WO2000021588A1

WO2000021588A1 - Fluid venting in ophthalmic irrigation/aspiration system

Info

Publication number: WO2000021588A1
Application number: PCT/US1999/024085
Authority: WO
Inventors: James T. Perkins; Jeffery A. Knight
Original assignee: Bausch & Lomb Surgical, Inc.
Priority date: 1998-10-15
Filing date: 1999-10-14
Publication date: 2000-04-20
Also published as: AU1706300A

Abstract

A fluid venting ophthalmic irrigation/aspiration system (10) is disclosed that results in faster venting by reducing the volume to be vented.

Description

Fluid Venting in Ophthalmic Irrigation/ Aspiration System

Background of the Invention

1. Field of the Invention

This invention relates to fluid venting in an ophthalmic irrigation/aspiration

system that utilizes a positive displacement pump. Specifically, a structure and method

of fluid venting is disclosed that results in faster venting by providing a way to reduce

the volume within which pressure must be relieved.

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 the 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 the 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.

Claims

What is Claimed Is:

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).