Endoscopic surgical instrument

An endoscopic surgical instrument includes a housing, single access conduit formed in the housing, an irrigation port and an evacuation port, each port being connected through independent valves to the single access conduit. The single access conduit has a first end and a second end which is terminated in an aperture formed in the housing. A closure is provided for the aperture. A viewing device, such as an endoscope, is insertable through the aperture and the single access conduit, and is extended slightly beyond the first end. An electrode assembly having two or more retractable RF electrodes spaced a predetermined distance and angle apart, is also insertable through the aperture and the single access conduit, and is extendable beyond the first end. Each RF electrode is in electrical communication with a means for supplying R.F. energy and for continuously measuring impedance across the electrodes. Also, each RF electrode is extendable beyond and completely retractable into a guiding sheath. Each RF electrode is extendable beyond its guiding sheath by a predetermined length. Also, each RF electrode may be extended in such a manner to form a predetermined angular value with the longitudinal centerline of the single access conduit.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a surgical instrument and more particularly to an 
instrument with the capability for continuous irrigation and evacuation of 
fluid into and out from a body cavity of a patient during Laparoscopic or 
Endoscopic surgical procedures, and for the simultaneous measurement of 
tissue impedance and the ablation of tissue with fixed or retractable 
electrodes using R.F. energy. 
2. Brief Description of the Prior Art 
Laparoscopic/endoscopic surgical procedure allows a surgeon to see inside 
the body cavity of a patient without the necessity of large incisions. 
This reduces the chances of infection and other complications related to 
large incisions. The endoscope further allows the surgeon to manipulate 
microsurgical instruments without impeding the surgeon's view of the area 
under consideration. 
During these surgical procedures it is desirable for as few lines as 
possible to enter the body of the patient. This reduces the size of the 
incision the surgeon needs to make. It follows from this that the greater 
the number of functions provided by a single instrument or the greater the 
number of instruments able to be passed through a single line entering the 
patient's body, the better. 
Furthermore, in certain procedures it may be desirable to irrigate the area 
under consideration. This in turn necessitates the evacuation of the 
irrigation fluid or, when bleeding has occurred, the blood or smoke or 
tissue residue generated by the surgical procedure. 
From what has been said above it should be apparent that it is preferable 
for both irrigation and evacuation to be conducted along a single conduit 
which, also, acts as an access line for surgical instruments. 
A typical device which is used in endoscopic procedures is an 
electrosurgical probe. Typically such a probe will comprise a radio 
frequency (i.e. R.F.) energy conductive tube covered with a dielectric 
material such as polyolefin or Teflon. At one end, for convenience called 
the operational end, each probe could have any one of a number of 
functionally shaped monopolar or bipolar electrodes. In addition a probe 
could have its end formed specifically for irrigation and/or evacuation. 
Monopolar and bipolar electrode probes are known in the prior art. 
Monopolar electrode probes include a single active electrode which is 
surgically introduced into a body cavity and engagable with and insertable 
into a tissue portion of the cavity. A passive electrode is attached to 
the outer body surface of the patient, e.g. typically a conducting plate 
is adhesively attached to the patient's leg. The body of the patient 
serves to complete the electrical circuit. Tissue ablation and coagulation 
is achieved by introducing sufficient power into the active electrode. 
Bipolar electrode probes include both active and passive electrodes which 
are similarly introduced together into the body cavity and are spaced 
apart from each other by a predetermined distance. Each electrode is 
engageable with and insertable into the tissue portion. Thus, the 
electrical circuit is completed by the body tissue disposed between the 
active and the passive electrodes and only the body tissue disposed 
between the two electrodes get coagulated. 
Furthermore, any valves controlling the evacuation and irrigation 
procedures should be constructed so as to minimize the possibility of the 
valve malfunctions if, for example, any tissue or blood coagulates around 
their moving parts. Similarly if any of the instrumentation is to be 
reusable, such instrumentation, including the valves, should be capable of 
being efficiently cleaned by, for example, flushing. 
U.S. Pat. No. 4,668,215 (Allgood) discloses a valve for switching between 
an evacuation and an irrigation conduit and allowing both such evacuation 
and irrigation to be done via a single line entering the patient. The 
mechanism for switching between the irrigation, evacuation and closed 
configurations is by means of a L-valve or T-valve. This patent, in 
another embodiment thereof, further provides for a piston valve for making 
an on-off connection between an evacuation port and the line leading into 
the patient. 
The L- and T-valves have the disadvantage that they must be manipulated by 
rotation by the surgeon, usually using his/her free hand. The piston valve 
disclosed in this patent has the disadvantage that it has many areas where 
blood and tissue accumulation and coagulation can occur which may result 
in the malfunctioning of the valve. In addition, the piston valve has 
numerous "dead" areas where fluid flow would not occur. This precludes the 
device from being effectively cleaned by commonly used flushing 
techniques. Finally, the Allgood patent does not disclose a single body 
for housing an evacuation/irrigation control valve together with a housing 
for laparoscopic and microsurgical instrumentation. 
A surgical valve that the applicant is aware of is the piston valve 
illustrated in FIG. 1 of the accompanying drawings. 
In this valve a piston 10 is located within a cylinder 11. The piston 10 
can be moved along the bore of the cylinder 11 by means of a plunger 12, 
from a closed position (as shown) to an open position in which a conduit 
13 is aligned with an access port 14. This allows fluid flow along a path 
to or from access port 14, via conduit 13 and space 16 from or to a 
further port 15. Upon release of the plunger 12 the piston 10 returns to 
its closed position under action of a spring 17. 
This valve, although easy to use, has the disadvantage that blood and 
tissue accumulation occurs in space 16 and clogs both the space and the 
spring 17. This may result in undesirable over-evacuation or irrigation of 
the patient during surgical procedures. 
