Seal assembly for elastomeric infusion pump
View Patent ↗An infusion apparatus including a support member and an elastic sleeve surrounding the support member to define a fluid reservoir therebetween. The sleeve is expandable in a radial direction when the infusion apparatus is loaded with a fluid, such as a pain medication, and exerts a pressure on the fluid so that it may be delivered to a desired site, such as a surgical region of a patient. The elastic sleeve is sealed to the support member at spaced-apart locations by first and second sealing arrangements. Each sealing arrangement preferably includes a sealing member having a first end, a second end, and a body portion extending between the first and second ends. Desirably, the body portion is substantially annular in shape and is deflectable between a first inner diameter and a second inner diameter. The first inner diameter permits the sealing member to be passed over an end of the support and elastic sleeve, while the second inner diameter is configured to produce a force tending to create a fluid tight seal between the elastic sleeve and the support.
1. A method of assembling an infusion apparatus, comprising:
providing a support member at least partially defining an inlet and an outlet;
positioning an elastic sleeve over the support member, thereby defining a variable-volume fluid reservoir between the support member and the sleeve, the inlet and the outlet communicating with the fluid reservoir;
providing a pair of spring clips, each clip having a first end, a second end and a generally annular body portion extending between the first and second ends;
applying an opposing force to each of the first and second ends of one of the spring clips to deflect the spring clip into a deflected position and passing the spring clip over a first end of the support member and sleeve, releasing the first and second ends to permit the body portion to contact the sleeve and create a seal between the sleeve and the support member and thereby define a first end of the fluid reservoir;
applying an opposing force to each of the first and second ends of the other of the spring clips to deflect the spring clip into a deflected position and passing the spring clip over a second end of the support member and the sleeve, releasing the first and second ends to permit the body portion to contact the sleeve and create a seal between the sleeve and the support member and thereby define a second end of the fluid reservoir;
wherein the first and second ends of the spring clip have an initial length, additionally comprising the step of trimming the first and second ends to a shorter length after the respective spring clip is positioned onto the support member and sleeve.
2. The method of claim 1 , additionally comprising the step of securing a cap to the support member, the cap including a side wall portion covering the first and second ends of the spring clip.
3. The method of claim 1 , wherein an outer surface of the support member defines a pair of grooves spaced from one another, additionally comprising the step of positioning the spring clips such that the elastic sleeve is urged at least partially within the grooves.
4. An infusion apparatus, comprising:
an infusion pump including an elastic sleeve surrounding a support member, the sleeve and the support member cooperating to define a variable-volume fluid reservoir therebetween, the infusion pump including an inlet and an outlet in fluid communication with the fluid reservoir;
a pair of sealing assemblies, each assembly being configured to create a seal between the elastic sleeve and the support member to define first and second ends, respectively, of the fluid reservoir, each of the assemblies comprising a split ring and a cap, the split ring having a first end, a second end and a generally annular body portion extending between the first and second ends, the split ring being deflectable to an inner diameter sufficient to permit the split ring to pass over an end of the infusion pump, the cap being configured to apply a compressive force to the split ring, thereby deflecting the split ring to an inner diameter sufficient to create a seal between the elastic sleeve and the support member;
wherein each end portion of an outer surface of the support member defines an annular groove, each end of the elastic sleeve extending over the respective groove, an inner surface of the split ring defining a protrusion extending along the entire length of the body portion, the protrusion being sized and shaped to urge the elastic sleeve into the groove.
5. The infusion apparatus of claim 4 , wherein the split ring and the cap comprise an interlocking thread arrangement, the cap being threadable onto the split ring to apply the compressive force to the split ring.