CA2265722C - Fluid collection cassette identification scheme - Google Patents

Abstract

This invention is a method of identifying whether a particular fluid collection cassette (10) is designated to have a particular use, such as posterior surgery or anterior surgery. A reflux bulb (26) attached to a fluid collection cassette has a material disposed on or in said reflux bulb in a predetermined location. A sensor attached to the housing senses the existence, or non-existence of the material and sends a signal to a controller.

Description

10152025W0 98/10811CA 02265722 l999-03- llPCT/US97/15946Fluid Collection Cassette Identification SchemeTechnical FieldThis invention relates to fluid collection cassettes used in surgical systems and,more particularly, to a scheme for identifying particular fluid collection cassettes.Background ArtOphthalmic microsurgical systems typically are classified in accordance withthe surgical area of the eye to which the system is directed. Therefore, certainophthalmic microsurgical systems are considered to be anterior systems, while othersare considered to be posterior systems. Occasionally, these systems may be combinedinto one system which operates in both the anterior and posterior regions of the eye.In all ophthalmic microsurgical systems, some type of fluid collection reservoiris utilized to collect fluid byproducts of the surgical operation. The fluid reservoirmay take various forms. One form which is well known in the art is a fluid collectioncassette which is a hard plastic cassette defining a fluid collection reservoir.The prior art associated with such fluid collection cassettes utilize a reflux bulbmember attached at one end to the inlet of the fluid collection cassette and at the otherend to a tube which is itself connected to the hand piece.Regardless of the type of operating procedure used, posterior or anterior, thesize of the cassette remains constant. In fact, the only physical distinction that can bemade between a cassette for posterior surgery and a cassette for anterior surgery is thesize of the volume contained within the respective reflux bulbs. The volumecontained within the posterior surgery reflux bulb is approximately 1/10 (one tenth)the volume of the anterior reflux bulb. This difference in volumes is made necessaryfrom the very nature of the surgery itself.During surgery, the fluid line between the handpiece and the fluid collectioncassette may occasionally become clogged. When this occurs, a preferred way tounclog the line is to exert a back pressure pulse within the fluid line. This isaccomplished by punching a first finger down onto a first portion of the reflux bulb,1015202530W0 98/1081 1CA 02265722 l999-03- llPCT/US97/15946to pinch off and separate the fluid line into two parts. A second finger immediatelyadjacent the first finger, between the first finger and the handpiece, descends to alsopinch a portion of the fluid line. When the second finger descends, back pressure isexerted along the length of the fluid line towards the handpiece and "blows out" orunblocks the fluid line.The posterior reflux bulb volume is necessarily smaller than the anterior refluxbulb volume because posterior surgery occurs in the retinal portions of the eye. Alarge stream of fluid ejected from the handpiece into the retinal portions of the eyedue to the manipulation of the reflux bulb could damage the eye. Accordingly, thecross-sectional area of the fluid line comprehended by the posterior reflux bulb issized much smaller than the volume of the reflux bulb used with anterior surgery. Ineffect, the posterior reflux bulb will eject a much smaller stream of fluid in order tounclog the fluid line, which in posterior surgery may contain Balanced Salt Solution(BSS), vitreous, and blood, and in anterior surgery may comprise (BSS) andemulsified cataract.Because the difference in volume of the posterior and anterior reflux bulbs arevirtually impossible to distinguish externally with the naked eye, each type of refluxbulb is given a specific color. For posterior surgery, the color of the reflux bulb isyellow. For anterior surgery, the color of the reflux is blue.Ophthalmic microsurgical systems are unable to distinguish automatically(mechanically or electrically) whether a posterior cassette or an anterior cassette wasin use. In this situation, a dangerous volume of fluid may be expelled with eachreflux, potentially damaging the eye. To avoid this situation from developing, theonly safeguard to date is a reminder by the ophthalmic microsurgical system in anonscreen prompt to check the cassette, or written warnings associated with thepackaging of the cassette. Accordingly, it still remains possible for human error toallow an anterior cassette to be used in a posterior surgery.Accordingly, there is a need in the art to provide an automatic identificationscheme which will permit a machine to identify whether a posterior or an anteriorcassette is in the machine.10152025W0 98/1081 1CA 02265722 l999-03- llPCT/US97/15946Disclosure of InventionIt is in the view of the above problems that the present invention wasdeveloped. The invention is a method of identifying the type or class of a particularfluid collection cassette, such as posterior or anterior cassettes. A reflux bulbattached to a fluid collection cassette has a material disposed on or in said reflux bulbin a predetermined location. When the reflux bulb is disposed on the fluid collectioncassette, and the fluid collection cassette inserted into a housing, a sensor attached tothe housing senses the existence, or non-existence of the material and sends a signalconveying the information to a main controller which can disable the surgical machinefrom operating until the proper cassette is inserted.Two separate predetermined locations may be used, together with two sets ofmaterial and two sensors for a posterior reflux bulb, whereas a single predeterminedlocation, material and sensor may be utilized to covey the existence of an anteriorreflux bulb and to guarantee that the cassette originated from a source of guaranteedquality.Further features and advantages of the present invention, as well as thestructure and operation of various embodiments of the present