OBJECTS OF THE INVENTION 
It is therefore an object of this invention to provide a surgical 
instrument which includes control means to allow for the continuous 
irrigation and evacuation of a body cavity of a patient during 
microsurgical procedures, with both irrigation and evacuation being 
performed along a single line into the patient. The instrument should also 
act as a mounting for electrosurgical probes and microsurgical 
instruments. 
A further object of the invention is to provide a configuration for an 
instrument which, depending on the material it is constructed of, can be 
both disposable and non-disposable. In the event that the instrument is 
"reusable" or "reposable" it is an object of the invention to provide the 
instrument with conduits, access ports and valves which can easily be 
cleaned by means of commonly used cleaning techniques and conventional 
sterilization methods. 
It is another object of the invention to provide an electrosurgical 
instrument with fixed or retractable RF electrodes having the capability 
to simultaneously perform controlled ablation of tissue using 
monopolar/bipolar R.F. energy and precise measurement of tissue impedance. 
SUMMARY OF THE INVENTION 
According to this invention, an endoscopic surgical instrument comprises an 
irrigation and an evacuation port, each port being connected through 
independent valves to a single access conduit; a probe connector located 
at one end of the access conduit, the probe connector being for receiving 
and retaining a hollow surgical probe; and a monopolar or bipolar radio 
frequency connector which exits into the access conduit in such a manner 
so as to make radio frequency connection with a probe received by the 
probe connector. 
Preferably the connector for receiving an end, for convenience called the 
locating end, of the probe would be in the form of a receiving bore in the 
access conduit which would include a plurality of O-rings which provide a 
fluid-tight seal around the locating end of the probe. These O-rings also 
function to retain the probe in the receiving port while allowing the 
probe to be rotated. In one embodiment of the invention, the O-rings are, 
instead of being located within the receiving bore of the access conduit, 
located about the locating end of the probe. 
This invention also provides for a valve, for use as either an evacuation 
or an irrigation valve, the valve comprising a housing, an activator 
connected to the housing, at least a first and a second valve access 
conduit, both of which exit into the housing and a fluid impervious seal 
mounted within the housing such that activation of the activator causes 
the first valve conduit to move axially relative to the seal and the 
second valve conduit such that the seal is disengaged and the conduits are 
placed in direct fluid communication with each other. 
Typically, the instrument of the invention would contain two of the above 
described valves. One valve would act as an evacuator control while the 
other valve would act as an irrigation control. Both valves communicate 
into a single access conduit which, when the instrument is in use, 
continuously flows into the patient via the receiving bore and the hollow 
interior of the electrostatic probe. 
Preferably the endoscopic surgical instrument of the invention is in the 
form of a pistol with the "barrel" portion thereof having, at one end 
thereof, the receiving bore for the locating end of the endoscopic probe 
and, at the other end thereof, the access port for the microsurgical 
instruments and endoscopes. 
The valves for controlling the evacuation and irrigation procedures may be 
mounted in the "handle" portion of the pistol-shaped instrument. The 
valves may be mounted alongside one another in the handle portion and may 
protrude therefrom to allow finger control by the surgeon using the 
instrument. 
In one alternate embodiment of the invention the surgical instrument 
includes a housing, a single access conduit formed in the housing, an 
irrigation port and an evacuation port, each port being connected through 
independent valves to the single access conduit. The single access conduit 
has a first end, and a second end which is terminated in an aperture 
formed in the housing. A closure is provided for the aperture. A viewing 
device, such as an endoscope, is insertable through the aperture and into 
the single access conduit. The viewing device is of sufficient length such 
that it is extendable slightly beyond the first end. A retractable 
electrode assembly is also insertable through the aperture and into the 
single access conduit, and is of sufficient length such that it, too, is 
extendable beyond the first end. The retractable electrode assembly, in 
one embodiment, includes two retractable RF electrodes spaced apart by a 
predetermined width. Each RF electrode is made from a superelastic 
material, e.g. typically Nickel-Titanium (NiTi) metal, is sheathed within 
a guiding sheath, and is slidable within the sheath such that it is 
extendable beyond and retractable completely within the sheath. Also, each 
electrode is connected to a mechanism, operable by a surgeon, for moving 
the electrode within the sheath. Each electrode is extendable beyond its 
guiding sheath by a variable length and at a predetermined angle from a 
longitudinal axis of the single access conduit. Further, each electrode is 
electrically communicative with means for supplying R.F. energy and means 
for measuring impedance continuously on a realtime basis. 
These and other objects and advantages of the present invention will no 
doubt become apparent to those skilled in the art after having read the 
following detailed description of the preferred embodiment which is 
illustrated in the several figures of the drawing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
In FIG. 2 of the accompanying drawings, the endoscopic surgical instrument 
of the invention is generally indicated as 20. The instrument 20 is shown 
to include an irrigation port 21 and an evacuation port 22. Each port, 21 
and 22, is connected through independent valves 23 and 24, respectively, 
to a single access conduit 25. The connection between the valves 23 and 24 
and conduit 25 is along connector tubes 23a and 24a. 
The access conduit 25 leads from the valves and their respective valve 
conduits to a probe connector 26. This probe connector 26 is designed to 
receive one end, the locating end 27, of a surgical probe 28 which would 
be used during microsurgical procedures. The connector 26 is described in 
more detail with reference to FIGS. 4 and 5 hereafter. 
At or near the probe connector 26, a monopolar/bipolar radio frequency 
connector 29 is located. As illustrated, this is in the form of a R.F. 
connector. The advantage of a R.F. connector is that it is an industry 
standard and can be used for connecting the instrument 20 to standard R.F. 
energy sources marketed by a number of different manufacturers. 
The radio frequency connector 29 exits into the access conduit 25 where it 
makes connection with a point 30, on the locating end 27 of a probe 28 
received by the probe connector 26. 
The surgical instrument 20 also includes a port 31 which allows the surgeon 
to insert microsurgical instrumentation and viewing devices along the 
access conduit 25 and the bore of the hollow probe 28 to exit from the end 
32 thereof. The port 31 should provide a fluid-tight seal when no 
microsurgical instrumentation is being used with the surgical instrument 
20. This will prevent fluid, which may be moving along the access conduit 
25 to or from the patient, from leaking. 
