OPTICAL SCANNING DEVICE, CATHETER DEVICE, AND DISTANCE MEASURING DEVICE

• US 20190183348A1
• Filed: 12/18/2018
• Published: 06/20/2019
• Est. Priority Date: 12/19/2017
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: ONOE, Shinsuke, MATSUDA, Takahiro, SEO, Yoshiho, OUCHI, Satoshi, TANAKA, Tomohiko, TAKEZAKI, Taiichi, IMAI, Ryo
• Granted Patent: US 11,317,812 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: G01N 29/2418 using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046
• CPC Class Codes: G01S 17/08 for measuring distance only indirect measurement G01S17/46; active triangulation systems G01S17/48
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric means
• CPC Class Codes: G02B 26/10 Scanning systems
• CPC Class Codes: G02B 26/103 having movable or deformable optical fibres, light guides or waveguides as scanning elements light guides per se G02B6/00
• CPC Class Codes: H10N 30/2046 adapted for multi-directional bending displacement
• CPC Class Codes: H10N 30/802 Drive or control circuitry or methods for piezoelectric or electrostrictive devices not otherwise provided for

Abstract

An optical scanning device includes: an optical scanning unit configured to repeatedly scan an irradiation destination of irradiation light to a predetermined trajectory; a light emission control unit configured to control light emission of the irradiation light to irradiate irradiation points to the predetermined trajectory; and a driving signal generation unit configured to generate a driving signal for driving the optical scanning unit, wherein the light emission control unit irradiates the irradiation points to the predetermined trajectory so that the irradiation points are substantially uniformly dispersed in a region in which a density of the irradiation points is relatively low in a region in which the irradiation light is irradiated.

Claims

1. An optical scanning device, comprising:

an optical scanning unit configured to repeatedly scan an irradiation destination of irradiation light to a predetermined trajectory;

a light emission control unit configured to control light emission of the irradiation light to irradiate irradiation points to the predetermined trajectory; and

a driving signal generation unit configured to generate a driving signal for driving the optical scanning unit,

wherein the light emission control unit irradiates the irradiation points to the predetermined trajectory so that the irradiation points are substantially uniformly dispersed in a region in which a density of the irradiation points is relatively low in a region in which the irradiation light is irradiated.

2. The optical scanning device according to claim 1, wherein with respect to any irradiation point P in the region in which the density of the irradiation points is relatively low in the region in which the irradiation light is irradiated,

when a distance to an irradiation point A closest to the irradiation point P is defined as a, and a distance to an irradiation point B closest to the irradiation point P among the irradiation points existing in a direction that is not substantially parallel to a line segment PA with the irradiation point P as a base point is defined as b,

a distance between an irradiation point irradiated following the irradiation point P by the light emission control unit and the irradiation point P is equal to or more than the b, and the a and b are substantially equal.

3. The optical scanning device according to claim 2, wherein the optical scanning unit repeatedly scans the irradiation destination of the irradiation light to a spiral trajectory.

4. The optical scanning device according to claim 3, wherein the driving signal generation unit generates the driving signal using a sinusoidal component having a predetermined driving cycle T_drv as a main component, and

with respect to any irradiation point P irradiated to an outermost circumference of the region in which the irradiation light is irradiated when a radius of a substantially circular trajectory on an outermost circumference of the spiral trajectory is set to R,

when a distance to an irradiation point A closest to the irradiation point P is defined as a, and a distance to an irradiation point B closest to the irradiation point P among the irradiation points existing in a direction that is not substantially parallel to a line segment PA with the irradiation point P as a base point is defined as b,

a time T_dot taken to irradiate an irradiation point after the irradiation point P is irradiated by the light emission control unit satisfies the following Mathematical Formula (1), and

5. The optical scanning device according to claim 2, wherein the a and b satisfy the following Mathematical Formula (2).

[Mathematical Formula 32]

1≤

b/a≤

2 

 

(32)

6. The optical scanning device according to claim 1, wherein with respect to a substantially parallelogram constituted by four neighboring irradiation points in the region in which the density of the irradiation points is relatively low in the region in which the irradiation light is irradiated,

any two of the four irradiation points are not irradiation points continuously irradiated and lengths of adjacent sides of the substantially parallelogram are substantially equal.

7. The optical scanning device according to claim 1, wherein the optical scanning unit includes:

a light guide path configured to emit, from a light emitting end, light incident from a light incident end; and

a vibration unit configured to vibrate the light emitting end.

