Illuminated Cannula System

Abstract

Cannulas suitable for use in minimally invasive surgery are improved with highly polished, extremely smooth lumen walls and / or LEDs or other light sources oriented at specific angles relative to the axis of the cannula. The device improves illumination and / or reduces illumination requirements for cannulas used in minimally invasive surgery.

Description

[Technical field]

[0001] The invention described below relates to the field of minimally invasive brain or spinal surgery. [Background technology]

[0002] No. 10,172,525 discloses a cannula and proximally mounted camera system for improving visualization of the brain during minimally invasive surgery. The system includes a cannula with a camera mounted at the proximal end of the cannula to view the lumen and tissue within and below the lumen, and a prism, reflector, or other suitable optical element disposed between the camera and the lumen of the cannula to allow the camera to view into the cannula while minimizing obstruction to the lumen. The illumination mechanism disclosed in this patent includes a light source within the cannula, or a light source external to the assembly, or a light source mounted at the proximal end of the cannula to illuminate the distal end of the cannula or tissue near the distal end of the cannula. Summary of the Invention [Problem to be solved by the invention]

[0003] The devices and methods described below improve illumination and / or reduce the illumination requirements for cannulas used in minimally invasive surgery. [Means for solving the problem]

[0004] Cannulas suitable for use in minimally invasive surgery are improved with highly polished and extremely smooth luminal walls (surfaces) and / or LEDs or other light sources oriented at specific angles relative to the axis of the cannula. [Brief description of the drawings]

[0005] [Figure 1] Shown is an illuminated cannula system. [Diagram 2] Shown is an illuminated cannula system. [Diagram 3] Shown is an illuminated cannula system. [Figure 4] Shown is an illuminated cannula system. [Diagram 5] An illuminated cannula system is shown having a cannula tube with a non-uniform diameter. [Figure 6] An illuminated cannula system is shown having a cannula tube with a non-uniform diameter. [Figure 7] An illuminated cannula system is shown having a cannula tube with a non-uniform diameter. [Figure 8] An illuminated cannula system with a non-uniform diameter cannula tube and a proximal light source consisting of two LEDs is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] FIG. 1 shows a cannula system 1 for accessing a target site within a patient's body. The cannula system includes a cannula tube 2 and an illumination assembly 3 disposed immediately prior to the proximal end 2p of the cannula tube. The illumination assembly 3 includes a housing 4 having a plurality of light emitters 5 (LEDs, incandescent bulbs, etc.). The illumination assembly may be mounted on a ring or partial ring 6 as shown and may be permanently secured to the proximal end 2p of the cannula tube, or may be removably attached by a removable attachment means such as a C-ring expandable to engage a groove on the exterior surface of the proximal end, by an annular snap ring, or by a screw thread, or by other easily attachable and detachable mechanism. Alternatively, the illumination assembly may be secured directly to the proximal end of the cannula tube or secured to a ring 18 secured to the cannula tube (as shown in FIGS. 5-8). The cannula tube is characterized by having a distal end 2d and a proximal end 2p, a lumen 7 extending from the proximal end to the distal end, a central longitudinal axis 2L defined by the lumen, and a luminal surface 8 of the inner wall of the cannula tube. The cannula tube most conveniently has a circular radial cross-section, although the radial cross-section can be varied to provide access to a particular surgical site. The cannula tube may be made of an opaque material that does not transmit visible light, such as a metal, or the cannula tube may be made of a transparent or non-transparent material and have an opaque structure with an inner luminal surface made of an opaque material that does not transmit visible light (e.g., a metal-coated acrylic tube).

[0007] An illumination assembly (light source) 3 is positioned near the proximal end of the cannula tube and is configured to hold a light emitter 5 adjacent the proximal opening of the cannula tube for projecting light into the lumen of the cannula tube (although this is preferred, the light emitter may extend slightly distally into the lumen). The cannula tube may be made of an opaque material that does not transmit visible light, and is preferably made of a metal such as stainless steel or aluminum.

