 than the flow path area of the suction tube 2, the main axis 7 of the suction opening 6 being the long axis 8 of the suction tube 2 (Fig. 1).
is set according to. The microsurgery cannula according to the invention works as follows.

The hollow adapter head 1 (FIG. 1) is connected via a tapered inlet hole 4 to a syringe or an aspiration device (both not shown). The spatial end 5 of the suction tube 2 is inserted into the lens capsule (not shown) through an incision in the ocular tissue. A dilute condition is then created in the suction tube 2 by means of a syringe or suction device, whereby the crystalline mass is suctioned from the capsule of the lens through the suction opening 6. If the suction opening 6 is elliptical, the entrance resistance of the inner passage 3 of the microsurgery cannula is reduced and the best shape is created for the inflow of the crystalline mass, which inflow follows the long axis 8 of the suction tube 2. spreads along.

The extraction time of the crystalline mass is considerably reduced due to the relatively low hydraulic resistance created. The low hydraulic resistance is due to the suction tube 2, which is characterized by a monotonically increasing flow cross-section from the space end 5 to the hollow adapter head 1, which also reduces the contact time between the tissue and the instrument. Reduce the degree of trauma to the tissue.

A feature of the suction tube 2 is that the cross-sectional shape of the flow path can be varied in accordance with the specific extraction procedure of the crystalline mass and the physiological specificity of the eye to be operated on.

FIG. 3 shows the suction tube 2 having a flow path 9 with a circular cross section.
shows. This channel 9 provides better sealing of the surgical wound when used in closed room surgery compared to the circular suction tube of the prototype. Due to the shortening and warping, surgical trauma is reduced.A suction tube 2 with such a cross-sectional channel 9 minimizes the degree of closure of the surgical site area.

The suction tube 2 may have an oval cross-section channel 10 (FIG. 4). In "closed" room surgery, the oval cross-section channel 10 provides the best seal since the surgical wound is oval and the oval cross-section channel 10 maximizes the reduction of stress concentration at the corners of the surgical wound. provide.

Another aspect of the suction tube 2 is a flow path 1 having a biconvex cross section.
1 (FIG. 5). Such a biconvex channel 11 is
Reduces the closure of the inlet suction opening 6 in "closed" chamber surgery compared to the circular channel 9 (FIG. 3) and the oval channel 10 (FIG. 4) described above.

The operation of the microsurgery cannula having the suction tube 2 having the flow passages 9 (FIG. 3), 10 (FIG. 4), or 11 (FIG. 5) with various cross-sectional shapes is as described above. be.

In order to reduce surgical trauma by performing a single incision, to enable the best possible sealing of the surgical wound, and to achieve the best possible circulation of irrigation fluid for good cleaning of the crystalline mass, this book was developed. The microsurgery cannula of the invention includes an irrigation tube 12 (FIG. 6).

Said irrigation tube 12 is arranged coaxially with said suction tube 2 and forms an air gap therebetween, with an end 14 (seventh
It has an elliptical cross-sectional flow path that monotonically increases from the spatial end 13 with a diameter (see Fig.). In this case, the spatial end 5 (FIG. 6) of the suction tube 2, which is provided with the suction opening 6, is connected to the irrigation tube 12.
Extending outward from.

Said irrigation tube 12 is provided in the area of the hollow adapter head 1 , which is connected to an irrigation device (not shown) via a pipe connector 16 and a tube 17 and is provided with a tapered inlet hole 19 . is connected to.

In order to reduce the stress on the ocular tissue during the introduction of the microsurgery cannula into the surgical wound, the irrigation tube 12 has a symmetrical bevel 20 in the region of the end 14 (FIG. 7).
(FIG. 8), which is inclined towards the long axis of the irrigation tube 12 at an obtuse angle α to the principal axis of the oval suction opening 6 and which, at least in the region of the end 22, has a suction tube 2 (FIG. 7). ) is connected to. Symmetrical slope section 22 in irrigation tube 12
In addition to reducing the risk of tissue destruction during the introduction of the microsurgery cannula into the surgical wound, the attachment (FIG. 8) also generates laminar flow due to the increased effective cross-sectional area.

The irrigation tube 12 is used in a microsurgery cannula, and the suction tube 2 (FIG. 7) has a circular cross-section channel 9. In this case, the outer diameter of the suction tube 2 is equal to the diameter of the semi-minor axis of the oval cross-section channel of the irrigation tube.

The microsurgery cannula using the irrigation tube according to the invention works as follows.

