3D catheter-based ultrasound assembly with gimbal-mount transducer and single-coil drive

• US 9,247,925 B2
• Filed: 01/30/2014
• Issued: 02/02/2016
• Est. Priority Date: 01/31/2013
• Status: Active Grant

• Current Assignee: Muffin Incorporated
• Original Assignee: Muffin Incorporated
• Inventors: Havel, William J., McKinnis, Peter S.
• Primary Examiner(s): ROZANSKI, MICHAEL T
• Application Number:
  US14/168,279
• Publication Number:
  US 20140213907A1
• Time in Patent Office: 733 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 8/0891 for diagnosis of blood vessels
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: G01S 15/894 by rotation about a single axis
• CPC Class Codes: G01S 15/8993 Three dimensional imaging systems
• CPC Class Codes: G01S 7/52079 Constructional features constructional features of transducers B06B; mounting transducers G10K11/00; constructional features of ultrasonic medical diagnostic devices A61B8/44

Abstract

Described are embodiments of devices and methods for imaging a body conduit, such as a blood vessel. In particular embodiments, the catheter has a chamber within which is a transducer mounted to a pivot mechanism. A coil provides a pivot force to the transducer. A magnet is attached to the transducer and is receptive of a torque applied by a magnetic field produced by energizing of the coil. A driving mechanism receives an impact from the pivot member and causes the pivot mechanism to rotate about a rotation axis.

Claims

1. A medical device for insertion into a body of a patient, comprising:

a transducer for transmitting or receiving or transmitting and receiving ultrasound signals;

a pivot mechanism rotatable about a rotation axis;

a pivot member mounted to the pivot mechanism and pivotable along a pivot path that extends about a pivot axis that is substantially perpendicular to the rotation axis; and

a driving mechanism positioned within the pivot path of the pivot member, wherein during rotation about the pivot axis, a portion of the pivot member strikes the driving mechanism and causes the pivot mechanism to rotate about the rotation axis.

2. The medical device of claim 1, further comprising a coil positioned concentric to and along the rotation axis;

the pivot member further comprising a magnetic layer and the transducer, wherein the coil includes a plurality of electrically conductive windings, and wherein application of electric current to the coil creates a torque on the pivot member about the pivot axis.

3. The medical device of claim 2, wherein the pivot member reciprocatingly alternates between a driving pivot stroke and a non-driving pivot stroke such that the driving pivot stroke causes the pivot mechanism to rotate about the rotation axis and the non-driving pivot stroke does not cause the pivot mechanism to rotate about the rotation axis.

4. The medical device of claim 3, wherein the electric current is an alternating current.

5. The medical device of claim 4, wherein the driving pivot stroke has a torque which is larger than the torque of the non-driving pivot stroke, and wherein the electric current includes a direct current offset component to produce the difference in the torque between the driving pivot stroke and the non-driving pivot stroke.

6. The medical device of claim 3, wherein the magnetic layer includes a diametric permanent magnet having a first magnetic field with poles aligned substantially perpendicular to the pivot axis, wherein application of electric current to the coil creates a second magnetic field with poles aligned substantially along the rotation axis, wherein interaction between the first and second magnetic fields creates the torque.

7. The device of claim 2, further comprising a bias member, wherein the pivot member includes the transducer, and wherein the bias member is positioned to apply a bias member force to the transducer which biases the transducer to a neutral position about the pivot axis and relative to the pivot mechanism.

8. The device of claim 7, wherein the torque is dependant upon the electric current to the coil, and wherein when the torque is insufficient to overcome the bias member force, the bias member force returns the transducer to the neutral position.

9. The device of claim 7, wherein the bias member is a conductor configured for carrying signals from the transducer.

10. The medical device of claim 1, further comprising an engagement surface positioned cylindrically and concentric to the rotation axis, wherein the driving mechanism is positioned to engage the pivot member and the engagement surface, wherein the pivot member is pivotable through a range bounded by the driving mechanism, wherein during pivotal rotation of the pivot member, abutment of the pivot member against the driving mechanism moves the driving mechanism to engage the engagement surface, wherein engagement of the driving mechanism with the engagement surface causes the pivot mechanism to rotate about the rotation axis.

11. The medical device of claim 10, the driving mechanism further comprising a stop bar and a driving rod fixed relative to the stop bar, wherein the stop bar has a portion positioned within the pivot path of the pivot member, and wherein the driving rod is positioned to engage the engagement surface when the pivot member strikes the stop bar.

12. The medical device of claim 10, the driving mechanism further comprising a stop bar rotationally mounted about the rotation axis and a driving rod connected to the stop bar, wherein the stop bar has a portion positioned within the pivot path of the pivot member which is offset from the rotation axis, and wherein the driving rod is positioned to engage the engagement surface when the pivot member strikes the stop bar.

13. The medical device of claim 1, further comprising a ring gear positioned circumferentially and concentric relative to the rotation axis, the driving mechanism further comprising a stop bar with a toothed edge positioned to engage the ring gear, wherein the driving mechanism is positioned to engage the pivot member and ring gear, wherein the pivot member is pivotable through a range bounded by the stop bar, wherein during pivotal rotation of the pivot member, abutment of the pivot member against the stop bar causes the toothed edge to move along the ring gear.

14. The medical device of claim 1, further comprising a face gear positioned circumferentially and concentric relative to the rotation axis, the driving mechanism further comprising a first external gear rotationally coupled with the pivot mechanism and positioned to engage the face gear, wherein the first external gear is operatively disposed to rotate when the pivot member strikes the driving mechanism.

15. The medical device of claim 14, the driving mechanism further comprising an axle coupled with a tab, wherein the axle is operatively coupled with the first external gear, wherein the tab is positioned within the pivot path of the pivot member.

16. The medical device of claim 15, the driving mechanism further comprising a second external gear connected to the axle and positioned to engage the first external gear.

17. The device of claim 1, wherein the transducer is moveable throughout a range which defines a viewing window extending from the transducer, the device further comprising an opaque feature positioned within the viewing window, wherein the opaque feature provides angular positional information about the pivot member.

18. The device of claim 1, further comprising a tubular member for housing the transducer, driving mechanism, and pivot mechanism, the tubular member having a distal chamber defined at least in part by a wall portion of the tubular member, the distal chamber housing at least the transducer and a medium, the wall portion and the medium having similar acoustic impedance to the part of the body into which the tubular member is inserted, so that reflection of ultrasound at the boundary of the medium and the wall portion and at the boundary of the wall portion and body environment is reduced to a level acceptable for imaging through the boundary.

19. The device of claim 18, wherein the tubular member is a catheter.

20. A medical device comprising:

a transducer for transmitting or receiving or transmitting and receiving ultrasound signals;

a pivot mechanism rotatably mounted about a rotation axis;

a pivot member pivotally mounted to the pivot mechanism and pivotable about a pivot axis that is substantially perpendicular to the rotation axis;

an engagement surface positioned cylindrically and concentric to the rotation axis;

a driving mechanism positioned to engage the pivot member and the engagement surface; and

wherein the pivot member is pivotable through a range bounded by the driving mechanism, wherein during pivotal rotation of the pivot member, abutment of the pivot member against the driving mechanism moves the driving mechanism to engage the engagement surface to create a reactionary force which causes the pivot mechanism to rotate about the rotation axis.

21. The medical device of claim 20, the pivot member further comprising a magnetic layer and the transducer;

further comprising a coil positioned concentric to and along the rotation axis, wherein the coil includes a plurality of electrically conductive windings, and wherein application of electric current to the coil creates a torque on the pivot member about the pivot axis.