Abstract:
An irrigation/aspiration apparatus for supplying an irrigation fluid from an irrigation source to a surgical site through a surgical instrument to remove the irrigation fluid with residual tissue by aspiration, the apparatus including, a first cassette provided with a first fluid line for supplying the irrigation fluid and a second fluid line for removing the residual tissue by aspiration, and a second cassette attachable to, and detachable from, the first cassette, the second cassette being provided with a connecting fluid line and a coupling member for connecting at least either the first fluid line or the second fluid line to the surgical instrument.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an irrigation/aspiration apparatus which supplies an irrigation fluid to a surgical site and aspirates the irrigation fluid containing residual tissue. The present invention also relates to an irrigation/aspiration cassette to be attached to the apparatus. 
     2. Description of Related Art 
     One conventionally known irrigation/aspiration apparatus supplies an irrigation fluid through an irrigation tube into a surgical site and then the irrigation fluid and residual tissue are removed by suction. In the field of ophthalmological care, the irrigation/aspiration apparatus is utilized in cataract surgery and vitreous surgery. The irrigation fluid from an irrigation fluid source is injected into the surgical site through a surgical instrument such, for example, as a handpiece connected to the irrigation tube. To remove the residual tissue, suction pressure is applied to an aspiration tube connected to the surgical instrument at one end thereby to drain drainage and the residual tissue from the other end of the aspiration tube. 
     Recently, it has been suggested to house all or part of the irrigation/aspiration tubes. With this type of apparatus taking advantage of the case or the cassette, the whole case is replaced so as to reduce time and effort spent on tubing. Generally, the cassette is thrown away after one use for a sanitary reason. 
     As for the irrigation/aspiration apparatus used in the field of ophthalmological care, there is an irrigation/aspiration apparatus configured to suit both cataract surgery and vitreous surgery. However, each cassette to perform different surgery is different to suit a surgical instrument used in the surgery, such as a handpiece and the like. 
     For example, a cassette for cataract surgery is previously provided with a tube and the like for attachment of a surgical handpiece in order to reduce time and effort spent in tubing or to prevent improper tubing. On the other hand, an aspiration tube is provided to a reusable cutter, which is a surgical instrument used in vitreous surgery. Therefore, a cassette for vitreous surgery is not provided with an aspiration tube and the like, but provided with a connector for attachment the cutter via the aspiration tube. For these reasons, manufacturers has been providing cassettes exclusively for each surgical method or each surgical instrument used in the surgery. 
     However, it is uneconomical both for the manufacturers and users to prepare a whole set of cassettes for each surgical instrument. In addition, it requires time and effort to replace the whole cassette in case of performing different types of surgery alternately. Further, in case of performing both cataract surgery and vitreous surgery on a patient&#39;s eye, for the cassette being disposable, both of the cassettes for cataract surgery and vitreous cassette have to be disposed. 
     Also, in cataract surgery where different handpieces for phacoemulsification and for irrigation/aspiration should be used, it imposes burden on an operator to replace the cassette to which tubes and the like are connected for attachment of the handpiece or to change the tubing arrangement. In addition, if it takes long to change the cassette or the tubes, time spent in the surgery will be disadvantageously prolonged. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide an irrigation/aspiration apparatus and an irrigation/aspiration cassette therefore which can be used in surgery easily and economically without the need for replacing the whole cassette regardless of variety of surgical instruments used. 
     Also, another object of the present invention is to provide an irrigation/aspiration apparatus and an irrigation/aspiration cassette used therefore which are capable of performing surgery efficiently by eliminating the need to change the cassette or the tubing arrangement even in cases where a plurality of handpieces are used. 
     Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims. 
     To achieve the objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, an irrigation/aspiration apparatus for supplying an irrigation fluid from an irrigation source to a surgical site through a surgical instrument to remove the irrigation fluid with residual tissue by aspiration, the apparatus comprises a first cassette provided with a first fluid line for supplying the irrigation fluid and a second fluid line for removing the residual tissue by aspiration, and a second cassette attachable to, and detachable from, the first cassette, the second cassette being provided with a connecting fluid line and a coupling member for connecting at least either the first fluid line or the second fluid line to the surgical instrument. 
     In another aspect of the present invention, an irrigation/aspiration cassette for being attached to an irrigation/aspiration apparatus which supplies an irrigation fluid from an irrigation source to a surgical site through a surgical instrument to remove the irrigation fluid with residual tissue by aspiration, the cassette comprises a first cassette provided with a first fluid line for supplying the irrigation fluid and a second fluid line for removing the residual tissue by aspiration and a second cassette attachable to, and detachable from, the first cassette, the second cassette being provided with a connecting fluid line and a coupling member for connecting at least either the first fluid line or the second fluid line to the surgical instrument. 
