Abstract
A coronary-artery compatible optoacoustic catheter is demonstrated.
The catheter is composed of two optical fibers: one to provide optical
excitation and the other to detect the resulting ultrasound using
interferometry. The detection element is pi-phase-shifted fiber Bragg
grating with an effective length of 350 µm written in a single-mode fiber.
Pulse interferometry in reflection mode is used for the interrogation of the
ultrasound sensor. Illumination is provided by a multi-mode fiber with a
prism mounted on its tip for side illumination. Both fibers are housed in
a dual-lumen tube with a diameter of approximately 1 mm and aligned
to achieve maximum overlap between the illumination and the detection
field of the ultrasound sensor. Since the ultrasound sensor has radial
symmetry and therefore cannot discriminate between signals originating
at different angles, imaging is performed by rotating only the illumination
fiber. Thus, angular resolution in this configuration is determined solely by
the optical beam divergence, which in our design is approximately 10°.
Excitation is performed at an average power of 15 mW with pulses at a
rate of 1.4 kHz, enabling imaging at a rate of 200 revolutions per minute.
The performance of the catheter is demonstrated in imaging a stented
blood vessel ex vivo. Despite vibrations in the catheter caused by the
rotation of the illumination fiber, stable operation was maintained during
the imaging session.
The catheter is composed of two optical fibers: one to provide optical
excitation and the other to detect the resulting ultrasound using
interferometry. The detection element is pi-phase-shifted fiber Bragg
grating with an effective length of 350 µm written in a single-mode fiber.
Pulse interferometry in reflection mode is used for the interrogation of the
ultrasound sensor. Illumination is provided by a multi-mode fiber with a
prism mounted on its tip for side illumination. Both fibers are housed in
a dual-lumen tube with a diameter of approximately 1 mm and aligned
to achieve maximum overlap between the illumination and the detection
field of the ultrasound sensor. Since the ultrasound sensor has radial
symmetry and therefore cannot discriminate between signals originating
at different angles, imaging is performed by rotating only the illumination
fiber. Thus, angular resolution in this configuration is determined solely by
the optical beam divergence, which in our design is approximately 10°.
Excitation is performed at an average power of 15 mW with pulses at a
rate of 1.4 kHz, enabling imaging at a rate of 200 revolutions per minute.
The performance of the catheter is demonstrated in imaging a stented
blood vessel ex vivo. Despite vibrations in the catheter caused by the
rotation of the illumination fiber, stable operation was maintained during
the imaging session.
| Original language | American English |
|---|---|
| Pages | 8943-147 |
| State | Published - 2014 |
| Externally published | Yes |
| Event | SPIE Photonics West 2014 - San Francisco, United States Duration: 1 Feb 2014 → 6 Feb 2014 https://spie.org/conferences-and-exhibitions/past-conferences-and-exhibitions/photonics-west-2014 |
Conference
| Conference | SPIE Photonics West 2014 |
|---|---|
| Country/Territory | United States |
| City | San Francisco |
| Period | 1/02/14 → 6/02/14 |
| Internet address |