KNIGHT JEFFERY A
| WO1996040026A1 | 1996-12-19 | |||
| WO1989003230A1 | 1989-04-20 |
| US5562612A | 1996-10-08 | |||
| EP0536998A2 | 1993-04-14 |
| 1. | A portion of a fluid venting ophthalmic irrigation/aspiration system (10) comprising: an aspiration circuit (18) for removing fluid and body tissue from an eye, connected to a pump (14) and adapted at a first location (38) for contact with an eye; * a pinch valve (26) disposed between said pump (14) and said first location (38), having an open position and a closed position; and wherein said pinch valve (26) assumes a closed position when said aspiration circuit (18) is vented. |
| 2. | A fluid venting ophthalmic irrigation/aspiration system (10) comprising: an irrigation circuit (32) for delivering irrigating fluid to an eye, adapted at a first location (38) for contact with an eye; an irrigation pinch valve (22) to control said irrigation circuit (32), having an open and a closed position; an aspiration circuit (44) for removing fluid and body tissue from an eye, adapted at a second location (48) for contact with an eye, and connected to a pump (14); an aspiration pinch valve (26) to control said aspiration circuit (44) between said pump (14) and said second location (48), and having an open and a closed position; * a bridging circuit (40) having a first end and a second end, connected at one of said first and second ends to said irrigation circuit (32), and connected at the other of said first and second ends to said aspiration circuit (44) between said aspiration pinch valve (26) and said second location (48) of said aspiration circuit (44); * a bridging pinch valve (24) to control said bridging circuit (40) between said first and second ends of said bridging circuit (40), and having an open and a closed position; wherein, upon fluid venting, said aspiration pinch valve (26) assumes a closed position, said bridging pinch valve (24) assumes an open position, and said irrigation pinch valve (22) assumes an open position. |
| 3. | A fluid venting ophthalmic irrigation/aspiration system (10) comprising: an irrigation circuit (32) for delivering irrigating fluid to an eye, adapted at a first location (38) for contact with an eye and connected at a second location to a source of irrigating fluid (12); an irrigation pinch valve (22) to control said irrigation circuit (32), having an open and a closed position; an aspiration circuit (44) for removing fluid and body tissue from an eye, adapted at a third location for contact with an eye, and connected to a pump (14); an aspiration pinch valve (26) to control said aspiration circuit (44) between said pump (14) and said third location, and having an open and a closed position; * a bridging circuit (40) having a first end and a second end, connected at one of said first and second ends to said irrigation circuit (32), and connected at the other of said first and second ends to said aspiration circuit (44) between said aspiration pinch valve (28) and said third location of said aspiration circuit; * a bridging pinch (24) valve to control said bridging circuit (40) between said first and second ends of said bridging circuit (40), and having an open and a closed position; wherein, upon fluid venting, fluid is delivered from said irrigation circuit (32) through said bridging circuit (40) to said aspiration circuit (44). |
2. Related Art All ophthalmic irrigation and aspiration systems currently on the market provide only one means for venting. The term"venting"refers to the common practice of reducing or eliminating a vacuum or pressure differential between components of an irrigation/aspiration system, or between the irrigation/aspiration system and ambient atmosphere pressure.
The term"fluid venting"refers to the reduction of pressure differentials between the portion of the aspiration circuit that contacts the eye and remainder of the aspiration circuit by way of a connection between the irrigation fluid path and the aspiration path.
The term"air venting"or"atmospheric venting"refers to the reduction of pressure differentials between the portion of the aspiration circuit that contacts the eye and remainder of the aspiration circuit by way of a connection between the aspiration path and ambient air at atmospheric pressure.
In ophthalmic irrigation/aspiration systems that utilize a peristaltic pump, fluid venting is the most commonly used method. For example, Figure 1 illustrates an irrigation/aspiration schematic of the Accurus microsurgical system sold by Alcon Laboratories. This system uses fluid venting in its peristaltic-pump-based irrigation/aspiration system. No other type of venting is utilized in this system. In order to vent, the pump is stopped and both pinch valves, labeled"PV"are placed in an open position. As a result, residual pressure in the aspiration circuit pulls fluid from the bottle, through the first pinch valve, through the second pinch valve and into the aspiration side of the circuit until the pressure is reduced.