     Also, in another aspect of the present invention, an irrigation/aspiration apparatus for supplying an irrigation fluid from an irrigation source to a surgical site through a surgical instrument to remove the irrigation fluid with residual tissue by aspiration, the apparatus comprises a cassette provided with a first fluid line for supplying the irrigation fluid and a second fluid line for removing the residual tissue by aspiration, at least either the first fluid line or the second fluid line includes a plurality of divided fluid lines, and a selector for selecting from a plurality of the divided fluid lines. 
     Further, in another aspect of the present invention, an irrigation/aspiration cassette for being attached to an irrigation/aspiration apparatus which supplies an irrigation fluid from an irrigation source to a surgical site through a surgical instrument to remove the irrigation fluid with residual tissue by aspiration, the cassette comprises a cassette provided with a first fluid line for supplying the irrigation fluid and a second fluid line for removing the residual tissue by aspiration, at least either the first fluid line or the second fluid line includes a plurality of divided fluid lines. 
     As described above, according to the present invention, the sub assembly instead of the whole irrigation/aspiration cassette needs to be replaced to correspond to the surgical instrument or the surgical method. Therefore, manufacturing cost and running cost can be reduced. In addition, it is comparatively easy for the operating staff to complete the replacement. 
     Also as described above, according to the present invention, even in case of using a handpiece by switching a plurality of fluid lines, the fluid lines remain comparatively simple and thus, the tubing arrangement can be easily done. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present invention and, together with the description, serve to explain the objects, advantages and principles of the invention. In the drawings, 
     FIG. 1 is a view showing an external representation of an irrigation/aspiration apparatus embodying the present invention; 
     FIG. 2 is a view showing an external representation of an irrigation/aspiration cassette embodying the present invention; 
     FIG. 3 is a schematic view showing an important part of the irrigation/aspiration apparatus and the irrigation/aspiration cassette shown in FIGS. 1 and 2; 
     FIGS. 4A-4C are views showing examples of connections to a sub assembly; 
     FIG. 5 is a view showing a detecting mechanism which detects a sub assembly; 
     FIG. 6 is a schematic view showing an important part of a modified irrigation/aspiration apparatus and a modified irrigation/aspiration cassette embodying the present invention; and 
     FIGS. 7A-7C are views showing a modified sub assembly applied to the apparatus and the cassette shown in FIG.  6 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A detailed description of one preferred embodiment of an irrigation/aspiration apparatus and an irrigation/aspiration cassette therefore embodying the present invention will now be given referring to the accompanying drawings. FIGS. 1 and 2 are views respectively showing external representations of an irrigation/aspiration apparatus and an irrigation/aspiration cassette therefore of the preferred embodiment. FIG. 3 is a schematic view showing an important part of the configuration of the apparatus and the cassette. 
     A main body  1  is provided with a control panel  2 , an irrigation pole  3 , a cassette receiving portion  4 , into which a cassette  10  is inserted, and the like. The cassette  10  will be described in detail hereinafter. A control unit  40  drives and controls a vertical motion driving unit  42  so as to vertically move the pole  3  to a height set with the use of the control panel  2 . An irrigation bottle  5  filled with an irrigation fluid is adjusted its height by the vertical movement of the pole  3  thereby to regulate pressure of the irrigation fluid. 
     The irrigation/aspiration cassette  10  is essentially made up from a main assembly  20  and a sub assembly  30 . The main assembly  20  and the sub assembly  30  are detachably connected to each other via a connecting unit  22 . The sub assembly  30  is provided in a plurality of different types to suit a surgical instrument used in surgery or the surgical method (as hereinafter described). 
     An irrigation tube  6  extending from the bottle  5  is connected to the main assembly  20  via an irrigation connecting unit  23 . In the main assembly  20 , an irrigation fluid line  24  trifurcates (branches) into two irrigation fluid lines: a first irrigation fluid line  25   a  and a second irrigation fluid line  25   b,  for providing an irrigation fluid and a bypass fluid line  26  which is connected to an aspiration side. Each of the branch fluid lines are made of pliable tubes having flexibility. Openings  12   a,    12   b  and  12   c  are formed through a housing of the main assembly  20  at points directly above each fluid line and there is provided a first pinch valve  43   a  and a second pinch valve  43   b  for irrigation and a pinch valve  44  for vent on the main body  1 . With this configuration, the valves  43   a,    43   b  and  44  are capable of cutting and opening the flow through each tube (the fluid lines  25   a,    25   b  and  26 ). In this embodiment, each pinch valve is a solenoid valve which opens and closes by electromagnetic operation. The control unit  40  controls each pinch valve inserted into the main assembly  20  through the respective openings  12   a - 12   c  so as to accomplish opening and closing of each fluid line selectively by pressing each tube. 