Typically, the access port 31 is in the form of a commercially available 
tricuspid valve as illustrated in FIGS. 3(a) and (b). In these figures, 
the valve 31 is shown as being constituted by three segments 35 which in 
plan view are wedge-shaped and which together form the disc shaped sealing 
portion of the valve. The segments 35 are held together by means of a 
circumferential ring 33 which biases the three segments 35 together to 
form a fluid-tight seal. In use, the microsurgical instrumentation are 
inserted through the valve at a point 34 where the apexes of the segments 
35 come together. This insertion forces the elements of the valve apart to 
allow ingress of the microsurgical instrumentation. The effect thereof is 
shown in broken lines in FIG. 3(b). When the instrumentation is removed 
from the valve 31, the segments 35 are pulled together to form the seal. 
In FIG. 4a the probe connector 26 is shown to be constituted by a receiving 
bore which is coaxial with the fluid access conduit 25. In practice, the 
diameter of this bore would be the same as that of the access conduit 25 
and would be sized to receive the locating end 27 (FIG. 4b) of the probe 
28 in a relatively close fit. Within the bore forming the probe connector, 
a plurality, typically two, O-rings 36 are located. When the locating end 
27 is inserted into the bore 26 these O-rings provide a snug, fluid-tight 
seal about the end 27. Once the locating end 27 of the probe is received 
within the bore 26 it is capable of being rotated about its longitudinal 
axis, by means of a knurled rotation knob 37 located between the locating 
end 27 and the operational end 32 of the probe 28. 
The probe 28 would typically be made of a electrostatic conductive material 
coated with a non-conductive material such as heat shrink polyolefin or 
Teflon. Electrostatic/radio frequency energy is passed along the probe 28 
from the radio frequency connector 29 via electrostatically conductive 
plates 38 located within the bore of the probe connector 26 and onto the 
end 30 of the probe 28. The end 30 is so designed such that when the 
locating end 27 of the probe is received by the probe connector 26, 
electrostatic connection is made between the plate 38 and the connector 
30. This allows the surgeon to pass energy into the patient being operated 
on. 
An alternative radio frequency connector is illustrated in FIG. 5a and 5b. 
In this case, the R.F. connector 29 exits into the bore 26 in the form of 
a pin 39. In the conductive end 30 of the probe 28 an L-shaped slot 40 is 
formed. As the probe 28 is inserted into the receiving bore 26, the pin 39 
engages the axially-orientated leg 41 of the L-shaped slot 40. When the 
probe can be inserted no further along the bore it is twisted, in this 
case in an anti-clockwise direction, such that the pin 39 and the axially 
transverse leg 42 of the L-shaped slot 40 engage each other to lock the 
probe 28 into position. In this embodiment the probe 28 cannot be rotated 
by means of the knurled knob 37. 
FIG. 5b further illustrates an alternative positioning of the O-rings 36. 
In this case they are located on the locating end 27 of the probe 28. 
From FIGS. 4 and 5, although not shown, it will be apparent that the 
diameter of the operational shank 28a of the probe 28 can be variable. 
Typically, the probe, as shown, would have a diameter of 5 mm. This 
diameter can, however, be increased to 10 mm which would be close to the 
diameter of the locating end 27 of the probe, as well as that of the 
internal bore diameter of the access conduit 25. The advantage of 10 mm 
diameter probes is that the evacuation of removed tissue and objects such 
as the gall-stones can be more effectively achieved. Obviously, when the 
bore of the operating shank 28a of the probe, the locating end 27 and the 
access conduit 25 are all 10 mm in diameter, the diameter of the 
evacuation port 22 and its related valve 24 and connector tube 24a must 
also be 10 mm. 
In FIG. 6(a) to (i), sides view of a number of different electrode shapes 
are illustrated. It will be appreciated that the electrode tips could be 
either monopolar or bipolar. In the case of bipolar electrodes, only one 
electrode is illustrated since a second electrode is fully obscured by the 
visible electrode. These electrode tips would be located on the operating 
end of the probe 28. 
As can be seen from the figure, a number of the tips are not symmetrical 
about the longitudinal axis of the probe 28. It is for this reason that it 
is desirable for the probe 28 to be mounted on the instrument in such a 
manner to allow for a rotation of the probe about its longitudinal axis. 
As has been previously indicated, this will give the surgeon the 
opportunity of rotating any non-symmetrical tips, inside the patient, 
without having to rotate his or her wrist. 
This invention extends also to an electrostatic probe 28, substantially as 
described in any of the FIGS. 4 to 6. 
The details of one type of irrigation/evacuation valve are illustrated in 
FIGS. 7 and 8. The valve 24 indicated in both figures comprises a housing 
constituted by a hollow tube 50 and an activator in the form of a button 
51 formed integrally with the tube 50. A fluid impervious seal 52 is 
located within the tube 50. Referring specifically to FIG. 7, in which the 
valve is shown in the shut position, it can be seen that the seal 52 lies 
between a first valve conduit 53 which leads to the evacuation port 22 
(not shown) and a second valve conduit in the form of connector tube 24a 
which leads into the primary access conduit 25 of the surgical instrument. 
In effect, the seal 52 prevents the conduits 53 and 24a from being in 
communication with each other. 
The first valve conduit 53 is mounted onto the wall of the tube 50 and 
opens into the interior of the tube 50 through a hole 54. Between the seal 
52 and the button portion 51 of a tube 50, a spring 55 is located. On the 
side of the seal 52, opposite to which the spring is located, a tubular 
insert 56 is located. This tubular insert has a snug but slidable fit over 
the outer wall of the second valve conduit 24a as well as a tight, fluid 
impervious fit into the inner bore of the tube 50. This tube 56 acts as a 
stop which prevents the spring 55 from pushing the seal 52 out of the 
hollow tube 50. 
