Vortex smoke remover for electrosurgical devices

A smoke removing device used with an electrosurgical device consists of a a hollow tube for evacuating the smoke, a tubular housing including vortex means for creating a vortex at an entrance end of the tubular housing, and an exit end of the tubular housing connected to one end of the hollow tube, another end of the hollow tube being connected to a suction means for creating suction to remove the smoke from the air near the electrosurgical device.

FIELD OF THE INVENTION 
The present invention relates to improvements in smoke removal and, more 
particularly, to smoke generating devices such as an surgical 
electrocautery device having a vortex creating vacuum smoke remover. 
BACKGROUND OF THE INVENTION 
The use of hand-held electrosurgical instruments such as electrocautery or 
laser surgical devices is used in many branches of surgery for the 
bloodless cutting of tissue, and for the cauterizing of vessels to stop 
bleeding During surgical use the localized heat generated by the 
electrical discharge cause large amounts of noxious smoke to be produced. 
This high temperature smoke rises rapidly from the point of the cautery 
instrument. Various studies have indicated that the smoke may contain 
carcinogenic elements, potentially harmful to the operating room staff. In 
addition the smoke is sometimes produced in such volume that the surgeon's 
view of the operative field is obscured In other circumstances, the 
anatomy causes the smoke to be trapped. Such a case is the dissection of 
the left internal mammary artery for subsequent coronary artery bypass 
grafting The internal mammary artery lies beneath the left rib cage, 
several centimeters to the left of the midline incision. The smoke 
generated during the dissection of the vessel tends to collect in the 
chest cavity. It is therefore desirable to provide a smoke collection 
system to remove the nuisance, smell and potential hazard of the smoke. At 
the same time, the collection system should not unduly interfere with the 
surgeon's field of view of the tissues being cut, nor can the device 
interfere with the use of the electrosurgical instrument. 
A number of electrosurgical devices are available which do not include any 
suction capabilities for removing smoke from the operating area. For 
example, U.S. Pat. Nos. 4,074,718, 4,112,950, 4,170,234, and 4,688,569. 
Additionally, other U.S. patents disclose devices which do include suction 
capabilities. For example, U.S. Pat. Nos. 2,275,167, 3,266,492, and 
3,906,955 disclose such devices. These devices include a tube connected to 
a source of vacuum which runs parallel to the cautery blade. U.S. Pat. No. 
4,362,160 discloses an endoscope which includes passages for feeding in 
and drawing off scavenging or flushing liquid which extend longitudinally 
behind the cutting or coagulating loop. 
It is further known to attach suction means to electrocoagulating devices, 
as shown in U.S. Pat. Nos. 2,808,833, 2,888,928, and 4,686,981. However, 
U.S. Pat. Nos. 2,808,833 and 4,686,981 include suction means for the 
express purpose of withdrawing excess blood prior to coagulating the 
remaining blood. U.S. Pat. No. 2,888,928 discloses a coagulating surgical 
instrument which includes a plurality of openings disposed at right angles 
with respect to the longitudinal axis of the cautery tip. Therefore, the 
suction operates to clear an area which is not immediately adjacent to the 
coagulating instrument. Other patents, such as U.S. Pat. Nos. 3,974,833, 
4,562,838, 4,683,884, and 4,719,914 disclose an electrosurgical instrument 
with a smoke dissipating means which is concentric with the cutting blade, 
or in the case of U.S. Pat. No. 3,982,541 concentric with the laser beam 
passage. 
The processes using electrosurgical devices such as cauterization, laser 
surgery, and coagulation, are very different procedures. Cauterization 
involves the use of a hot iron, an electric current or a caustic substance 
to destroy to tissue. Laser surgery involves the use of a precisely 
controlled laser beam to cut or destroy tissue. Coagulation deals with the 
process of blood clot formation. 
Although the various patents dealing with these devices disclose the 
general principle of providing a suction passage to the cutting or 
business end of the device, their particular constructions create 
difficulties in their use. Namely, they are limited by their structure to 
removing smoke which is close to the inlet of the suction means. In 
particular, the structures are such that the vacuum input tube remains 
very close to the tip of the electrocautery blade generating the smoke. 
