Spring Assisted Medical Device Deployment Assembly

• US 20140214046A1
• Filed: 01/07/2014
• Published: 07/31/2014
• Est. Priority Date: 01/30/2013
• Status: Active Grant

• Current Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Medical Incorporated (Cook Group Incorporated)
• Inventors: Puckett, Dean
• Granted Patent: US 9,901,471 B2
• Time in Patent Office: Days
• US Class Current: 606/108
• CPC Class Codes: A61F 2/966 with relative longitudinal movement between outer sleeve and prosthesis, e.g. using a push rod
• CPC Class Codes: A61M 2205/10 with powered movement mechanisms

Abstract

A medical device deployment assembly includes a retractable sheath and a catheter positioned inside the retractable sheath. A medical device is compressed between an outer surface of the catheter and an inner surface of the retractable sheath. A spring is positioned inside the retractable sheath, and a pusher band is positioned inside the retractable sheath between the medical device and the spring. The spring biases the medical device deployment assembly toward a deployment configuration in which a distal tip of the retractable sheath is proximal to a proximal tip of the medical device.

Claims

1. A medical device deployment assembly, comprising:

a retractable sheath;

a catheter positioned inside the retractable sheath;

a medical device compressed between an outer surface of the catheter and an inner surface of the retractable sheath;

a spring positioned inside the retractable sheath;

a pusher band positioned inside the retractable sheath between the medical device and the spring; and

wherein the spring biases the medical device deployment assembly toward a deployment configuration in which a distal tip of the retractable sheath is proximal to a proximal tip of the medical device.

2. The medical device deployment assembly of claim 1, further including:

a handle attached to a proximal end of the retractable sheath; and

a hub and cannula operatively coupled to a proximal end of the catheter;

wherein the hub is located a deployment distance proximal of the handle in a pre-deployment configuration, the deployment distance is greater than a length of the medical device, and the hub contacts the handle in the deployment configuration.

3. The medical device deployment assembly of claim 1, wherein the spring is compressed with a pre-load of at least five Newtons.

4. The medical device deployment assembly of claim 1, wherein the retractable sheath is a stepped sheath with a long proximal segment having a small diameter and a short distal segment having a large diameter, and the spring is compressed between the pusher band and a transition shoulder of the stepped sheath where the stepped sheath transitions from the long proximal segment to the short distal segment.

5. The medical device deployment assembly of claim 1, wherein the catheter is a first catheter and the medical device deployment assembly further includes a second catheter positioned inside the first catheter, and wherein the pusher band is attached to move with the second catheter and the spring is compressed between the pusher band and a distal end of the first catheter.

6. The medical device deployment assembly of claim 5, wherein the medical device deployment assembly further includes a relaxed configuration in which the distal end of the first catheter is a long distance from the pusher band, and a delivery configuration in which the distal end of the first catheter is a short distance from the pusher band.

7. The medical device deployment assembly of claim 6, further including a catch that is disengaged in the relaxed configuration, but engaged in the delivery configuration to hold the first catheter relative to the second catheter against a pre-load of the spring.

8. The medical device deployment assembly of claim 1, wherein a ratio of a length of the medical device to an outer diameter of the retractable sheath is greater than fifty.

9. The medical device deployment assembly of claim 8, further including:

a handle attached to a proximal end of the retractable sheath; and

a hub and cannula operatively coupled to a proximal end of the catheter;

wherein the hub is located a deployment distance proximal of the handle in a pre-deployment configuration, the deployment distance is greater than a length of the medical device, and the hub contacts the handle in the deployment configuration.

10. The medical device deployment assembly of claim 9, wherein the spring is compressed with a pre-load of at least five Newtons.

11. A method of operating a medical device deployment assembly that includes a catheter positioned inside a retractable sheath;

a medical device compressed between an outer surface of the catheter and an inner surface of the retractable sheath;

a spring positioned inside the retractable sheath; and

a pusher band positioned inside the retractable sheath between the medical device and the spring, the method comprising the steps of;

positioning the medical device of the medical device deployment assembly at a deployment location; and

deploying the medical device at the deployment location;

wherein the deploying step includes sliding the retractable sheath with respect to the catheter while maintaining the catheter stationary with respect to the deployment location;

wherein the sliding step includes pushing the retractable sheath with respect to the catheter with a pushing force using the spring.

12. The method of claim 11, wherein the sliding step further includes applying a sliding force to a handle attached to a proximal end of the retractable sheath, wherein the sliding force and the pushing force of the spring combine to initiate sliding movement of the retractable sheath with respect to the catheter.

13. The method of claim 12, wherein the retractable sheath is slid a deployment distance that is greater than a length of the medical device during the deploying step.

14. The method of claim 13, wherein the pushing step includes applying a force greater than five Newtons with the spring.

15. The method of claim 14, further including a step of compressing the spring between the pusher band and a transition shoulder of the retractable sheath where the retractable sheath transitions from a long proximal segment to a short distal segment.

16. The method of claim 12, wherein the catheter is a first catheter, the medical device deployment assembly further includes a second catheter positioned inside the first catheter, and the pusher band is attached to move with the second catheter, and wherein the method further includes compressing the spring between the pusher band and a distal end of the first catheter.

17. The method of claim 16, further including:

moving the medical device deployment assembly from a relaxed configuration to a deployment configuration prior to the deploying step;

wherein the distal end of the first catheter is a long distance from the pusher band in the relaxed configuration, and the distal end of the first catheter is a short distance from the pusher band in the delivery configuration;

wherein the moving step includes applying a pre-load to the spring.

18. The method of claim 17, further including engaging a catch at an end of the moving step, wherein the catch is disengaged in the relaxed configuration, but engaged in the delivery configuration to hold the first catheter relative to the second catheter against the pre-load of the spring.

19. The method of claim 11, wherein a ratio of a length of the medical device to an outer diameter of the retractable sheath is greater than fifty.

20. The method of claim 11, further including sliding the medical device deployment assembly over a wire guide during the positioning step.