System For Controlling Fluid And Suction Pressure

Abstract

A system for controlling pressurized fluid and suction pressure to be supplied to an instrument, such as an instrument for performing surgical operations. The system permits a variety of flow configurations to the instrument including either pressurized fluid or suction pressure alone or combinations of the two at adjustable pressures. The flow configurations are readily selectable by an operator under the control of an electrical operating system.

Description

In many applications in the field of surgery where operations are performed, it is necessary to be able to supply fluid to an operating field and to remove fluid from the same location. The former task is usually accomplished by supplying the fluid under pressure to the desired location and the latter by providing suction pressure.

The present invention relates to a system for providing both pressurized fluid and suction pressure at regulated pressures to a desired location in which the system operator can readily select the application of either or both to the location. This affords the operator a high degree of flexibility in controlling fluid flow to and from the operating field.

As a typical application in which the system of the present invention can be utilized, when operating in the eye's anterior or posterior chamber, suction pressure is used for aspiration or retainment of tissue to be removed or otherwise treated. During the course of the same operation, pressure is used for injecting a liquid or providing an irrigating liquid to retain the pressure in the eye above atmospheric pressure to prevent its collapse. This way, all eye components remain in their approximate relative positions of normal use and in such position the operation field will remain constant to the doctor or technician performing the operation.

In accordance with the invention, a system is provided which is capable of providing at the selection of the operator a number of fluid flow conditions. These conditions include:

1. Providing a pressurized fluid to the operating area to maintain it in a predetermined shape without any suction pressure being applied.

2. Providing a pressurized fluid to the operating area for irrigation or injection purposes in the absence of suction pressure to compensate for fluid loss from the operating area.

3. Providing pressurized fluid to the operating area for injection or irrigation purposes while at the same time removing fluid from the area by suction pressure at several different levels.

4. Providing a reverse pressure flow to the instrument to eject unwanted material which may inadvertently have been drawn into it.

The foregoing functions are accomplished according to the present invention by a system including a number of valves which are interconnected and operated in a novel manner by an electrical circuit, the latter being controllable by the operator.

In the preferred embodiment of the invention to be described, the pressurized fluid and suction pressure are supplied over separate conduits to a single instrument which is capable of utilizing both the fluid and suction at the same time. It should be understood, however, that the system is also useful in supplying the various flow configurations to any type of instrument or to conduits which are to be placed in the operating field.

It is therefore an object of the present invention to provide a fluid pressure control system for providing suction and/or pressurized fluid to a particular location.

Another object is to provide a fluid control system which is capable of selectably providing a number of fluid control conditions such as supplying a pressurized fluid to an operating area and drainage and evacuation, of the area.

Still a further object is to provide a system for selectively providing pressurized fluid and/or suction to a desired area under the control of an operator by the operation of several electrical switches.

Other objects and advantages of the present invention will become more apparent upon reference to the following specification and annexed drawings, in which:

FIG. 1 is a flow diagram, partially in schematic form, of a preferred embodiment of a system according to the present invention;

FIG. 2 is a flow diagram, partially in schematic form, of a modified version of the system of FIG. 1;

FIGS. 3 and 4 are schematic diagrams of the electrical circuits for the systems of FIGS. 1 and 2, respectively;

FIG. 5 is an elevational view, partly in cross-section of one type of device for the controller stage;

FIG. 6 is a top view in cross-section of the device of FIG. 5, taken along lines 6--6 of FIG. 5;

FIG. 7 is an elevational view, one taken in cross-section of one form of device used as a filtering stage;

FIG. 8 is a top view, in cross-section, along lines 8--8 of FIG. 7;

FIG. 9 is an elevational view, partly in cross-section, of one form of device used for a flow restricting element and shown in a first operating position;

FIG. 10 is a top view in cross-section along lines 10--10 of FIG. 9; and

FIG. 11 is a view similar to that of FIG. 9 showing the device of FIG. 9 in a second operating position.

SYSTEM CONSTRUCTION

A. General Description

FIG. 1 shows a preferred form of the invention utilized with a surgical instrument 10 of a type, for example, which is more fully described in my copending application Ser. No. 799,476, filed Feb. 14, 1969, which is now U.S. Pat. No. 3,732,858, granted on May 15, 1973. It should be understood, however, that the system can be used with any type of instrument or instrument set-up which requires pressurized flow of a liquid and/or suction. In the embodiment of the invention being described, the instrument is shown as having pierced through a section of the eye, for example after an incision has been made. The tip of the instrument is shown adjacent the lens of the eye to remove tissue therefrom or to treat the eye. It should be understood that the system can be used with any compatible type of instrument to perform operations or treatment in any portion of the body of a mammal.

The instrument 10 of FIG. 1 includes an inner tubular member 12 forming an inner passage 14 through which a suction flow can be provided. The instrument also has an outer tubular member 16 around member 12 defining a passage 17 between the two members 12 and 16 through which a pressurized fluid can be applied.

