Blood flow measurement device

Abstract

In an embodiment, a controller included in a blood flow measurement apparatus controls a scanner to iteratively scan one or more cross sections of an interested blood vessel. An image forming unit forms a phase image that represents chronological change in phase difference in the one or more cross sections based on data acquired through iterative scan. An image processor outputs a predetermined signal based on the chronological change in phase difference represented by the phase image. Upon receiving the predetermined signal, the controller controls the scanner to start scan for acquiring blood flow information on the interested blood vessel.

1 . A blood flow measurement apparatus for acquiring blood flow information on an interested blood vessel of a living body, comprising:
 a scanner configured to scan a cross section that intersects the interested blood vessel using optical coherence tomography;   an image forming unit configured to form an image of the cross section based on data acquired by the scanner;   an image processor configured to process the image; and   a controller, wherein   the controller controls the scanner to iteratively scan one or more cross sections of the interested blood vessel,   the image forming unit forms a phase image that represents chronological change in phase difference in the one or more cross sections based on data acquired through iterative scan,   the image processor outputs a predetermined signal based on the chronological change in phase difference represented by the phase image, and   upon receiving the predetermined signal, the controller controls the scanner to start scan for acquiring the blood flow information.   
     
     
         2 . The blood flow measurement apparatus of  claim 1 , wherein the image processor comprises a monitoring unit configured to monitor chronological change in signal intensity in at least part of the phase image to detect a predetermined time phase of blood flow, and to output the predetermined signal at a timing corresponding to the predetermined time phase. 
     
     
         3 . The blood flow measurement apparatus of  claim 2 , wherein the monitoring unit monitors chronological change in signal intensity in at least part of a blood vessel region in the phase image corresponding to the interested blood vessel. 
     
     
         4 . The blood flow measurement apparatus of  claim 1 , wherein
 the controller controls the scanner to perform, as the scan for acquiring the blood flow information, first scan that iteratively scans a first cross section of the interested blood vessel and second scan that scans two or more second cross sections, wherein at least one of the two or more second cross sections is different from the first cross section,   the image forming unit forms a phase image that represents chronological change in phase difference in the first cross section based on data acquired through the first scan, and forms two or more images of the two or more second cross sections based on data acquired through the second scan, and   the image processor comprises:   a blood vessel region specification unit configured to specify a first blood vessel region corresponding to the interested blood vessel in the phase image of the first cross section, and specify two or more second blood vessel regions corresponding to the interested blood vessel in the two or more image of the two or more second cross sections;   a gradient calculation unit configured to calculate a gradient of the interested blood vessel at the first cross section based on the two or more second blood vessel regions; and   a blood flow information generation unit configured to generate the blood flow information based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel.   
     
     
         5 . The blood flow measurement apparatus of  claim 4 , wherein upon receiving the predetermined signal, the controller controls the scanner to alternately perform the first scan and the second scan. 
     
     
         6 . The blood flow measurement apparatus of  claim 5 , wherein
 the controller controls the scanner to perform the second scan so as to scan two second cross sections, and   one of the two second cross sections is the first cross section.   
     
     
         7 . The blood flow measurement apparatus of  claim 4 , wherein upon receiving the predetermined signal, the controller controls the scanner to start the second scan, and to start the first scan after the completion of the second scan. 
     
     
         8 . The blood flow measurement apparatus of  claim 4 , wherein upon receiving the predetermined signal, the controller controls the scanner to start the first scan, and to start the second scan after the first scan. 
     
     
         9 . The blood flow measurement apparatus of  claim 4 , wherein the blood flow information generation unit comprises a blood flow velocity calculation unit configured to determine chronological change in blood flow velocity at the first cross section for blood flowing through the interested blood vessel based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel. 
     
     
         10 . The blood flow measurement apparatus of  claim 9 , wherein the blood flow information generation unit comprises:
 a blood vessel diameter calculation unit configured to calculate diameter of the interested blood vessel at the first cross section based on an image formed from data acquired through scan of the first cross section; and   a blood flow amount calculation unit configured to calculate blood flow amount of blood flowing through the interested blood vessel based on the chronological change in blood flow velocity and the diameter of the interested blood vessel.   
     
