ENDOSCOPE INSERTION CANNULA ASSEMBLY

Abstract: An endoscope insertion cannula assembly (10) including an endoscope housing (14) and axially projecting body (16) having an endoscope tip (17). An adapter (22) is affixed about the endoscope housing (14), and a guide (24) is affixed about the adapter (22). A spring (32) and a seal (66) are also affixed about the adapter (22). The endoscope instrument (12), to­ gether with the associated adapter (22), spring (32) and guide (24), are inserted into a cannula housing (18). A pin (30) on the inside of the cannula housing (18) interacts with an angled slot (25) on the distal surface (28) of the guide (24) to rotate the endoscope instrument (12) into its proper rotational orientation A hole (36) in a cam surface (34) of the spring (32) then receives the pin (30) on the inside of the cannula housing (18) to control the axial orientation of the tip (17) of the endoscope instrument (12) with respect to the tip (21) of the cannula tube (20)

Description: FIELD OF THE INVENTION The present invention relates to an assembly comprising an endoscope element and a cannula element for permitting the endoscope instrument element to be inserted through the cannula element into the body in known orientation and for locking said cannula element and said endoscope element in that known orientation during use comprising: means cooperatively associated with this endoscope element and with said cannula element for controlling the rotational orientation and axial position of one element with respect to the other, said cooperative means including: a protrusion from one of said cooperating elements; a guide surface on said other element for operatively engaging said protrusion to control the rotational orientation of said protrusion; and resiliently biased locking means for restraining the protrusion in a desired axial position, said locking means including a cam surface which moves against said protrusion as said endoscope element is inserted into said cannula element, said cam surface being adapted to move out of the way as said endoscope element moves into said cannula element and then to return toward its original position as said protrusion reaches its desired axial position; whereby said instrument element is positioned in its desired rotational orientation and axial position during use. An assembly of this type is known from EP-A-0 008 451.EP-A-0 008 451 shows a catheter placement assembly having axial and rotational alignment means comprising a flexible plastic catheter having distally tapered distal ends, winged catheter insertion means having lumen therethrough, with proximal end of said catheter in communication with said lumen of said catheter insertion means via its distal end, a flexible tubing having its distal end in communication with said lumen of said catheter insertion means via its proximal end, a tube hub having lumen therethrough, the proximal end of said flexible tubing in communication with said lumen of said tube hub via its distal end, and a needle insertive through said catheter, winged catheter insertion means, flexible tubing and tube hub, said needle having a sharpened distal end extending beyond said distal end of said catheter and a proximal end attached to a needle hub. Said catheter assembly comprises complementary means associated with said lumen of said winged catheter's insertion means and said needle mechanically interlocked to provide axial and rotational alignment of said needle relative to said catheter unit at all times. The proximal end can be formed of a plastic insert moulded into a recess from the lumen of the tubular portion of said winged catheter insertion means. Said tubular portion can also be moulded as a single piece. On assembly, the needle is inserted into the catheter unit until the complementary means associated with the lumen of tubular portion and shoulders of the needle meet and mechanically interlock. When that mechanical interlock has been achieved, the bevel at the distal end of said needle will be facing upwardly and projecting from the distal end of catheter a chosen pre-determined distance. The mechanical interlock will also prevent further distal movement of the needle with respect to the catheter unit. Rotational misalignment or rotational movement of the needle with respect to catheter unit is likewise prevented. US-A-3 347 575 discloses a detent guide for telescopic tube units wherein a preferably cylindrical radially slideable detent projects from an inner tube through a side opening near the end which projects into the outer tube. The outer end of the detent being of rounded form. The detent is mounted at its inner end and within tube on one end of a folded leave spring disposed within said tube; such spring acting to yieldably urge the detent radially outward. The outer tube is provided with a longitudinally extending row of evenly spaced detent-receiving holes which are disposed closely adjacent but to one side of a bead; said row of holes being parallel to such bead. When it is desired to set two tubes of the unit in a given position of longitudinal adjustment, the inner tube is initially inserted into the outer tube with a normally radially projecting detent depressed and engaged in said tube against the side of the bead opposite the row of holes. The inner tube is then further advanced into the outer tube until the proper position of longitudinal adjustment is reached; the detent riding bead as a guide and then being in the zone of the row of holes. Relative rotative pressure applied to the tubes causes