     The fluid lines  25   a  and  25   b  are respectively connected to irrigation fluid line  31   a  and  31   b  in the sub assembly  30  via the connecting unit  22 . The sub assembly  30  (and a sub assembly  30   a ) shown in the FIGS. 3 and 4A, for example, is for cataract surgery and has tubes to be connected to an ultrasonic handpiece  9   a  (hereinafter referred to as US handpiece) to emulsify and aspirate a crystalline lens using ultrasonic vibrations and an irrigation/aspiration handpiece  9   b  (hereinafter referred to as I/A hand piece). The fluid line  31   a  is being connected to the irrigation tube  32   a  at one end for enabling attachment of the US handpiece  9   a  at the other end. Likewise, the fluid line  31   b  is being connected to the irrigation fluid line  32   b  for attachment of the I/A handpiece  9   b.  In the case of using the US handpiece  9   a,  the ultrasonic vibrations are controlled by the control unit  40  via a cable  8 . 
     Further, aspiration tubes  33   a  and  33   b  are connectable to the US handpiece  9   a  and the I/A handpiece  9   b  at one end and are being connected to aspiration fluid lines  34   a  and  34   b  at the other end respectively. The fluid lines  34   a  and  34   b  are respectively connected to a first aspiration fluid line  27   a  and a second aspiration fluid line  27   b  provided in the main assembly  20  via the connecting unit  22 . The fluid lines  27   a  and  27   b  are also made of tubes having flexibility. As is the case with the irrigation fluid lines, openings  12   d,    12   e  are formed through the housing of the main assembly  20  at points directly above each fluid line and a first pinch valve  45   a  and a second pinch valve  45   b  for aspiration are provided on the main body  1 . The pinch valves  45   a  and  45   b  are capable of cutting and opening the flow through each tube (the fluid lines  27   a  and  27   b ). The control unit  40  drives and controls the first pinch valve  45   a  and the second pinch valve  45   b  so as to select the fluid line to which aspiration pressure is applied. 
     The fluid lines  27   a  and  27   b  join into a tube  28  with its end extending to a drainage bag  11  to drain drainage out. The tube  28  is partially exposed at an intermediate point through a notch  13  formed in the main assembly  20 . That is to say, when the main assembly  20  is inserted into the main body  1 , the exposed portion of the tube  28  at the notch  13  is positioned under a driving portion of a peristaltic pump  41  which produces suction. By driving the pump  41 , suction pressure is produced within the tube  28  so as to effect aspiration of the drainage from the operative site through the surgical instrument connected thereto via the sub assembly  30 . 
     The tube  28  has a connection upstream from the notch  13  to a balloon portion  29  provided with an air chamber for suppressing pulsation. The balloon portion  29  has a rubber membrane in which air is sealed so as to absorb the pulsation due to producing the suction pressure in the tube by the peristaltic pump  41 . The balloon portion  29  is connected to the bypass fluid line  26  at a side thereof. The fluid line  26  is provided, at an intermediate point thereon, with a chamber  19  being in engagement with a pressure sensor  45  of a load detecting type provided on the main body  1 . Normally, the pinch valve  44  is closed and the suction pressure produced by the pump  41  is transmitted through the balloon portion  29  to the chamber  19 . The chamber  19  is provided with a moving member therein which moves in response to change of the pressure. The sensor  45  detects the suction pressure based on the moving load. When the aspiration is stopped, the pinch valve  44  is opened so as to let the irrigation fluid in the tube  28 . As a result, the suction pressure remained in the tube  28  (on the surgical handpiece side from the aspiration/suction pump) is reduced. 
     As described above, the main assembly  20  has two systems of irrigation fluid lines and aspiration fluid lines respectively. Therefore, by selectively opening and closing the fluid lines, the surgical instruments being connected to the sub assembly  30  can be switched to another suitable for a different surgical operation with ease. For example, the above-mentioned Us handpiece  9   a  and I/A handpiece  9   b  are connected to the sub assembly  30 . In this case, when the US handpiece  9   a  is in use, the pinch valves  43   a  and  45   a  are opened to allow the flow through the fluid lines  25   a  and  27   a  but the pinch valves  43   b  and  45   b  are closed to cut the flow through the fluid lines  25   b  and  27   b.  When the I/A handpiece  9   b  is in use, on the other hand, the pinch valves  43   b  and  45   b  are opened to allow the flow through the fluid lines  25   b  and  27   b  but the pinch valves  43   a  and  45   b  are closed to cut the flow through the fluid lines  25   a  and  27   a.    