[0008] The effectiveness of the illumination is preferably enhanced by providing a very smooth surface on the inner wall of the cannula tube. The luminal surface has an average roughness of 8 micro-inches or smoother (8×10) to enhance light transmission from the proximal end of the cannula to the distal end of the cannula and beyond the distal end of the cannula to the target site. -6 Preferably, the surface is highly polished / smoothed to approximately 1 / 4 inch, i.e., Ra(μm) 0.2 (0.2 microns), equivalent to or smoother than a US #8 finish, Japanese buff #300, or ISO N4. The light emitter of FIG. 1 may have a total output of 200-700 lumens, which in combination with the smooth luminal surface will provide sufficient light to funnel into the treatment site at the distal end of the cannula tube. A slightly rougher surface may be used in combination with a higher power light source. The luminal surface may be formed to an average roughness of 9 to 32 micro-inches (0.22 to 0.81 micro-meters, i.e., ISO N5 or N6 finish, #6 or #7 finish (approximately), Japanese buff #100, or smoother) and the illuminant may be selected to provide additional lumens at the higher end of the range. Alternatively, the luminal surface may be formed to an average roughness of 33 to 63 micro-inches (0.82 to 1.6 micro-meters, i.e., an ISO N7 finish, a US #3 or #4 finish) and the illuminant may be selected to provide additional lumens at the higher end of that range.

[0009] As shown in FIG. 2, the light emitter 5 is characterized by a main optical axis 9, which is angled downward (distal) from the radial axis 2R at an angle α of between 70° and 85°, preferably about 80°. 1 or, in other words, inwardly at an angle β of 5° to 15°, preferably about 10°, relative to the longitudinal axis 2L of the cannula tube. 1 In this embodiment, the cannula has a distal portion with a straight bore (of constant diameter throughout the entire length of the distal portion) and a proximal conical portion with a conical bore that is larger than the diameter of the straight bore at the proximal end of the proximal conical portion and necks down to match the diameter of the straight bore of the straight distal portion.

[0010] As shown in FIG. 2, the light source is characterized by a main optical axis 9, which is angled α 80° from the radial axis 2R. 1 or at an angle β of 10° to the luminal surface of the cannula tube. 1 (towards the center of the lumen).

[0011] Although Figures 1 and 2 show a system with a cannula tube having a conical lumen in the proximal portion of the cannula tube, the cannula tube may have a constant or uniform inner diameter and straight lumen walls from the proximal end to the distal end, without a conical or necked-down portion, and may be of equal diameter along its entire length.

[0012] FIG. 3 is a bottom view of the cannula system or a view of the distal end of the cannula tube. As shown in this figure, the optical axis 9 may be oriented to intersect the central axis 2C of the cannula tube or may be oriented at an angle γ from the radial axis 2R (a line between the LEDs and the central axis 2C or a line along a chord of a circle defined by the cannula tube). This angle is preferably about 10-30°. As shown in FIGS. 3 and 4, the light source may consist of only two LEDs placed on (close to) the proximal end of the cannula tube, either directly or via a ring 6. The LEDs are aligned along a first arc α of 50°-70°, preferably about 60°, as shown in FIG. 2 (Or, conversely, as shown in FIG. 3, a second arc β of 290° to 310°, preferably about 300° 2 ). The light source may consist of two pairs of closely spaced light emitters with the pairs similarly spaced apart. The light emitters and any associated lenses are preferably located adjacent to the proximal opening of the cannula tube without extending distally into the lumen. The proximal end of the cannula tube has a conical bore / lumen with a proximal opening slightly larger in diameter than the distal portion of the cannula tube.

[0013] As shown in FIG. 1, the cannula system may include a camera assembly 10 secured to the proximal end of the cannula, with a portion of the camera assembly overhanging the lumen and extending into the cylindrical space defined by the lumen of the cannula tube. The camera assembly has a distal-most optical surface, which may be the distal surface of an objective lens or prism (prism 11 is shown in FIG. 2 and distal-most optical surface 12 is seen in the distal view of FIG. 3), with the distal-most optical surface located just before the proximal end of the cannula tube. The objective lens or prism may be the portion of the camera assembly that overhangs the lumen. The distal-most optical surface of the camera system is shown spaced proximally from the proximal end of the cannula tube, but may be located slightly distal from the proximal-most edge of the cannula tube (without extending to the distal end of the cannula tube). As also shown in Figure 1, the cannula system may include tabs 13 for securing the cannula to a table-mounted flexible arm. As shown in Figures 3 and 4, the most distal optical surface of the camera assembly is between the two emitters and is spaced apart by the smaller arc α that separates the two emitters. 2 A gap in the housing between the two light emitters (or two pairs of light emitters) provides an unobstructed line of sight between the distal-most optical surface and the operating space at the distal end of the cannula tube, and the distal-most optical surface of the camera assembly is located within or adjacent to this gap.