The inner, suction flow, member 14 has an opening 19 at the end thereof through which suction pressure is applied to the operation field. The other, pressure flow, member 16 has an opening 21 in its wall through which fluid is ejected into the operation field. The lower ends of the two members 12 and 16 are shaped so that a cutting surface or edge 23 is formed between the ends 19 and 16a. Pressurized fluid exits only through the wall opening 21 so that it does not interfere with the suction. Cutting of a piece of tissue 25, for example the lens of an eye, may be obtained by suitable rotation or reciprocation of the two members 12 and 16 with respect to each other so that the cutting surface 23 is actuated. This is more fully described in my aforesaid copending application.

The system of FIG. 1 provides a regulated suction flow and a regulated pressure flow both of which are selectable and controllable by the operator. The system includes a number of servo, or solenoid, valves which are each designated by the reference letters SV and a suffix number. These valves are of conventional construction and are preferably of the type which can be electrically operated between fully closed and fully opened conditions. The electrical circuit is described below. A number of adjustment valves are also used which are designated by the prefix letter A. These are conventional valves, for example, needle type valves, or calibrated bushings, which can be adjusted to vent a desired amount of pressure or suction pressure.

Considering first the suction portion of the system, this includes a suitable suction source, that is, a source of reduced pressure, which can be of any conventional type, for example, a motor operating a vacuum type pump or other similar pump which can provide the desired volume of suction pressure flow. The suction source 70 has a drain line 70-2 and a working line 70-1. The drain line 70-2 is operated by servo valves SV-1 and SV-4 to clear out a controller stage 54 into which waste tissue or other matter may be lodged. The flow path is from the atmosphere, through valve SV-3, the controller stage 54 and valve SV-4 into a waste bottle 56. The latter has a suitable closure 56a to seal it off with the two conduits shown.

The working line 70-1 operates through valve SV-2 to provide the working suction pressure to the instrument 10 and the operation field. The suction flow path is through SV-2, the controller stage 54, a flow restricting element 52, a valve SV-11 and filter and flow detector stages 50 and 49 to a conduit 11 leading to the instrument suction passage 14. The suction pressure is controlled to a desired level by two adjustment valves A-1 and A-2 and the suction pressure is read out on a gauge P-2.

As is described in detail below, the controller stage 54 is a device through which suction is supplied to the instrument and tissue is removed from the active portion of the system. The flow detector 49 measures the suction pressure flow and if it is too high, it closes valve SV-11. In essence, it is a pneumatically operated electrical switch. The filtering stage 50 filters particles of removed tissue out of the suction path while the flow restricting element 52 controls the rate of suction flow into the controller stage 54.

The pressure portion of the system of FIG. 1 supplies liquid to replace the liquid lost through the incision in the body being operated upon and any liquid removed through the instrument 10 to maintain a relatively constant pressure within the interior of the operating field. In general, the pressure in the field, the eye in this case, should always be several millimeters of mercury above atmospheric pressure to maintain the eye formed at all times for better visualization and retainment of all components in their relative position. This is important to be able to maintain a predetermined distance between the active portion of the instrument and portions of the eye and also to prevent delicate tissue from coming into contact with the instrument so that the latter will not be damaged. Further, in the case of operating in the eye, the pressure on the retina of the eye should be maintained to prevent its separation from the choroid.

The pressure source 30 can be of any desired type, for example, an electrically or mechanically operated pump. The pump can directly supply fluid of the desired type, such as benign fluid, inert fluid, medicated treatment fluid or sterile water to the operating field. Alternativly, the fluid can be contained in a suitable container, such as bottle 37, which is pressurized, as described below, to supply fluid to a conduit 40 and thence to the fluid passage 17.

When suction pressure is being supplied to instrument 10, pressure is applied from source 30 over line 32-1 through valve SV-7 into bottle 37. The pressure in the bottle 37 is read out on a pressure gauge P-1. Adjustment valve A-5, located in line 32-1, controls the pressure in bottle 37 which supplies fluid to the instrument 10 over line 40.

In supplying pressurized fluid, by pressure in line 32-1, during the time that suction is also being used, a sufficient amount of liquid solution is pumped into the operating field to provide a fluid-flow path through the instrument and into the suction portion of the system, thus maintaining pressure in the operating fluid.

A relatively low time constant coupling between the tip of the instrument and the controller 54 is provided. That is, changes in the operating condition of the system which appear at the controller 54 are produced substantially instantaneously at the instrument tip due to the fact that there is a continuous column of liquid between the controller and the instrument tip through the various elements 49, 50, SV-11 and 52.

Pressure line 32-2 is used, during the time that suction is not used, to provide a sufficient amount of fluid under pressure to the operation field. When the operation field is located above fluid bottle 37, gravity cannot drain the fluid from the operating field into the bottle. Thus, fluid is supplied to maintain the interior of the operation field at a predetermined pressure level, to prevent collapse and to achieve proper placement of the various components of the body being operated upon. Fluid is also pumped into the operation field to compensate for fluid losses through the incision or instrument. The flow path at this time is through valves SV-10 and SV-6. An adjustment valve A-4 sets the level of pressure supplied at this time.

A third pressure line 32-3 is used to supply pressure at the instrument tip to clear out any material which is not to be operated upon but which may have been inadvertently moved into the cutting surface area of the tip by the suction pressure. With valves SV-9 and SV-8 open, pressure passes through controller stage 54, flow restricting element 52, SV-11, filter and flow detector stages 50 and 49 into conduit 11 and the suction passage 14. This pressure is set by valve A-3 and read out on gauge P-3. This pressure flow is not a liquid.