invention, are describedbelow in detail with reference to the accompanying drawings.Brief Description of DrawingsThe accompanying drawings, which are incorporated in and form a part of thespecification, illustrate the embodiments of the present invention and together with thedescription, serve to explain the principles of the invention. In the drawings:Figure 1 illustrates an exploded view of a fluid collection cassette of thepresent invention;Figure 1A illustrates an exploded detail view of the upper right portion of thefluid collection cassette illustrated in Figure 1;Figure 2 illustrates the fluid collection cassette of the present inventiondisposed within a housing.1015202530W0 98/10811CA 02265722 l999-03- llPCT/US97/ 15946Best Mode for Carrying Out the InventionReferring to the accompanying drawings in which like reference numbersindicate like elements, Figure 1 and Figure 1A show an exploded view of a fluidcollection cassette shown generally at 10 of the present invention. Fluid collectioncassette 10 comprises a main body portion 12, an inlet tube barb 14, an outlet tubebarb 16, outlet tube portion 18, and outlet tube adapter 20.Preferably, main body portion 12, inlet tube barb 14, outlet tube barb 16 andoutlet tube portion 18 are integrally molded. Outlet tube adapter 20 is provided witha stem 22 which is press fit into outlet tube portion 18. Alternatively, outlet tubeadapter 20 may be provided with a stem 22 which is threaded (not shown) to matewith matching threaded portion (not shown) of outlet tube portion 18.A reflux bulb 26 comprises first end 28 located in first body portion 30,second body portion 32, third body portion 34, and second end 36 located in thirdbody portion 34. At a first predetermined location shown generally at 38 on refluxbulb 26, a first material 40 is disposed in or on reflux bulb 26. At a secondpredetermined location shown generally at 42, a second material is disposed in or onreflux bulb 26.Preferably, first material 40 and second material 44 are both metal strips ormetal circles to permit use as or in connection with a capacitive proximity switch.Alternatively, first and second materials, 40, 44, are of a material which would permitan alternate type of sensor to determine the existence or non-existence of first material40 and second material 44 at first predetermined location 38 and secondpredetermined location 42, respectively.First material 40 and second material 44 may be disposed in reflux bulb 26which would raise the manufacturing cost, but would provide a greater guarantee ofoverall integrity. When first material 40 and second material 44 are both disposed onreflux bulb 26, preferably by adhesive, there is always some chance that one of thematerials, 40, 44, could become disassociated with reflux bulb 26.Overall, reflux bulb 26 has or may have an overall length of two inches. Firstbody portion 30 may have a length of approximately 3/8 (three-eighths) of an inch.1015202530W0 98/10811CA 02265722 l999-03- llPCT/US97/15946The distance from first end 28 to the center of first material 40 may be approximately3/16 (three—sixteenths) inches. Similarly, the distance from second end 36 to thecenter of second material 44 may be approximately 3/16 (three-sixteenths) of an inch.As Figure 1 shows in exploded view, it is clear that the hole 54 defined byreflux bulb 26 extends through the length of reflux bulb 26. These holes are pushedonto and held by inlet tube barb 14 and outlet tube barb 16.Reflux bulb 26 may assume a square cross—section measuring 5/16 (five-sixteenth) inch on each side.In operation, as shown in Figure 2, fluid collection cassette 10 is disposedwithin housing 56. Housing 56 is located within an ophthalmic microsurgical system.Attached to housing 56 is a first sensor 58 and a second sensor 60. First and secondsensors, 58-60, are preferably capacitive proximity switches and may be obtainedreadily from many electrical equipment manufacturers such as Balluff, Inc. ofFlorence, Kentucky. However, first and second sensors, 58-60, may also be of thesonic type (and the materials, 40, 44, respectively, suitable for reflecting sonicwaves), or may be of the light (LED, laser, etc.) type (and the materials, 40, 44,respectively, suitable for reflecting light waves.In operation, first and second sensors, 58-60, form one side of a capacitor,respectively, and first and second materials, 40, 44 form the other side of a capacitor,respectively. Accordingly, first and second sensors, 58-60, can sense the existence ornon-existence of first material 40 and second material 44. The existence or non-existence information is communicated from each sensor 58-60 to a controller whichcan act on this information and either enable or disable the operation of theophthalmic microsurgical machine, using a logical well known in the art.In view of the foregoing, it will be seen that the several objects of theinvention are achieved and other advantages are attained. The embodiments werechosen and described in order to best explain the principles of the invention and itspractical application to thereby enable others skilled in the art to best utilize theinvention in various embodiments and with various modifications as are suited to theparticular use contemplated. As various modifications could be made in the10CA 02265722 l999-03- 11WO 98110811 PCT/US97/15946constructions and methods herein described and illustrated without departing from thescope of the invention, it is intended that all matter contained in the foregoingdescription or shown in the accompanying drawings shall be interpreted as illustrativerather than limiting. For example, the predetermined locations, 38 and 42, are notrequired to be on the same side of reflux bulb 26. Another modification falling withinthe scope of the present invention involves using three or more predeterminedlocations in conjunction with the application of sensing material at each location toassist in identifying a function other than anterior or posterior. Thus, the breadth andscope of the present invention should not be limited by any of the above-describedexemplary embodiments, but should be defined only in accordance with the followingclaims appended hereto and their equivalents.