the detent to snap across the bead to the other side thereof and in to the plane of said row of holes. If the detent is not then aligned with one of said holes so as to drop into the same, a slide relative longitudinal movement of the tubes in one direction or the other, while keeping the detent engaged with the side of the bead will align the detent with said hole and allow said detent to engage therein. FR-A-2 439 022 discloses an assembly comprising a catheter or a cannula which is imovably mounted in a connecting sleeve of the housing and a metallic perforation tube extends from said head. This metal tube has an outer pointed end extending from said head and extends through a channel of the housing and a soft tube of the cannula to securing fingers made of elastic material extend from said head in the same direction at opposite sides of the housing and in a longitudinal direction of it, wherein said fingers are placed outside of a longitudinally shiftable cylindrical piece which is engaged by said fingers. These fingers engaged by means of a corresponding cam surface of a flange and cooperate also with an edge at the outer end of said flange by means of a further cam surface. In operation the head is introduced into the connecting sleeve and the outer end of the metal tube of which the free end extends beyond the outer end of a flexible catheter tube. The shiftable cylindrical piece is positioned such that a pressing board cooperating with portions of incline surfaces of said shiftable piece do not radially press the pressing board against the flexible cylindrical piece. Therefore, the assembly can be used because the surgeon can grip the fingers with his hand and can introduce the tip of the perforating tube and the free end of the tube into a blood vessel of a patient and thereafter by means of a finger of the same hand or by means of the other hand, the surgeon can hold the support until the end of the perforation procedure. When the head is maintained with one of the fingers of one hand the catheter tube can be introduced into a patient and the shiftable cylindrical piece can be displaced by means of another finger of the same hand to open or to close the flexible cylindrical piece. Said flexible cylindrical piece is only axially movable. BACKGROUND OF THE INVENTION Endoscopy instruments may be inserted into the body by introducing them into a cannula which has previously been inserted through the skin using a conventional trocar. A cannula is a thin, hollow tube with an open tip on the distal end and a hub of expanded diameter on the proximal end. The hub acts as a guide for directing an instrument or a trocar into the lumen of the tube portion of the cannula. A trocar is an instrument whose sharpened tip projects a short distance beyond the distal end of a surrounding cannula tube. The cannula and the trocar form a small puncture wound in the body as they are inserted through the body tissue. The trocar is then removed leaving the cannula in position with its distal end located in a desired position in the body and with its proximal hub extending outside the body. Thus, the cannula provides an entry site for various endoscopy instruments into the body. A variety of surgical tools and appliances can be inserted through a cannula, for instance a surgical cutting instrument, an aspiration or irrigation tube, or various optical or fiberoptic viewing devices, for example, telescopes which permit the surgeon to inspect the interior of the body. Particularly with viewing instruments, like telescopes, it is important that the orientation of the optical system inside the body be readily observable from outside the body. Very often the tip of the telescope is designed to look at an angle to its axis rather than straight ahead. The distal end of the telescope is placed at the distal end of the insertion cannula tube so that the telescope will be protected during use by the surrounding tip of the cannula tube, which is usually made of metal or a relatively hard plastic. The distal tip of the cannula tube is also cut at an angle corresponding to the angle of the telescope to permit side viewing. When this side viewing configuration is contemplated, it is important to have the telescope in proper rotational registration with the distal end of the cannula tube. Otherwise, the telescope will focus on the confronting surface of the protective cannula tube rather than at the body structures. It is, thus, important that the precise axial position of the end of the telescope and its rotational orientation be known and controllable. It is also important to orient the telescope properly with respect to any light source that is inserted into the body so as to reduce glare and shadows. It is also important in the operating room environment that the telescope or other endoscopy instrument can be easily inserted through the cannula and locked into position so that the surgeon will not have to spend valuable operating time adjusting and aligning the telescope or other instrument. It is also desirable to have tight sealing engagement between the cannula assembly and the endoscopy instrument to permit irrigation or aspiration of fluid with respect to the operative site. It would be desirable to have an insertion cannula with a locking mechanism which would allow the surgeon to insert a endoscopic instrument, for example a telescope, quickly and easily and be assured that the telescope is in its proper rotational and axial position and that that position could be maintained without constant monitoring and