Thus, the surgical field may be obscured from view either by smoke, or by 
the vacuum input tube itself. In those patents in which the vacuum input 
tube is far from the cutting surface, the suction is likely to be 
ineffective in removing all smoke from the surgical field because of the 
distance between the vacuum input tube and the cutting surface. 
Further, in a number of these prior art devices, it is not possible to 
effectively remove the smoke because the suction tube or passage becomes 
clogged with blood. It is of the utmost importance that smoke created by 
the electrocautery, laser surgical or coagulation device be efficiently 
removed from the surgical field. Smoke created by these devices is 
suspected of being carcinogenic and mutagenic. Thus, it is necessary to 
remove the smoke from the surgical field to insure the surgeon's safety. 
The smoke created by these devices must also be efficiently removed from 
the surgical field because it obscures the surgeon's view of the surgical 
field and is an irritant to the surgeon's eyes. The smoke is odorous and 
interferes with the surgeon's concentration during the operation. 
U.S. Pat. Nos. 818,891, 3,394,533 and 3,495,385 disclose devices which 
include helical shaped members through which fluids fIow, although none of 
there patents discuss the use of a helical element for smoke removal. 
SUMMARY OF THE INVENTION 
The present invention improves smoke removability by providing a vortex 
creating portion in the form of a helical member at the intake of the 
smoke removing tube. Webster's New Collegiate Dictionary defines a vortex 
as "a mass of fluid having a whirling or circular motion tending to form a 
cavity or vacuum in the center of the circle, and to draw toward this 
cavity or vacuum bodies subject to its action." In the present invention, 
the creation of the vortex suction causes smoke to be pulled in from a 
wider area, from a greater distance, and at a quicker rate than that 
available using an unaltered smoke removing tube. 
It is therefore one of the object of the present invention to provide an 
improved smoke removal device which can be used during electrosurgery to 
remove smoke created during an operation. 
It is a further object of this invention to provide an improved smoke 
removal device which is in combination with an electrosurgical device. 
It is a further object of this invention to provide an improved smoke 
removal device which efficiently removes smoke from the surgical field. 
It is a further object of this invention to provide a smoke removing device 
which insures the surgeon's safety. 
It is a further object of this invention to provide a smoke removing device 
which efficiently removes smoke from the surgical field so that the 
surgeon's concentration is not interfered with during the surgical 
procedure. 
It is a further object of this invention to provide a smoke removing device 
which uses a vortex in a tube to create a whirlpool motion outside the 
tube resulting in increased amounts of smoke being sucked into the tube. 
It is a further object of this invention to provide a smoke removing device 
by which smoke is removed more effectively then the prior art devices when 
the tube inlet is farther away from the cutting surface. 
It is a further object of this invention to use the smoke removal device of 
the present invention to remove smoke, or other noxious atmospheres, as 
required in other fields including, but not limited to, smoke removal 
necessary for restaurants, fire fighting, and various other industrial 
applications. 
According to the present invention, a device for removing smoke from the 
air near a smoke generator is provided comprising a hollow tube for 
evacuating the smoke, a tubular housing including vortex means for 
creating a vortex at an entrance end of the tubular housing, and an exit 
end of the tubular housing adapted to be connected to one end of the 
hollow tube, another end of the hollow tube being adapted to be connected 
to a suction means for creating suction to remove the smoke from the air 
near the smoke generator. 
The smoke generator may be an electrosurgical device. 
An electrosurgical device is provided which includes a cutting and 
cauterizing means in electrical communication with an external power 
source, a tube having a vortex end and adapted to be connected to a vacuum 
generator for removing smoke created with the cutting and cauterizing 
means from an adjacent immediate area, and means for turning on and off 
the vacuum suction device located at a distance spaced from the cutting 
and cauterizing end of the device. 
Still other objects, features and attendant advantages of the present 
invention will become apparent to those skilled in the art from a reading 
of the following detailed description of the embodiments constructed in 
accordance therewith, taken in conjunction with the accompanying drawings

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1 schematically shows a typical electrosurgical cutting or coagulating 
device 12. One embodiment of the present invention is one in which the 
smoke remover device 10 is removably attached to device 12. The remover 10 
can be attached to the electrosurgical device using various types of 
attaching means 14 such as mounting brackets or the like. The 
electrosurgical device 12 receives power from a power source (not shown) 
through plug 16, which can be adapted to fit various power sources, and 
then through electrical cord 18 to the device 12. 
