Patent Application
20100185209
The present invention relates to fetal procedures, particularly fetotomy and more particularly to a method and device for removing the limbs of a deceased fetus. The invention also relates to fetal repositioning procedures.
The birthing of animals, including humans and livestock, has presented substantial problems for doctors, farmers and veterinary doctors for many years. The problem has been most severe in the cattle industry where current trends in genetic selection commonly cause calves to be born at a larger size. Cattle giving birth at 24 months or younger are particularly at risk of having birthing difficulty because their birth canal has not yet reached full adult size. Not uncommonly, a veterinary doctor or livestock handler will be faced with a serious problem when a fetus has died during the birthing process and is incorrectly positioned or physically too large to be delivered. If the dead fetus is not delivered promptly, infection and shock can cause death to the mother. Conventional devices to extract the entire fetus by pulling on the fetus while pushing against the hindquarters of the mother can be dangerous because extreme traction often causes fatal injury to the uterus and birth canal. A costly caesarian operation has the often fatal risk of infection due to the delivery of a rotting fetus through a surgical incision. An area of veterinary obstetrics called fetotomy has been developed to provide an alternative delivery technique. Fetotomy pertains to separating the fetus into parts and removing the fetus through the birth canal one piece at a time. Special knives and wire saws are typically used to perform this procedure. Wire saws present problems due to the extreme difficulty of passing a rough wire around fetal structures in a very confined space without injury to the mother animal. In addition, once the cuts are made, sharp surfaces of cut bones may be exposed to the delicate structures of the uterus and birth canal.
The various embodiments of the present invention may, but do not necessarily, achieve one or more of the following advantages:
the ability to fully remove limbs from a fetus with minimal cutting;
provide a method and device for removing fetal limbs without cutting the bones of the limb;
provide reduced risk of injury to the mother;
provide a method and device for fetotomy where the tractional forces are placed entirely on the dead fetus; and
provide a method and device for repositioning of a fetus within the uterus or birth canal.
These and other advantages may be realized by reference to the remaining portions of the specification, claims, and abstract.
In an embodiment of the invention there is provided a method for performing fetotomy. The method provides a brace around a first portion of a fetal limb of a fetus and an attachment at a second portion of the fetal limb. Tension is provided to the fetal limb between the first and second portions sufficient to separate the fetal limb from the fetus.
In an embodiment of the invention there is provided a device for performing a fetotomy comprising a brace that engages a first portion of a fetal limb of a fetus and an attachment that engages a second portion of the fetal limb. A traction device applies relative traction between the brace and the attachment to cause the limb to separate from the fetus between the brace and the attachment.
In an embodiment of the invention there is provided a device for performing fetotomy comprising a brace and an extension bar extending from the brace. The brace comprises a rigid loop configured to pass around a fetal limb and engage a fetus at the base of the fetal limb.
In an embodiment of the invention there is provided a method for performing fetal repositioning. In a first step, a fetal repositioning device is provided into a birth canal of a mother animal. The fetal repositioning device comprises a brace, an extension piece extending from the brace and a handle at an opposite end of the extension piece from the brace. The brace is located at the base of the fetal limb of a fetus within the birth canal to maintain tension on the fetal limb and the handle is used to manipulate the fetus with the brace. In another embodiment, a secondary attachment is attached between the handle and the fetal limb to provide additional tension on the fetal limb, thus providing more efficient rotation and manipulation of the entire fetus compared to previous methods.
