SHAPE-TRANSFERRING CANNULA SYSTEM AND METHOD OF USE
A rigidizable medical device may include an inner element and an outer element. The outer element of the device may be positioned at least in part around the inner element so as to define a space radially between the inner element and the outer element. The medical device may further include a stiffening material positioned in the space between the inner and outer elements. The stiffening material may be transitionable between a first relatively compliant state and a second relatively stiff state, upon a change in energy applied to the stiffening material. In the first state of the stiffening material, at least a portion along a length of the device where the stiffening material is located is flexible. In the second state of the stiffening material, at least the portion along the length of the device where the stiffening material is located is rigidized.
1 . A rigidizable medical device comprising:
an inner element of the device and an outer element of the device, wherein the outer element of the device is positioned at least in part around the inner element so as to define a space radially between the inner element and the outer element; and
a stiffening material positioned in the space between the inner and outer elements,
wherein the stiffening material is transitionable between a first relatively compliant state and a second relatively stiff state, upon a change in energy applied to the stiffening material,
wherein in the first state of the stiffening material, at least a portion along a length of the device where the stiffening material is located is flexible, and
wherein in the second state of the stiffening material, at least the portion along the length of the device where the stiffening material is located is rigidized.
2 . The medical device of claim 1 , wherein the stiffening material substantially fills the space between the inner and outer elements.
3 . The medical device of claim 1 , wherein the stiffening material comprises an electrorheological fluid or a magnetorheological fluid.
4 . The medical device of claim 1 , further comprising a separating material positioned in the space between the inner and outer elements along a length of the device where the stiffening material is located.
5 . The medical device of claim 4 , wherein the stiffening material changes viscosity upon the change in energy and the separating material restricts flow of the stiffening material upon the change in energy.
6 . The medical device of claim 4 , wherein the separating material comprises a woven mesh.
7 . The medical device of claim 1 , further comprising one or more features positioned in the space between the inner and outer elements along a length of the device where the stiffening material is located.
8 . The medical device of claim 7 , wherein the stiffening material changes viscosity upon the change in energy and the one or more features restrict flow of the stiffening material upon the change in energy.
9 . The medical device of claim 1 , further comprising an electrically insulative material positioned in the space between the inner and outer elements.
10 . The medical device of claim 1 , wherein the energy is chosen from magnetic, electrical, thermal, and vibrational energy.
11 . The medical device of claim 1 , wherein the stiffening material has a first viscosity in the first state and a second viscosity in the second state, the second viscosity being larger than the first viscosity.
12 . The medical device of claim 1 , wherein the medical device is part of a cannula system.
13 . The medical device of claim 12 ,
wherein the medical device is a core of the cannula system, and
wherein the core is flexible in the first state of the stiffening material and rigidized in the second state of the stiffening material.
14 . The medical device of claim 12 ,
wherein the medical device is a sheath of the cannula system, and
wherein the sheath is flexible in the first state of the stiffening material and rigidized in the second state of the stiffening material.
15 . A rigidizable medical device comprising:
a rigidizable element actuatable between a first state and a second state, wherein the rigidizable element is flexible in the first state and rigid in the second state; and
a stiffening material, wherein the stiffening material is transitionable between a first relatively compliant state and a second relatively stiff state, upon a change in energy applied to the stiffening material,
wherein in the first state of the stiffening material, at least a portion along a length of the rigidizable element is flexible, and
wherein in the second state of the stiffening material, at least the portion along the length of the rigidizable element is rigidized.
16 . The medical device of claim 15 , wherein the stiffening material surrounds at least the portion of the length of the rigidizable element.
17 . The medical device of claim 16 , wherein at least the portion of the length of the rigidizable element is positioned concentrically within the stiffening material.
18 . The medical device of claim 15 , wherein at least the portion of the length of the rigidizable element surrounds the stiffening material.
19 . The medical device of claim 18 , wherein the stiffening material is positioned concentrically within at least the portion of the length of the rigidizable element.
20 . The medical device of claim 15 , wherein the stiffening material comprises an electrorheological fluid or a magnetorheological fluid.
21 . The medical device of claim 15 , wherein the energy is chosen from magnetic, electrical, thermal, and vibrational energy.
22 . The medical device of claim 15 , wherein the stiffening material has a first viscosity in the first state and a second viscosity in the second state, the second viscosity being larger than the first viscosity.
23 . The medical device of claim 15 , wherein the medical device is part of a cannula system.
24 . The medical device of claim 23 ,
wherein the medical device is a core of the cannula system, and
wherein the core is flexible in the first state of the stiffening material and rigidized in the second state of the stiffening material.
25 . The medical device of claim 23 ,
wherein the medical device is a sheath of the cannula system, and
wherein the sheath is flexible in the first state of the stiffening material and rigidized in the second state of the stiffening material.