adjusting. In order to achieve the above-mentioned object the present invention is characterized in that said protrusion includes a pin projecting from the inside of said cannula element and said endoscope element includes a generally cylindrical adapter having a distal end projecting into said cannula and a proximal end extending proximally of said cannula, the proximal end of said adapter being adapted to receive an endoscope telescope, said adapter having an axial opening extending entirely therethrough for receiving the endoscope telescope, the proximal end of said adapter including sealing means cooperating with the interior walls of said cannula element for providing a liquid tight seal between the interior of said cannula and the exterior of said adapter; said endoscope element further including a guide means disposed about the periphery of said adapter and affixed thereto and having a proximal end disposed at an angle to the axis of said adapter and defining said guide surface for engaging said protrusion, said guide means further including an axially extending slot extending from the proximal portion of said angled distal surface. Preferably, said locking means affixed to said adapter and extending proximally therealong and aligned in the slot of said guide means includes a strip of spring material and extending radially outwardly from the axis of said adapter as one moves from the distal toward the proximal end of said adapter, said spring strip presenting said cam surface to said protrusion; said spring having a hole therethrough for receiving said protrusion, the interaction of said protrusion and said hole defining the axial position of said endoscopy instrument element with respect to said cannula element. Said angled distal end of said guide means can include a straight bias cut. These and other features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiment taken in conjunction with the following drawings. Brief Description of the Drawings Figure 1 shows an exploded perspective view of the endoscope insertion cannula assembly of the present invention; Figure 2 shows a cross-sectional view of the cannula assembly and cannula tube; Figure 2A shows a sectional view of an obturator extending past the tip of the cannula tube; Figure 2B shows the sharpened tip of a trocar extending past the end of the cannula tube; Figure 3 shows an elevation of a trocar used with the cannula housing and tube of the present invention; Figure 4 shows an assembled, cross-sectional view of the elements of the present invention shown partly in section; Figure 5 shows an end view of the apparatus shown in Figure 4; Figure 6 shows a plan view, partly in section, of part of the present invention; Figure 7 shoes an end view of the apparatus shown in Figure 6; Figure 8 shows an end view of a part of the present invention; Figure 9 shows a side view, taken along lines 9-9 in Figure 8; Figure 10 shows a top view of the apparatus shown in Figure 8. Detailed Description of the Preferred Embodiment Referring now to Figure 1 there is shown an exploded perspective of the cannula assembly of the present invention, generally designated as 10, together with endoscopy instrument 12, preferably a telescope, having a housing 14 and an axially extending body 16 which may be a flexible scope encased in a flexible sheath or a rigid scope encased in a rigid sheath. Cannula housing 18 is adapted to receive an endoscopy instrument 12, and cannula tube 20 projecting from the distal end of cannula housing 18 receives endoscope body 16. Endoscope 12 is a viewing instrument, and the distal tip 17 of body 16 is cut as a bias to facilitate side viewing. This bias tip can be cut at any convenient angle, but 30°, 45°, or 60° is usually used. Adapter 22 is a generally cylindrical device which receives the endoscope 12. The internal dimensions of different adapters 22 may be varied to accommodate different endoscopes. The external dimensions of adapters 22 remain the same for different internal dimensions, so that all adapters 22 may be received within the same cannula housing 18. Guide 24 is adapted to fit around the exterior of adapter 22 and is rigidly affixed thereto by, for example, a pin 26. Guide 24 has a generally annular configuration with its distal end surface 28 placed at an angle to the center line of instrument 10 and including an axially extending slot 25 which runs from the proximal portion of distal surface 28 axially along the sidewall of guide 24. Distal surface 28 of guide 24 and a pin 30 projecting from the interior of cannula housing 18 cooperate to control the rotational orientation of guide 24 and, correspondingly, adapter 22 and scope 12 with respect to cannula housing 18. A spring 32 is fixed to adapter 22 and includes a cam surface 34 having a hole 36 therein. When adapter 22 and guide 24 are assembled, cam surface 34 of spring 32 is disposed in slot 25 on guide 24, so that when endoscope 12, adapter 22 and guide 24 are slid together into cannula housing 18, pin 30 will enter slot 25, interact with cam surface 34 and lodge in hole 36. The dimensions of the cam surface 34, hole 36 and pin 30 and their position on their relative parts are chosen so that the axial position of the tip 17 of endoscope body 16 is properly aligned with the tip 21 of cannula tube 20. The interaction of pin 30 and distal surface 28 of guide 24 provide the proper rotational orientation for the end 17 of endoscope body 16 with respect to the end 21 of cannula tube 20. The individual parts of instrument 10 will now be discussed in greater