BI-VALVED CAST

• US 3,701,349 A
• Filed: 05/13/1971
• Issued: 10/31/1972
• Est. Priority Date: 05/13/1971
• Status: Expired due to Term

• Current Assignee: Leighton W. Larson
• Original Assignee: Leighton W. Larson
• Inventors: Larson, Leighton W.
• Primary Examiner(s): Trapp, Lawrence W.
• Application Number:
  US05/142,907
• Time in Patent Office: 537 Days
• Field of Search: 128/87-89,93,82.1,DIG.20
• US Class Current: 602/14
• CPC Class Codes: A61F 5/05816 Inflatable splints

Abstract

A bi-valved cast for immobilizing broken limbs in which complementary rigid shells, each having an inflatable liner, are releasably secured together about the limb or other body portion to be immobilized, so that upon pressurizing the liners, the limb or other body portion will be immobilized. A significant feature of the disclosed invention resides in the provision of air entry passages through which ventilating air reaches the interface between the immobilized limb and the inner surfaces of the inflatable liners.

Claims

1. In a bi-valved cast for immobilizing a body portion, wherein the cast comprises complementary separate rigid shells, which when joined together form a rigid cast conforming in contour to the body portion to be immobilized, wherein means are provided to releasably secure the shells in joined relation, and wherein each shell has an inflatable liner extending over substantially the entire inner surface thereof so that the introduction of air under pressure into the liners after the shells are secured in joined relation immobilizes the body portion in the cast, the improvement which resides in:

means for introducing air from the exterior of the cast to the inner surface of the liners so that the interface between an immobilized body portion and the liners is ventilated.

2. The bi-valved cast of claim 1, wherein said means for introducing air to the inner surface of the liners comprises perforated tube means on the inner surface of the liners, said perforated tube means having open ends opening to the exterior of the cast.

3. The bi-valved cast of claim 2, wherein said tube means comprises open ended perforated tubes affixed to the inner surface of the liners, with at least one open end thereof projecting beyond an extremity of the liner so as not to be closed when the liner is pressurized.

4. The bi-valved cast of claim 1, wherein said means for introducing air to the inner surface of the liners comprises means sealing the inner and outer walls of the liners to one another at spaced apart localized areas, openings through said localized areas, and openings through the walls of the shells.

5. In the bi-valved cast of claim 1, the further improvement which resides in the means for releasably securing the rigid shells in joined relation and which comprises:

A. a locking pin rotatably mounted on an edge portion of one shell and protruding therefrom for entry into a hole in the adJacent edge portion of the other shell;

B. interengageable means on the locking pin and said adjacent edge portion of said other shell to secure the locking pin against withdrawal from said hole when the locking pin is turned; and

C. means on the locking pin by which the same may be turned, said last named means requiring the use of a special tool.

6. A bi-valved walking type cast for immobilizing a foot, comprising:

A. complementary separate rigid shells which, when joined together, form a rigid cast conforming in contour to the foot to be immobilized, said shells being generally channel shaped in cross section and having edges which mate when the shells are joined, one of said shells being shaped to embrace the heel of the foot and the other shell being shaped to overlie the front of the foot;

B. retaining means on the shells for releasably securing the same in joined relation;

C. inflatable liner means in each shell extending over substantially the entire inner surface thereof, the liner means in said shell which embraces the heel of the foot being divided into two separate compartments, one of which underlies the sole of the foot and the other of which embraces the back of the lower leg; and

D. air introduction means on said liner means including one for each of said separate compartments of the liner means in the shell which embraces the heel, through which said inflatable liner means may be pressurized to immobilize the foot in the cast.

7. The bi-valved cast of claim 6, further characterized by a heel secured to the underside of the shell which is shaped to embrace the heel of the foot.