Miniature actuator mechanism for intravascular optical imaging
The present invention relates to a new intravascular imaging device based on a Shape Memory Alloy (SMA) actuator mechanism embedded inside an elongate member such as a guide wire or catheter. The present invention utilizes a novel SMA mechanism to provide side-looking imaging by providing movement for an optical coherence tomography (OCT) element. This novel SMA actuator mechanism can be easily fabricated in micro-scale, providing an advantage over existing imaging devices by offering the ability to miniaturize the overall size of the device. Because the device does not require a rotating shaft or fiber optic along the length of the catheter, it also allows for a more flexible catheter or guide wire, and provides room for other interventional devices. The device simplifies the manufacture and operation of OCT by allowing a straight fiber optic directed by an independent, oscillating reflector or prism controlled by the actuator mechanism located only in the distal tip of the device. A variation uses the actuator mechanism to rotate only the distal end of the optical fiber, eliminating the need to spin the entire fiber via a remote mechanism. Also disclosed are methods of using the same.
1 . A side-looking intravascular optical coherence tomography apparatus comprising:
an elongate member having a proximal end and a distal end, wherein at least a portion of said distal end is at least partially transparent to light energy;
an actuator mechanism disposed in said distal end, said actuator mechanism comprising a first anchor, a second anchor, at least one movable element, a first SMA actuator connected to said first anchor and at least one movable element, and a deformable component connected to said second anchor and at least on movable element, wherein said anchor elements are secured relative to said elongate member;
an optical fiber having a proximal and a distal end, said distal end of said optical fiber disposed in said distal end of said elongate member substantially parallel to a longitudinal axis of said elongate member; and
a reflector connected to said movable element, said reflector oriented to reflect light energy from a distal tip of said optical fiber through said transparent portion of said distal end at an angle of between about 15° to about 165° relative to said longitudinal axis of said elongate member;
wherein said first SMA actuator has an activated and a deactivated state; and
wherein said movable element and mirror move in a first direction relative to the elongate member upon activation of said first SMA actuator.
2 . The apparatus of claim 1 , wherein said deformable component comprises a second SMA actuator;
wherein said second actuator has an activated and a deactivated state; and
wherein activation of said second SMA actuator following deactivation of said first SMA actuator moves said movable element and reflector relative to the elongate member in a second direction of movement which is counter to said first direction of movement.
3 . The apparatus of claim 1 , wherein said deformable component is elastic or superelastic;
wherein said deformable component has a relaxed state and a deformed state;
wherein said deformable component is in a relaxed state when said first SMA actuator is deactivated;
wherein said movement of said movable element and reflector in said first direction upon activation of said first SMA actuator deforms said elastic or superelastic deformable component; and
wherein following deactivation of said first SMA, said elastic or superelastic deformable component substantially returns to said relaxed state, said movable element and reflector moving in a second direction of movement which is counter to said first direction of movement.
4 . The apparatus of claim 2 , wherein said first and second direction of movement is rotational about the longitudinal axis of said elongate member, or substantially parallel to the longitudinal axis of said elongate member.
5 . The apparatus of claim 3 , wherein said first and second direction of movement is rotational about the longitudinal axis of said elongate member, or substantially parallel to the longitudinal axis of said elongate member.
6 . The apparatus of claim 1 , wherein said elongate member is a guide wire.
7 . The apparatus of claim 1 , further comprising:
a lumen traversing the longitudinal axis of the elongate member; and
wires disposed in said lumen to electrically connect said first SMA actuator and optionally said deformable component to one or more devices at the proximal end of said elongate member.
8 . The apparatus of claim 7 , wherein said device is a signal processor.
9 . The apparatus of claim 1 , wherein said angle is between about 80° and about 110°.
10 . The apparatus of claim 1 , wherein the diameter of said distal end of said elongate member is not more than about 0.060 inches.
11 . The apparatus of claim 1 , further comprising a connecting arm;
said connecting arm connecting said reflector to a movable element;
wherein said movable element, connecting arm and reflector move in a first direction relative to the elongate member upon activation of said first SMA actuator.
12 . The apparatus of claim 11 , wherein said deformable component comprises a second SMA actuator;
wherein said second actuator has an activated and a deactivated state; and
wherein activation of said second SMA actuator following deactivation of said first SMA actuator moves said movable element, connecting arm and reflector relative to the elongate member in a second direction of movement which is counter to said first direction of movement.