The three pressure lines 32-1, 32-2 and 32-3 operate alternately. As described below, pressure line 32-2 operates with drain line 70-2 during a "release" condition when the controller stage 54 is being cleared and a desired liquid pressure is to be maintained in the operation field; pressure line 32-1 operates to supply fluid at a different pressure level (usually higher) at the same time suction can be supplied over a working line 70-1 so that the operating field (the eye) remain formed; and pressure line 32-3 operates to clear the instrument tip when no suction pressure is used.

SYSTEM OPERATION

A. General

A desired operating condition is produced by controlling the various servo valves. In so doing, different flow conditions are established at the various conduits connected to the pressure and suction pumps and thereby at the tip of the instrument.

During the course of an operation, the usual sequence of flow conditions needed at the instrument tip is as follows:

1. The system is energized and a "release" condition is produced to clear out the controller stage. This condition is also produced to obtain a state of readiness before an actual operation takes place, or between different steps of an operation when the surgeon is relocating the instrument or pausing.

2. Injection or irrigation fluid is supplied to the operation field.

3. Injection or irrigation fluid is supplied and aspiration (suction) is utilized at the same time.

4. Injection or irrigation fluid is supplied and aspiration with suction at a different level (usually higher) than in mode (3) is utilized.

5. A reverse flow of fluid is supplied to the suction passage of the instrument from the controller stage to clear the tip.

The five operating modes and the manner in which they are produced by the various valves are described below.

B. Electrical System

An electrical circuit for operating the pressure and suction system of FIG. 1 is schematically shown in FIG. 3. The electrical circuit comprises a number of solenoids (sometimes called relays) which operate, and are usually part of the respective servo valves designated SV in FIG. 1. The solenoids are designated with the same number as the corresponding servo valves with a prefix letter "R", for example, solenoid R2 operates servo valve SV-2.

The electrical circuit includes several switches which are operated by the person utilizing the system. Switch S-1 controls a relay K, which in turn operates a gauged switch S-2 with two movable contact arms. Switches S-3A and S-3B are individually operated as is switch S-4. The switches can be of any suitable type. Preferably, they are operated by foot controls so that the user of the system will have his hands free to perform the operation. For example, switch S-1 can be operated by the heel of the foot, energizing or de-energizing switch S-2, while the front of the foot can operate switches S-3A, S-3B and S-4. When S-3A S-3B and S-4 are to be operated, S-1 must be released.

The electrical circuit of FIG. 3 can be either AC or DC operated. Where an AC source is utilized, it is preferred that suitable transformers and isolation be provided so that the system will be safe. This is in accordance with conventional techniques. The two input voltage lines to the relays are designated +V and -V. When a relay coil is connected across both lines, it has current flowing therethrough, the relay is energized and the respective servo valve is moved to an open flow condition to convey fluid or suction.

Relay R11, which operates SV-11, is connected across lines -V and +V at all times. It is energized unless the switch provided by the flow detector opens in response to an excessive flow rate condition.

C. Valve Operating Sequence

Table I below shows the states of the various servo valves for the five operating modes of the system. A "1" signifies that the valve's respective relay is energized and that the valve is in an open flow condition. An "0" signifies that the relay is de-energized and the valve is closed. SV-11 is not shown since it is open all the time unless closed by the flow detector. ##SPC1##

D. Mode (1) -- Released Condition

When the system is first turned on, the switches are in the position shown in FIG. 3, resulting in the energization of valves SV-1, SV-3, SV-4, SV-6 and SV-10. This is shown with respect to Table I.

With valves SV-10 and SV-6 open, pressure is supplied over line 32-2 to the fluid container 37 and fluid to the instrument through conduct 40. Fluid is thus being delivered into the operational field, the pressure being set by the adjustment of the valve A-4 and the pressure being read out on the gauge P-1. There is no pressure flow in either of lines 32-1 or 32-3 since valves SV-7 and SV-9 are closed.

In the suction portion of the system, valves SV-1, SV-3 and SV-4 are open to provide suction from line 70-2 through controller stage 54 to the atmosphere through SV-3 to empty the stage into the waste bottle 56.

The mode (1) condition is usually needed when the instrument is in the operational field and suction at the instrument tip is not used. The pressure in line 32-2 pressurizes the fluid in container 37 to the extent required to maintain a desired quantity of liquid in the operational field. The amount of pressure is adjusted by the valve A-4 and observed on gauge P-1. In the case of an operation performed in the eye or other closed member, the liquid pressure inside the eye is maintained high enough to keep the eye formed in its proper shape at all times for better visualization. Without the pressure in line 32-2 in this mode, the eye would be drained through the fluid injection line 40 by gravity. The supply of liquid also compensates for losses of liquid from the eye through the incision or leakage through the instrument due to possible differential pressures between the instrument tip and the controller stage 54.

The suction in drain line 70-2 evacuates air from the waste bottle 56. The bottle being connected to the controller stage 54, which in turn communicates with the atmosphere through SV-3, a differential pressure is created which moves residual liquid, if present, from the controller stage to waste bottle 56.