[0014] FIG. 5 illustrates a second variation of a cannula system for accessing a target site within a patient's body. The cannula system 14 of FIG. 5 includes a cannula tube 15 and an illumination assembly 16 disposed immediately prior to the proximal end of the cannula tube. The illumination assembly 16 includes a number of light emitters 17 (LEDs, incandescent bulbs, etc.) mounted on a ring 18 (although a partial ring may be used or the ring may be omitted) as shown, and may be permanently fixed to the proximal end of the cannula tube or may be removably attached via a removable attachment means such as an annular snap ring, a threaded fitting (or a C-ring expandable to engage a groove on the exterior surface of the proximal end). The cannula tube is characterized by a distal end 15d and a proximal end 15p, as well as a lumen 19 extending from the proximal end to the distal end, a central longitudinal axis 15L defined by the lumen, and a luminal surface 20 of the inner wall of the cannula tube. The inner diameter of the proximal end 15p of the cannula tube is isodiametric along its length (straight walled, not conical as in FIG. 2), the inner diameter of the distal end 15d of the cannula tube is isodiametric along its length and is smaller than the inner diameter of the proximal end of the cannula tube, and the proximal end 15p and the distal end 15d of the cannula tube are joined by a necked-down portion 15N of the cannula tube.

[0015] Similar to the structures described with respect to Figures 1-3, the illumination assembly 16 of Figure 5 is positioned just prior to the proximal end of the cannula tube and is configured to project light into the lumen of the cannula tube. The cannula tube may be constructed of an opaque material that is non-transmissive to visible light, preferably a metal such as stainless steel or aluminum. The luminal surface is highly polished / smoothed with an average roughness of less than 8 micro-inches to enhance transmission of light from the proximal end of the cannula to the distal end of the cannula and beyond the distal end of the cannula to the target site. The light emitter of Figure 5 may have a total output of 1500-2500 lumens, which in conjunction with a smooth luminal surface will provide sufficient light to funnel to the treatment site at the distal end of the cannula tube. As with the cannula tube of Figure 1, for luminal walls with average roughness in the range of 9-32 micro-inches or 33-63 micro-inches, the light source can be selected to provide additional lumens at the higher end of the range.

[0016] 6, the illumination assembly 16 may include a number of LEDs 17 disposed at the proximal end of the cannula tube, either directly secured to the proximal end or secured to a ring 18 secured to the cannula tube. The ring 18 may be permanently secured to the proximal end 15p of the cannula tube, or may be removably attached by a removable attachment means such as an expandable C-ring that engages a groove on the exterior surface of the proximal end, by an annular snap ring, or by a screw thread, or other easily attachable and detachable mechanism.

[0017] As shown in the cross-sectional view of Figure 7, light emitter 17 is characterized by a primary optical axis 21 that may be oriented parallel to a straight sidewall or to a portion of the luminal surface of the inner wall of the proximal end of the cannula tube (i.e., the optical axis of each LED may be parallel to a portion of the luminal surface of the inner wall of the cannula). Alternatively, as in the systems of Figures 1 and 2, primary optical axis 21 may also be angled downward (distally) from radial axis 2R at an angle α of 70° to 85°, preferably about 80°. 1 or, in other words, at an angle β of 5° to 15°, preferably about 10°, relative to the lumen surface of the cannula tube. 1 (towards the center of the lumen).

[0018] The cannula system of FIG. 5 may include a camera assembly 10 secured to the proximal end of the cannula, with a portion of the camera assembly overhanging the lumen and extending into the cylindrical space defined by the lumen of the cannula tube. The camera assembly has a distal-most optical surface, which may be the distal surface of an objective lens or prism, which may be located just before the proximal end of the cannula tube, which may be the portion of the camera assembly overhanging the lumen. The camera system's distal-most optical surface is shown spaced proximally from the proximal end of the cannula tube, but may be located slightly distal from the proximal-most edge of the cannula tube.