To open the valve, as is illustrated in FIG. 8, an activating force, 
applied along a line F to the button 51, will cause the button to move 
from the position indicated in broken lines to the illustrated open-valve 
position. As the button moves, so does the hollow tube 50, taking the 
first valve conduit 53 along with it. In addition, the leading edge 57 of 
the second valve conduit 24a bears against the seal 52 causing the seal to 
move relatively to the tube 50. This in turn disengages the seal from 
sealing the hole 54 in the wall of the tube 50. The movement of the first 
valve conduit 53, relative to the second valve conduit 24a, places the 
respective openings 54 and 58 of these two conduits in fluid communication 
with each other thereby allowing an unobstructed fluid flow along both 
access conduits. 
Upon release of the force on the button 51, the bias of the spring 55 will 
return the valve to its shut position. 
It is evident from the construction of the valves illustrated in FIGS. 7 
and 8 that they can be readily cleaned by commonly used cleaning such as 
flushing. In addition, the valves have almost no areas where blood and 
tissue accumulation and coagulation can occur, and if such accumulation 
and coagulation does occur the valves cannot be jammed in the open 
position. This is because the spring biasing the valve into its closed 
position is located in an effectively sealed area. Furthermore these 
valves have been tested to a pressure of up to 100 psi without the 
integrity of the valve seal being adversely affected. 
An alternative form of valve, to that illustrated in FIGS. 7 and 8 above, 
is shown in FIG. 9. In the figure the valve is shown to include a 
generally cylindrical valve body 60, an activating button 61 and a plunger 
62. A hollow bore runs down the center of the valve body 60 and contains 
the valve seal 63. The valve seal 63 is made up of a circular washer 63a 
and a sealing O-ring 63b and is screwed onto the bottom of plunger 62. The 
valve seal 63 is biased into its illustrated sealing position by means of 
a spring 64 located in the bottom part of the valve body 60. 
To open the valve, the button 61 is depressed so that the plunger 62 forces 
the valve seal 63 downwards against the bias of the spring 64 to a 
position shown in broken lines 63', in the figure. As a result, a fluid 
path, indicated by arrows 65, is opened between an upper pair of cutouts 
66 and a lower pair of cutouts 67. Each pair of cutouts opens into the 
hollow bore in the center of the valve body 60 and, when this valve is 
inserted into the surgical instrument, into either an evacuation or 
irrigation conduit. Closure of the valve is achieved by releasing the 
button and allowing the spring 64 to return the valve seal 63 to the 
sealing position. 
One advantage of this embodiment of the valve is that it is easily removed 
from and inserted into the surgical instrument of the invention. 
Accordingly the valve can easily be removed for cleaning or disposal and 
replacement. This is further illustrated below with respect to FIG. 13. It 
is sufficient here to mention only that the surgical instrument is 
provided with a receiving bore for each valve and that the valve includes 
a plurality (in this case 3) O-rings 68 which, when the valve is inserted 
into its respective receiving bore, provide a number of fluid tight seals 
against the inside of the bore. 
Either of the two types of valve described in FIGS. 7 to 9 can be used on 
the instrument 20. Typically one valve would act as an evacuation valve 
while the other as an irrigation valve. Different types of arrangements of 
valves and valve activation means are illustrated in the following 4 
figures. 
One way of activating the valve is by means of a rocker-shaped trigger 70 
illustrated in FIG. 10. The trigger 70 is pivotally mounted on a point 72 
on the handle 74 of the pistol. Depressing the trigger 70 to operate the 
irrigation valve 71 would not interfere with the operation of the 
evacuation valve 73. Similarly, operation of the trigger 70 to operate the 
evacuation valve 73 would in no way effect the operation of the irrigation 
valve. 
In FIG. 11 a trigger mechanism 76 is shown for operation of only one of the 
buttons. The other button 78 would be located for operation by means of 
the surgeon's thumb in a position removed from the trigger 76. This could, 
for example, be near the top end of the handle portion of the instrument. 
Yet a further positioning of the buttons 71 and 73 is indicated in FIG. 12. 
In this instance, the buttons protrude from the top rear of the pistol 
handle and are located side-by-side. To prevent confusion between 
evacuation and irrigation procedures, the tops of the buttons have 
different shapes. So, for example, the button to manipulate the evacuation 
valve could be concave while the button for manipulating the irrigation 
valve could be convexly shaped. 
FIG. 13 illustrates still another arrangement of buttons and valves, in 
this case an arrangement particularly suited to the valve shown in FIG. 9. 
In this figure only the pistol grip 90 of the surgical instrument of the 
invention is shown. An irrigation port 92 and evacuation port 94 enter the 
pistol grip 90 at the bottom of its handle portion. The ports 92, 94 are, 
in use, respectively connected to irrigation and evacuation conduits (not 
shown) and, to this end, suitable connectors, as illustrated, are 
provided. 
The irrigation port 92 communicates with the main access conduit 96 
(referenced as 25 in FIGS. 2, 4 and 5) along an irrigation conduit 98 
which extends from the irrigation port 92 and into the rear of the bore 
100 which houses an irrigation valve 102. From there it extends along the 
bore 100 to a point near the front of the bore from where it exits into 
the body of the grip 90 to enter rear of the bore 104 which houses an 
evacuation valve 106. The irrigation conduit extends directly across the 
bore 104 at this point and becomes a central conduit 108 which 
communicates with the access conduit. 
On the other hand, the evacuation port 94 communicates with an evacuation 
conduit 105 which extends along the pistol grip 90 directly into the front 
of the bore 104, down to the bore 104 to its rear from where it exits into 
the central conduit 108. 