E. Mode (2) -- Injection or Irrigation

To place the system in mode (2), switch S-3A is moved from the contact position shown in FIG. 3 to the lower position. With the electrical circuit in this condition, valves SV-1, SV-3, SV-4 and SV-7 are open. The difference between mode (1) and mode (2), insofar as the pressure portion of the system is concerned, is that pressure line 32-2 is closed and line 32-1 is open. The container 37 receives pressure on line 32-1 through SV-7 and liquid is supplied through line 40 to the instrument and the operational field. The pressure of liquid in the operational field is proportional to the pressure in the liquid containing bottle 37. In the case of an eye being operated upon, the pressure should be within limits not harmful to its structure.

The pressure in container 37 is set by adjustment valve A-5 and is observed on pressure gauge P-1. The pressure at the tip of the instrument varies when the two portions of the instrument are either receiprocated or turned to close the opening, such as when tissue is being cut, or when suction is applied to the operational field. A constant fluid pressure in the container 37 is maintained through the line 32-1.

During mode (2) operation, the suction flow of mode (1) is maintained, as described above, i.e. the controller stage 54 is being cleared through the drain line 70-2.

F. Mode (3) -- Irrigation and Suction

In mode (3), irrigation or injection of fluid is to take place and a suction force is to be produced at the tip of the instrument 10 for aspiration of the fluid or tissue in the operation field. A differential pressure, caused by supplying fluid from container 37 and having suction at the same time, creates a flow from the operation field to the controller stage 54 for tissue removal. Tissue from mass 25 is aspirated into the opening of the instrument tip where it is to be separated by the cutting action of the instrument or emulsification, or where it is to be retained against the instrument for treatment such as, for example, by another instrument (not shown).

In mode (3), the electrical circuit is conditioned so that the contacts of switch S-1, S-2 and S-4 are left in the position shown in FIG. 3 and both contacts S-3A and S-3B are moved downward. This energizes the respective relays to open valves SV-2, SV-7 and SV-12. With valves SV-7 open, pressurized fluid is produced in the operation field by the pressure in line 32-1 as in mode (2).

Valve SV-1 is now closed and there is no suction in drain line 70-2. However, SV-2 is open and suction is supplied to the instrument over working line 70-1. The path is through container 60, SV-2 controller stage 54 and conduit 11 to the instrument where it is available at the tip opening 19. The suction pressure is read on gauge P-2.

Adjustment valve A-2 located in the line 70-1 sets a high level reference pressure for the suction. Since SV-12 is also open in mode (3), adjustment valve A-1 is also available to set a lower level suction pressure which is used in mode (3) at the instrument tip.

In mode (3) the controller stage 54 accumulates the liquid and small particles of tissue suspension evacuated from the operation field and not removed by filter 50. When suction at the instrument tip is no longer needed, the operator switches the system back into mode (1) so that the controller stage 54 can be evacuated in the manner previously described. As can be seen, the suction lines 70-1 and 70-2 are operated alternately, 70-1 operated to move tissue from the operation field into the controller stage and 70-2 to clear the controller stage 54. Line 70-1 and its components preferably are of small volume and low resistance to evacuate the controller stage 54 in the shortest possible time.

G. Mode (4) -- Irrigation With Maximum Suction Pressure

When a higher suction force is required at the end of the instrument tip than is provided in mode (3), this is accomplished by closing SV-12. This takes adjustment valve A-1 out of the system and sets the suction pressure at the reference level set by valve A-2. To obtain the mode (4) condition, the switches of the circuit of FIG. 3 are operated in the same manner as in mode (3) with the exception of switch S-4. That is, switches S-1 and S-2 are as shown, the contacts S-3A and S-3B are moved down and S-4 is open. In this configuration only valves SV-2, SV-7 are open.

The difference between modes (3) and (4) is that in the former, both adjustment valves A-1, A-2 are available, A-1 setting a lower reference level suction pressure than A-2. With SV-12 closed, only valve A-2 is in the system. If A-2 is adjusted to be closed, the maximum suction pressure of the source 70 is available.

H. Mode (5) -- Released Condition Plus Reverse Flow

In some instances, tissue is inadvertently aspirated into the instrument 10 and has to be ejected. Here, a flow reverse to the one generated by suction is to be created in conduit 11 and in the passage 14 of instrument 10 normally receiving suction. To accomplish this, pressure is supplied over line 33-3 to controller stage 54 to send pressure through conduit 11 and passage 14 of the instrument 10 and out through the tip opening 19.

In mode (5) switch S-1 is closed thereby energizing relay K1 and moving the two contact arms of S-2 to the down position. Switches S-3A, S-3B and S-4 are as shown in FIG. 3. With this circuit, SV-1, SV-5, SV-8 and SV-9 are open. The two pressure lines 32-1 and 32-2 are both closed since their respective valves SV-7 and SV-10 are closed. Since SV-9 and SV-8 are open, pressure is supplied to the controller 54, the quantity being adjusted by valve A-3 and read out on gauge P-3.

Suction line 70-2 is still open, SV-1 being open, and SV-5 is open to vent this line and waste container 56 to atmospheric pressure. Valves SV-2, SV-3 and SV-4 are closed so that the pressure in line 33-3 does not back up into the suction source or atmosphere through controller 54. The pressure flows over line 32-3, valves SV-9 and SV-8, the controller 54 and the other elements to conduit 11. This provides pressure to instrument passage 11 to clear the tip.

