Endoscopic OCT probes with immersed MEMS mirrors
Methods and apparatuses for enlarging the optical scan angle of imaging probes are provided. The optical scan angle of endoscopic probes can be increased by employing the “Snell's Window” effect. An endoscopic probe can include an endoscope shell, a device for capturing electromagnetic radiation, and a liquid or gel provided between the device for capturing electromagnetic radiation and the endoscope shell. The endoscope probe can further include a first mirror placed such that electromagnetic radiation entering through the endoscope shell can bounce off the first mirror and enter the device for capturing electromagnetic radiation. The first mirror can be a microelectromechanical systems (MEMS) mirror.
1. An endoscopic probe, comprising:
an endoscope shell;
a means for capturing electromagnetic radiation;
a first mirror disposed such that electromagnetic radiation entering through the endoscope shell is received at the first mirror and redirected to the means for capturing electromagnetic radiation; and
a liquid or a gel provided within the endoscope shell between the means for capturing electromagnetic radiation and the first mirror, and between the first mirror and the endoscope shell.
2. The endoscopic probe according to claim 1 , wherein the first mirror is a microelectromechanical systems (MEMS) mirror.
3. The endoscopic probe according to claim 2 , wherein the MEMS mirror is immersed in the liquid or gel.
4. The endoscopic probe according to claim 1 ,
wherein the first mirror is configured to tilt in at least one direction,
wherein the first mirror is configured to be raised and lowered, and
wherein the first mirror comprises at least one of the following: a first bimorph actuator for tilting the first mirror, raising the first mirror, or both; a piezo electric crystal for tilting the first mirror, raising the first mirror, or both; and second bimorph actuator that is an inverted-series-connected (ISC) AI/SlO 2 bimorph actuator for tilting the first mirror, raising the first mirror, or both.
5. The endoscopic probe according to claim 1 , wherein the means for capturing electromagnetic radiation is a fiber or a camera.
6. The endoscopic probe according to claim 1 , wherein the means for capturing electromagnetic radiation is a single mode fiber (SMF).
7. The endoscopic probe according to claim 1 , further comprising a lens between the means for capturing electromagnetic radiation and the first mirror, wherein the liquid or the gel is provided between the first mirror and the lens and between the lens and the means for capturing electromagnetic radiation.
8. The endoscopic probe according to claim 7 , wherein the lens is a gradient-index (GRIN) lens.
9. The endoscopic probe according to claim 1 , further comprising a second mirror positioned to reflect electromagnetic radiation coming from the first mirror and to the means for capturing electromagnetic radiation, wherein the liquid or the gel is provided between the first mirror and the second mirror.
10. The endoscopic probe according to claim 1 , wherein the electromagnetic radiation comprises visible light.
11. The endoscopic probe according to claim 1 , wherein the electromagnetic radiation comprises infrared light.
12. The endoscopic probe according to claim 1 , wherein the electromagnetic radiation comprises ultraviolet (UV) light.
13. The endoscopic probe according to claim 1 , wherein a cross section of the endoscope shell is oval or circular.
14. The endoscopic probe according to claim 1 , wherein the endoscope shell comprises a flattened optical window.
15. The endoscopic probe according to claim 1 , further comprising a seal ring.
16. The endoscopic probe according to claim 1 , further comprising a means for delivering electromagnetic radiation to the endoscopic probe, and wherein means for delivering electromagnetic radiation comprises at least one of the following: an optical fiber; a light-emitting diode (LED); and an electromagnetic radiation transmitting fiber.
17. The endoscopic probe according to claim 1 , wherein the means for capturing electromagnetic radiation is immersed in the liquid or gel.
18. A method for capturing images using an endoscopic probe comprising an endoscope shell containing a liquid or a gel, the method comprising:
providing a means for capturing electromagnetic radiation within the endoscope shell;
receiving electromagnetic radiation through the endoscope shell at a first mirror;
redirecting the received electromagnetic radiation from the first mirror to the means for capturing electromagnetic radiation; and
using Snell's window effect based on the liquid or the gel positioned between the first mirror and the endoscopic shell and between the means for capturing electromagnetic radiation and the endoscopic shell to expand a field of view captured by the means for capturing electromagnetic radiation.
19. The method according to claim 18 wherein the first mirror is a MEMS mirror.
20. The method according to claim 18 ,
wherein the first mirror is configured to tilt in at least one direction,
wherein the first mirror is configured to be raised and lowered, and
wherein the first mirror comprises at least one of the following: a first bimorph actuator for tilting the first mirror, raising the first mirror, or both; a piezo electric crystal for tilting the first mirror, raising the first mirror, or both; and second bimorph actuator that is an inverted-series-connected (ISC) AI/SlO 2 bimorph actuator for tilting the first mirror, raising the first mirror, or both.
21. The method according to claim 18 , wherein the means for capturing electromagnetic radiation is a fiber or a camera.
22. The method according to claim 18 , wherein the means for capturing electromagnetic radiation is a single mode fiber (SMF).
23. The method according to claim 18 , further comprising providing a lens between the means for capturing electromagnetic radiation and the mirror.
24. The method according to claim 23 , wherein the lens is a GRIN lens.
25. The method according to claim 18 , further comprising providing a second mirror positioned to reflect electromagnetic radiation coming from the first mirror and to the means for capturing electromagnetic radiation.
26. The method according to claim 18 , wherein the electromagnetic radiation comprises visible light.
27. The method according to claim 18 , wherein the electromagnetic radiation comprises infrared light.
28. The method according to claim 18 , wherein a cross section of the endoscope shell is oval or circular.
29. The method according to claim 18 , wherein the endoscope shell has a flattened optical window.