The smoke remover 10 consists of a hollow tubular base 30 and a vortex 
creating member 25 attached to the base 30. Tube 21 and base 30 may be 
constructed of plastic The vortex creating member 25 includes a twisted 
piece of material 20, for example, stainless steel fit within a tube 21 As 
an example, a section of drill bit wedged within an appropriately sized 
tube will provide the desired effect. The vortex creating member 25 is 
removably inserted onto the end of base 30. 
A set of interchangeable tips including the straight vortex tip shown in 
the present embodiment in FIG. 1 may be provided. The various tips are 
interchangeable as the situation requires to enable the operating surgeon 
to clear away the maximum amount of smoke. Some of the various tips that 
could be used include the straight vortex tip 20 of the embodiment shown 
in FIG. 1, a sharply or roundly curved vortex tip such as shown in FIG. 5, 
and various other tips Additionally, various tips may be provided in which 
the twisted material 20 is of different lengths. 
The smoke remover 10 is attached at attaching joint 22 to a vacuum hose 24 
which is attached to a suction source 32 shown schematically on FIG. 1 at 
the opposite end of hose 24. 
FIG. 1A shows a prior art laser tipped cutting instrument as an example of 
the laser type hand-held prior art electrosurgical instruments listed in 
the "BACKGROUND OF THE INVENTION" section above. 
This prior art device is shown having a laser beam 26A and a laser source 
26B which function to permit bloodless cutting of tissues in an equivalent 
manner to prior art electrocautery devices also listed with such prior art 
hand-held electrosurgical instruments. 
An alternative embodiment of the present invention is shown in FIGS. 2 and 
3. In these embodiments the vortex tip 120 concentrically surrounds the 
base 126 of the cutting blade 26. The vortex tip 120 can be either 
removably or permanently attached to the electrosurgical device 112. If 
the tip 120 is removable then it may be part of a set of interchangeable 
tips which can be used as the situation requires. A tube 130 is shown 
coming out of the back of the electrosurgical device 112 to carry the 
removed smoke to hose 24, which meets tube 130 at intersection joint 22 
(not shown) Of course, the tube 130 could be eliminated with the hose 24 
directly to the smoke removal device 120 or the back of the 
electrosurgical device 112. 
FIG. 4 shows cut-away cross-sections of three different vortex creating 
members, along the line III--III of FIG. 1, which could be used in the 
present invention. The member may be formed in a variety of different 
shapes, length, and sizes. For example, the piece 20 within the tip may be 
one-quarter, one-half or one inch long. Additionally, a different number 
of vanes may be provided in different tips. The member may be either a 
single or a double helix. For example, FIG. 4A has a single vortex 
creating opening and would be relatively easy and inexpensive to 
manufacture. FIGS. 4B and 4C includes two and three vanes, for creating 
two and three vortex creating openings, respectively and are more 
complicated and would thus be more expensive to manufacture. FIGS. 2 and 3 
illustrate different helical configurations for the vortex member. Other 
variations of vortex creating members can be easily created and all are 
intended to be included in the present invention. 
The smoke remover 10 system works in the following manner. As the heated 
cutting blade or electrode 26 of the electrosurgical device 12 makes 
contact with the patient, smoke is produced from the burning tissue. When 
the vortex tip 20 is attached to the smoke remover 10, the pressure 
differential created by the vortex causes increased circulation of the air 
and smoke just outside of the vortex. Because of the funnel or whirl pool 
effect created by the pressure differential, smoke can be sucked to the 
openings form between the vortex creating member and the inside of the 
tube in from a wider area, from a greater distance, and at a quicker rate. 
In fact, the suction of the device 10 is continuous. The suction can be 
applied even when the blade 26 is not cauterizing. Therefore a negative 
pressure exists around the blade prior to generation of any smoke and the 
smoke is never given an opportunity to accumulate at the point of surgery. 