SYSTEM COMPONENTS

A brief description of the various components of the system, not already described, is given below.

A. Flow Detector

A flow detector 49 is located in front of the filtering stage and as close to the instrument 10 as possible. The element 49 stops the flow of removed fluid from the operating field, if it exceeds a given value. This protects the operating field from being over-drained. In the case of an eye, if the outflow of fluid is greater than the inflow, the eye will collapse.

The flow detector 49 operates solenoid valve SV-11 located after the filtering stage 50 and also close to the instrument. The fluid removed from the operating field passes through SV-11 after it has been filtered to prevent clogging of SV-11 and the flow-restricting element 52. Valve SV-11 is wired in the electrical circuit to be normally open. If the flow exceeds a certain rate, a switch is actuated to close SV-11. Due to the wiring of SV-11, if power fails, valve SV-11 will close, blocking flow of the suction lines. This is a fail safe type of arrangement.

Flow detector 49 is basically a pressure operated switch and any suitable switch of this type can be used. One such type includes a membrane, or diaphragm, which is moved in response to the differential pressure caused by the liquid flowing through the switch. The diaphragm in turn actuates a switch to the open position when the flow rate is excessive. Another type of switch is a differential pressure transducer which measures the pressure at inlet and outlet ports by strain gauges and produces an electrical signal when the difference exceeds a predetermined value corresponding to an excessive flow rate. This signal in turn actuates a solid state switching device which is in circuit with the relay coil R-11.

The line, or conduit, 11 connecting the central member 12 of the instrument to the flow detector and filtering stage 50 is preferably of an uncollapsible material, for example, a heavy walled plastic, having a small internal bore diameter. The volume of liquid carried by this line should be small to prevent changes in its shape due to elasticity caused by the storage of energy which is released or accumulated when the flow rate is changed. This would add a time delay between controller 54 and the tip opening.

B. Filter Stage

One form of device for the filtering stage 50 is shown in FIGS. 7 and 8. The filter is used to prevent small particles of tissue from entering the flow-restricting element 52 and clogging its orifices, thus changing the rate of flow, or stopping it entirely. Slowing down the flow rate at a given suction pressure increases the time needed to achieve a desired suction force at the instrument tip while stopping the suction flow prevents a force from being built up at the instrument tip and thereby prevents particles from being removed from the operating field.

The filter stage shown in FIGS. 7 and 8 includes a cylindrical sleeve 110 having upper and lower covers 11a and 11b each with a respective O-ring 113 to provide a seal. Sleeve 110 is preferably made of glass and is removable from covers 111 for easy cleaning. An inlet passage 112 is formed in the bottom cover member 111b and has an extension 112a which extends upwardly part way within the housing 110. Fluid from the flow detector 52 flowing into the housing 110 passes upwardly through a coarse mesh screen 114 and a finer mesh screen 116 which are spaced apart in the upper portion of housing 110. The two screens 114 and 116 are held in a jig or fixture 118 having flow passages 119 in its central portion to provide a fluid flow path between screens 114 and 116.

The fixture 118 fits around a central conduit 120 and rests on a shoulder 120a. The conduit 120 extends for substantially the entire length of the housing and its ends are held in respective recesses 113a and 113b in the top and bottom covers 111a and 111b. Conduit 120 has a plurality of openings 122 located above the fine mesh screen 116 in a conical depression 123 in the upper cover 111a to prevent an air cushion from building up, which would introduce a time delay. The lower portion of conduit 120 fits into an outlet passage 124 in the bottom cover 111b.

Fluid enters through passage 112 from flow detector 52. After passing through filter screens 114 and 116, the fluid enters the conduit openings 122, flows down its length and leaves the filter through the outlet 124 to valve SV-11.

The two different size mesh screens are used so that the lower, coarse mesh one, 114 retains only large pieces of removed tissue and the upper, fine mesh one, 116 retains smaller pieces. The mesh size of screen 116 is smaller than the diameter of the smallest orifice of the flow-restricting element 52, to be described. The two filter screens shear coagulated tissue loose from the liquid to decrease the possibility of clogging of the remainder of the suction system.

The filter element 50 is preferably used in a vertical position as shown in FIGS. 7 and 8 so that the flow of liquid is upwardly. Therefore, particles with density larger than the liquid solution and which cannot be moved upward by the differential pressure causing the flow are suspended close to the bottom of the housing 110 or rest on the lower cover 111b and do not load the filter screens.

C. Controller Stage

The controller stage 54 is the portion of the system where operational conditions produced by the suction source 70 or pressure source 30 during a return flow are presented at the desired pressure level. One suitable device for performing this is shown in FIG. 5.

During an operation, conditions in the controller stage 54 are transmitted through a non-interrupted column of liquid to the tip of the instrument 10 through the flow-restricting element 52, SV-11, filtering stage 50 and flow detector 49. Any air bubbles which accumulate and release energy, change the flow rate of fluid through the instrument. In the case of an eye operation, if the outflow of liquid from the eye cannot be controlled, the eye may collapse and the operation be unsuccessful.

