Hysterosonogram/hysterosalpingogram cannula with soft seal

A cannula which has a semi-rigid hollow shaft and a soft seal for endocervix to prevent the cannula from slipping out of position during medical procedures, which may be straight, curved or angled at the distal inner end.

BACKGROUND OF THE INVENTION 
This invention relates, in general, to cannula, and, in particular, to 
cannula with a soft seal attached thereto. 
DESCRIPTION OF THE PRIOR ART 
In the prior art various types of cannula have been proposed. For example, 
U.S. Pat. No. 85.995 to Buffon discloses a syringe with a soft sponge 
surrounding a rigid shaft to collect waste fluid. 
U.S. Pat. No. 3,385,300 to Holter discloses a cervical cannula having a 
shaft and a tapered cone shaped seal made from a flexible material. 
U.S. Pat. No. 3,796,211 to Kohl discloses a biopsy sampler having a shaft 
surrounded by a cone shaped seal. 
U.S. Pat. No. 4,585,438 to Makler discloses an injector with a semi-rigid 
tubular member surrounded by a seal. 
U.S. Pat. No. 5,195,964 to Kletzky et al discloses a cannula with a 
flexible shaft and a cone shaped seal. 
SUMMARY OF THE INVENTION 
The present invention is directed to a cannula which has a semi-rigid 
hollow shaft and a soft seal for endocervix to prevent the cannula from 
slipping out of position during medical procedures. 
It is an object of the present invention to provide a new and improved 
cannula with a soft seal for endocervix, which will hold the cannula in 
position during medical procedures. 
It is an object of the present invention to provide a new and improved 
cannula with a semi-rigid shaft to enhance the maneuverability of the 
cannula. 
These and other objects and advantages of the present invention will be 
fully apparent from the following description, when taken in connection 
with the annexed drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings in greater detail, FIG. 1 shows the cannula 1 
of the present invention. The cannula has a first end 5 which is 
cone-shaped in order to receive instruments such as a syringe 11, as shown 
in FIG. 3. Adjacent to the first end 5 is a flexible looped segment 4 
which can be used by the physician to manipulate the instrument during the 
procedure. Connected to the flexible looped segment 4 is a relatively 
straight, hollow segment 2. This segment should be made from a material 
that is semirigid which will allow the physician to more easily manurer 
the cannula through the vagina 9 and into the cervix 10, as shown in FIG. 
3. 
The cannula of the prior art make this segment rather flexible, which can 
make maneuvering the cannula difficult, and due to the flexibility of the 
prior art cannula, it can kink or bend during insertion. If the cannula is 
bent, it will be difficult or impossible to insert instruments or 
medication through the hollow cannula and have the instruments or 
medication delivered to the desired location. With the semi-rigid nature 
of the shaft segment 2 the physician can be assured that the cannula 1 
will not kink or bend, thereby blocking the internal passage through the 
cannula for instruments or medication. Also, the semi-rigid nature of the 
shaft segment 2 will make it easier for the physician to maneuver the 
cannula as he/she inserts the instrument. 
Another problem with the prior art cannula is that the seal or seating 
member that surrounds the distal end 3 is made from a relatively smooth, 
hard material. For example, the seal 44 shown in the Kletzky et al 
reference (U.S. Pat. No. 5,195,964) is made from a semi-rigid silicone 
rubber or plastic, and, as shown in FIG. 3a of Kletzky et al, the outer 
surface of the seal is smooth. Generally, the outer surface is made smooth 
in order to prevent irritation to the patient as the cannula is inserted 
and/or maneuvered. However this smooth outer surface means that the 
cannula will not have a strong anchor when placed into position. 
Manipulation by the physician or an attempt to pass instruments or 
medication through the hollow cannula, can cause the seal to slip out of 
position. The alternative solution shown in the prior art has been to make 
the outer surface of the seals with irregularities such as the teeth 16 
shown in the Holter reference (U.S. Pat. No. 3,385,300). While the teeth 
of Holter will secure the seal more firmly in place, they can also cause 
irritation to the patient. 
The cone-shaped seal 6 of the present invention solves these problems by 
making the seal 6 from a soft material such as the material used to make 
sponges. The soft material will prevent irritation to the patient as the 
physician inserts and manurers the cannula. In addition, the outer surface 
of the soft material of the seal 6 has a plurality of irregular valleys 12 
and lands 13, as shown in FIG. 2, which will allow the seal to contact the 
inner walls of the opening to the cervix 10 and to firmly, but gently, 
secure the seal in place. Therefore, when the seal 6 is in position, there 
will be little, if any irritation to the patient because of the soft 
material of the seal. In addition, the irregular shaped valleys and lands 
will assure that the cone-shaped seal is firmly secured in place and will 
not become dislodged as the physician manurers instruments (not shown) 
through the hollow cannula, or inserts medication through the cannula by 
means of the syringe 11. 
The embodiment shown in FIG. 2 is essentially the same as the FIG. 1 
embodiment except the FIG. 2 embodiment is made in two parts with the 
shaft 2' separate from the flexible loop segment 4 and the end 5. This 
will allow the physician to dispose of the shaft 2' after each use, 
without disposing of the entire cannula. Also, this will make it easier to 
make the shaft 2' from a different material than the portion containing 
the flexible loop segment 4. That is the shaft 2' can be made from a 
semi-rigid material and the portion containing the flexible loop segment 4 
can be made from a softer material. Also, the end 8 on the shaft 2' should 
be made cone-shaped in order to more easily receive the end 7. In all 
other respects the embodiment shown in FIG. 2 is essentially the same as 
the FIG. 1 embodiment and works in the same manner. 
Although the Hysterosonogram/Hysterosalpingogram Cannula with Soft Seal and 
the method of using the same according to the present invention has been 
described in the foregoing specification with considerable details, it is 
to be understood that modifications may be made to the invention which do 
not exceed the scope of the appended claims and modified forms of the 
present invention done by others skilled in the art to which the invention 
pertains will be considered infringements of this invention when those 
modified forms fall within the claimed scope of this invention.