13 . The apparatus of claim 11 , wherein said deformable component is elastic or superelastic, and has a relaxed and deformed state;
wherein said deformable component is in a relaxed state when said first SMA actuator is deactivated;
wherein said movement of said movable element, connecting arm and reflector in said first direction upon activation of said first SMA actuator deforms said elastic or superelastic deformable component; and
wherein following deactivation of said first SMA actuator, said elastic or superelastic deformable component substantially returns to said relaxed state, said movable element, connecting arm and reflector moving in a second direction of movement which is counter to said first direction of movement.
14 . The apparatus of claim 12 , wherein said first and second direction of movement is rotational about the longitudinal axis of said elongate member, or substantially parallel to the longitudinal axis of said elongate member.
15 . The apparatus of claim 14 , wherein said rotational motion is between about 1 and about 400 degrees, and said longitudinal motion is from about 1 mm to about 20 mm.
16 . The apparatus of claim 13 , wherein said first and second direction of movement is rotational about the longitudinal axis of said elongate member, or substantially parallel to the longitudinal axis of said elongate member.
17 . The apparatus of claim 16 , wherein said rotational motion is between about 1 and about 400 degrees, and said longitudinal motion is from about 1 mm to about 20 mm.
18 . The apparatus of claim 11 , wherein said angle is between about 80° and about 110°.
19 . The apparatus of claim 11 , wherein the diameter of said distal end of said elongate member is not more than about 0.060 inches.
20 . A side-looking intravascular optical coherence tomography apparatus comprising:
an elongate member having a proximal end and a distal end, wherein at least a portion of said distal end is transparent to light energy;
an actuator mechanism disposed in said distal end, said actuator mechanism comprising a first anchor, a second anchor, a movable element, a first SMA actuator connected to said first anchor and said movable element, and a deformable component connected to said second anchor and said movable element, wherein said anchor elements are secured relative to said elongate member;
an optical fiber having a proximal and a distal end, said distal end of said optical fiber disposed in said distal end of said elongate member substantially parallel to a longitudinal axis of said elongate member, said moveable element connected to said distal end of said optical fiber; and
a reflector connected to a distal tip of said optical fiber, said reflector oriented to reflect light energy from said distal tip of said optical fiber through said transparent portion of said distal end at an angle between about 15° to about 165° relative to said longitudinal axis of said elongate member;
wherein said first SMA actuator has an activated and a deactivated state; and
wherein said movable element, distal tip of said optical fiber and said reflector move in a first direction relative to the elongate member upon activation of said first SMA actuator.
21 . The apparatus of claim 20 , wherein said deformable component comprises a second SMA actuator;
wherein said second actuator has an activated and a deactivated state; and
wherein activation of said second SMA actuator following deactivation of said first SMA actuator moves said movable element, distal tip of said optical fiber and said reflector relative to the elongate member in a second direction which is counter to said first direction of movement.
22 . The apparatus of claim 20 , wherein said deformable component is elastic or superelastic, and has a relaxed and deformed state;
wherein said deformable component is in a relaxed state when said first SMA actuator is deactivated;
wherein said movement of said movable element, distal tip of said optical fiber and said reflector in said first direction upon activation of said first SMA deforms said elastic or superelastic deformable component; and
wherein following deactivation of said first SMA actuator, said elastic or superelastic deformable component substantially returns to said relaxed state, said movable element, distal tip of said optical fiber and said reflector moving in a second direction of movement which is counter to said first direction of movement.
23 . The apparatus of claim 21 , wherein said first and second direction of movement is rotational about the longitudinal axis of said elongate member, or substantially parallel to the longitudinal axis of said elongate member.
24 . The apparatus of claim 23 , wherein said rotational motion is between about 1 and about 400 degrees, and said longitudinal motion is from about 1 mm to about 20 mm.
25 . The apparatus of claim 22 , wherein said first and second direction of movement is rotational about the longitudinal axis of said elongate member, or substantially parallel to the longitudinal axis of said elongate member.
26 . The apparatus of claim 25 , wherein said rotational motion is between about 1 and about 400 degrees, and said longitudinal motion is from about 1 mm to about 20 mm.
27 . The apparatus of claim 20 , wherein said angle is between about 80° and about 110°.
28 . The apparatus of claim 20 , wherein the diameter of said distal end of said elongate member is not more than about 0.060 inches.
29 . A method for visualizing the interior of a patient's vasculature, said method comprising:
inserting the distal end of the apparatus of claim 1 into the vasculature of a patient;
generating a cyclical movement of said movable element and reflector by alternating the activation and deactivation of said first SMA actuator and optionally said deformable component, such that said movable element and reflector are moved in said first and said second direction;
transmitting light energy from said proximal end of said optical fiber to said distal tip, reflecting said energy on said reflector;
receiving light energy reflected from the interior of the vasculature on reflector and reflecting said energy on said distal tip of said optical fiber;
transmitting said energy from said distal tip of said optical fiber to said proximal end of said fiber; and
producing an image from said reflected energy.