The controller stage 54 is small in volume so that conditions inside can change substantially instantaneously, that is, pressure can be released and vacuum obtained, and vice versa, in a relatively short time and also so that the desired pressure or vacuum equilibrium level can be reached in a short time. Controller stage 54 is located as close as possible to the instrument 10, in terms of the volume of liquid between the instrument and controller stage 54. This minimizes time delays between activating a control of the system and obtaining a desired condition in stage 54 and at the instrument tip.

Referring to FIGS. 5 and 6, the controller stage 54 has a cylindrical sleeve 130, which is also preferably made of glass, whose top and bottom are sealed by covers 133a and 133b having O-rings 134. The lower cover 133b is formed with an inlet coupling and passage 135 which is coupled to receive fluid flow from the flow restrictor 52.

A central conduit 137 has its bottom end fastened to cover 133b and its top end in cover 133a where it communicates with an outlet coupling and passage 139 which continues through 133a. A number of openings 140 are formed near the upper end of conduit 137 adjacent a conical recess 142 in upper cover 133a to allow a maximum amount of fluid to enter. The outlet 139 is connected to SV-2, SV-3 and SV-8. Here, a suitable coupling member is used.

Another outlet passage and coupler 144 is formed in the lower cover 133b to communicate with the interrior of housing 130 and with SV-4.

In operation, when there is no suction on the working line 70-1, such as in modes (1) and (2), SV-2 is closed closing off the working line 70-1. Since SV-3 is open and vented to the atmosphere and SV-4 is also open, a flow path is created between the atmosphere and suction pressure line 70-2 through SV-3, coupling 139, openings 140 in central conduit 137 and out coupling 144. This evacuates and drains out the interior of the controller housing 130 into the waste bottle 56.

When suction is being applied to the instrument tip, such as in modes (3) and (4), SV-4 is closed closing off controller outlet 144. The flow path is now from instrument 10 through the flow restricting element 52 and into controller housing 130 through inlet coupling 135. Air is evacuated through the openings 140 conduit 137 and passes to the small safe bottle 60 through outlet coupling 139 and SV-2. Liquid is allowed to collect in the controller stage. During this time, SV-4 closes off suction line 70-2; SV-3 closes off the vent; and SV-8 closes off line 32-3.

In mode (5), pressure enters from line 32-3 and through SV-8 into the housing 130 through coupling 139. Since SV-2, SV-3 and SV-4 are all closed, the pressure can only go to the flow restrictor 52 and thence to the instrument 10 over the suction line conduit 11.

D. Flow Restrictor

The flow-restriction element 52, located between the valve SV-11 and the controller stage 54, determines the maximum flow rate from the operating field to the controller stage 54 at a selected suction pressure. The flow restricting element can be a simple needle valve where the flow is regulated by the position of the needle. In a preferred embodiment of the invention, two flow-regulating orifices of different diameters and an arrangement to switch between the two is utilized. This is shown, in FIGS. 9-11 where the element 52 includes a housing 152 having a central bore 154 in which a shaft 155 is slidable and rotatable. Shaft 155 has a central passage 156 through the upper portion thereof which communicates with a pair of annular orifices 157 and 158 which have respectively different sized diameter flow passages to the central passage 156.

The shaft 155 has a lug 159 (FIG. 10) fastened thereto which rides in one or the other of upper and lower arcuate tracks, or grooves 160a and 160b which are formed in the bonnet 162 of the housing. The two tracks 160a and 160b are joined by a vertical track 160c. The bonnet 162 is held to housing 152 by a member of screws 163. To move the shaft 155 from the position of FIG. 9 to that of FIG. 11, the shaft control knob 155a is turned to bring shaft lug 159 into the vertical track 160c and the knob is then pulled down to bring the lug into bottom arcuate track 160b. Knob 155a is then turned to move the lug 159 away from vertical track 160c. To move from the position of FIG. 11 to that of FIG. 9, the reverse procedure is followed. The maximum flow rate is set by setting the position of the shaft.

Housing 152 has an inlet coupling and passage 165 which receives fluid from valve SV-11. The fluid goes through one of the orifices 157 or 158 on shaft 155, the shaft central passage 156 and out of the housing through a passage 166 formed in the upper part of the housing and an outlet passage and coupling 167. The latter is connected to the inlet of the controller stage 54.

In the position shown in FIG. 9, the shaft furthest into the housing, flow communication is made between the inlet 165 and the orifice 157 having the smallest diameter passage into the shaft central passage 156. In the position shown in FIG. 11, shaft 155 aligns the inlet 165 with the orifice 158 having the maximum diameter flow passage.

The device shown in FIGS. 9-11 is preferred as the restricting element instead of a needle valve since a plurality of orifices have a better chance of permitting passage of particles to the waste bottle more than twice the size of particles which would pass through a needle valve having the same passage cross-section.

E. Miscellaneous Components

It is preferred that flexible plastic tubes be used for the conduits 11 and 40 connected to the instrument and in the other portions of the system where possible. Where these tubes are to be connected to metal couplings, for example at the stoppers of the various bottles 37, 56 and 60, and between the various stages 49, 50, 52 and 54, for easy plug-in attachment spring-loaded connectors are preferably used.

The various bottles are preferably made of glass and are commercially available with sterile contents to be pressurized. The stoppers for the bottles preferably are stainless steel caps, which can be sterilized, and which are screwed on. Any other suitable material can be used. The various couplings or tubes which extend into the bottle can be of plastic or metal.

