Final Design

Figure 2.1: Final Girdle CAD and Product

The final design of the Brachytherapy Pelvic Girdle is shown in Figure 2.1. It consists of a fabric girdle with several straps that serve as the foundation for an articulating arm. The arm screws into a plastic base that is inserted into the small removable pocket shown in Figure 2.2. The fabric girdle is folded according to the sequence shown in Figure 2.3. After securing the center strap across the pubic bone, the pocket is placed at the midpoint of the center strap and attached with velcro. The crossed straps are then secured by “threading” the arm through the long rectangular cut-out of both cross straps (as shown in Figure 2.1) and cinching them down tight. With the girdle and articulating arm secured to the patient, the free-end of the arm clamps onto the tandem of the applicator and is set to the desired position by tightening the internal locking mechanism of the arm.

Figure 2.3: Fabric Girdle Folding Sequence

Both the fabric girdle and the articulating arm designs are crucial to achieving the stability and patient comfort required for brachytherapy. The cross strap design allows the girdle to conform to the female anatomy while increasing stability of the arm by applying direct pressure to the base. The backing of the fabric girdle also features (6) plastic inserts that increase rigidity and stability of the girdle by maintaining uniform tension throughout the fabric. A common complaint among patients was the discomfort caused by the weight tandem pulling down inside of the patient. The arm shown in Figure 2.4 was chosen for the final design because it was significantly lighter than the existing C-arm and it provided the best resistance to moment forces produced by the weight of the applicator.

Figure 2.2: Final Removable Pocket Design

Figure 2.4: Noga DG61003 Aluminum Articulating Arm

Patients reported that the final pelvic girdle felt sturdier and more secure. It significantly increased patient comfort during brachytherapy treatments, especially when compared to the previous methods involving the existing C-arm. The final design also maintained proper positioning of the applicator by allowing the articulating arm to follow movement of the patient's pelvis. Despite initial concerns of the fabric girdle flexing under the large moments forces, the fabric proved to be secure enough to resist the moment of the extended arm. The body centric design of the final Brachytherapy Pelvic Girdle showed significant improvement over previous girdle iterations and original brachytherapy methods.

Sequence

Step2 Fold the main strap and place the pocket on desired position.

Step1 the girdle and pocket

(A small piece of plastic is inserted on the top of the side strap for hold and pull)

Step3 Fold the side strap and while locate the pocket hole in the gap of the side strap.

Step4 Repeat step3 and attach the leg strap.