     Next, a different type of the sub assembly  30  will be described. First, the sub assembly  30   a  shown in the FIG. 4A is the example for cataract surgery previously described with reference to the FIG.  3 . 
     In this case, for attachment of two kinds of handpieces (US, I/A) for performing irrigation and aspiration, the irrigation tubes  32   a  and  32   b  are being connected to the fluid lines  31   a  and  31   b,  and the aspiration tubes  33   a  and  33   b  are being connected to the fluid lines  34   a  and  34   b  respectively beforehand. Generally in cataract surgery, a US handpiece and an I/A handpiece are used alternately. For this reason, it saves trouble of connecting the tubes if both handpieces are connected beforehand. It is also possible to connect an irrigation handpiece (hereinafter referred to as IRR handpiece) instead of either of the two (in this case, the aspiration fluid lines connected to the IRR handpiece are out of use, and thus to be closed). 
     A sub assembly  30   b  shown in FIG. 4B is an example for cataract surgery and vitreous surgery used in case of performing cataract surgery and vitreous surgery alternately. In the example, the irrigation tube  32   a  and the aspiration tube  33   a  for attachment of a handpiece for cataract surgery (the US handpiece  9   a  or the I/A handpiece  9   b ) at one end are respectively connected to the fluid line  31   a  and to the fluid line  34   a  in the sub assembly  30  at the other end beforehand. Also, the fluid line  31   b  is connected to an irrigation tube  35  at one end in advance for attachment of an unillustrated irrigation cannula at the other end. The other fluid line  34   b  is provided with a connector  37  for attachment of an unillustrated vitreous cutter via an aspiration tube. As described, even in the case of performing cataract surgery and vitreous surgery alternately, by connecting surgical instruments for each surgical operation in advance, the trouble of piping arrangement can be avoided. 
     A sub assembly  30   c  shown in the FIG. 4 c  is an example for vitreous surgery and the fluid line  31   b  is being connected beforehand to the irrigation tube  35  for attachment of an irrigation cannula. The fluid lines  34   a  and  34   b  are provided with the connectors  37  for attachment of aspiration tubes being connected to a vitreous cutter and to a needle tip for aspiration in vitreous surgery. only one system of irrigation fluid lines is sufficient for vitreous surgery, consequently the fluid line  31   a  is closed. 
     The tube  36  shown in the FIGS. 4B and 4C is to vent the air and its connecting terminal  36   a  is connected to an unillustrated FGX connector to be used in case where air, instead of the irrigation fluid, is sent to the patient&#39;s eye. 
     As described, the cassette  10  is allowed to be divided into the main assembly  20  and the sub assembly  30  and the sub assembly  30  is designed exclusively for each surgical instrument used in cataract surgery or vitreous surgery. In so doing, the main assembly  20  can be commonly used in all surgical operations. This permits reductions in the manufacturing cost of the overall cassette as well as the running cost of the user. In addition, in case of performing cataract surgery and vitreous surgery alternately, for example, only the sub assembly  30 , instead of the whole cassette needs to be replaced and thus easily handled. In case of throwing away the cassette after one use, to perform both cataract surgery and vitreous surgery on the patient&#39;s eye, one main assembly and two (or possibly more) sub assemblies have to be disposed. Yet, the cost is relatively low as compared with disposing the whole cassette for cataract surgery and another for vitreous surgery. 
     The main body  1  is further provided with a detecting mechanism to recognize different types of the sub assemblies described above. This detecting mechanism is described hereinafter with reference to the FIG.  5 . 
     The sub assembly  30  is provided with a plurality of tags  50  in predetermined positions at the top thereof (the number and the positions of the tags  50  are set differently in accordance with each type of the sub assemblies). When the main assembly  20  and the sub assembly  30  are connected to each other to integrally form the cassette  10  and the cassette  10  is attached to the main body  1  with the use of cassette receiving portion  4 , each of the tags  50  is inserted into sensors  51  having a shape of the inverted U provided on the main body  1  (the sensors  51  are set to respond to all the combinations of tags  50 , which are different in accordance with each type) Each sensor  51  is comprising a light emitting portion  51   a  and a light receiving portion  51   b  provided in opposed positions. Whether or not the light receiving portion  51   b  detects the light from the light emitting portion  51   a  allows to detect the presence or absence of each tag  50 . 
