U.S. patent number 3,812,855 [Application Number 05/208,282] was granted by the patent office on 1974-05-28 for system for controlling fluid and suction pressure.
This patent grant is currently assigned to Surgical Design Corp.. Invention is credited to Anton Banko.
United States Patent |
3,812,855 |
Banko |
May 28, 1974 |
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.
Inventors: |
Banko; Anton (Bronx, NY) |
Assignee: |
Surgical Design Corp. (Long
Island City, NY)
|
Family
ID: |
22774003 |
Appl.
No.: |
05/208,282 |
Filed: |
December 15, 1971 |
Current U.S.
Class: |
604/31; 604/120;
137/205; 601/6 |
Current CPC
Class: |
A61M
1/79 (20210501); A61M 1/0058 (20130101); A61F
9/00736 (20130101); Y10T 137/3109 (20150401) |
Current International
Class: |
A61F
9/007 (20060101); A61M 1/00 (20060101); A61m
001/00 () |
Field of
Search: |
;128/2A,2V,24A,276,277,278 ;137/205 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Rosenbaum; Charles F.
Attorney, Agent or Firm: Mortimer; Harvey W.
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.
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.
* * * * *