[0019] FIG. 8 shows an illuminated cannula system having a cannula tube of non-uniform diameter with a proximal light source consisting of two LEDs 5. FIG. 8 shows that the cannula tube of FIG. 5 can be combined with the two LED light source of FIGS. 1-4 to take advantage of the larger proximal lumen in a system using a two LED light source. In this embodiment, the two LEDs (or two pairs) can be pointed directly distally with the optical axis parallel to the side wall of the cannula tube, as in FIG. 7, or the optical axis can be angled toward the center of the lumen, as in FIG. 2.

[0020] The utmost smoothness of the luminal surface provides sufficient reflection of light from a proximal light source into the distal end of the cannula, minimizing shadows cast by instruments placed within the cannula lumen, and eliminating the need for more complex tubing structures such as optical fibers embedded within the cannula wall, light transmission mechanisms from a light emitter ring into the transparent wall, or structures in the cannula wall that act as light guides with rough surface features necessary for light capture and delivery at the proximal end of the cannula tube. The cannula tube can be made of a transparent material, but is more conveniently made of a metal, such as stainless steel or aluminum, which can be made with thinner walls than plastics, can be sterilized and reused, and is not abraded or scraped by dissection instruments (more important for spinal surgery). Thus, the cannula tube can be made of an opaque material, preferably metal, without embedded optical fibers or waveguiding features. The cannula tube can also be made of a transparent polymer without embedded optical fibers or waveguiding features, although transparency of the tube is not required to obtain the benefits of the inventive features of the cannula system.

[0021] Alternatively, the cannula tube can be made from other materials with a highly reflective material attached to the lumen wall, which still provides good light transmission from the proximal illumination assembly without embedded optical fibers or light wave guiding features.

[0022] The luminal surface of the cannula tube can be coated to improve performance in various aspects. The luminal surface can be coated with an electrically insulating Parylene or other dielectric compound for use in procedures requiring the delivery of cutting energy by an instrument inserted through the cannula tube to the procedure site. The luminal surface can be coated with a hydrophobic, oleophobic, or oleophobic coating to minimize adhesion of body fluids or cleaning fluids during use.

[0023] While preferred embodiments of the apparatus and method have been described in relation to the context in which they were developed, these embodiments are merely illustrative of the principles of the invention. Elements of the various embodiments may be incorporated in each of the other embodiments to obtain the advantages of those elements in combination with those other embodiments, and various advantageous features may be incorporated in the embodiments alone or in combination with each other. Other embodiments and configurations may be devised without departing from the spirit of the invention and the scope of the appended claims.

Claims

1. 1. A cannula system for accessing a target site within a patient's body, comprising: a distal end and a proximal end, and a lumen extending from the proximal end to the distal end; a cannula tube having a central longitudinal axis defined by the lumen and a luminal surface on an inner wall of the cannula tube; a light source disposed near a proximal end of the cannula tube and configured to project light into a lumen of the cannula tube; forming a smooth surface on the inner surface of the cannula tube to enhance the effect of illumination by the light source, the inner surface of the cannula tube being polished to transmit light from the proximal end of the cannula tube to the distal end of the cannula tube and beyond the distal end of the cannula tube to the target site; the light source has an output in the range of 200 to 700 lumens; the luminal surface of the cannula has an average roughness of 0.2 microns (8 microinches) or smoother; A cannula system comprising:

2. A cannula system for accessing a target site within a patient's body, comprising: a distal end and a proximal end, and a lumen extending from the proximal end to the distal end; a cannula tube having a central longitudinal axis defined by the lumen and a luminal surface on an inner wall of the cannula tube; a light source disposed near a proximal end of the cannula tube and configured to project light into a lumen of the cannula tube; forming a smooth surface on the inner surface of the cannula tube to enhance the effect of illumination by the light source, the inner surface of the cannula tube being polished to transmit light from the proximal end of the cannula tube to the distal end of the cannula tube and beyond the distal end of the cannula tube to the target site; the light source has an output in the range of 200 to 700 lumens; the smooth surface formed on the inner wall of the cannula tube has an average roughness of 0.22 to 0.81 microns (9 to 32 microinches); A cannula system comprising:

3. A cannula system for accessing a target site within a patient's body, comprising: a distal end and a proximal end, and a lumen extending from the proximal end to the distal end; a cannula tube having a central longitudinal axis defined by the lumen and a luminal surface on an inner wall of the cannula tube; a light source disposed near a proximal end of the cannula tube and configured to project light into a lumen of the cannula tube; forming a smooth surface on the inner surface of the cannula tube to enhance the effect of illumination by the light source, the inner surface of the cannula tube being polished to transmit light from the proximal end of the cannula tube to the distal end of the cannula tube and beyond the distal end of the cannula tube to the target site; the light source has an output in the range of 200 to 700 lumens; The luminal surface has an average roughness of 0.82 to 1.6 microns (33 to 63 microinches). A cannula system comprising:

4. 4. The cannula system according to claim 1, wherein the entire cannula tube is made of a material that is opaque to visible light.

5. The cannula system according to any one of claims 1 to 3, wherein the cannula tube is made of a material that is transparent to visible light, and the luminal surface member is made of a material that is not transparent to visible light.

6. 4. The cannula system of claim 1, wherein the light source comprises a plurality of light emitters disposed at the proximal end of the cannula tube, the light emitters being characterized by a primary optical axis, the primary optical axis being oriented at an angle of approximately 80° from a radial axis of the cannula tube.

7. 4. The cannula system of claim 1, wherein the light source comprises a plurality of light emitters disposed at the proximal end of the cannula tube, the light emitters being characterized by a primary optical axis, the primary optical axis being oriented at an angle of approximately 10 degrees relative to the luminal surface of the cannula tube.

8. 4. The cannula system of claim 1, wherein the light source comprises a plurality of light emitters disposed at the proximal end of the cannula tube, the light emitters being characterized by a primary optical axis, the primary optical axis being oriented parallel to a portion of the luminal surface of the inner wall of the cannula.

9. 4. The cannula system of claim 1, wherein the light source is characterized by a main optical axis, the main optical axis being oriented at an angle of 10 to 30 degrees from a radial axis of the cannula tube.

10. 10. The cannula system of claim 4, wherein the light source is disposed at the proximal end of the cannula tube and comprises two light emitters separated by a first arc of approximately 60 degrees, or two pairs of closely spaced light emitters separated by a first arc of approximately 60 degrees.

11. 10. The cannula system of claim 4, wherein the inner diameter of the proximal end of the cannula tube is conical and the inner diameter of the distal end of the cannula tube is isodiametric.

12. 10. The cannula system of claim 4, wherein the inner diameters of the proximal ends of the cannula tubes are isodiametric, the inner diameters of the distal ends of the cannula tubes are isodiametric, the inner diameter of the distal end of the cannula tube is smaller than the inner diameter of the proximal end of the cannula tube, and the proximal end of the cannula tube and the distal end of the cannula tube are joined by a necked-down portion of the cannula tube.

13. 10. The cannula system of claim 4, wherein the inner diameter of the cannula tube is equal in diameter from the proximal end to the distal end.

14. The cannula system according to any one of claims 4 to 9, wherein the cannula tube is made of metal.

15. 10. The cannula system of claim 4, wherein the visible light opaque material of the cannula tube is completely free of optical fibers.

16. a camera assembly secured to the proximal end of the cannula, a camera assembly, a portion of which overhangs the lumen and extends into a cylindrical space defined by the lumen of the cannula tube; the camera assembly has a distal-most optical surface, the distal-most optical surface being disposed immediately prior to the proximal end of the cannula tube. A cannula system according to any one of claims 4 to 9.

17. a camera assembly secured to the proximal end of the cannula, a camera assembly, a portion of which overhangs the lumen and extends into a cylindrical space defined by the lumen of the cannula tube; the camera assembly has a distal-most optical surface, the distal-most optical surface being disposed immediately prior to the proximal end of the cannula tube; the camera assembly is positioned radially between the two light emitters within the first arc of approximately 60°; The cannula system of claim 10.

18. The cannula system of claim 4 , further comprising an electrically insulating coating on the luminal surface of the cannula tube.

19. The cannula system of claim 4 , further comprising a hydrophobic coating on the luminal surface of the cannula tube.

20. 10. The cannula system of claim 4, further comprising an oleophobic or oleophobic coating on the luminal surface of the cannula tube.

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