Medical devices including textured inflatable balloons
A medical device includes an elongate body and an inflatable balloon attached to and partially surrounding at least a section of the elongate body. The inflatable balloon is selectively inflatable between a deflated state and an inflated state. Engagement between the balloon and a physiological lumen is provided, in part, by multiple protrusions extending from the inflatable balloon and having various physical and functional characteristics. In certain implementations, the balloon may be configured to exhibit various separation forces by applying different strains to the balloon, such as by varying the degree to which the balloon is inflated or deflated.
1. A medical device configured to be inserted into a physiological lumen of a patient, the physiological lumen including a lumen wall, the medical device comprising:
an elongate body;
an inflatable balloon attached to and partially surrounding at least a section of the elongate body, the inflatable balloon being selectively inflatable between an uninflated state and an inflated state in which the inflatable balloon is strained; and
a plurality of protrusions extending from the inflatable balloon, the plurality of protrusions configured to selectively and atraumatically engage the lumen wall;
wherein:
a protrusion of the plurality of protrusions extends outwardly from the inflatable balloon when the inflatable balloon is in the uninflated state, and
the protrusion comprises an outwardly concave top surface having a first radius of curvature in the uninflated state and a second radius of curvature in the inflated state, the second radius of curvature being less than the first radius of curvature.
2. The medical device of claim 1 , wherein the inflatable balloon comprises at least one material selected from the group consisting of low-density polyethylene, latex, polyether block amide, silicone, poly-siloxane, polyethylene terephthalate, nylon, and polyurethane.
3. The medical device of claim 1 , wherein the protrusions have a height from and including about 300 μm to and including about 500 μm tall.
4. The medical device of claim 1 , wherein the protrusions have a cross-sectional width from and including about 5 μm to and including about 700 μm.
5. The medical device of claim 4 , wherein the protrusions have a cross-sectional width of about 400 μm.
6. The medical device of claim 1 , wherein the protrusions have an aspect ratio up to and including about 10, the aspect ratio being a ratio between a height of the protrusions and a cross-sectional width of the protrusions.
7. The medical device of claim 6 , wherein the aspect ratio is from and including 0.5 to and including 2.0.
8. The medical device of claim 1 , wherein the protrusions are evenly spaced with a center-to-center spacing from and including about 20 μm to and including about 1,000 μm.
9. The medical device of claim 1 , wherein the protrusions are integrally formed with the inflatable balloon.
10. The medical device of claim 1 , wherein the inflatable balloon is one of a plurality of inflatable balloons distributed along a length of the medical device.
11. The medical device of claim 1 , wherein the elongate body is one of an endoscope body, an endoscope overtube, a catheter, and a guide wire.
12. The medical device of claim 1 , wherein, when in the uninflated state, a first portion of the inflatable balloon has a first diameter and a second portion of the inflatable balloon including at least a portion of the protrusions extends to a second diameter, the second diameter being less than the first diameter.
13. The medical device of claim 1 , wherein, when in the inflated state, each of a portion of the protrusions extends in a respective first direction, and when in the uninflated state, each of the portion of the protrusions extends in a second respective direction, the first respective direction being in a more outwardly radial direction as compared to the second respective direction.
14. The medical device of claim 1 , wherein each of the plurality of protrusions has a height from and including about 5 μm to and including about 1000 μm tall and a stiffness at least equal to the stiffness of the lumen wall.
15. The medical device of claim 1 , wherein the protrusion has a frustoconical shape.
16. A medical device configured to be inserted into a physiological lumen of a patient, the physiological lumen including a lumen wall and formed of a lumen material, the medical device comprising:
an elongate body; and
an inflatable balloon attached to and partially surrounding at least a section of the elongate body, the inflatable balloon adapted to be inflated within the physiological lumen to engage with the lumen wall and to be changed from a first state to a second state by one of inflating and deflating the inflatable balloon; and
a plurality of protrusions extending from the inflatable balloon, wherein:
the inflatable balloon is strained in at least one of the first state and the second state,
a protrusion of the plurality of protrusions has a top surface,
when in the first state, the top surface has a first radius of curvature, such that when adhered to a surface formed of the lumen material, a first separation force is required to disengage the inflatable balloon from the surface,
when in the second state, the top surface has a second radius of curvature that is different than the first radius of curvature, such that when adhered to the surface of the lumen material, a second separation force different than the first separation force is required to disengage the inflatable balloon from the surface, and
when in the at least one of the first state and the second state, the top surface is outwardly concave.
17. The medical device of claim 16 , wherein:
when changing from the first state to the second state includes inflating the inflatable balloon, the inflatable balloon is subject to a strain in the second state, and
when changing from the first state to the second state includes deflating the inflatable balloon, the inflatable balloon is subject to a strain in the first state.
18. The medical device of claim 16 , wherein in the first state, a first strain is applied to the inflatable balloon, and in the second state, a second strain different than the first strain is applied to the inflatable balloon.
19. The medical device of claim 18 , wherein at least one of the first strain and the second strain is a biaxial strain.
20. The medical device of claim 16 , wherein each of the protrusions has a first shape having a first surface area when the inflatable balloon is in the first state and each of the protrusions has a second shape having a second surface area when the inflatable balloon is in the second state, the first surface area being different than the second surface area.
21. The medical device of claim 20 , wherein the top surface is outwardly concave in each of the first state and the second state.