Kidney stone suction device

1. An endoscopic suction device, comprising:

a conduit extending from a proximal end to a distal end along a longitudinal axis, the proximal end configured to be coupled to a vacuum source and the distal end configured to extend into a subject's body;

an expandable suction head at the distal end of the conduit, the suction head being configured to expand from a contracted configuration to an expanded configuration within the body in response to the application of heat or current, and

a filter positioned transverse to the longitudinal axis, wherein the filter is positioned in a proximal portion of the expandable suction head, a distal portion of the conduit, or both the proximal portion of the expandable suction head and the distal portion of the conduit, and wherein the filter spans a cross-sectional area of the endoscopic suction device to prevent material from entering the conduit.

2. The device of claim 1 , wherein the distal end of the conduit is sized to extend into the body through a lumen of a medical device, and wherein the suction head is configured to transform from a contracted configuration within the lumen to an expanded configuration outside the lumen.

3. The device of claim 2 , wherein the lumen is a lumen of an ureteroscope.

4. The device of claim 1 , further including an activation device configured to apply the heat or current to the suction head to transform the suction head from the contracted configuration to the expanded configuration.

5. The device of claim 1 , wherein, in the expanded configuration, a cross-sectional area of the suction head transverse to the longitudinal axis decreases from a distal-most end of the suction head to a proximal end of the suction head.

6. The device of claim 1 , wherein a cross-sectional area of the suction head transverse to the longitudinal axis is greater in the expanded configuration than in the contracted configuration, and

wherein the suction head includes a distal portion, and wherein, in the expanded configuration, the distal portion extends parallel to the conduit, the proximal portion extends at an angle to the conduit, and a longitudinal length of the distal portion is greater than a longitudinal length of the proximal portion.

7. The device of claim 1 , wherein the conduit and the suction head are formed as a single part.

8. The device of claim 1 , wherein the suction head is configured to contract from the expanded configuration to the contracted configuration in response to the removal of the applied heat or current.

9. A method of using a suction device to remove an object from a subject's body, the suction device including an expandable suction head at a distal end of a conduit, wherein the conduit extends from a proximal end to a distal end along a longitudinal axis, the proximal end configured to be coupled to a vacuum source and the distal end configured to extend into a subject's body, wherein the expandable suction head includes a shape-memory alloy and is configured to expand from a contracted configuration to an expanded configuration within the body when extended outside of a lumen of a medical device, and further including a filter positioned at a junction between a proximal end of the suction head with the distal end of the conduit,

the method comprising:

extending the suction device into the body through a lumen of a medical device;

expanding the suction head from a contracted configuration to an expanded configuration within the body by applying heat or current;

applying suction to move the object into the expanded suction head, wherein the filter prevents the object from entering the conduit; and

removing the suction device with the object from the body.

10. The method of claim 9 , wherein expanding the suction head includes transforming the suction head from a contracted configuration within the lumen to an expanded configuration outside the lumen.

11. The method of claim 9 , wherein removing the suction device includes removing the suction device through the lumen.

12. The method of claim 9 , wherein removing the suction device includes removing the medical device along with the suction device from the body.

13. An endoscopic suction device, comprising:

a conduit extending from a proximal end to a distal end along a longitudinal axis, the proximal end configured to be coupled to a vacuum source and the distal end configured to extend into a subject's body; and

an expandable suction head at the distal end of the conduit, the suction head including a shape-memory alloy and being configured to expand from a contracted configuration to an expanded configuration within the body when extended outside of a lumen of a medical device,

wherein the expandable suction head includes a filter positioned at a junction between a proximal end of the suction head and the distal end of the conduit to prevent material from entering the conduit.

14. The device of claim 13 , wherein the suction head is formed of a wire mesh of the shape-memory alloy coated with a polymeric material.

15. The device of claim 13 , wherein the suction head is transparent, and wherein in the expanded configuration, the suction head forms a distally-facing hemispherical shape.