Surgical cassette loading and unloading system

Abstract: A system for loading and unloading a surgical cassette (34) having a peristaltic pump tube (26) from a cassette receiving portion (36) of a surgical console (38) comprising : a peristaltic pump roller head (12) having a flared and beveled notch (22), the roller head (12) being located in the cassette receiving portion (36) of the surgical console (38); an engagement means (28) to engage with the peristaltic pump tube (26), the engagement means being extendable or displaceable and being located within the cassette receiving portion (36) of the surgical console (38). A surgical cassette comprising: a peristaltic pump roller head (12) having a flared and beveled notch (22); a cassette (34) having a peristaltic pump tube (26) stretchable over the peristaltic pump roller head (12); and an engagement means (28) to engage the peristaltic pump tube (26), the engagement means being extendable or displaceable is also described.

Description: Background of the Invention The present invention relates to a system for loading and unloading surgical cassettes and to a surgical console incorporating the system. The use of cassettes with surgical instruments to help manage irrigation and aspiration flows into a surgical site are well-known. U.S. Patent Nos. 4,493,695, 4,627,833 (Cook), 4,395,258 (Wang, et al.), 4,713,051 (Steppe, et al.), 4,798,580 (DeMeo, et al.), 4,758,238, 4,790,816 (Sundblom, et al.) and 5,267,956, 5,364,342 (Beuchat) all disclose tubeless or tube-type surgical cassettes. One of the primary function of the cassettes disclosed above is to control aspiration (vacuum) level at the surgical site. The vacuum generating device generally is contained within the surgical system control console and may be a venturi, diaphragm or peristaltic pump. When a peristaltic pump is used, the cassette generally contains a peristaltic pump tube that may be compressed within a race by a rotating pump roller head (e.g. U.S. Patent No. 4,713,051, Steppe, et al.) or may be stretched over the rotating pump roller head ( e.g . U.S. Patent Nos. 5,267,956 and 5,364,342, Beuchat). When the pump tube is stretched over the roller head, it may be difficult not only to install the pump tube over the roller head, but also to remove the pump tube from the roller head. The operation of peristaltic pump roller heads, and particularly peristaltic pump roller heads used in ophthalmic instruments, is more fully disclosed in U.S. Patent Nos. 5,230,614 (Zanger, et al.), and 5,387,088 (Knapp, et al.). WO83/03121 discloses an infusion pump apparatus having shaped rotor fingers designed to pick up an infusion tube on rotation of the rotor thus loading the tube in the apparatus automatically. US patent no. 3, 756,752 discloses a peristaltic pump including a replaceable tube with nipples fixed to the tube ends and which fit into, and are anchored by, sockets in a pump casing. A rotor disk is provided which has a tube guide for guiding a replacement tube into an operative position in the casing. US 5,387,088 referred to above, discloses a peristaltic pump assembly for easy loading of a tube. The pump has a pump housing with a curved surface and a pump rotor. The pump rotor has a notch which urges the tube into the desired position when the rotor it rotated. Accordingly, a need exists for a system to assist in loading and unloading a surgical cassette. Brief Description of the Invention The present invention relates to a system for loading and unloading surgical cassettes as set forth in claim 1, and a surgical console as set Forth in claims. The system includes a peristaltic pump roller head with a flared and beveled notch in combination with an engagement means such as a plunger or probe that engages the cassette peristaltic pump tube. When the cassette is installed in the console, the roller head is rotated so that the flared notch of the roller head engages the tube and pulls the tube over the roller head. When the cassette is removed from the console, the roller head is counter-rotated while the plunger telescopes to push the pump tube away from the roller head. The counterrotation of the roller head together with the bevel on the roller head and the action of the plunger disengages the pump tube from the roller head. Accordingly, one objective of the present invention is to provide a system for simplifying the loading and unloading of surgical cassettes. Another objective of the present invention is to provide a system for loading a peristaltic pump tube onto a peristaltic pump roller head. Still another objective of the present invention is to provide a system for unloading a peristaltic pump tube from a peristaltic pump roller head. These and other objectives and advantages of the present invention will become apparent from the detailed description and claims which follow. Brief Description of the Drawings FIG. 1 is an exploded perspective view of the present invention. FIG. 2 is an exploded perspective view of the present invention, similar to FIG. 1 but depicting the peristaltic pump tube engaged on the peristaltic pump roller head. FIG. 3 is a partial elevational view of the present invention depicting the peristaltic pump tube engaged on the peristaltic pump roller head FIG. 4 is a cross-sectional view of the present invention taken along line 4-4 in FIG. 3. FIG. 5 is a cross-sectional view of the present invention taken along line 5-5 in FIG. 3. Detailed Description of the Invention As best seen in FIGS. 1 and 2, system 10 of the present invention generally consists of roller head 12 and plunger assembly 14. Roller head 12 generally consists of inner plate 16 and outer plate 18 joined by a plurality of rollers 20. Outer plate 18 contains notch 22 and, as best seen in FIG. 4, outer plate 18 has flared portion 24 and beveled portion 40, both bordering notch 22. Notch 22, flared portion 24 and beveled portion 40 operate to assist in the loading and unloading of peristaltic pump tube 26 in the manner described below. Plunger assembly 14 generally consists of cylinder 28 and tip 30. Cylinder 28 may be any of a variety of electrically or hydraulically extendable cylinders, but a pneumatic cylinder with a power generation range or a holding force of between 5.4-6.8 Newton metres(between 4.0 pound-feet and 5.0 pound feet), and an extension range of up to 1.3 cm (0.5 inches) is preferred while an extension range of 1.0 cm (0.4 inches) is more preferred. Suitable cylinders 28 are commercially available from sources such as American Cylinder Company, Inc. Tip 30 preferably is approximately 2.54 cm (1 inch) long and made from aluminum or an aluminum alloy. As can be seen in FIGS. 1,2 and 5, tip 30 contains an arcuate portion or cutout 32 of approximately the same radius as pump tube 26 (e.g. 0.32 cm/0.125 inches) so that tip 30 engages pump tube 26 without slipping off. In use, cassette 34 containing pump tube 26 is installed within cassette receiving portion 36 of surgical console 38 so that pump tube 26 is pressed against outer plate 18 of roller head 12. In order to provide peristaltic pumping action, pump tube 26 must be stretched over rollers 20 contained in roller head 12. To assist is this process, flared portion 24 of outer plate 18 projects out from outer plate 18. As roller head 12 is rotated, flared portion 24 engages pump tube 26, thereby threading pump tube 26 over rollers 20. To disengage pump tube 26 from rollers 20, cylinder 28 is extended so that arcuate cutout 32 on tip 30 engages pump tube 26 (as seen in FIGS. 3, 4 and 5). Further extension of cylinder 28 pushes pump tube 26 away from cassette receiving portion 36 of console 38. When roller head 12 is counter-rotated, flared portion 24 and beveled portion 40 of outer plate 18 unthreads pump tube 26 from rollers 20. This description is given for purposes of illustration and explanation. It will be apparent to those skilled in the relevant art that changes and modifications may be made to the invention described above without departing from the scope of the appended claims.

