Sheaths for medical devices

A device for therapeutic and/or diagnostic use in or on a patient's body comprising:

• a sheath comprising a laminate comprising reinforcement fibers wherein the laminate has a failure strain of less than 0.30;
• and
• a tool at least partially within the sheath, wherein the tool is fixedly attached to the sheath, and wherein the tool has a sheathed tool length measured along the length of tool within the sheath, and wherein the tool comprises a bending portion within the sheath, the bending portion configured to bend from a first position to a second position, wherein the sheathed tool length in the first position is less than about 10% different than the sheathed tool length in the second position.

A device for therapeutic and/or diagnostic use in or on a patient's body comprising:

• a sheath comprising a laminate including reinforcement fibers and a reinforcement member wherein the reinforcement member is more rigid than the laminate;
• and
• a tool releasably attached to the sheath, wherein the sheath has an unsupported burst pressure of greater than about 150 psi.