Redundant wall retractor is tubular and is obturated for insertion. It has a duct which terminates in an opening at the top of the anterior end and terminates with a tube fitting at the bottom at the posterior end. It is made of dielectric synthetic polymer composition material, preferably transparent to retract tissues during loop electrode excision procedures with the duct positioned for withdrawing smoke.

FIELD OF THE INVENTION 
This invention is directed to an electro-cautery speculum particularly 
useful in loop electrode excision procedures wherein the speculum is 
dielectric and a smoke-withdrawal duct is positioned at the anterior end 
to aid in maintaining a clear field. 
BACKGROUND OF HE INVENTION 
Electro-cautery presents a set of problems which are not satisfied with any 
present speculum. Loop electrode excision procedures employ an electrode 
at a significant voltage. Thus, the present metallic speculums are 
unsatisfactory because of the chance of the loop touching and charging the 
metallic speculum. This problem is exacerbated by the employment of a 
redundant wall speculum to maximize the field, but the present-day 
redundant wall speculums are also metallic. In addition, in loop electrode 
excision procedures, smoke is created, but a smoke-withdrawal tube is not 
placed in the optimum position. The use of a separate smoke-withdrawal 
tube obstructs the field. Thus, there is need for an electro-cautery 
speculum which provides safety and which improves vision of and access to 
the field. 
SUMMARY OF THE INVENTION 
In order to aid in the understanding of this invention, it can be stated in 
essentially summary form that it is directed to an electro-cautery 
speculum which is substantially a right circular cylindrical tube of 
dielectric thermoplastic material and which is preferably transparent. The 
speculum has an obturator for closing the anterior end during insertion 
and is, thereupon, removed through the posterior end. A duct is provided 
at an optimum location at the anterior end to withdraw smoke from the 
speculum. 
It is, thus, an object and advantage of this invention to provide a 
dielectric electro-cautery speculum which renders the patient safe from 
electrical shock which would be caused by loop electrode contact with a 
metallic speculum. 
It is another object and advantage of this invention to provide an 
electro-cautery speculum which places a smoke-withdrawal duct inlet at the 
optimum location a the anterior of the speculum so as to withdraw smoke to 
maximize clarity of vision at the field. 
It is another object and advantage of this invention to provide an 
electro-cautery speculum which is tubular in form and which has a 
removable obturator so that the speculum can be comfortably inserted and 
the obturator then withdrawn from the posterior end to provide access to 
the field. 
It is another object and advantage of this invention to provide an 
electro-cautery speculum which is inexpensively manufactured of synthetic 
polymer composition materials so that the speculum can be economically 
provided and disposed of after a single use. 
Other objects and advantages of this invention will become apparent from a 
study of the following portion of the specification, the claims and the 
attached drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
The electro-cautery speculum of this invention is generally indicated at 10 
in FIGS. 1 and 3. The purpose of the speculum is to retract the vaginal 
walls to allow access to the cervix for electro-cautery thereof. A duct 
for withdrawal of smoke resulting from the electro-cautery procedure is 
placed at an optimum location. The speculum 10 has two body parts, as is 
best seen in FIG. 3. The outer tube 12 and inner tube 14 are thin-walled 
generally conical tubes with enough cone to provide the draft helpful in 
the injection-molding process. Except for this molding draft and the duct 
built into the tubes 12 and 14, they could be right circular cylindrical 
tubes. 
As is seen in FIGS. 3 and 4, inner tube 14 has a duct wall 16 which is 
substantially in the form of a hemi-cylindrical tube in that portion of 
the wall. Similarly, outer tube 12 preferably may have a companion ridge 
18 extending radially outward in the outer tube and extending the length 
thereof so that the duct wall 16 and ridge 18 form a duct 20 throughout 
the length of inner tube 14. The anterior end of duct 20 forms duct 
opening 22. At the posterior end, a one-quarter annular duct ring 24 is 
formed on outer tube 12. A companion three-quarter annular duct ring 26 is 
provided on the posterior end of inner tube 14. It is understood that the 
inner and outer tubes are each a one-piece injection molding. When they 
are fitted together, as shown in FIG. 3, it is seen that the duct 20 is 
formed and the annular duct 28 is also formed, with the ducts joined 
together. The joints are sealed by adhesive or other joining methods, such 
as ultrasonic welding. Tube fitting 30 forms a part of duct ring 26. It is 
significant to note that the tube fitting 30 is diametrically opposite the 
duct opening 22. This positioning is so that the duct opening 22 can be 
positioned above the site of the procedure and the tube fitting 30 is 
below the opening into the posterior end of tube 14. FIGS. 5 and 6 show 
the details by which the annular duct 28 is formed and is connected to the 
duct 20 and tube fitting 30. 
In order to provide for comfortable insertion, the speculum is obturated 
during insertion Obturator 32 fills the anterior opening of the speculum 
during insertion. Obturator 32, together with the anterior end of inner 
tube 14, forms a hemispherical dome, as seen in FIG. 1. The dividing line 
between the obturator 32 and the anterior end of tube 14 is of double 
curve configuration, as seen in FIG. 1. The anterior end 34 of the tube 14 
has a substantially half-cylindrical concave wall 36 and substantially 
quarter-circular cylindrical convex walls 38 and 40. This configuration 
leaves an upper flange 42 and a lower flange 44. The walls 36, 38 and 40 
on the flanges are substantially parallel to the axial center line, left 
to right through FIGS. 1 and 3 and perpendicular to the sheet at the 
center of FIGS. 2 and 4. The dome of the obturator 32 completes the 
hemispherical shape of the anterior end, and the obturator has 
corresponding walls which lie against the walls 36, 38 and 40. The 
obturator 32 lies against the inside of the flanges 42 and 44 to define a 
forward limit for the obturator. In addition, the obturator carries a stem 
46 which has thereon ring 48. The ring 48 is engaged with the thumb, while 
the index and middle fingers grasp the anterior side of the duct ring to 
hold the obturator in place and guide the speculum during insertion. 
At completion of insertion, the obturator is withdrawn by grasp on the ring 
48 and withdrawal of the obturator in the posterior direction. A vacuum 
tube is connected onto fitting 30. The speculum is then in place for 
electro-cautery procedures. A sufficient opening is provided at the 
anterior end for an adequate surgical field. Smoke is withdrawn at the top 
of the field to maximize visibility during the procedure. The tube on 
fitting 30 drapes away without obstructing the field. The electro-cautery 
speculum 10 is preferably made of injection-moldable thermoplastic 
synthetic polymer composition material of dielectric nature to prevent 
electric shock problems. Furthermore, it is preferably made of a 
transparent polymer so that adjacent tissues may also be observed. The 
speculum 10 can be manufactured in a sufficiently inexpensive manner that 
it can be disposed of after a single use. It can be supplied in sterile 
packaging and disposed of after the single use to avoid contamination. 
This invention has been described in its presently contemplated best mode, 
and it is clear that it is susceptible to numerous modifications, modes 
and embodiments within the ability of those skilled in the art and without 
the exercise of the inventive faculty. Accordingly, the scope of this 
invention is defined by the scope of the following claims.