8. The optical scanning device according to claim 1, comprising:

a receiving unit configured to receive a physical phenomenon occurring as a result of the irradiation of the irradiation light; and

an imaging unit configured to image an image based on the received physical phenomenon.

9. The optical scanning device according to claim 8, wherein the receiving unit receives a sound wave as the physical phenomenon occurring as the result of the irradiation of the irradiation light, and

the imaging unit images the image based on the received sound wave.

10. The optical scanning device according to claim 8, wherein the receiving unit receives a reflected light as the physical phenomenon occurring as the result of the irradiation of the irradiation light, and

the imaging unit images the image based on the received reflected light.

11. The optical scanning device according to claim 1, wherein the light emission control unit periodically controls the emission of the irradiation light.

12. The optical scanning device according to claim 3, wherein the light emission control unit periodically controls the emission of the irradiation light depending on a light emission frequency f_dot,

the driving signal generation unit generates the driving signal using a sine wave of a frequency f_drv as a main component,

the number of substantially circular trajectories constituting the spiral trajectory is N_frame, and

α

is defined by the following Mathematical Formula (3), and

[Mathematical Formula 33]

α

=f_dot/f_drv 

 

(33)

among positive integers equal to or less than 0.1 times N_frame, when N making α

×

N most approximate an integer value is defined as N_p,

the following Mathematical Formula (4) is satisfied.

13. The optical scanning device according to claim 3, wherein the light emission control unit periodically controls the emission of the irradiation light depending on a light emission frequency f_dot,

the driving signal generation unit generates the driving signal using a sine wave of a frequency f_drv as a main component, and

when the number of substantially circular trajectories constituting the spiral trajectory is N_frame, the following Mathematical Formula (5) is satisfied.

14. The optical scanning device according to claim 1, comprising:

a frequency change unit configured to change a frequency of a sine wave which is a main component of the driving signal,

wherein the frequency change unit changes the frequency of the sine wave while avoiding a predetermined frequency band.

15. The optical scanning device according to claim 1, wherein the light emission control unit changes a time interval T_dot from irradiation of any irradiation point in the region in which the density of the irradiation points is relatively small in the region in which the irradiation light is irradiated to irradiation of a next irradiation point.

16. The optical scanning device according to claim 1, wherein the driving signal generation unit generates the driving signal using a sine wave of a frequency f_drv as a main component,

the light emission control unit changes a time interval T_dot from irradiation of any irradiation point to irradiation of a next irradiation point, and

the time interval T_dot satisfies the following Mathematical Formula (6).

17. The optical scanning device according to claim 3, wherein the number of substantially circular trajectories constituting the spiral trajectory is N_frame,

α

is defined by the following Mathematical Formula (7), and

[Mathematical Formula 37]

α

=f_dot/f_drv 

 

(37)

among positive integers equal to or less than 0.1 times N_frame, when N making α

×

N most approximate an integer value is defined as N_p,

the light emission control unit changes a time interval T_dot from irradiation of any irradiation point in the region in which the density of the irradiation points is relatively low in the region in which the irradiation light is irradiated to irradiation of a next irradiation point within (N_p−

1)×

T_drv.

18. A catheter device, comprising:

an optical scanning unit configured to repeatedly scan an irradiation destination of irradiation light to a predetermined trajectory;

a light emission control unit configured to control light emission of the irradiation light to irradiate irradiation points to the predetermined trajectory;

a driving signal generation unit configured to generate a driving signal for driving the optical scanning unit;

a receiving unit configured to receive a sound wave occurring as a result of the irradiation of the irradiation light; and

an imaging unit configured to image an image based on the received sound wave,

wherein the light emission control unit irradiates the irradiation points to the predetermined trajectory so that the irradiation points are substantially uniformly dispersed in a region in which a density of the irradiation points is relatively lower in a region in which the irradiation light is irradiated.

19. A distance measuring device, comprising:

an optical scanning unit configured to repeatedly scan an irradiation destination of irradiation light to a predetermined trajectory;

a light emission control unit configured to control light emission of the irradiation light to irradiate irradiation points to the predetermined trajectory;

a driving signal generation unit configured to generate a driving signal for driving the optical scanning unit;

a receiving unit configured to receive a reflected light occurring as a result of the irradiation of the irradiation light to an object; and

a distance measuring unit configured to measure a distance to the object based on the received reflected light,

wherein the light emission control unit irradiates the irradiation points to the predetermined trajectory so that the irradiation points are substantially uniformly dispersed in a region in which a density of the irradiation points is relatively lower in a region in which the irradiation light is irradiated.