In the position shown, both the irrigation and evacuation valves 102, 106 
respectively, are shown in the off or shut configurations and neither 
evacuation or irrigation can take place. Should irrigation of the patient 
be required, the dish-shaped irrigation button 110 is depressed and the 
valve 102 opens (ie. its valve seat moves to the right in the drawing) to 
allow irrigation fluid to pass along the irrigation conduit 98 and into 
the bore 104. In this bore 104 the evacuation valve 106 is in the off 
configuration. However, a fluid path exists across the pair of cutouts (67 
in FIG. 9) and therefore the irrigation fluid can pass through the body of 
the valve 106 and into the central conduit 108 and, from there, into the 
access conduit 96. 
When evacuation is desired the irrigation button 110 is released and the 
spring associated with the irrigation valve 102 biases it into the shut or 
off configuration. Thereafter the flat topped evacuation button 112 is 
depressed to open the evacuation valve 106. This allows the patient to be 
evacuated along the main access conduit 96, into the central conduit 108, 
then from the rear to the front of the bore 104 and, from there, out along 
the evacuation conduit 105. 
As has been indicated earlier, the valves 102, 106 are easily inserted into 
and removed from their respective bores 100, 104. This allows the pistol 
grip 90 (which is typically stainless steel and is reusable) to be cleaned 
efficiently. The valves, typically being of plastic and being difficult to 
clean, can be discarded and replaced with new valves. 
A variation on this theme of discardable valves is illustrated in FIG. 14. 
In this figure the surgical instrument is shown to include a pistol grip 
120, a surgical probe 122, which can be screwed into the front of the 
pistol grip 120 and a radio frequency connector 124 which screws into the 
back of the grip 120. 
The instrument also includes a removable (and disposable) valve cartridge 
126. The cartridge 126 includes an irrigation pipe 128 and an evacuation 
pipe 130 both of which are individually operated by valves (as will be 
further illustrated in FIG. 15) under action of button-shaped actuators 
132. Both the irrigation and evacuation pipes communicate into a single 
conduit (not shown) which runs down the center of a male connector fitting 
134. Where the cartridge 126 is inserted into the grip 120 the connector 
134 fits into the base of a central conduit 136 which, in turn, opens up 
into the main access conduit 138 of the instrument. When the cartridge 126 
is located in the grip 120 the actuators 132 are located directly below a 
pair of operating triggers 140 which can be used to operate the 
irrigation/evacuation procedures described before. 
Finally, when the cartridge 126 is in place, it is held there by means of a 
retainer clip 142 which clips in behind the cartridge 126. The retainer 
clip 142 has apertures 144 formed in it to allow the irrigation and 
evacuation pipes 128, 130 to pass through it. 
Although it will be apparent that the valve types described above are also 
suitable for use in the cartridge 126, a further valve configuration is 
illustrated in FIG. 15, which illustrates the cartridge 126 in greater 
detail. 
In this figure, the cartridge 126 is shown to include an irrigation conduit 
150 and an evacuation conduit 152, both of which lead to a central access 
conduit 154 which extends down the center of the male connector 134. 
Irrigation and evacuation procedures are controlled by irrigation and 
evacuation valves 156 and 158, respectively. 
The irrigation valve 156 consists of a valve seal 160 mounted onto a stem 
which is screwed into an activator button 132a. A fluid tight seal is 
provided for the valve 156 by an O-ring 168 mounted onto the cap 132a. The 
valve seal 160 seals against a valve seat, formed at the junction between 
the irrigation conduit 150 and the central access conduit 154 and is held 
in the sealing position (as shown) by a spring 162. 
Access to the valve seat is through a hole 164 formed into the top (as 
shown in the drawing) of the cartridge 120. This hole 164 can be closed 
off with a cap 166 and allows the irrigation valve 156 to be inserted into 
the cartridge 126. This is done by inserting the valve seal 160 and its 
associated stem into the hole 164 from above and inserting the spring 162 
from below. Thereafter the cap 132a can be screwed onto the stem to hold 
the entire valve 156 in place. 
To operate an irrigation procedure the button 132a is depressed to move the 
valve seal 160 clear of its seal to open a fluid path between the 
irrigation conduit and the central access conduit. Releasing the button 
132a causes the spring 162 to force the seal 160 back into its seat 
thereby automatically shutting the valve. 
The evacuation valve 158 is of a different construction. In this valve 158, 
the valve seal 170, in its off position as shown, seals the mouth of the 
evacuation conduit 152. 
In operation, the seal 170 is moved under action of a plunger and 
evacuation button 132b from the position shown to a position 170' in which 
an end of a conduit 174, formed through the seal 170, aligns with the 
central access conduit 154. At the same time the other end of the conduit 
174 is aligned with the evacuation conduit 152 and evacuation can be 
accomplished. By releasing the button 132b, the spring 172 biases the seal 
170 back into its sealing position. 
Assembly of this evacuation valve 158 is by inserting the entire valve 
mechanism into its valve bore and sealing a collar 176 in the bore. 
As has been indicated with reference to FIG. 14, the cartridge 126 is of 
the disposable type and is intended for use only once. Accordingly the 
considerations of valve flushing (during cleaning) are not entirely 
applicable here. 
In FIG. 16 yet another type of valve, which can be used as either an 
irrigation or an evacuation valve, is illustrated. 
The valve, generally indicated as 180, is shown to include a hollow 
cylindrical valve body 182 which is sealed at its lower end by a valve 
seal 184 and at the other by an activator button 186. The activator button 
186 seals against the valve body with an O-ring 188 and is connected to 
the valve seal 184 by means of a plunger 190. 
To open the valve 180, the button 186 is depressed against the bias of a 
spring 192 to move the valve seal 184 to the position indicated in broken 
lines. This opens a fluid path 194 between an opening 196 formed in the 
sidewall of the valve body and its lower end. Releasing the button 186 
allows the spring 192 to force the seal 184 back into the closed position. 
One advantage of this valve is that it is very simple and inexpensive to 
manufacture and can, therefore, readily be disposed of. 
Finally, it will be apparent to anyone skilled in the art, that the 
surgical instrument of this invention could be made from any suitable 
material. In the event that the instrument is intended for single use, 
plastic material could be used. Alternatively, for reusable or reposable 
instrument, the instrument can be made of a more durable material. 