detail. Cannula housing 18 and its associated cannula tube 20 will be discussed in conjunction with Figure 2. Cannula housing 18 has a surrounding sidewall 40 defining a passage 42 which has several sections. The proximal portion of passage 42 is defined by a generally cylindrical bore 44 which extends into cavity 42 and meets a conic section 46 whose diameter decreases as one moves in the distal direction, which in turn meets a second cylindrical portion 48, which in turn meets a second conical portion 50 of decreasing diameter as one proceeds in the distal direction. A third cylindrical bore 52, having a diameter slightly larger than the smallest diameter of conic portion 50, extends from the distal end of conic portion 50 to the distal end of cannula housing 18. Cylindrical bore 52 receives cannula tube 20. An irrigation port 51 is provided in sidewall 40 in the area of conic portion 50 to provide a means for introducing or aspirating fluid through cannula tube 20. Pin 30 extends from sidewall 40 in the vicinity of cylindrical bore 44. A small taper 54 is provided on the inside of the proximal end of wall 40 in the vicinity of pin 30 to provide a clearance for spring 32 when pin 30 and spring 32 are engaged. Also, a small cutout 56 is provided in the area of taper 54 for the same reason. Figure 3 shows a particular endoscopy instrument that can be used to assist in the insertion of the cannula, called a trocar 60. Trocar 60 has a sharp point 62. When trocar 60 is fully inserted inside cannula housing 18, trocar point 62 projects a short distance beyond the end of cannula tube 20, as shown best in Figure 2B. The proximal end of trocar 60 has a hub portion 64 much like adapter 22 shown in Figure 1. Hub portion 64 supports an O-ring 61 and a spring 68 much like the spring 32, as shown on adapter 22 in Figure 1. Spring 68 has a cam surface 69 and a hole 70 in cam surface 69. Located proximally of spring 68 is a flange 72 and a handle portion 74 for grasping the trocar. Trocar 60 is inserted into cannula housing 18 until point 62 projects a short distance beyond the tip 21 of cannula tube 20. O-ring 66 will mate with cylindrical portion 48 to provide a tight liquid seal, and hole 70 of cam surface 69 of spring 68 will engage pin 30 to lock trocar 60 and cannula housing 18 together in proper axial orientation. Since it is not important to control the rotational orientation of the trocar tip 62 with respect to cannula tube tip 21, there is no guide like that of guide 24 of Figure 1 associated with hub 64. The cannula tube 20 is inserted into the body by using projecting trocar tip 62 to make a small hole in the body, and then inserting cannula tube 20 and trocar 60 together into the desired location within the body, and then removing trocar 60 leaving cannula tube 20 in its desired location within the body. Now that cannula tube 20 is in its proper place inside the body, a variety of endoscopy instruments may be introduced through this cannula tube. As previously discussed when one is using a viewing instrument like a telescope 12, it is important that both the rotational and axial orientation of the end 17 of the telescope body 16 with respect to the end 21 of the cannula tube 20 be in proper registration with one another to facilitate side viewing. If the end 17 of telescope body 16 is not in proper rotational orientation with respect to the end 21 of cannula tube 20, the user could be looking at the inside of cannula tube 20 or could be looking into an illuminating light source. An obturator may be inserted within cannula tube 20, and its use is shown in Figure 2A. An obturator is essentially the same as a trocar except it has a blunt end 76. Referring now to Figures 6 and 7, there is shown the adapter 22. Adapter 22 has a generally cylindrical shape with a first recess 80 near its distal end for receiving an O-ring 66 and a second recess 82 for receiving the mounting prongs of spring 32. The proximal end of adapter 22 includes a threaded flange 84 which is adapted to receive an inner locking ring 86 for holding endoscope housing 14 in place (see particularly Figure 4). The proximal end of adapter 22 also includes a shoulder 88 for receiving an outer locking ring 90 for holding endoscope housing 14 in place. Adapter 22 has an axially extending cavity running throughout its length defined by the sidewall 92 of adapter 22. A bore 94 in sidewall 92 is adapted to receive pin 26 to hold adapter 22 and guide 24 together (see Figure 1). Referring again to Figure 6, the interior cavity of adapter 22 has a geometry adapted to accept a particular endoscope housing 14 and endoscope body 16. The interior dimensions may vary from one adapter 22 to another, while the exterior dimensions of adapters 22 remain the same so that different endoscope instruments may be used with the same cannula housing 18. A flat 96 runs along the exterior surface of adapter 22 between shoulder 88 and spring recess 82. Referring now to Figures 8, 9 and 10, there is shown the guide 24 with guide surface 28 and slot 25. Guide surface 28 is preferably cut at an angle of 45° to the axis of instrument 10 and to the axis of guide 24. However, any convenient angle may be used. It is also possible that the guide surface 28 may be concave or convex if desired. A bore 98 in the sidewall 100 of guide 24 is provided to accept pin 26 through which guide 24 is fixed to adapter 22. Referring now to Figures 4 and 5, there is shown an assembled view, partly in section, of the cannula housing 18, guide 24, adapter 22, locking rings 86 and 90, spring 32 and