Orthopedic system for immobilizing and supporting body parts
View Patent ↗A unitized cast system for immobilizing and supporting a body part. The unitized casting system includes a first inner layer for padding and dissipating heat against the patient's skin. A second layer is formed from a thermoformable structural material such as perforated plastic. A protective third outer layer is provided to provide insulation for the second layer. These three layers are formed together to form a unitized cast system that is easily formed and applied to the patient.
1. A cast system for supporting a body part, said cast system comprising:
a protective shell configured to be generally positioned at least partially circumferentially around the body part and moldable during a patient forming process at a target temperature range between 160 and 220 degrees Fahrenheit that is maintained by said shell during said patient forming process for a target dwell time of between 3 and 10 minutes, said shell having:
an inner layer defining an area generally facing toward the body part;
an outer layer defining an area generally facing away from the body part, said area of said outer layer being generally similar to said area of said inner layer; and
a middle layer generally coextensive with said areas of said inner layer and said outer layer and completely encapsulated and sandwiched between said inner layer and said outer layer,
wherein said inner layer and said outer layer each comprise a foam layer and said middle layer comprises a polymer layer that is thermoformable within said target temperature range and generally rigid at temperatures below said target temperature range, and
wherein said foam layers have a lower density than said polymer layer of said middle layer and said foam layers and said middle layer are integrally formed as a composite layer material,
such that said foam layers stretch to conform to a moldable shape of said middle layer during said patient forming process and said foam layers insulate said middle layer to maintain said middle layer at said target temperature range during said target dwell time when said shell is heated to an initial temperature before said patient forming process of not more than 300 degrees Fahrenheit.
2. The cast system of claim 1 , wherein said target temperature range is between 175 and 200 degrees Fahrenheit.
3. The cast system of claim 1 , wherein said middle layer is heated only to an initial temperature before said patient forming process of not more than 250 degrees Fahrenheit.
4. The cast system of claim 1 , wherein said middle layer includes varying thickness to provide greater rigidity at thicker areas and greater flexibility at thinner areas of said middle layer.
5. The cast system of claim 1 , wherein at least one of said foam layers is not thermoformable within said target temperature range.
6. The cast system of claim 1 , wherein said shell includes a split circumferential cross-section defined along at least a portion of one dimension of said shell that includes an overlap of one edge of said split circumferential cross-section with an opposite edge of said split circumferential cross-section, and wherein said shell further comprises an attachment mechanism configured to facilitate adjustment of an amount of said overlap such that said cross-section of said shell is adjustable about the body part.
7. The cast system of claim 6 wherein said portion of said one dimension is substantially all of a longest dimension of said shell.
8. A cast system for a body part, said cast system comprising:
a shell means for positioning at least partially circumferentially around and for molding to the body part during a patient forming process having a target dwell time of between 3 and 10 minutes and a target temperature range of between 160 and 220 degrees Fahrenheit, said shell means including:
an inner layer defining an area generally facing toward the body part;
an outer layer defining an area generally facing away from the body part, said area of said outer layer being generally similar to said area of said inner layer; and
a middle layer generally coextensive with said areas of said inner layer and said outer layer and completely encapsulated and sandwiched between said inner layer and said outer layer and integrally formed with said inner layer and outer layer as a composite layer material,
wherein said middle layer comprises polymer means for thermoforming within said target temperature range during said patient forming process and for assuming a generally rigid moldable shape at temperatures below said target temperature range after said patient forming process; and
wherein said inner layer and said outer layer each comprise foam means for stretching to conform to said moldable shape within said target temperature range during said patient forming process and for insulating said middle layer to maintain said middle layer at said target temperature range during said target dwell time when said shell means is heated to an initial temperature before said patient forming process of not more than 300 degrees Fahrenheit.
9. The cast system of claim 8 , wherein said target temperature range is between 175 and 200 degrees Fahrenheit.
10. The cast system of claim 8 , wherein said middle layer is heated only to an initial temperature before said patient forming process of not more than 250 degrees Fahrenheit.
11. The cast system of claim 10 , wherein said middle layer includes perforations that remove between 20 to 60 percent by area of said middle layer.
12. The cast system of claim 11 , further comprising ventilation holes separate from said perforations and created coextensively through all of said inner layer, said middle layer and said outer layer.