Depending on the circumstances of the surgery involved, different vortex 
tips could be selected to maximize the benefits available using the vortex 
tip according to the present invention. In situations where the smoke is 
dissipating over a wider area, the straight vortex tip may provide the 
most benefit. However, in situations where the smoke is dissipating very 
slowly over a small area, a venturi vortex tip having a tapered end may be 
the most efficient choice. In situations where the cutting tip 26 is bent 
at an angle, the most efficient smoke removing tip might be the bent 
vortex tip. Additionally, the surgeon could also change the tips for 
obtaining a vortex having a different strength depending on the length of 
the helical member. Since the surgeon ca easily change tips on the smoke 
remover, the surgeon will quickly become familiar with which tip is most 
effective for each situation incurred. 
The on-off switch for the electrocautery device is shown at 19 in FIG. 1. 
This is separate from the on-off for the suction. 
The suction for the smoke remover 10 can be turned on using various types 
of valves such as valve 28 on the hose 24. The valve 28 is preferably 
placed on the hose 24 a few feet away from the smoke remover 10 so that 
the physician can ask a nurse or another member of the support staff to 
turn the suction on and off, thus keeping his free hand available for 
other purposes. The valve 28 could just as easily be placed on the smoke 
remover itself near the cutting edge although it is less desirable for the 
aforementioned reason. The presence of the valve allows the surgeon to 
request that the suction be turned off when it is not required in order to 
eliminate the noise created by the suction source. 
The system according to the embodiments shown in FIGS. 2 and 3 is operated 
in the same manner as the first embodiment with the only difference being 
that smoke can be removed immediately after it forms since the smoke 
remover 120 is so close to the source of the smoke. 
A number of tests were carried out in order to determine the efficacy of 
different devices to clear smoke from an operating area. 
TEST 1 
In a first experiment, smoke was generated using a regular Bovie machine, 
coagulation set at 100. In the first test, smoke was generated from a 
blood clot, in the second test, from a small piece of adipose tissue. In 
both cases the tissue was placed on a regular grounding pad. While smoke 
was generated, a regular operating room suction device was held with the 
other hand, and its position was changed in relation to the electrocautery 
tip (i.e above or below the tip). In addition, the suction was moved 
closer and away from the source of the smoke. Five different tips were 
attached to the suction: 
1) A regular 1/4" tube. 
2) A narrowed tip. 
3) A 1/4" tube into which a piece of approximately 1/2" long of a 1/4" 
drill bit was snugly inserted 
4) Similar to #3, but with a 1" piece of drill bit. 
5) A mold made of acrylic on a 1/4" drill, 1 and 1/4" long. 
The second tip was designed to create a bernouli effect The last three tips 
were designed to generate a vortex suction. 
Although a precise quantitative measurement of the smoke clearance could 
not be done, an assessment of the clearance and the relative effectiveness 
of each tip could be accomplished. Testing of each tip was repeated about 
10 times and the impressions were consistent. The most effective clearance 
was accomplished with tip #4, tips #3 and #5 were about the same, and tips 
#1 and #2 were the least effective. The effectiveness was manifested by 
the wider area of smoke clearing and by the degree of completeness of 
clearing. Positioning of the suction tip below the pencil did not detract 
significantly from its function. At times, two streams of smoke could be 
seen entering the suction tip. 
TEST 2 
A second experiment was carried out in order to substantiate the previous 
observation that the #4 vortex tip was superior to the other tips. This 
tip (1/4" tubing into which a 1" long portion of a 1/4" drill bit was 
inserted), was compared to a regular 1/4" tubing. In this experiment, a 
piece of beef fat was used, 5.times.5.times.10 cm, utilizing again a 
regular bovie and suction system. Two method for assessment of the 
efficacy of smoke clearance were used, each repeated 10 times. 
The first experiment was done while the bovie pencil was held straight up, 
and the suction tip perpendicular to the pencil, 1.5" above the pencil 
tip. In this position, the generated smoke climbed as a column along the 
pencil. When the suction tip was held very close to the pencil, there was 
a very efficient smoke clearance. As a matter of fact, the smoke could be 
clearly seen to divert abruptly from the pencil in a right angle towards, 
and opposite from, the suction tip. As the suction tip was slowly moved 
away from the pencil, the column of smoke initially continued to be 
cleared in a similar fashion, until a certain distance, in which part of 
the smoke was not cleared any more and rose upwardly. This distance was 
always longer when the vortex tip was employed, by approximately 30 to 
40%, when compared to the clearance distance of the non-vortex tip. The 
distance was dependent on the amount of smoke generated. When high 
quantities of smoke were generated, the suction tip had to be held 
relatively closer in order to achieve a complete clearance, and visa 
versa. Yet, for any amount of smoke, the vortex tip was able to clear the 
smoke from a longer distance. 