FIG. 17 is a perspective view of an endoscopic surgical instrument 200 
which is an alternate embodiment of the surgical instrument 20 described 
above. FIG. 18 is a partial sectional view of a portion of the instrument 
200 taken along the line 18--18 of FIG. 17 and FIG. 19 is another view of 
the instrument 200 taken as indicated by the line 19--19 of FIG. 17. FIG. 
20 illustrates the retractable electrode assembly 202. When viewed 
together, FIGS. 17-20, illustrate the instrument 200 including an 
endoscopic instrument 201, a retractable RF electrode assembly 202, an 
continuous irrigation and evacuation assembly 203, a R.F. energy source 
285, and a tissue impedance monitoring device 284. It will be appreciated 
that, although two retractable RF electrodes are illustrated and 
subsequently described, in alternate embodiments the retractable electrode 
assembly could have one or more than two retractable RF electrodes. Also, 
although a bipolar retractable RF electrode assembly is illustrated and 
subsequently described, it will be appreciated that a monopolar 
retractable RF electrode assembly could be used. 
The assembly 203 includes a housing 210, an irrigation valve assembly 214, 
and an evacuation valve assembly 220. The housing 210 includes an 
elongated portion 228 having a generally oval cross section. The portion 
228 includes a free tip end 230 and a secured end which is attached to a 
handle portion 232. The portion 232 is held by the surgeon, and the 
portion 228 is surgically introduced into a body cavity (not shown) of the 
patient. A single access conduit 212 (a portion of which is best seen in 
FIG. 18 and 19) is formed between an inner surface of the portion 228 and 
the objects carried within the portion 228. The conduit 212 is disposed 
along the entire longitudinal length of the portion 228 and is 
functionally similar to the conduit 25 (FIG. 2) in that it permits the 
irrigation and evacuation of fluids into and out from the body cavity into 
which the portion 228 is inserted. The conduit 212 is open at the tip end 
230 and can be accessed, at its opposite end, via an aperture and 
associated closure 226 formed in the handle portion 232. The closure 226 
is in the form of a tricuspid valve and is substantially similar to the 
valve 31 illustrated and described above (FIG. 2). 
The irrigation valve and the evacuation valve assemblies 214, 220 are 
substantially similar to the irrigation and evacuation valves 23, 24 
described above (FIG. 2). The valve assemblies 214, 220 operate in a 
similar manner to valves 23, 24 (FIG. 7, 8). Depressing the valve 
assemblies 214 or 220 permits the communication of fluid in a valve first 
conduit 216 (or 222) with a valve second conduit 218 (or 224). Each of the 
valve second conduits 218 and 224 are in fluid communication with the 
conduit 212 (in the same manner that the conduits 23a, 24a are in fluid 
communication with the conduit 25, FIG. 2). Thus, when the valve assembly 
214 is operated, irrigation fluid can be communicated to the conduit 212 
and out through the tip end 230, and delivered to the body cavity. In a 
similar manner, fluids in the body cavity can be evacuated if the valve 
assembly 220 is operated. 
The retractable electrode assembly 202 includes a means for guiding the 
angular orientation of the electrode or guide sheath 248, an endoscope 
sheath 238, a electrode movement mechanism 236, a tissue impedance 
measurement device 284, and a R.F. energy source 285. The sheath 248 is 
generally parallel to the scope sheath 238. The sheath 248 and the sheath 
238 are each insertable into an opening of an insert flange 242, into the 
aperture of the handle portion 232 of the assembly 203. The sheath 248 and 
the sheath 238 are insertable within the conduit 212 and are each of 
sufficient length such that when each is fully inserted within the conduit 
212, each extends slightly beyond the tip end 230 of the cylindrical 
portion 228. 
The endoscopic instrument or endoscope 201 is substantially similar to the 
endoscope instrument described above, and can be any of a number of 
devices known in the prior art. An eyepiece 204 is shown attached to the 
endoscope 201. The endoscope 201 is slid into the scope sheath 238 until 
the eyepiece 204 engages a flange 240 which is attached to the sheath 238. 
Thus, the endoscope 201, and the sheath 248 of the retractable electrode 
assembly 202 are both insertable within the portion 228 of the irrigation 
and evacuation assembly 203. 
Each of two RF electrodes 250a, 250b is sheathed within its respective 
guide sheath 248a, 248b. Although the illustrated embodiment depicts two 
RF electrodes, it will be appreciated that the assembly 202 could have one 
or more than two electrodes. Each electrode 250a, 250b includes a first or 
distal end 249a, 249b, a second, or proximal end 247a, 247b, and a central 
portion (not shown) disposedly connected therebetween. A coating of 
insulation 246 is disposed onto the bare electrode 250. The insulation 
coating 246 may be in the form of a tube of material (such as teflon) heat 
shrunk around the bare electrode 250. Alternately, the insulating coat 246 
may be powder deposited, using vacuum deposition techniques, onto the bare 
electrode 250. In either case, nearly the entire length of the bare 
electrode 250 is covered by the insulating coat 246. 
The electrodes 250a, 250b have a generally constant diameter throughout its 
entire length and are sized such that they can be slid within the sheaths 
248a, 248b. That is, there exists a sufficient clearance (e.g. 0.005 inch) 
between the outside diameter of each of the insulating coats 246a, 246b of 
the electrodes 250a, 250b and the inner diameter of the respective sheaths 
248a, 248b. Each electrode 250a, 250b is made from a superelastic metal 
material, e.g. typically a Nickel-Titanium (NiTi) metal alloy. The guide 
sheaths 248a, 248b are made from a rigid plastic or coated metal tubing 
which forms a rigid conduit that guides, i.e. deforms, the electrode along 
a predetermined path. 