The hollow adapter head 1 (FIG. 6) is connected via a tapered inlet hole 4 to the suction pipeline of a suction-irrigation device (not shown). Similarly, the hollow adapter head 18 is connected by a tapered inlet hole 19 to the irrigation pipeline of the device. The space end 5 of the suction tube 2 is provided with a lens (not shown).
inserted into the capsule of The flow of irrigation fluid is supplied to the hollow adapter head 18, the tube 17, the pipe connector 16, the chamber 15 and the inner passageway 23 of the irrigation tube 12, and the hole 14 in the end 22 of the irrigation tube 12 (FIG. 7). The flow from the water washes the crystalline mass. At the same time, the cleaned crystalline mass is removed (suctioned) from the suction opening 6, the inner passage 3 of the suction tube 2 and the hollow adapter head 1. The hollow adapter head 1 communicates with the appropriate pipelines of the device.

In order to make the above effect even more effective, the suction tube 2
and the irrigation tube 12 may be curved (not shown).

The microsurgery cannula according to the invention reduces the water pressure through the suction tube by a factor of 2.5 by providing the suction tube characterized by a monotonically increasing wave cross-section from the spatial end 5 to the hollow adapter head. In addition, the feature of having the same diameter as the spatial end of the suction tube increases the suction time of crystalline lumps by 1.5% compared to the prototype.
reducing the risk of damage to ocular tissue at the same time.

The gradient on the end of the irrigation tube distributes the fluid flow to efficiently clean the crystalline mass.

Furthermore, the best head pressure of the fluid flow at the outlet of the irrigation tube is made possible by selecting the ratio of the inclined trapezoidal angles of the internal passageway of the irrigation tube.

[Brief Description of the Drawings] Fig. 1 is an overall explanatory diagram of the microsurgery cannula according to the present invention, Fig. 2 is an enlarged view of the suction opening taken along the arrow in Fig. 1, and Fig. 3 is an enlarged view of the suction opening taken along the arrow in Fig. 1. 1 is a sectional view of a suction tube according to the invention having a circular cross-sectional flow path along the line III--III in FIG. 1; FIG. 5 is a sectional view of a suction tube according to the invention with a biconvex cross-sectional channel along the line V-V of FIG. 1; FIG. 7 is a sectional view taken along the line Vll-vII in FIG. 6, and FIG. 8 is a view taken in the direction of arrow B in FIG. 6. 1°, . 2. 30. . 19 51. . 69. . Hollow adapter head suction tube suction tube internal passage 10. Tapered inlet hole suction tube space end suction opening 7. 8. . 9. 10゜11゜12゜13゜14゜15゜16゜17゜18゜20゜21゜22゜23゜α. d. b. Suction opening Main axis Suction opening Long axis Circular cross section Channel Oval cross section Channel Biconvex cross section Channel Irrigation tube Irrigation tube Space end End chamber Pipe coupler Tube adapter Head Symmetric Gradient section Irrigation tube Long axis Irrigation tube end Irrigation tube inner passage A: Oblique suction tube outer diameter Irrigation tube oval cross-sectional area semi-minor axis FID, 5

Claims (7)

[Claims] 1. It consists of a suction tube (2) communicating with the hollow adapter head (1) at one end and having a suction opening (6) on the side surface of the other end (5) of the space, the flow path of said suction tube (2) A microsurgery cannula characterized in that a cross section monotonically increases over the entire length from the other end of the space (5) to the hollow adapter head (1). 2. The suction opening (6) on the side of the suction tube (2) is oval shaped and its area is defined by the suction opening (
6) larger than the flow path cross-sectional area of the suction tube (2) in the area, and the main axis (7) of the oval suction opening (6) is along the long axis (8) of the suction tube (2); The microsurgery cannula of claim 1, characterized in that: 3. Microsurgery cannula according to claim 2, characterized in that the suction tube (2) has a circular cross-section channel (9). 4. The suction tube (2) has an oval cross-section flow path (10)
The microsurgery cannula according to claim 2, characterized in that it has: 5. The suction tube (2) has a biconvex cross-sectional flow path (11)
3. The microsurgery cannula of claim 2, further comprising: 6. Said suction tube (2) is housed in and coaxially arranged with the irrigation tube (12) and has an air gap therebetween, said irrigation tube extending from the spatial end (13) forming an end hole (14). The spatial end (5) of the suction tube (2), which has a monotonically increasing elliptical cross-sectional flow path and is provided with the suction opening (6), is connected to the irrigation tube (1).
4. The microsurgery cannula of claim 3, wherein the microsurgery cannula extends from 2). 7. Said irrigation tube (12) forms a symmetrical gradient section (20) in the region of said end hole (14), said symmetrical gradient section forming a main axis (7) of said suction opening (6) with said oval cross-section channel. At an obtuse angle (α) to the irrigation tube (12
Microsurgery cannula according to claim 6, characterized in that it is oblique to the long axis (21) of the tube and communicates with the suction tube (2) at least in the end region (22).