In the second set of experiments, the diameter of the area from which the 
smoke was cleared was assessed. When the bovie pencil tip was brought from 
the side rather than from above, the smoke was generated in all 
directions, and was spreading like a ball. At times, smoke was even coming 
out from areas not in direct contact with the bovie tip. Comparison of the 
suction tips was performed by moving them towards and away from the bovie 
tip where the smoke was generated. When the non-vortex suction tip was 
used, the smoke "ball" was very large, and the suction tip had be held 
fairly close to the bovie tip in order to clear all the smoke. In 
contrast, the vortex tip could be held at a distance approximately twice 
as long, and still cleared the smoke very effectively. The smoke could be 
seen spreading like a ball, at times 5-7 cm in diameter, and converge back 
towards the suction tip. 
From these experiments, it can be seen that the vortex suction effects the 
air surrounding the tip in both distance and diameter. Thus vortex suction 
is capable of creating a more effective suction by the same vacuum source 
TEST 3 
A third test was conducted to further demonstrate the efficiency of the 
vortex tube. 
The objective of this experiment was to determine the smoke removal 
efficiency for the following tip configurations: 
(a) determine the efficiency, with and without a vortex inducer in the tip; 
and 
(b) vary the diameter of the proposed vacuum cautery orifice. 
In summary, it was demonstrated that an orifice with a increased diameter 
and a vortex inducing insert showed significantly greater smoke removal. 
Using a vortex enabled placement of the orifice approximately 50% further 
away from the smoke source as compared to an orifice without the vortex 
and without reducing the efficiency of smoke removal. 
In order to carry out the experiment, three orifice diameters were machined 
into a block of clear acrylic to a depth of 25.4 mm (1.0 inches--see FIG. 
6). The diameters were 6.35 mm (1/4"), 4.76 mm (3/16"), and 2.38 mm 
(3/32"). The corresponding drill bit sizes were cut to a length of 25 mm 
and inserted into the block when measurements were needed "with vortex". 
The drills acted to induce spiral air flow. A 1/4" I.D. hole on the distal 
side of the acrylic block served to connect the vacuum source with the 
test orifice. The sides of the orifice tips were at sharp right angles. It 
was estimated that the drills blocked approximately 40% of the orifice 
area. 
The 6.35 mm (1/4") maximum size orifice was chosen because it was equal to 
the vacuum hose I.D. used in the operating room. Any larger diameter would 
decrease the vacuum efficiency by dissipating the air flow lines from the 
orifice. 
The circuit was set up per FIG. 7a. A vacuum was drawn through 6.35 mm 
(1/4") tubing at a regulated 25 liters/minute gas flow rate. The distal 
end of the tubing was attached to the orifice of interest and vacuum flow 
initiated. Each orifice was tested without the drill first, then with the 
drill. 
The smoke source (filtered cigarettes) was placed 6 cm inferior to the 
orifice and moved either towards or away from the vacuum. If no vacuum was 
applied, the smoke rose in a concentrated stream for approximately 10-12 
cm and then progressively dissipated. Data was taken in both directions. 
Care was taken to avoid any interfering movement of air. A total of five 
samples were recorded for each parameter. 
The "critical distance" was defined as the distance "d" (in mm) at which 
the entire (100%) smoke flow curved towards the vacuum source and was 
drawn into the vacuum orifice at an obvious right angle to the non-vacuum 
rising flow (see FIG. 7b). The accuracy of the measurements was estimated 
to be .+-.2 mm. The critical distance is the measure of the smoke removal 
efficiency. 
All data is shown in Table 1 and illustrated in FIG. 8. The statistical 
results are in Table 2. 
TABLE 1 
______________________________________ 
Critical Distance Measurements with Different 
Orifice Sizes (distance that smoke is attracted 
into an orifice with a constant velocity) 
"out-to- "in-to- 
in" out" 
Tip critical Per-cent 
critical 
Per-cent 
Type Diameter dist. Improve- 
dist. Improve- 
of Orifice 
(mm) (mm) ment (mm) ment 
______________________________________ 
w/o vortex 
6.35 24.0 .+-. 27.4 .+-. 