As best seen in FIG. 19, the electrodes 250a, 250b and their respective 
sheaths 248a, 248b are contained within the cross sectional envelope of 
the portion 228. Thus, the required incision into the patient need only 
accommodate the cross sectional area of the portion 228. The presence of 
the extendable electrodes does not increase the size of the required 
incision. It should be also noted that each electrode 250a, 250b descends 
downwardly into the field of view of the endoscope 201. In this manner the 
surgeon is able to view the extension of each electrode 250a, 250b beyond 
the end of the sheath 248a, 248b. 
The two electrodes 250a, 250b and their respective insulators 246a, 246b 
are encased within their respective guide sheaths 248a, 248b which are 
encased within a plastic insulating covering 244. The electrodes 250a and 
250b encased within the plastic covering 244 exits the housing 232 through 
the opening in the flange 242. 
Each electrode 250a, 250b is in parallel electrical communication with a 
tissue impedance measuring device 284 and a R.F. energy source 285. The 
covering 244 enters the movement mechanism 236 through an opening 260 
formed in a sleeve 256 of the mechanism 236. The electrodes 250a, 250b and 
their respective insulators 246a, 246b exit from the covering 244 and each 
of the second ends 247a, 247b, of each of the electrodes 250a, 250b are 
attached to connecting pins 272a, 272b, respectively. The connecting pins 
272a, 272b are mounted at an end of a plunger 264. Each connecting pin 
272a, 272b is in communication with a wire 274a, 274b each of which passes 
through the plunger 264, through an opening 278, and into an insulated 
line 276 which is terminated in a plug 280 which is matingly engagable 
with a receptacle 282 of the tissue impedance measuring device 284. The 
R.F. source 285 is in electrical communication with the impedance 
measuring device via electrical lines 283a and 283b. The source 285 and 
the impedance measuring device 284 are connectable in parallel in order to 
get realtime impedance measurement of tissue engaged between the first 
ends 249a, 249b of each of the electrode 250a, 250b. 
The movement mechanism 236 includes a finger ring portion 252, and a thumb 
ring portion 254. The finger ring portion 252 is a generally flat plate 
having finger loops 251a, 251b formed therein. A passage 262 is formed 
through the finger ring portion 252 such that the longitudinal axis of the 
passage 262 is disposed between each finger loop and lies coplanar with 
the plane of each finger loop. The sleeve 256, and a cylinder 258 are 
partially inserted into opposite ends of the passage 262. The sleeve 256 
has a passage longitudinally formed therein so as to receive the covering 
244. The cylinder 258 has a passage longitudinally formed therein which is 
aligned with the passage of the sleeve. The plunger 264 is slidable within 
the passage of the cylinder 258. One end of the plunger is attached to the 
thumb ring portion 254, and the connection pins 272a, 272b are mounted to 
the other end of the plunger 264. The outer surface of the plunger 264 is 
visible through an access cutout 270 formed in the cylinder 258. In one 
embodiment, an indicator post 266 is attached to the outer surface of the 
plunger 264 and passes through the access cutout 270 to give an immediate 
visual indication of the position of the plunger 264 within the cylinder 
258. In a preferred embodiment, the outer surface of the plunger 264 is 
scored with a plurality of indicator marks 268 to provide a visual 
indication of the position of the plunger 264 within the cylinder 258, 
which corresponds to variable length of extension of each of the 
electrodes beyond their respective insulating sheaths. 
In operation, the irrigation and evacuation valves, and the endoscope 
operate as described above. Regarding the retractable electrode assembly 
202, a free hand of the surgeon is used to operate the movement mechanism 
236. The surgeon's fingers are engaged within the finger ring loops and 
the thumb is engaged within the thumb ring portion. The thumb either 
pushes or pulls on the thumb ring thereby moving the attached plunger 264 
into or out of the cylinder 258 and the passage 262. As the plunger 264 
moves each of the first ends 249a, 249b of each of the electrodes 250a, 
250b move because the connection pins 272a, 272b mounted to the plunger 
are attached to each of the second ends 247a, 247b of each of the 
electrodes 250a, 250b. Thus, as the plunger moves in the direction of the 
arrow A, the central portions of each of the electrodes moves within their 
respective insulators in the direction of the arrow B, and the first ends 
249a, 249b move in the direction of the arrow C. 
FIG. 21 illustrates the first end 249 of the electrode 250. The guide 
sheath 248 is formed with a bend at one end. The electrode 250 slides 
within the sheath 248 and exits the sheath 248 under the guidance of the 
sheath 248. The insulating cover 246 permits the easy sliding of the 
electrode within the sheath 248. Although a bend of 90 degrees is 
illustrated, it will be appreciated that a bend of any angle may be formed 
in the sheath 248 so as to guide the electrode 250 into a variety of 
angular dispositions. It should be noted that the electrode 250 is bare in 
the vicinity of the first end 249. A predetermined length value L, 
measured from the tip of the electrode to the end 255 of the insulating 
coat 246, represents the length of the electrode 250 that is bare or 
uncoated. Typical values for L range from 0 to 3 cm. 
The first ends of each electrode extends beyond its respective sheath 248 
by a length greater than the predetermined extension length L in order to 
permit the bare electrode to penetrate a tissue portion up to the full L 
value. Further, the first ends of each needle electrode are separated by a 
predetermined separation width W (typically 0.1-2.0 cm) and each first end 
forms a predetermined angle .theta. with respect to the longitudinal axis 
of portion 228. In the illustrated embodiment, the angle .theta. is 90 
degrees. Typical values for .theta. range between 0 and 360 degrees. 
During surgical procedures, the tip end 230 of the portion 228 of the 
instrument 200 is brought adjacent to a target tissue area of the body 
cavity. The first ends of each electrode are extended beyond their 
respective sheaths such that each first end is embedded into the soft 
target tissue area thereby defining a tissue portion engaged between the 
adjacent first ends of each electrode. The power source is energized and 
R.F. energy is transmitted from one electrode to the adjacent electrode. 