Figure 2 illustrates an irrigation/aspiration schematic of a microsurgical system sold by Surgical Design. In this example, the irrigation and aspiration circuits are joined only through the eye. In order to vent, the pump is stopped and the aspiration pinch valve, labeled"PV"is opened. As a result, residual pressure in the aspiration circuit pulls fluid from the bottle, through the first pinch valve and into the aspiration circuit.
In some peristaltic systems, such as that commercialized by AMO, venting is accomplished through pump reversal. Thus, as illustrated in Figure 3, the irrigation/aspiration circuit is structurally identical to that of the Alcon system.
However, venting is accomplished in a very different way. To vent, the pump is stopped, and then run in reverse. This pulls fluid or air from the bag and into the aspiration circuit to relieve the residual pressure.
For venturi aspiration systems, such as that commercialized by Bausch & Lomb Surgical in its Storz Millennium Microsurgical System product, air venting is used. As illustrated in Figure 4, air venting is accomplished by simply stopping the pump and maintaining pinch valve"PV"in an open position. Because the pump is not a positive displacement pump, residual pressure draws air from one end of the pump, through the bag, and into the main aspiration circuit.
In Bausch & Lomb Surgical's Phacotron Gold product air venting is also used.
As illustrated in Figure 5, air venting is accomplished by stopping the pump and maintaining pinch valve"PV"in an open position. Residual pressure in the aspiration circuit draws ambient air into the aspiration circuit until the residual pressure is relieved.
In all the prior art, many different variations are utilized to relieve the pressure in the circuit. However, it is believed that there is a need in the art for a new approach that actually temporarily changes the aspiration circuit by reducing the volume of the aspiration circuit within which the residual pressure must be relieved. None of the prior art teaches or suggests a reduction in the volume of the aspiration circuit in fluid venting mode.
A reduction in volume has many benefits. By reducing the volume, the residual pressure will be relieved more quickly. Keeping in mind that the residual pressure is also applied to the eye, faster relief of pressure reduces the risk of damage to occular structures. In addition, a reduction in volume by eliminating the volume of any pressure transducer within the circuit also provides substantially faster pressure relief because the transducer may have a volume equal to the rest of the circuit. The present invention is particularly helpful when the aspiration handpiece tip is occluded and the pump is generating a flow. Other advantages include elimination of any effect the pump may have by completely isolating the pump.
Summary of teste Invention It is in view of the above problems that the present invention was developed.
The invention provides a reduction in the aspiration circuit volume in fluid venting mode by closing a pinch valve located between the eye and the pump to provide faster relief of residual pressure present within the aspiration circuit that is applied to the eye.
Further features and advantages of the present invention, as well as the structure and operation of various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
Brief Description of the Drawings The accompanying drawings, which are incorporated in and form a part of the specification, illustrate the embodiments of the present invention and together with the description, serve to explain the principles of the invention. In the drawings: Figure 1 illustrates an irrigation/aspiration circuit of a positive displacement pump system that utilizes fluid venting; Figure 2 illustrates an irrigation/aspiration circuit of a second positive displacement pump system that utilizes fluid venting; Figure 3 illustrates an irrigation/aspiration circuit of a third positive displacement pump system that utilizes a motor reverse fluid venting scheme; Figure 4 illustrates an irrigation/aspiration circuit that is air vented; Figure 5 illustrates an irrigation/aspiration circuit that is air vented.
Figure 6 illustrates an irrigation/aspiration circuit of the present invention.
Detailed Description of tSte Preferred Embodiments Referring to the accompanying drawings in which like reference numbers indicate like elements, Figure 6 illustrates In view of the foregoing, it will be seen that the several advantages of the invention are achieved and attained.
The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated.
As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.