13. The cast system of claim 8 , wherein said middle layer includes varying thickness to provide greater rigidity at thicker areas and greater flexibility at thinner areas of said middle layer.
14. The cast system of claim 8 , wherein said shell means includes a split circumferential cross-section defined along at least a portion of one dimension of said shell means that includes an overlap of one edge of said split circumferential cross-section with an opposite edge of said split circumferential cross-section, and wherein said shell means further comprises an attachment means for adjusting an amount of said overlap such that said cross-section of said shell means is adjustable about the body part.
15. The cast system of claim 14 , wherein said portion of said one dimension is substantially all of a longest dimension of said shell.
16. The cast system of claim 8 , wherein at least one of said foam means is not thermoformable within said target temperature range.
17. A method for applying a cast to a body part of a patient, said cast including an protective shell having an inner layer defining an area generally facing toward the body part, an outer layer defining an area generally facing away from the body part, said area of said outer layer being generally similar to said area of said inner layer, and a middle layer generally coextensive with said areas of said inner layer and said outer layer and completely encapsulated and sandwiched between said inner layer and said outer layer, wherein said inner layer and said outer layer each comprise a foam layer that is stretchable within a target temperature range of between 160 and 250 degrees Fahrenheit and said middle layer comprises a polymer layer that is thermoformable within said target temperature range and generally rigid at temperatures below said target temperature range, and wherein said foam layers have a lower density than said polymer layer of said middle layer and said foam layers and said middle layer are integrally formed as a composite layer material, the method comprising:
heating said shell to an initial temperature of less than 300 degrees Fahrenheit;
applying said shell at least partially circumferentially to the body part of the patient; and
forming said shell as said cast about the body part during a target dwell time of 3 to 10 minutes by:
thermoforming said polymer layer of said middle layer to a moldable shape during said target dwell time that generally conforms to the body part;
utilizing said foam layers of said outer layer and said inner layer to insulate said middle layer to maintain said middle layer at said target temperature range during said dwell time when said shell is heated to said initial temperature;
causing said foam layers of said outer layer and said inner layer to stretch to conform to a moldable shape of said polymer layer of said middle layer without thermoforming at said target temperature range; and
allowing said polymer layer of said middle layer to cool after said target dwell time to assume a generally rigid version of said moldable shape.
18. The method of claim 17 , wherein said target temperature range is between 175 and 200 degrees Fahrenheit.
19. The method of claim 17 , wherein thermoforming said middle layer further comprises:
applying compression to the shell to assist in forming said moldable shape to the body part.
20. The method of claim 17 , wherein thermoforming said middle layer further comprises:
stretching said at least one of said foam layers without thermoforming said at least one foam layer at said target temperature range.
21. A method, comprising:
providing a cast system for supporting a body part, said cast system including:
a shell formed of a composite layer material having an inner layer defining an area generally facing toward the body part, an outer layer defining an area generally facing away from the body part, said area of said outer layer being generally similar to said area of said inner layer, and a middle layer generally coextensive with said areas of said inner layer and said outer layer and completely encapsulated and sandwiched between said inner layer and said outer layer,
wherein said inner layer and said outer layer each comprise a foam layer that is stretchable within a target temperature range and said middle layer comprises a polymer layer that is thermoformable within said target temperature range and generally rigid at temperatures below said target temperature range, and wherein said foam layers have a lower density than said polymer layer of said middle layer and said foam layers and said middle layer are integrally formed as a composite layer material,
providing instructions for applying said cast system to the body part of the patient, the instructions including:
heating said shell to an initial temperature of less than 300 degrees Fahrenheit;
applying said shell at least partially circumferentially to the body part of the patient; and
forming said shell as said cast about the body part during a target dwell time of 3 to 10 minutes by:
thermoforming said polymer layer of said middle layer to a moldable shape during said target dwell time that generally conforms to the body part; and
allowing said polymer layer of said middle layer to cool after said target dwell time to assume a generally rigid version of said moldable shape,
such that said foam layers of said outer layer and said inner layer are utilized to insulate said middle layer to maintain said middle layer at said target temperature range during said dwell time when said shell is heated to said initial temperature and said foam layers of said outer layer and said inner layer stretch to conform to a moldable shape of said polymer layer of said middle layer.