The energy transmission causes a coagulation of the tissue portion engaged 
between the adjacent electrodes and ablation of the target tissue. 
Using the present invention, the surgeon can predict and control the amount 
of tissue ablation/coagulation with greater accuracy and safety. As 
described above, the spacing between the two parallel first ends of each 
electrode remains constant at some predetermined W value, e.g. 1.0 cm. 
Also, the extension of the electrodes beyond the insulators at a given 
angle, i.e. The depth of penetration of each first ends of each electrode 
into the soft tissue portion, can be precisely controlled by observing the 
indicator marks on the plunger. Predictable and precise tissue ablation is 
therefore possible with the present invention because the depth of each 
first end of each electrode in soft tissue can be precisely controlled by 
the surgeon. That is, the surgeon can predict a cylindrical zone of 
ablation by controlling the depth of the retractable first ends into the 
soft tissue portion. This precise depth control enables the surgeon to 
predict the zone of ablation with greater accuracy and safety than prior 
art non-retractable monopolar RF devices, or prior art laser delivery 
systems. 
The cellular structure of body tissue contains water which is a conductor 
of electrical energy. Consequently, a portion of body tissue also has an 
associated resistance or impedance value. In prior art monopolar electrode 
devices, tissue impedance is difficult to measure. However, in the present 
invention, precise impedance measurement of the soft tissue in the 
proximity of the bipolar electrodes is possible. In the present invention, 
during the tissue coagulation process simultaneous measurement of the 
impedance of the tissue engaged between the extended first ends of the 
electrodes signals the completion of the tissue coagulation process and 
provides assurance and confirmation to the surgeon. 
R.F. energy applied to the tissue engaged between the first ends of the two 
electrodes causes the tissue to coagulate which decreases the water 
content associated with the tissue. As the water content decreases the 
conductivity of the tissue decreases. For a constant R.F. energy, as the 
conductivity decreases the impedance (or resistance) associated with the 
tissue increases. The tissue impedance is highest when the tissue is 
completely coagulated, since coagulated tissue has a minimum amount of 
water content and current flow is blocked from one electrode to the other 
electrode. However, at the beginning of the ablation procedure, the tissue 
impedance is at a minimum because the water content of the tissue is at 
its highest level and the tissue is a good conductor and allows the 
maximum current to flow from one electrode to the other. During the 
ablation procedure, as the tissue coagulates the water content decreases 
and the tissue impedance increases. The tissue impedance measurement 
device 284 can be designed to transmit an variable frequency audible 
signal, i.e. a beeping tone, when the tissue impedance is at its lowest 
value. As more tissue is ablated and as the tissue impedance reaches its 
highest value the audible signal decreases in frequency. In the present 
invention, the tissue impedance is monitored or measured on a relative 
basis. That is, the impedance measured or monitored is the impedance of 
the tissue engaged between the two needle electrodes. 
FIG. 22A through 22H illustrate alternate electrode configurations. It will 
be noted that the preferred embodiment of the present invention includes 
two electrodes with a .theta. of 90 degrees, and a L value of 0-3 cm, and 
a W value of 0.1-2.0 cm. It will be appreciated that a variety of 
electrode configurations, with associated L, W, and .theta. values within 
the above specified ranges, are possible. However, it is generally 
preferable to limit the total number of electrodes to six or less. 
It will be noted that in the embodiments illustrated in FIG. 22A-22C, 
22G-22H, the electrodes 250 are guided by the shape of the sheath 248. 
That is, the electrodes can be directed towards or away from each other if 
the guide sheaths are angled towards or away from each other. Similarly, 
different .theta. values are possible if the sheaths are formed with the 
appropriately angled bends. 
However, in the embodiments illustrated in FIG. 22D-22F, the sheaths are 
substantially straight and the electrodes themselves are bent in order to 
direct them in certain orientations. This feature is more clearly shown in 
FIG. 23 which illustrates a typical electrode having a bend formed at the 
location depicted by numeral 257. When the electrode is disposed within 
the sheath 248, the electrode 250 is in contact with at least one portion 
259 of the inner surface of the sheath 248 because of the bend 257. When 
the electrode is extended beyond the sheath (shown in phantom lines), the 
electrode "flattens" within the sheath 248 while the electrode tip angles 
away from the sheath centerline in accordance with the bend 257 formed in 
the electrode. 
FIG. 24 illustrates a retractable electrode surgical instrument 300 which 
is an alternate embodiment of the retractable electrode instrument 200 
(FIG. 17). The instrument 300 includes many of the same elements as the 
instrument 200. These identical elements are identified with the same 
reference numeral as shown in FIG. 17. In this embodiment, each electrode 
250a, 250b is enclosed within a bendable guiding sheath 290a, 290b. A 
guide wire 293a, 293b is disposed within each sheath 290a, 290b and 
includes a first end 289a, 289b and a second end 291a, 291b. Each first 
end 289 of each guide wire 293 is attached (e.g. welded or adhesively 
bonded) to an inner surface of a bendable or bellows portion 292 of the 
sheath 290 at a location proximate the open end of the sheath 290. Each 
second end 291 is attached to a lever or knob 294 which is mounted to an 
outer surface of a housing 291. The housing 291 is similar to the housing 
232 and includes communication ports for an irrigation valve and an 
evacuation valve (neither shown). In operation, when there is no tension 
on the guide wires the sheaths are straight within the conduit, i.e. 
.theta. is 0 degrees. As the surgeon pulls back on the knob or lever, the 
wires are tensioned and the tips of each sheath is pulled back as 
illustrated until a desired .theta. value is obtained. In this embodiment, 
both the L and the .theta. values can be adjusted by the surgeon in situ. 
Although the present invention has been described above in terms of a 
specific embodiment, it is anticipated that alterations and modifications 
thereof will no doubt become apparent to those skilled in the art. It is 
therefore intended that the following claims be interpreted as covering 
all such alterations and modifications as fall within the true spirit and 
scope of the invention.