The pressure gauges P-1, P-2 and P-3 are of any suitable conventional type.

SYSTEM OF FIG. 2

A. General Operation

In some cases it is desired to introduce liquid into the operating field through the opening 23 of the instrument. In the system of FIG. 1, the suspension of liquid and tissue previously aspirated would be conveyed back into the operating field. FIG. 2 shows a system capable of providing clean fluid through opening 23.

The system of FIG. 2 is similar to that of FIG. 1 with the exception of the pressure line 32-3. The same reference numbers have been used where applicable.

In FIG. 2, pressure line 32-3 pressurizes a fluid bottle 200 through SV-9 and SV-8. The bottle contains fluid of any desired type. Adjustment valve A-3 sets the pressure in the bottle which is read out on gauge P-3. The output of bottle 200 is applied through a conduit 201 to a coupling (not shown) in line 11 to the suction member 14 of the instrument. The coupling is preferably located as close to the inlet of the instrument as possible.

As is described below, the fluid from bottle 200 is provided in mode (5) operation only. To prevent the fluid from bottle 200 in conduit 201 from flowing back into the flow detector and controller stage 54 over line 11 during mode (5) and also to preclude suction from reaching conduit 201 during the other modes of operation, a suitable shut-off arrangement (not shown) is utilized between the coupling for lines 11 and 201 and the flow detector 52 and bottle 200. This arrangement can be a clamp in each line which is actuated manually or electrically to close off one line when the other is left open. A simple arrangement is a pressure type clamp which operates selectively to close off one of the lines 11 or 200 while at the same time opening the other. This can be a rotatable member operating to deform the wall of the line, which is of plastic material, to a sufficient extent to close it.

B. Electrical Circuit

The electrical circuit for the system of FIG. 2 is shown in FIG. 4. The same reference characters for the components of the circuit of FIG. 2 are used.

As seen, R11 to operate SV-11 is wired as in FIG. 2 and operates in the same manner when power is supplied to the system. The circuit of FIG. 4 has a switch S-5 which controls a relay K5 and its three sets of contacts S-5A, S-5B and S-5C. Another switch S-6 controls a relay K-6 and its contacts S-6A, S-6B and S-6C. S-4 is again provided. As before, the switches S-4, S-5 and S-6 can be located on a foot controlled switch.

The various operating modes of the system of FIG. 2, which are produced by the circuit of FIG. 4, are the same as that previously described for the system of FIG. 1 with the exception that mode (2) is not available. The valve operating table for the circuit of FIG. 2 also applies here.

C. System Operation for FIG. 2

The four operating modes are described below. Mode (2) of FIG. 1, irrigation only, is not available.

1. Released

In this mode, switch S-4 is closed and switches S-5 and S-6 are open so that the two relays K-5 and K-6 are de-energized and the relay contacts are as shown in FIG. 4. Therefore, valves SV-1, SV-3, SV-4, SV-6 and SV-10 are open. The operation of the system is as described with respect to FIGS. 1 and 2 for mode (1).

2. Irrigation and Suction

In this mode, switches S-4 and S-5 are closed and switch S-6 open. This energizes relay K-5 so that the contacts S-5A, S-5B and S-5C are moved down. This opens valves SV-2, SV-7, and SV-12. The operation of the system in this mode is as described with respect to FIGS. 1 and 2 for mode (2).

3. Irrigation and Maximum Suction

In this mode switch S-5 is left closed, as in mode (3), and switch S-4 is opened in addition to switch S-6. Valve SV-12 is now closed leaving only SV-2 and SV-7 opened so that irrigation and maximum suction are applied. The operation is the same as mode (3) of FIGS. 1 and 2.

4. Reverse Flow

In this mode, switch S-4 is again closed, switch S-5 is opened and switch S-6 is now closed. This energizes relay K-6 and moves contacts S-6A, S-6B and S-6C down while relay K-5 is de-energized so that contacts S-5A, S-5B and S-5C are in the up position. Valves SV-1, SV-5, SV-8 and SV-9 are now open.

In this configuration, pressure lines 32-1 and 32-2 are closed. Pressure is applied over line 32-3 through SV-9 and SV-8 to the container of clear fluid 200 and applied over line 201 to the suction conduit 11 of the instrument. This fluid can be used to clear tissue from the opening 23 of the instrument and/or provide additional fluid to the operating area. Valves SV-1 and SV-5 operate as previously described with respect to FIGS. 1 and 2 for mode (5).

As should be apparent, a novel system has been described for providing suction and/or pressure to an operating field under the selective control of the operator.

Claims

What is claimed is:

1. Apparatus for aspirating fluid and any solid material entrained therein from an operating field comprising a source of suction pressure, controller means having an inlet and an outlet, first conduit means connected between said controller inlet and the source of suction pressure, second conduit means connected to the controller outlet and having an end through which the fluid to be aspirated from the operating field enters, means for selectively controlling the flow of the suction pressure from the source to said controller means to produce suction pressure at the end of said second conduit means, and means connected between said source of suction pressure and said controller means for removing the fluid aspirated from the operating field from said controller means while removing the suction pressure from said second conduit means.

