1. A method comprising:
monitoring movement of a scanning beam image acquisition device;
acquiring images with the scanning beam image acquisition device using a first image acquisition mode when the monitoring indicates that the scanning beam image acquisition device is moving; and
acquiring images with the scanning beam image acquisition device using a second image acquisition mode when the monitoring indicates that the scanning beam image acquisition device is substantially still, wherein the second image acquisition mode is different than the first image acquisition mode.
2. The method of claim 1, wherein a frame rate of the first image acquisition mode is higher than a frame rate of the second image acquisition mode.
3. The method of claim 1, wherein a number of lines of image resolution of the first image acquisition mode is lower than a number of lines of image resolution of the second image acquisition mode.
4. The method of claim 1, wherein a frame rate of the first image acquisition mode is greater than a frame rate of the second image acquisition mode, and wherein a number of lines of image resolution of the first image acquisition mode is less than a number of lines of image resolution of the second image acquisition mode.
5. The method of claim 1:
wherein acquiring the images using the first image acquisition mode comprises scanning a beam in a first spiral having a first number of windings;
wherein acquiring the images using the second image acquisition mode comprises scanning the beam in a second spiral having a second number of windings; and
wherein the second number of windings is greater than the first number of windings.
6. The method of claim 1, wherein monitoring the movement comprises sensing the movement with a sensor.
7. The method of claim 6, wherein sensing the movement comprises sensing the movement with a sensor that moves with the scanning beam image acquisition device.
8. The method of claim 7, wherein sensing the movement with the sensor that moves with the scanning beam image acquisition device comprises sensing the movement with a miniature magnetic tracking device.
9. The method of claim 6, wherein sensing the movement comprises sensing the movement of a cable coupling the scanning beam image acquisition device with a base station.
10. The method of claim 1, wherein monitoring the movement comprises computing the movement from images acquired with the scanning beam image acquisition device.
11. The method of claim 1, further comprising comparing monitored movement with at least one threshold.
12. The method of claim 11, wherein comparing the monitored movement with the at least one threshold comprises comparing the monitored movement with two or more different thresholds, wherein the two or more different thresholds are operable to reduce rapid switching back and forth between the first and second modes.
13. The method of claim 11, further comprising determining that a waiting time has elapsed before switching between the first and second image acquisition modes.
14. The method of claim 1, wherein acquiring the images with the scanning beam image acquisition device using the first and second modes comprises acquiring the images with a scanning fiber image acquisition device.
15. The method of claim 14, wherein acquiring the images with the scanning beam image acquisition device using the first and second modes comprises vibrating a cantilevered optical fiber within a Q-factor of a resonant frequency.
16. The method of claim 1, further comprising a user overriding automatic switching between the first and second image acquisition modes and forcing image acquisition to be performed with only one of the first and second modes.
17. The method of claim 1, further comprising inserting the scanning beam image acquisition device into a patient.
18. An apparatus comprising:
a connector interface to allow a scanning beam image acquisition device to be attached;
a light source to provide light to the scanning beam image acquisition device through the connector interface; and
an actuator driver operable to provide actuator drive signals to an actuator of a scanning beam image acquisition device through the connector interface,
wherein the actuator driver is operable to provide the actuator drive signals according to a first image acquisition mode responsive to an indication that the scanning beam image acquisition device is moving, and
wherein the actuator driver is operable to provide actuator drive signals according to a second image acquisition mode responsive to an indication that the scanning beam image acquisition device is substantially still, and
wherein the second mode is different than the first mode.
19. The apparatus of claim 18, wherein a frame rate of the first image acquisition mode is higher than a frame rate of the second image acquisition mode.
20. The apparatus of claim 18, wherein a number of lines of image resolution of the first image acquisition mode is lower than a number of lines of image resolution of the second image acquisition mode.
21. The apparatus of claim 18, wherein a frame rate of the first image acquisition mode is greater than a frame rate of the second image acquisition mode, and wherein a number of lines of image resolution of the first image acquisition mode is less than a number of lines of image resolution of the second image acquisition mode.