Claims (8)

Claims

1. A method of identifying a fluid collection cassette comprising the steps of:
(a) disposing a material to be sensed in a first predetermined location on a reflux bulb; and (b) disposing said reflux bulb on said fluid collection cassette such that a sensor for sensing said material may sense the existence of said material.

2. A method of identifying a fluid collection cassette according to claim 1, wherein the step of disposing a material to be sensed in a first predetermined location on a reflux bulb is accomplished by attaching said material to a surface of said reflux bulb.

3. A method of identifying a fluid collection cassette according to claim 1, further comprising the steps of:
(c) adapting a housing to receive said fluid collection cassette; and (d) attaching a first sensor to said housing at a location which will permit said first sensor to sense the existence of said material when said fluid collection cassette is disposed in said housing.

4. A method of identifying a fluid collection cassette according to claim 1, further comprising the following step between steps (a) and (b):
(aa) disposing a material to be sensed in a second predetermined location on a reflux bulb;
(c) adapting a housing to receive said fluid collection cassette; and (d) attaching a first sensor to said housing at a location which will permit said first sensor to sense the existence of said material at said first predetermined location when said fluid collection cassette is disposed in said housing; and (e) attaching a second sensor to said housing at a location which will permit said second sensor to sense the existence of said material at said second predetermined location when said fluid collection cassette is disposed in said housing.

5. A method of identifying a fluid collection cassette comprising the steps of:
(a) disposing a material to be sensed in a first predetermined location in a reflux bulb; and (b) disposing said reflux bulb on said fluid collection cassette such that a sensor for sensing said material may sense the existence of said material.

6. A method of identifying a fluid collection cassette according to claim 5, wherein the step of disposing a material to be sensed in a first predetermined location in a reflux bulb is accomplished by attaching said material under the outer surface of said reflux bulb.

7. A method of identifying a fluid collection cassette according to claim 5, further comprising the steps of:
(c) adapting a housing to receive said fluid collection cassette; and (d) attaching a first sensor to said housing at a location which will permit said first sensor to sense the existence of said material when said fluid collection cassette is disposed in said housing.

8. A method of identifying a fluid collection cassette according to claim 5, further comprising the following step between steps (a) and (b):
(aa) disposing a material to be sensed in a second predetermined location in a reflux bulb;
(c) adapting a housing to receive said fluid collection cassette; and (d) attaching a first sensor to said housing at a location which will permit said first sensor to sense the existence of said material at said first predetermined location when said fluid collection cassette is disposed in said housing; and (e) attaching a second sensor to said housing at a location which will permit said second sensor to sense the existence of said material at said second predetermined location when said fluid collection cassette is disposed in said housing.