1Table of Contents Abstract……………………………………………………………………………..2 I. Current Products………………………………………………………………….3 II. Client Design Requirements………………………………………………….…4 III. Design………………………………………………………………………..…4 IV. Prototype and Testing…………………………………………………………..6 V. Ethics and Safety………………………………………………………………..7 VI. Future Work……………………………………………………………...…….7 VII. Conclusion…………………………………………………………….………8 Appendix A: References and Special Thanks.....…………………………………..9 Appendix B: Instrument Specifications...…………………………………………10 Appendix C: Product Design Specifications……………………………………...11 2Abstract Tubal sterilization is a relatively inexpensive and effective form of birth control. By physically closing off the fallopian tubes, the pathway of the egg from the ovary to the uterus is interrupted, thus insuring against fertilization. This project deals specifically with a laparoscopic device, which makes the procedure minimally invasive. The device currently used by our client, Dr. Thomas M. Julian, secures a band around the fallopian tubes, closing the tube to block the egg’s pathway. This device often tears the tube and releases the bands improperly. He asked us to address these issues when we redesign the device. We developed a design for a device that includes a suction mechanism to secure the tubes more gently, a more gradual band release mechanism to achieve a better accuracy, as well as a band separator to ensure that only one band is released on each fallopian tube. Last semester we created an enlarged prototype to test the fundamental concepts of our design and then made a couple alterations. This semester we made a 2:1 scale prototype, tested the suction mechanism on sheep fallopian tube tissue, and tested the band release function with and without the separator. 3Introduction Tubal Ligation is a surgery, and although it is minimally invasive there are risks and chances for complications. Complications occur up to 20% of the time with the current product, which is far too high in a surgical procedure. The fallopian tube can be torn and damaged. This causes excess bleeding, and scar tissue to form inside the patient. It also reduces the chance that the surgery could be successfully reversed, since more of the fallopian tube is damaged. Another problem with the device is the band release. The procedure involves placing an elastomer band over the fallopian tube to create a mechanical blockage, but sometimes the band does not come off or two are placed on the same fallopian tube. If the latter occurs, the doctor has to take out the device and load a new rubber band on it. This prolongs the procedure and requires more work of the surgeon. These errors need to occur less frequently in order to decrease time spent in the operating room and reduce risks for the patient. I. Current Products Tubal ligation is a fairly common procedure, done approximately one million times each year. All procedures are reversible to some extent; however, if the fallopian tube is severed or otherwise damaged, the reversal becomes much more difficult. There are many different procedures that all produce the same desired result. All are laparoscopic surgeries, which use a small incision to insert a camera into the abdominal cavity in order for the surgeon to watch what he is doing with a second device that alters the fallopian tube (4). This device is inserted through a second hole. These procedures alter the fallopian tube, which connects the ovary to the uterus in females. All of the procedures create a physical or mechanical blockage to the fallopian tube, which prohibits the eggs from reaching the uterus for fertilization. Some versions are the Pomeroy technique, coagulation, clipping, and banding (1). The Pomeroy technique (as seen in Figure 1) is a common version where the surgeon ties off a section of the fallopian tube and removes it. The ligature that binds the two sides of the fallopian tube together eventually dissolves and tissue covers the two sections. There is no longer a connection between the uterus and the ovaries (1). The coagulation technique, as shown in Figure 2, is arguably the most common version of tubal ligation in the United States. A forceps grasps the fallopian tube for this procedure and passes an electrical current through the tube between the two ends, cauterizing the tissue. The fallopian tube can then be snipped in two (1). Figure 1: The Pomeroy technique (1). Figure 2: The coagulation technique (1). Figure 3: The clipping technique (1). 4 Clipping, as shown in Figure 3, is yet another form of female sterilization. It is easier to reverse than the previously mentioned techniques and involves placing a spring clip on the fallopian tube, creating a mechanical obstruction(1). The last technique, which is the one the client would like us to improve, is the banding technique (shown in Figure 4). For this procedure the fallopian tube is mechanically obstructed with a band. The fallopian tube must be brought through the band to be closed off (1). The current (and only known) banding product is produced by the ACMI Corporation. The device is called the Falope-Ring band (shown in Figure 5). It is usually a one-time use device that costs approximately $400 for the device and bands. The forceps (pointed out with the arrow) grab the fallopian tube and pull it inside the cylindrical column of the device. The bands are pushed off with a spring mechanism (one at a time) and slide onto the fallopian tube, sealing it off, and preventing eggs from transversing the tube to the uterus. The pinchers then release the fallopian tube and the procedure is completed. It is designed to allow loading of two rubber bands simultaneously; one for each tube, so only one insertion in the abdominal cavity is required (2). II. Client Design Requirements The device we are designing should perform easily reversible laparoscopic tubal sterilization in women. The device should be sterile because it will be inserted into the human body.
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