Other

Olympus Optical Company, Ltd.

Case Western Reserve University

The Cleveland Clinic Foundation

Michael V Sivak

Joseph A Izatt

Andrew M Rollins

Manish Dinkarrao Kulkarni

Tadashi Hirata

Akihiro Horii

Shuhei Iizuka

Siavash Yazdanfar

Manish D Kulkarni

Jiro Narita

George J Skipper

A method is described for determining depth-resolved backscatter characteristics of scatterers within a sample, comprising the steps of: acquiring a plurality of sets of cross-correlation interferogram data using an interferometer having a sample arm with the sample in the sample arm, wherein the sample includes a distribution of scatterers therein, and wherein the acquiring step includes the step of altering the distribution of scatterers within the sample with respect to the sample arm for substantially each acquisition; and averaging, in the Fourier domain, the cross-correlation interferogram data, thereby revealing backscattering characteristics of the scatterers within the sample.

Depth-resolved spectroscopic optical coherence tomography

A method for generating a velocity-indicating, tomographic image of a sample in an optical coherence tomography system includes the steps of (a) acquiring cross-correlation data from the interferometer; (b) generating a grayscale image from the cross-correlation data indicative of a depth-dependent positions of scatterers in the sample; (c) processing the cross-correlation data to produce a velocity value and location of a moving scatterer in the sample; (d) assigning a color to the velocity value; and (f) merging the color into the grayscale image, at a point in the grayscale image indicative of the moving scatterer's location, to produce a velocity-indicating, tomographic image. Preferably a first color is assigned for a positive velocity value and a second color is assigned for a negative velocity value.

Doppler flow imaging using optical coherence tomography

An Optical Coherence Tomography (OCT) device irradiates a biological tissue with low coherence light, obtains a high resolution tomogram of the inside of the tissue by low-coherent interference with scattered light from the tissue, and is provided with an optical probe which includes an optical fiber having a flexible and thin insertion part for introducing the low coherent light. When the optical probe is inserted into a blood vessel or a patient's body cavity, the OCT enables the doctor to observe a high resolution tomogram. In a optical probe, generally, a fluctuation of a birefringence occurs depending on a bend of the optical fiber, and this an interference contrast varies depending on the condition of the insertion. The OCT of the present invention is provided with polarization compensation means such as a Faraday rotator on the side of the light emission of the optical probe, so that the OCT can obtain the stabilized interference output regardless of the state of the bend.

Optical imaging device

The present invention provides an improved optical coherence tomography system and involves estimating the impulse response (which is indicative of the actual reflecting and scattering sites within a tissue sample) from the output interferometric signal of an interferometer according to the following steps: (a) acquiring auto-correlation data from the interferometer system; (b) acquiring cross-correlation data from the interferometer system having the biological tissue sample in the sample arm; and (c) processing the auto-correlation data and the cross correlation data to produce an optical impulse response of the tissue. The impulse response may be obtained from the cross-correlation and auto-correlation data by: (d) obtaining an auto-power spectrum from the auto-correlation data by performing a Fourier transform on the auto-correlation data; (e) obtaining a cross-power spectrum from the cross-correlation data by performing a Fourier transform on the cross-correlation data; (f) obtaining a transfer function of the LSI system by taking a ratio of the cross-power spectrum to the auto-power spectrum; and (g) obtaining the optical impulse response of the LSI system by performing an inverse-Fourier transform on the transfer function. Preferably, coherent demodulation is used in combination with the above deconvolution technique to resolve closely-spaced reflecting sites in the sample. By utilizing both the magnitude and phase data of the demodulated interferometric signals, the OCT system of the present invention is able to distinguish between closely spaced reflecting sites within the sample.

Image enhancement in optical coherence tomography using deconvolution

An injector is disclosed for treating esophageal varices and other disorders with injected medications. The injector includes a needle which has a tubular bore for injecting the medication into the varices. The needle has an exposed length which is sufficiently long to enter a vein wall but not sufficiently long to pass through the vein and esophagus walls. A tubular connector has an internal bore connected with the needle and has a flange for inhibiting the connector from following the needle through a puncture. The tubular connector has a shank portion which is connected with a flexible tube. The flexible tube, tubular connector, and needle are slidingly receivable in a biopsy channel of a flexible, fiberoptic endoscope. A syringe is connected to the other end of the flexible tube for selectively forcing medications through the tube, connector, and needle into the varices.

Esophageal varices injector

Growing community of inventors

Cleveland Heights, OH, United States of America

Michael V Sivak