2. Apparatus as in claim 1 wherein said means for selectively controlling the flow of the suction pressure includes means for selectively producing two different rates of suction flow.

3. Apparatus as in claim 1 further comprising means connected in said second conduit means for filtering particulate material from the aspirated fluid.

4. Apparatus as in claim 1 further comprising means connected in said second conduit means for selectively restricting the flow rate of the aspirated fluid to said controller means.

5. Apparatus as in claim 4 wherein said flow rate restricting means includes means having two different sized orifice openings, and means for selecting one of said orifice openings to achieve the desired flow rate.

6. Apparatus as in claim 1 further comprising means connected in said second conduit means for sensing the pressure differential of the fluid between said one end of said second conduit means and said controller means and for closing the suction pressure flow in said second conduit means when the pressure differential sensed exceeds a predetermined value.

7. Apparatus as in claim 1 further comprising means for supplying fluid under pressure including a third conduit means having an outlet end at which the pressurized fluid is produced, said means for selectively controlling the flow of suction pressure to said controller means also selectively controlling the flow of pressurized fluid at the outlet end of said third conduit means.

8. Apparatus as in claim 7 wherein said means for selectively controlling the flow of suction pressure and the flow of pressurized fluid operates to provide fluid under pressure from said third conduit means at the same time that the fluid in said controller means is being removed.

9. Apparatus as in claim 7 wherein said means for selectively controlling the flow of suction pressure and the flow of fluid under pressure operates to provide suction pressure at said end of said second conduit and pressurized fluid at said outlet end of said third conduit means at the same time.

10. Apparatus for aspirating fluid and any solid material entrained therein from an operating field comprising a source of suction pressure, controller means having an inlet and an outlet, first conduit means connected between said controller inlet and the source of suction pressure, second conduit means connected to the controller outlet and having an end through which the fluid to be aspirated from the operating field enters, means for selectively controlling the flow of the suction pressure from the source to said controller means to produce suction pressure at the end of said second conduit means, and means for supplying fluid under pressure including a third conduit means having an outlet end at which the pressurized fluid is produced, said means for selectively controlling the flow of suction pressure to said controller means also selectively controlling the flow of pressurized fluid at the outlet end of said third conduit means to provide suction pressure at said end of said second conduit and pressurized fluid at said outlet end of said third conduit means at a first pressure level at the same time and also operates in another mode to provide pressurized fluid from said outlet of said third conduit means at a second pressure level.

11. Apparatus as in claim 10 wherein said means to selectively control the flow of suction pressure operates to remove the contents from the controller means while removing the suction pressure from said second conduit means.

12. Apparatus for supplying fluid to and aspirating fluid and solid material entrained therein from an operating field comprising in combination an instrument for removing material from a larger mass, an aspirating passage and a fluid supply passage formed in said instrument, suction pressure fluid supply means, pressurized fluid supply means, first conduit means connected between said source of suction pressure fluid and said aspirating passage of said instrument, second conduit means connected between said pressurized fluid supply means and said fluid supply passage, means for selectively controlling the flow in said first and second conduit means to selectively provide suction pressure fluid in said aspirating passage and pressurized fluid in said fluid supply passage, means located in the flow path of said first conduit means for sensing the differential pressure between the outlet of the aspirating passage and the suction pressure of the source, means operated by said sensing means for closing said first conduit means when said differential pressure exceeds a predetermined amount, and means for clearing material from said first conduit means without losing the suction pressure in said aspirating passage.

13. Apparatus as in claim 12 further comprising first container means in the path of said second conduit means between said pressurized fluid supply means and said fluid supply passage into which the pressurized fluid is applied, and respective means in said first and said second conduit means to adjust the suction pressure and the pressure of the fluid in said first container means respectively.

14. Apparatus as in claim 13 further comprising means for also operating said selective controlling means to apply pressurized fluid from the outlet of said first container means at the same time that suction pressure is removed from said first conduit means.

15. Apparatus as in claim 12 further comprising means located in the flow path of said first conduit means for selectively restricting the flow of the suction pressure.

16. Apparatus for supplying fluid to and aspirating fluid and solid material entrained therein from an operating field comprising in combination an instrument for removing material from a larger mass, an aspirating passage and a fluid supply passage formed in said instrument, suction pressure fluid supply means, pressurized fluid supply means, first conduit means connected between said source of suction pressure fluid and said aspirating passage of said instrument, means for applying fluid under pressure to said first conduit means including third conduit means connected between said pressurized fluid supply means and said first conduit means, second conduit means connected between said pressurized fluid supply means and said fluid supply passage, means for selectively controlling the flow in said first and second conduit means to selectively provide suction pressure fluid in said aspirating passage and pressurized fluid in said fluid supply passage and means for clearing material from said first conduit means without losing the suction pressure in said aspirating passage.

17. Apparatus as in claim 16 wherein said selectively operated flow control means operates to remove suction pressure from said first conduit means when fluid under pressure is supplied from said third conduit means to said first conduit means.

18. Apparatus as in claim 16 wherein said means for applying fluid under pressure to said first conduit means supplies gas under pressure.

19. Apparatus as in claim 16 wherein said means for applying fluid under pressure to said first conduit means includes means for supplying a liquid.