     When the tags  50  are inserted, the light from the light emitting portion  51   a  is cut and consequently the corresponding light receiving portion  51   b  does not detect the light. Based on signals from the sensors  51  (the light receiving portions  51   b ), the control unit  40  recognizes that the tags  50  are inserted. The tags  50  are provided in different positions and number in accordance with each type of the sub assembly  30 , so that the detection by the sensors  51  allows the apparatus to automatically recognize which type of the sub assembly  30  is being used. 
     As described above, the type of the sub assembly is automatically detected and recognized thereby to allow automatic setting which is suitable for the surgical instrument corresponding to the type of the sub assembly. In addition, in case of connecting a wrong sub assembly which does not match the surgical method as such, an error signal may be generated to inform of the error or operation signals may be rocked so as to prevent operating errors. Further, it is possible to make automatic setting of parameters in accordance with the sub assembly being connected upon detecting the sub assembly. For example, a US handpiece is connected commonly to the sub assembly provided with two systems of fluid lines for cataract surgery shown in the FIG.  4 A and to the sub assembly for cataract surgery and vitreous surgery shown in FIG.  4 B. Yet, the aspiration pressure in each surgery is different. Consequently, the automatic setting of the parameters upon connection will reduce the burden imposed on the operator and simplify the setting. 
     Hereinafter, operations of the apparatus having above-described configuration will be given briefly. The operator integrates the cassette  10  by attaching the suitable sub assembly  30  for the surgery to be performed to the main assembly  20 . Thereafter the operator inserts the integrated cassette  10  into the cassette receiving portion  4  provided in the main body  1  (and connects a surgical instrument to the tubes being connected to the sub assembly). upon inserting the cassette  10  into the cassette receiving portion  4 , the cassette  10  is moved to a predetermined position in the main body  1  and set in the position. When the cassette  10  is set, the control unit  40  recognizes the type of the sub assembly  30  based on a signal form the sensor  51  and displays the type of the sub assembly  30  on a display of the control panel  2 . In addition, conditions such as the aspiration pressure, the amount of aspiration fluid and the like are set as previously determined in accordance with the type of the sub assembly  30 . If necessary, these conditions can be changed using the switches provided on the control panel  2 . 
     Changeover between the two systems of the irrigation and aspiration fluid lines (control of each pinch valve) is done by operating a changeover switch  16  provided either on the control panel  2  or on a foot-pedal  15 . Since the type of the sub assembly  30  and its combination of fluid lines are found from the signal generated by the sensor  51 , the control unit  40  drives and controls each pinch valve to open and close each fluid line. 
     As described above, operating the changeover switch  16  alone effects changeover among a plurality of hand pieces. This frees the operator from the inconvenience of connecting the tubes and the like, letting the operator concentrate on the surgery. Further, by providing a plurality of irrigation fluid lines and aspiration fluid lines within the detachable cassette, complications in tubing arrangements or setting can be lessened. 
     FIGS. 6 and 7 show a modification. In the modification shown in FIG. 6, one of the two irrigation fluid lines and the aspiration fluid lines (the fluid lines  25   a  and  27   a ) are connected to a surgical instrument directly from the main assembly  20 , while the other irrigation fluid line and the aspiration fluid line (the fluid lines  25   b  and  27   b ) are connected to the sub assembly  30 ′ (the fluid lines  31   b  and  34   b ). In the case of performing both cataract surgery and vitreous surgery using one and the same apparatus, the US handpiece  9   a  is kept in connection, and the I/A handpiece  9   b  needs to be changed to the irrigation cannula and the vitreous cutter. In such a case where one of the surgical instruments is changed more often then the other, this modification may be suitable. Applying this modification will further reduce cost of the sub assembly in comparison with the aforementioned preferred embodiment. FIGS. 7A,  7 B and  7 C show the modified sub assembly corresponding to the sub assembly shown in FIGS. 4A,  4 B and  4 C respectively. 
     Also, another modification may be made to provide one system each for the irrigation fluid line and the aspiration fluid line for enabling attachment of only one surgical instrument. In this modification, providing the sub assembly in wider variety makes it possible to deal with various surgical methods. It goes without saying that the types of the sub assembly are not limited to the ones mentioned in the embodiments described herein. 
     In the aforementioned embodiments, the detecting mechanism uses the optical sensor. However, a physical or electronic detecting mechanism such as a microswitch or the like may as well be used. 
     Also, the pinch valves and the vent valves described above are solenoid ones. However, it is possible to use various kinds of valves, for example, a pressure valve by fluid such as air, oil or the like. It is further possible to provide valves within the cassette and connect the valves to the main body via electric connectors thereby to control the valves by the control unit. 
     The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in the light of the above teachings or may be acquired from practice of the invention. The embodiments chosen and described in order to explain the principles of the invention and its practical application to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto, and their equivalents.