The above description sets forth, rather broadly, a summary of one embodiment of the present invention so that the detailed description that follows may be better understood and contributions of the present invention to the art may be better appreciated. Some of the embodiments of the present invention may not include all of the features or characteristics listed in the above summary. There are, of course, additional features of the invention that will be described below and will form the subject matter of claims. In this respect, before explaining at least one particular embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and to the arrangement of the components set forth in the following description or as illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
In the following detailed description of the particular embodiments, reference is made to the accompanying drawings, which form a part of this application. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
In
The device 10 includes a brace 12 which may be a circle, oval or other looped shape of a suitable material. In one embodiment, the brace 12 is a loop of ½ inch (12 mm) stainless steel approximately 6 inches (150 mm) in diameter, though other materials and dimensions may be used. The device 10 further includes an extension bar 14 to which the brace 12 is secured at a first end 15. The brace 12 may be fitted to the extension bar in a secure manner such as by welding or by attachment mechanisms such as rivets, bolts, and similar attachment devices. Alternatively, the brace 12 and extension bar 14 may be integrally formed, such as by cutting from solid material or by casting. In one embodiment, the extension bar may be a ½ inch (12 mm) stainless steel square or round rod, though other materials and dimensions may be used. The extension bar 14 may be of a material that can withstand extreme compressive force of the type that will be described below. The length of the extension bar 14 may be any suitable length such as to locate a tensioning device, described below, outside of the birth canal. In one embodiment, the length of the extension bar is at least the length of a fetal limb. In one embodiment the length of the extension bar is approximately 19 inches (475 mm) such that the extension bar 14 and brace 12 together have a combined length of approximately 25 inches (625 mm).
At an opposite end 16 of the extension bar 14, there is provided a coupler 18 for engagement with a tensioning or traction device 20. One such tensioning device, illustrated in
A method for performing a fetotomy using the device 10 will now be described with reference to
The handle 24 of the friction jack 26 is then operated to move the friction jack 26 along the bar 22 in the direction away from the brace 12. As the tensioning device 20 is operated, tension is placed on the secondary attachment device 31 while the extension bar 14 and brace 12 are rigid and remain fixed. Once the secondary attachment device is tensioned, further operation (step 104) of the tensioning device 20 will pull on the foot through the secondary attachment 31 while pushing at the base 39 of the limb with the brace 12. The effect is to cause traction of the fetal limb 29 between the brace 12 and the point of attachment of the secondary attachment device 31, e.g. the fetal foot 38. When sufficient tension is applied, the fetal limb 29 will tear away from the fetal body 37, as shown in
The result is an extraction of the fetal limb(s) and associated muscle groups with the absence of sharp bone fragments. Because there are no stumps left, the doctor or livestock handler is provided with more room to manipulate the remainder of the dead fetus into the correct (head-forward) position in order to make delivery of the remaining portion of the fetus easier. In addition, the remaining portion of the fetus is narrower at the shoulders and/or the hips, further simplifying the delivery. Further manipulation of the dead fetus may include the removal of additional fetal limbs using the device 10 in the manner described above. As shown in
In one embodiment, an incision 36 (
An advantage of using the device 10 in the method described above is that the forces involved are entirely on the dead fetus. That is, the brace pushes against the base of the fetal limb while the secondary attachment device pulls on the fetal foot, or more toward the base of the fetal limb if required. Thus no forces are exerted on the mother.
A further advantage is that no bones are cut and thus no bone cutting implements are required to be inserted into the birth canal. The only incision that is required, in some embodiments, is the release of the skin of the fetal limb. The method described above allows the entire front limb to be removed, including the shoulder blade. Similarly, the rear leg will separate at the hip joint, leaving no sharp edges.
While the embodiments describe the tensioning device with specific reference to a friction jack, alternative tensioning devices may be used provided they are adapted to apply sufficient tensioning forces between the device 10 and the secondary attachment 31. Alternative tensioning devices include other forms of friction jack, as well as a cable winch, pulley, ratchet system, hydraulic pump, electrical motor or lever.
In an alternative embodiment illustrated in
An alternative tensioning device is illustrated in
The embodiments described above and illustrated in the drawings make specific reference to fetotomy of calf fetuses. However, the device and technique may be applied to other livestock and other mammals, including humans. In one example, the device may be used for performing fetotomy and/or fetal repositioning in zoological cases, with appropriate resizing of the device 10 where required.
Although the description above contains many specifications, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the embodiments of this invention. Thus, the scope of the invention should be determined by the appended claims and their legal equivalents rather than by the examples given.