     
         11 . A blood flow measurement apparatus for acquiring blood flow information on an interested blood vessel of a living body, comprising:
 a scanner configured to scan a cross section that intersects the interested blood vessel using optical coherence tomography;   an image forming unit configured to form an image of the cross section based on data acquired by the scanner;   an image processor configured to process the image;   a storage unit configured to store the data acquired by the scanner;   an instruction input unit configured for inputting a user's instruction; and   a controller, wherein   the controller controls the scanner to start iterative scan of one or more cross sections of the interested blood vessel, and upon receiving the user's instruction from the instruction input unit, the controller reads out data that is stored in the storage unit during a period between an input timing of the user's instruction and a timing before the input timing by a predetermined time length,   the image forming unit forms a phase image that represents chronological change in phase difference in the one or more cross sections based on the data read out by the controller,   the image processor generates the blood flow information based on the phase image.   
     
     
         12 . The blood flow measurement apparatus of  claim 2 , wherein
 the controller controls the scanner to perform, as the scan for acquiring the blood flow information, first scan that iteratively scans a first cross section of the interested blood vessel and second scan that scans two or more second cross sections, wherein at least one of the two or more second cross sections is different from the first cross section,   the image forming unit forms a phase image that represents chronological change in phase difference in the first cross section based on data acquired through the first scan, and forms two or more images of the two or more second cross sections based on data acquired through the second scan, and   the image processor comprises:   a blood vessel region specification unit configured to specify a first blood vessel region corresponding to the interested blood vessel in the phase image of the first cross section, and specify two or more second blood vessel regions corresponding to the interested blood vessel in the two or more image of the two or more second cross sections;   a gradient calculation unit configured to calculate a gradient of the interested blood vessel at the first cross section based on the two or more second blood vessel regions; and   a blood flow information generation unit configured to generate the blood flow information based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel.   
     
     
         13 . The blood flow measurement apparatus of  claim 3 , wherein
 the controller controls the scanner to perform, as the scan for acquiring the blood flow information, first scan that iteratively scans a first cross section of the interested blood vessel and second scan that scans two or more second cross sections, wherein at least one of the two or more second cross sections is different from the first cross section,   the image forming unit forms a phase image that represents chronological change in phase difference in the first cross section based on data acquired through the first scan, and forms two or more images of the two or more second cross sections based on data acquired through the second scan, and   the image processor comprises:   a blood vessel region specification unit configured to specify a first blood vessel region corresponding to the interested blood vessel in the phase image of the first cross section, and specify two or more second blood vessel regions corresponding to the interested blood vessel in the two or more image of the two or more second cross sections;   a gradient calculation unit configured to calculate a gradient of the interested blood vessel at the first cross section based on the two or more second blood vessel regions; and   a blood flow information generation unit configured to generate the blood flow information based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel.   
     
     
         14 . The blood flow measurement apparatus of  claim 5 , wherein the blood flow information generation unit comprises a blood flow velocity calculation unit configured to determine chronological change in blood flow velocity at the first cross section for blood flowing through the interested blood vessel based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel. 
     
     
         15 . The blood flow measurement apparatus of  claim 6 , wherein the blood flow information generation unit comprises a blood flow velocity calculation unit configured to determine chronological change in blood flow velocity at the first cross section for blood flowing through the interested blood vessel based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel. 
     
     
         16 . The blood flow measurement apparatus of  claim 7 , wherein the blood flow information generation unit comprises a blood flow velocity calculation unit configured to determine chronological change in blood flow velocity at the first cross section for blood flowing through the interested blood vessel based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel. 
     
     
         17 . The blood flow measurement apparatus of  claim 8 , wherein the blood flow information generation unit comprises a blood flow velocity calculation unit configured to determine chronological change in blood flow velocity at the first cross section for blood flowing through the interested blood vessel based on the first blood vessel region in the phase image of the first cross section and the gradient of the interested blood vessel.