30 . A method for visualizing the interior of a patient's vasculature, said method comprising:
inserting the distal end of the apparatus of claim 2 into the vasculature of a patient;
generating a cyclical movement of said movable element and reflector by alternating the activation of said first SMA actuator and said second SMA actuator, such that said movable element and reflector are moved in said first and said second direction;
transmitting light energy from said proximal end of said optical fiber to said distal tip, reflecting said energy on said reflector;
receiving light energy reflected from the interior of the vasculature on reflector and reflecting said energy on said distal tip of said optical fiber;
transmitting said energy from said distal tip of said optical fiber to said proximal end of said fiber; and
producing an image from said reflected energy.
31 . A method for visualizing the interior of a patient's vasculature, said method comprising:
inserting the distal end of the apparatus of claim 11 into the vasculature of a patient;
generating a cyclical movement of said movable element, connecting arm and reflector by alternating the activation and deactivation of said first SMA actuator and optionally said deformable component, such that said movable element, connecting arm and reflector are moved in said first and said second direction;
transmitting light energy from said proximal end of said optical fiber to said distal tip, reflecting said energy on said reflector;
receiving light energy reflected from the interior of the vasculature on reflector and reflecting said energy on said distal tip of said optical fiber;
transmitting said energy from said distal tip of said optical fiber to said proximal end of said fiber; and
producing an image from said reflected energy.
32 . A method for visualizing the interior of a patient's vasculature, said method comprising:
inserting the distal end of the apparatus of claim 12 into the vasculature of a patient;
generating a cyclical movement of said movable element, connecting arm and reflector by alternating the activation of said first SMA actuator and said second SMA actuator, such that said movable element, connecting arm and reflector are moved in said first and said second direction;
transmitting light energy from said proximal end of said optical fiber to said distal tip, reflecting said energy on said reflector;
receiving light energy reflected from the interior of the vasculature on reflector and reflecting said energy on said distal tip of said optical fiber;
transmitting said energy from said distal tip of said optical fiber to said proximal end of said fiber; and
producing an image from said reflected energy.
33 . A method for visualizing the interior of a patient's vasculature, said method comprising:
inserting the distal end of the apparatus of claim 20 into the vasculature of a patient;
generating a cyclical movement of said movable element, distal tip of said optical fiber and said reflector by alternating the activation and deactivation of said first SMA actuator and optionally said deformable component, such that said movable element, distal tip of said optical fiber and said reflector are moved in said first and said second direction;
transmitting light energy from said proximal end of said optical fiber to said distal tip, reflecting said energy on said reflector;
receiving light energy reflected from the interior of the vasculature on reflector and reflecting said energy on said distal tip of said optical fiber;
transmitting said energy from said distal tip of said optical fiber to said proximal end of said fiber; and
producing an image from said reflected energy.
34 . A method for visualizing the interior of a patient's vasculature, said method comprising:
inserting the distal end of the apparatus of claim 21 into the vasculature of a patient;
generating a cyclical movement of said movable element, distal tip of said optical fiber and said reflector by alternating the activation of said first SMA actuator and said second SMA actuator, such that said movable element, distal tip of said optical fiber and said reflector are moved in said first and said second direction;
transmitting light energy from said proximal end of said optical fiber to said distal tip, reflecting said energy on said reflector;
receiving light energy reflected from the interior of the vasculature on reflector and reflecting said energy on said distal tip of said optical fiber;
transmitting said energy from said distal tip of said optical fiber to said proximal end of said fiber; and
producing an image from said reflected energy.
35 . A side-looking intravascular optical coherence tomography apparatus comprising:
an elongate member having a proximal end and a distal end, wherein at least a portion of said distal end is transparent to light energy;
an optical fiber having a distal end, said distal end of said optical fiber disposed in said distal end of said elongate member;
a reflector means disposed in said distal end of said elongate member; and
an actuator mechanism means for providing cyclical motion to said reflector;
wherein said reflector and distal end of said optical fiber is oriented to transmit light energy through said light transparent portion of said distal end of said elongate member at an angle of between about 15° to about 165° relative to a longitudinal axis of said elongate member.
36 . The side-looking intravascular optical coherence tomography apparatus of claim 35 , wherein said actuator mechanism means comprises a first anchor, a second anchor, a movable element, a first SMA actuator connected to said first anchor and said movable element, and a deformable component connected to said second anchor and said movable element, wherein said anchor elements are secured relative to said elongate member.