0.7 0.5 
with vortex 
6.35 27.6 .+-. 
15.0 31.0 .+-. 
13.1 
0.5 1.0 
w/o vortex 
4.76 21.8 .+-. 25.4 .+-. 
0.5 0.9 
with vortex 
4.76 25.0 .+-. 
14.7 27.6 .+-. 
8.7 
0.7 1.1 
w/o vortex 
2.38 16.6 .+-. 21.0 .+-. 
0.5 0.7 
with vortex 
2.38 22.2 .+-. 
33.7 25.2 .+-. 
20.0 
0.8 0.4 
______________________________________ 
Notes: 
(1) The velocity (measured by a rotometer flowmeter) was 25 LPM for the 
orifices without drills, but dropped approximately 1 LPM (to 24) for the 
orifices with drills. This drop was attributed to the increase in 
resistance from the drill crosssection area. The flowmeter was adjusted 
back to 25 LPM so that the results would be comparable for both sets of 
data. 
(2) The n = 5 for all data. All data reported as Mean .+-. 1 S.D. 
(3) See previous discussion for the definition of "critical distance". 
TABLE 2 
______________________________________ 
Statistical Analysis Results (T-test) 
Data Comparison Significant at 
Direction 
Description p value 0.95? 
______________________________________ 
out-to-in 
6.35 mm with vortex vs 
0.0010 
Yes 
(towards without vortex 
the orifice) 
4.76 mm with vortex vs 
0.0012 
Yes 
without vortex 
2.38 mm with vortex vs 
0.0010 
Yes 
without vortex 
in-to-out 
6.35 mm with vortex vs 
0.0011 
Yes 
(away from without vortex 
the orifice) 
4.76 mm with vortex vs 
0.0213 
Yes 
without vortex 
2.38 mm with vortex vs 
0.0010 
Yes 
without vortex 
______________________________________ 
The efficiency of smoke removal (=increased critical distance) was greatest 
with the largest orifice diameter. This is consistent with flow line 
theory which states that the area of the orifice is proportional to the 
amount of air that it can "attract". It is also consistent with resistance 
to flow physics (the larger the orifice diameter the less the resistance 
to that flow). 
The efficiency of smoke removal was also larger with the vortex inserts in 
place (see Table 2 for p values). The spirals formed seem to enhance the 
flow lines and increase the drawing power. There is a high probability 
that machining a small radius on the sharp right angles of the orifice 
tips would also enhance the vacuum efficiency. 
There is also a possibility that the area lost to the drill cross section 
actually skews the results. If the orifice size was to be redefined as 
"effective open area" rather than orifice diameter, then it would be 
correct to compare, for example, data from the 6.35 mm (with vortex) to 
the 4.76 mm (without vortex). If this hypothesis holds true, the rationale 
of using a vortex would become even more apparent. 
Finally, during the testing it was noticed that the closer that the orifice 
(vacuum source) is to the smoke source, the greater the efficiency. This 
was intuitively clear and was substantiated by observations. 
TEST 4 
A fourth set of tests were performed which used the large diameter orifice 
(6.35 mm) from Test 3 but varied the turn density of the insert. It 
concluded that a spiral density of 2 turns/25 mm has greater efficiency 
than a spiral density of 1 turn/25 mm. 
The objective of this experiment was to determine the smoke removal 
efficiency for the following tip configurations: 
a) Vortex that has one (1) turn in 26 mm. 
b) Vortex that has one and one-half (11/2) turns in 25 mm. 
c) Vortex that has two (2) turns in 25 mm. 
In summary, it was demonstrated that increasing the turns on the vortex 
inducing insert showed significantly greater smoke removal. There was an 
11.2% increase in efficiency when the turn density was increased from 1 
turn to 2 turns per 25 mm. 
The products used in this experiment are described below. 
Three vortex turn densities were constructed out of brass stock (1/4" wide 
and 1/32" thick) to fit inside an acrylic block (machined for Test 3 
described previously) to a depth of 25 mm. (per/25 mm) were one (1), one 
and one-half (1/2) and two (2). All fit inside the 0.635 mm (1/4") I.D. 
hole on the distal side of the acrylic block. The sides of the orifice 
tips were at sharp right angles. It was estimated that the spirals blocked 
approximately 3% of the orifice area (as compared to the approximately 40% 
blockage for the drill inserts--see Test 3). 