pin 30 together with a part of endoscope housing 14 and endoscope body 16. Figure 4 shows the relationship between the pin 30 and cam surface 34 of spring 32 with pin 30 in hole 36. It can be seen from Figure 1 that the end 17 of endoscope body 16 and the end 21 of cannula tube 20 are in correct rotational and axial orientation with respect to one another. Endoscope 12 can be removed from cannula housing 18 by the user, using only one hand. The user grasps endoscope housing 14 in his palm, placing his thumb on the handle portion 31 of spring 32, and depresses handle 31 so as to disengage hole 36 from pin 30. The user then merely extracts endoscope housing 14 and its associated endoscope body 16 from cannula housing 18. The operation of endoscopy instrument cannula assembly 10 will now be described principally in connection with Figures 1 and 4. It can be seen that as endoscopy instrument 12, with its associated adapter 22 and guide 24 attached to it, is inserted into cannula housing 18, angle-cut distal end surface 28 of guide 24 will engage pin 30 and interact therewith to rotate instrument 12 until pin 30 is aligned with guide slot 25. End surface 28 acts as an orienting mechanism for making sure that pin 30 and, hence, instrument 12 are aligned in the proper rotational orientation with guide slot 25 regardless of the orientation of instrument 12 when it is first inserted into cannula 18. Referring now particularly to Figure 4; it can be seen that as pin 30 enters guide slot 25, it will begin to interact with cam surface 34 of spring 32 and depress cam surface 34 until pin 30 enters hole 36. The interaction of pin 30 and hole 36 controls the axial orientation of endoscope 12 with respect to cannula housing 18. It will be appreciated that the present invention provides a convenient and effective assembly for quickly introducing an endoscopy instrument into a cannula assembly and automatically providing correct and locked rotational and axial alignment for the instrument with respect to the tip of the cannula.

Claims: An assembly comprising an endoscope element and a cannula element for permitting the endoscope element (12) to be inserted through the cannula element (18) into the body in known orientation and for locking said cannula element (18) and said endoscope element (12) in that known orientation during use comprising: means cooperatively associated with said endoscope element (12) and with said cannula element (18) for controlling the rotational orientation and axial position of one element with respect to the other, said cooperative means including: a protrusion (30) from one (18) of said cooperating elements (12; 18); a guide surface (28) on said other element (12) for operatively engaging said protrusion (30) to control the rotational orientation of said protrusion (30); and resiliently biased locking means (32) for restraining the protrusion (30) in a desired axial position, said locking means including a cam surface (34) which moves against said protrusion (30) as said endoscope element (12) is inserted into said cannula element (18), said cam surface (34) being adapted to move out of the way as said endoscope element (12) moves into said cannula element (18) and then to return toward its original position as said protrusion (30) reaches its desired axial position; whereby said endoscope element (12) is positioned in its desired rotational orientation and axial position during use, wherein said protrusion includes a pin (30) projecting from the inside of said cannula element (18) and said endoscope element includes a generally cylindrical adapter (22) having a distal end projecting into said cannula (18) and a proximal end extending proximally of said cannula (18), the proximal end of said adapter (22) being adapted to receive an endoscope telescope, said adapter (22) having an axial opening extending entirely therethrough for receiving the endoscope telescope (12), the proximal end of said adapter (22) including sealing means (66) cooperating with the interior walls (48) of said cannula element (18) for providing a liquid tight seal between the interior of said cannula (18) and the exterior of said adapter (22); said endoscope element further including a guide means (24) disposed about the periphery of said adapter (22) and affixed thereto and having a distal end disposed at an angle to the axis of said adapter (22) and defining said guide surface (28) for engaging said protrusion (30), said guide means (24) further including an axially extending slot (25) extending from the proximal proximal portion of said angled distal surface (28). The apparatus of claim 1 wherein said locking means affixed to said adapter (22) and extending proximally therealong and aligned in the slot (25) of said guide means (24) includes a strip of spring material (32); and extending radially outwardly from the axis of said adapter (22) as one moves from the distal toward the proximal end of said adapter (22), said spring strip (32) presenting said cam surface (34) to said protrusion (30); said spring (32) having a hole (36) therethrough for receiving said protrusion (30), the interaction of said protrusion (30) and said hole defining the axial position of said endoscope element (22) with respect to said cannula element (18). The apparatus of claim 1 wherein said angled distal end of said guide means (24) includes a straight bias cut.

Inventors: DIGIANTOMMASO, MICHAEL, SANTANGELO, JOHN A.
Applicants: CODMAN & SHURTLEFF INC.
Application year: 1985
Main classification: A61M25
IPC codes: A61M25, A61B1, A61B17