22. The apparatus of claim 18:
wherein the actuator drive signals according to the first mode are operable to cause the scanning beam image acquisition device to scan a beam in a first spiral having a first number of windings;
wherein the actuator drive signals according to the second mode are operable to cause the scanning beam image acquisition device to scan a beam in a second spiral having a second number of windings; and
wherein the second number of windings is greater than the first number of windings.
23. The apparatus of claim 18, further comprising a sensor to sense movement of the scanning beam image acquisition device.
24. The apparatus of claim 23, wherein the sensor comprises a sensor attached to the scanning beam image acquisition device.
25. The apparatus of claim 24, wherein the sensor comprises miniature magnetic tracking device.
26. The apparatus of claim 23, wherein the sensor comprises a sensor positioned relative to a cable coupling the scanning beam image acquisition device with the connector interface to sense movement of the cable.
27. The apparatus of claim 18, further comprising a movement monitoring unit to monitor movement of the scanning beam image acquisition device by computing movement from images acquired with the scanning beam image acquisition device.
28. The apparatus of claim 18, further comprising a mechanism to allow a user to force the actuator driver to use either the first mode or the second mode.
29. The apparatus of claim 18, wherein the first and second image acquisition modes each comprise a different set of one or more look-up tables in memory.
30. The apparatus of claim 18, wherein the first and second image acquisition modes comprise different algorithms implemented in instructions stored on a machine-readable medium, circuitry, or a combination thereof.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An ultrasonic actuator comprising:
an actuator body having a piezoelectric element and performing a bending vibration and a longitudinal vibration; and
a driver element which is attached to a side surface of the actuator body normal to a vibration direction of the bending vibration, and outputs a driving force by making an orbit motion in a plane including the vibration direction of the bending vibration and a vibration direction of the longitudinal vibration in response to the vibrations of the actuator body, wherein
the driver element is provided with an attachment surface, and is attached to the side surface with the attachment surface in surface contact with the side surface, and
a width of the attachment surface in the vibration direction of the longitudinal vibration is smaller than a maximum width of the driver element in the vibration direction of the longitudinal vibration.
2. The ultrasonic actuator of claim 1, wherein
the driver element is in the shape of a sphere which is at least partially truncated to form a flat section, and the section constitutes the attachment surface.
3. The ultrasonic actuator of claim 1, wherein
the driver element is in the shape of a cylindrical column which is at least partially truncated to form a flat section parallel to an axis of the cylindrical column, and the section constitutes the attachment surface.
4. The ultrasonic actuator of claim 1, wherein
the driver element is attached to a non-node part of the bending vibration of the actuator body.
5. The ultrasonic actuator of claim 4, wherein
the driver element is attached to an antinode of the bending vibration of the actuator body.
6. The ultrasonic actuator of claim 1, wherein
the driver element is in contact with a circumferential surface of a drive target which rotates about a rotation axis orthogonal to the plane including the vibration direction of the bending vibration and the vibration direction of the longitudinal vibration, and applies a driving force to the drive target.
7. The ultrasonic actuator of claim 6, wherein
the driver element is configured so that a normal at a point of contact between the driver element and the drive target passes through the attachment surface.
8. The ultrasonic actuator of claim 6, wherein
two driver elements are attached to the side surface of the actuator body to be aligned in the vibration direction of the longitudinal vibration,
sections of the driver elements and the drive target which are parallel to the plane including the vibration direction of the bending vibration and the vibration direction of the longitudinal vibration are substantially round, and
suppose that a distance between centers of the two driver elements in the vibration direction of the longitudinal vibration is l, a radius of the driver element is r, a width of the attachment surface of the driver element in the vibration direction of the longitudinal vibration is x, and a radius of the drive target is R, the following expression (2):
x>rl(R+r)\u2003\u2003(2)
is satisfied.
9. The ultrasonic actuator of claim 8, wherein
the driver element satisfies the following expression (3):
x<\u221a{square root over (2)}r\u2003\u2003(3).
10. The ultrasonic actuator of claim 1, wherein
the actuator body performs a first mode of the longitudinal vibration and a second mode of the bending vibration.