The circuit was set up per FIG. 10a. A vacuum was drawn through 6.35 mm 
(1/4") tubing at a regulated 25 liters/minute gas flow rate. The distal 
end of the tubing was attached to the orifice and vacuum flow initiated. 
The smoke source (filtered cigarettes) was placed 6 cm inferior to the 
orifice and moved towards the vacuum. If no vacuum was applied, the smoke 
rose in a concentrated stream for approximately 10-12 cm and then 
progressively dissipated. Care was taken to avoid any interfering movement 
of air. A total of five samples were recorded for each spiral. 
The "critical distance" was defined as the distance "d" (in mm) at which 
the entire (100%) smoke flow was drawn into the vacuum orifice at an 
obvious right angle to the non-vacuum rising flow (see FIG. 10b). The 
accuracy of the measurements was estimated to be .+-.2 mm. 
The "starting distance" was defined as the distance "d" (in mm) at which 
any smoke flow was drawn into the vacuum orifice. The accuracy of these 
measurements was estimated to be .+-.3 mm. 
All data is shown in Table 3 and illustrated in FIG. 9. The statistical 
results are in Table 4. 
The efficiency of smoke removal (=increased critical distance) was greatest 
with the most dense spiral (most turns/25 mm). 
The critical distance was also greater for this "low cross-sectional" 
spiral as compared to the data obtained in Test 3 (the mean critical 
distance was 31.2 mm for the brass insert (2 turns) and 27.6 mm for the 
drill insert--a 13.0% improvement). The reproducability of this data has 
not been substantiated at this time, however. 
The difference between the critical distance and the starting distance did 
not become significantly greater or smaller with an increase in turn 
density. 
TABLE 3 
______________________________________ 
Critical Distance and Starting Distance Measurements 
with Different Turn Densities (6.35 mm diameter) 
% Improve- % Improve- 
Turn Critical ment over Starting 
ment over 
Density 
Distance the previous 
Distance 
the previous 
(/25 mm) 
(mm) spiral density 
(mm) spiral density 
______________________________________ 
1 turn 28.0 .+-. 0.7 34.0 .+-. 0.7 
11/2 turns 
29.8 .+-. 0.8 
6.4 36.6 .+-. 0.5 
7.6 
2 turns 
31.2 .+-. 0.8 
4.7 37.8 .+-. 0.8 
3.3 
______________________________________ 
Notes: 
(1) The velocity (measured by a rotometer flowmeter) was 25 LPM. There wa 
no detachable drop in velocity when the brass spirals were added. 
(2) The n = 5 for all data. All data reported as Mean .+-. S.D. 
(3) See previous discussion for the definition of "critical distance" and 
"starting distance". 
TABLE 4 
______________________________________ 
Statistical Analysis Results (T-test) 
Comparison Significant at 
Description p value 0.95? 
______________________________________ 
1 turn to 11/2 turns 
0.0367 Yes 
1 turn to 2 turns 
0.0054 Yes 
11/2 turns to 2 turns 
0.0046 Yes 
______________________________________ 
TEST 5 
A fifth set of tests were performed which compared three orifices of 
constant diameter (again 6.35 mm) and constant turn density (1 turn/25 
mm), but of increasing spiral length. The results show that a longer (75 
mm) length yields greater efficiency than a shorter length (25 mm). 
The objective of this set of tests was to determine the smoke removal 
efficiency for the following brass spiral tip configurations: 
a) Vortex that has one (1) turn in 25 mm and is 25 mm in length. 
b) Vortex that has one (1) turn in 25 mm and is 50 mm in length. 
c) Vortex that has one (1) turn in 25 mm and is 75 mm in length. 
In summary, increasing the length of the vortex inducing insert showed 
significantly greater smoke removal. There was an 26.9% increase in 
efficiency when the length was increased from 25 mm to 75 mm. 
Three spiral lengths were constructed out of brass stock (1/4" wide and 
1/32" thick) to fit inside an acrylic block to a diameter of 6.35 mm (see 
FIG. 11). The turn density was one (1) per 25 mm. The lengths were 25, 50 
and 75 mm. The sides of the orifice tips were at sharp right angles. It 
was estimated that the spirals blocked approximately 3% of the orifice 
area (as compared to the approximately 40% blockage for the drill 
inserts--Test 3). 