Claims: A system for loading and unloading a surgical cassette (34) having a peristaltic pump tube (26) from a cassette receiving portion (36) of a surgical console (38) comprising: a) a peristaltic pump roller head (12), having a flared and bevelled notch (22) for engagement with the tube, the roller head (12) being locatable in the cassette receiving portion (36) of the surgical console (38); and b) an engagement means (28) to engage the peristaltic pump tube (26), the engagement means being extendable or displaceable and being locatable within the cassette receiving portion (36) of the surgical console (38). A system according to claim 1 wherein the engagement means (28) comprises an arcuate portion (32) of approximately the same radius as peristaltic pump tube (26), the arcuate portion being engagable with the peristaltic pump tube (26). A system according to claim 1 or 2 wherein the engagement means (28) comprises an extendable plunger assembly (14). A system according to claim 3 wherein the extendable plunger assembly (14) is a pneumatic cylinder. A surgical console (38), comprising a system according to any one of claims 1 to 4 wherein the pump roller head (12) and the engagement means (28) are located within a cassette receiving portion (36) of the surgical console (38). A console according to Claim 5 further comprising a peristaltic pump tube wherein the peristaltic pump tube (26) is stretchable over the peristaltic pump roller head (12).

Inventors: ZALESKI RICHARD L II, ZALESKI, RICHARD L., II
Applicants: ALCON LAB INC, ALCON LABORATORIES, INC.
Application year: 1996
Main classification: A61M1
IPC codes: A61M1, F04B43