The circuit was set up per FIG. 12a. A vacuum was drawn through 6.35 mm 
(1/4.) tubing at a regulated 26 liters/minute gas flow rate. The distal 
end of the tubing was attached to the orifice and vacuum flow initiated. 
The smoke source (filtered cigarettes) was placed 6 cm inferior to the 
orifice and moved towards the vacuum. If no vacuum was applied, the smoke 
rose in a concentrated stream for approximately 10-12 cm and then 
progressively dissipated. Care was taken to avoid any interfering movement 
of air. A total of five samples were recorded for each spiral length. 
The "critical distance" was defined as the distance "d" (in mm) at which 
the entire (100%) smoke flow was drawn into the vacuum orifice at an 
obvious right angle to the non-vacuum rising flow (see FIG. 12b). The 
accuracy of the measurements was estimated to be .+-.2 mm. 
The "starting distance" was defined as the distance "d" (in mm) at which 
any smoke flow was drawn into the vacuum orifice. The accuracy of these 
measurements was estimated to be .+-.3 mm. 
All data is shown in Table 5 and illustrated in FIG. 13. The statistical 
results are in Table 6. 
The efficiency of smoke removal (=increased critical distance) was greatest 
with the longest spiral length. 
The critical distance was also greater for this "low cross-sectional" 
spiral as compared to the data obtained in Test 3. 
The reproducability of this data seems to be quite good. If data from one 
(1) turn/25 mm density through a 6.35 mm diameter orifice of 25 mm spiral 
length is compared for the three tests done to date, results of 27.6 mm 
(Test 3), 28.0 mm (Test 4) and 29.0 mm (this test) are obtained. 
TABLE 5 
______________________________________ 
Critical Distance and Starting Distance Measurements 
with Increased Spiral Lengths (6.35 mm diameter) 
% Improve- % Improve- 
Spiral Critical ment over Starting 
ment over 
Length Distance the previous 
Distance 
the previous 
(mm) (mm) spiral length 
(mm) spiral length 
______________________________________ 
25 29.0 .+-. 0.7 34.4 .+-. 0.5 
50 31.0 .+-. 0.7 
6.9 36.4 .+-. 0.5 
5.8 
75 36.8 .+-. 0.8 
18.7 39.0 .+-. 0.7 
7.1 
______________________________________ 
Notes: 
(1) The velocity (measured by a rotometer flowmeter) was 25 LPM. There wa 
no detectable drop in velocity when the brass spirals were added. 
(2) The n = 5 for all data. All data reported as Mean .+-. 1 S.D. 
(3) See text for the definition of "critical distance" and "starting 
distance". 
TABLE 6 
______________________________________ 
Statistical Analysis Results (T-test) 
Comparison Significant at 
Description p value 0.95? 
______________________________________ 
25 to 50 mm 0.0217 Yes 
50 to 75 mm 0.001 Yes 
25 to 75 mm 0.001 Yes 
______________________________________ 
The smoke removal device is discussed herein as being associated with an 
electrosurgical device such as a cauterizing pencil. However, it can 
clearly be used with any other smoke-generating surgical technique, such 
as coagulation or laser surgery. Moreover, it should be understood that 
the vortex smoke removal is adaptable for many other uses, such as smoke 
removal in restaurants, fire fighting and other industrial applications. 
For example, if a vortex creating member of the appropriate size were 
attached to the end of a large hose, the hose could be inserted into a 
burning building to remove the smoke at a faster rate, allowing fire 
fighters to enter the building without fear of collapsing from smoke 
inhalation. Additionally, if a vortex creating member were attached to a 
hose placed above a restaurant stove, the smoke could be cleared faster, 
allowing the chef to work safely and comfortably. 
The foregoing description of the specific embodiments will so fully reveal 
the general nature of the invention that others can, by applying current 
knowledge, readily modify and/or adapt for various applications such 
specific embodiments without departing from the generic concept, and, 
therefore, such adaptations and modifications should and are intended to 
be comprehended within the meaning and range of equivalents of the 
disclosed embodiments. It is to be understood that the phraseology or 
terminology employed herein is for the purpose of description and not of 
limitation.