Photoacoustic measurement apparatus and photoacoustic measurement system

Patent metadata

Field	Value
Publication number	US-2017296061-A1
Application number	US-201715636947-A
Country	US
Kind code	A1
Filing date	Jun 29, 2017
Priority date	Jan 8, 2015
Publication date	Oct 19, 2017
Grant date	—

Abstract

In a photoacoustic measurement apparatus and a photoacoustic measurement system, blood flow information in a desired region can be generated using a photoacoustic image. A light source emits measurement light. A probe detects a photoacoustic wave generated in a subject after measurement light is emitted to the subject in each of the avascularized condition in which the subject is avascularized and the non-avascularized condition in which the subject is not avascularized. Photoacoustic image generation unit generates a photoacoustic image based on the detection signal of the photoacoustic wave. Blood flow information generation unit generates blood flow information based on the signal value of a photoacoustic image in a region of interest set in the photoacoustic image.

First claim

What is claimed is:

1 . A photoacoustic measurement apparatus, comprising:
a receiving circuit that receives a detection signal of a photoacoustic wave, which is generated in a subject due to emission of measurement light to the subject, in each of at least an avascularized condition in which the subject is avascularized and a non-avascularized condition in which the subject is not avascularized; a photoacoustic image generation unit for generating a photoacoustic image based on the detection signal of the photoacoustic wave; and a blood flow information generation unit for generating blood flow information based on a signal value of the photoacoustic image in a region of interest set in the photoacoustic image.

2 . The photoacoustic measurement apparatus according to claim 1 , further comprising:
a tourniquet capable of changing a cuff pressure in order to bring the subject into the avascularized condition and the non-avascularized condition.

3 . The photoacoustic measurement apparatus according to claim 2 , further comprising:
a cuff pressure control unit for controlling a cuff pressure of the tourniquet.

4 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the blood flow information generation unit binarizes the signal value by setting the signal value to a first value when the signal value is equal to or greater than a first threshold value and equal to or less than a second threshold value larger than the first threshold value and setting the signal value to a second value different from the first value when the signal value is less than the first threshold value or greater than the second threshold value, and generates the blood flow information based on the binarized signal value.

5 . The photoacoustic measurement apparatus according to claim 2 ,
wherein the blood flow information generation unit binarizes the signal value by setting the signal value to a first value when the signal value is equal to or greater than a first threshold value and equal to or less than a second threshold value larger than the first threshold value and setting the signal value to a second value different from the first value when the signal value is less than the first threshold value or greater than the second threshold value, and generates the blood flow information based on the binarized signal value.

6 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the blood flow information generation unit further generates a graph showing a relationship between the blood flow information and time.

7 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the receiving circuit further receives a detection signal of a reflected acoustic wave with respect to an acoustic wave transmitted to the subject, the photoacoustic measurement apparatus further comprising, a reflected acoustic wave image generation unit for generating a reflected acoustic wave image based on the detection signal of the reflected acoustic wave; and a region-of-interest tracking unit for tracking a position of the region of interest using the reflected acoustic wave image are further provided.

8 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the blood flow information generation unit generates, as blood flow information, a total value or an average value of the signal value in the region of interest.

9 . The photoacoustic measurement apparatus according to claim 1 , further comprising:
a pressure measurement unit for measuring an avascularization pressure of the subject, wherein the blood flow information generation unit further generates a graph showing a relationship between the blood flow information and the avascularization pressure.

10 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the blood flow information generation unit calculates a total value or an average value of the signal value in the region of interest, and generates, as the blood flow information, a score value based on a difference between a minimum value and a maximum value of the total value or the average value in a certain period.

11 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the blood flow information generation unit generates, as the blood flow information, a score value based on a difference between a total value or an average value of the signal value in the region of interest in the avascularized condition and a total value or an average value of the signal value in the region of interest in the non-avascularized condition.

12 . The photoacoustic measurement apparatus according to claim 1 ,
wherein, in a case where the subject is changed from the avascularized condition to the non-avascularized condition, the blood flow information generation unit generates, as the blood flow information, a score value based on a time change rate of a total value or an average value of the signal value in the region of interest.

13 . The photoacoustic measurement apparatus according to claim 1 ,
wherein, in a case where the subject is changed from the avascularized condition to the non-avascularized condition, the blood flow information generation unit generates, as the blood flow information, a score value based on a total value or an average value of the signal value in the region of interest after a certain time has passed from a reference time.

14 . The photoacoustic measurement apparatus according to claim 1 ,
wherein, in a case where the subject is changed from the avascularized condition to the non-avascularized condition, the blood flow information generation unit generates, as the blood flow information, a score value based on a time from a reference time to a time at which a total value or an average value of the signal value in the region of interest reaches a certain level.

15 . The photoacoustic measurement apparatus according to claim 1 ,
wherein the blood flow information generation unit further generates a blood flow information image based on the blood flow information.

16 . The photoacoustic measurement apparatus according to claim 15 ,
wherein, in a case where a plurality of the regions of interest are set, the blood flow information is generated for each of the plurality of regions of interest, and the blood flow information image is a space map image for displaying blood flow information of each region of interest in the region of interest.

17 . The photoacoustic measurement apparatus according to claim 16 ,
wherein, in the blood flow information image, each region of interest is displayed with a brightness corresponding to the blood flow information.

18 . The photoacoustic measurement apparatus according to claim 16 ,
wherein the blood flow information generation unit sets a display color of each region of interest in the blood flow information image to a different display color in a case where blood flow information at a first time is larger than blood flow information at a second time earlier than the first time and a case where the blood flow information at the first time is smaller than the blood flow information at the second time.

19 . The photoacoustic measurement apparatus according to claim 1 ,
wherein a plurality of the regions of interest are set in a grid form.

20 . A photoacoustic measurement system, comprising:
a light source that emits measurement light; and the photoacoustic measurement apparatus according to claim 1 .

Assignees

• Fujifilm Corp

Inventors

• Murakoshi Dai
• Irisawa Kaku
• Ebata Tetsuro
• Hara Shoji

Classifications

• A61B8/5223

  for extracting a diagnostic or physiological parameter from medical diagnostic data (for algorithms to analyse biomedical images G06T7/0012) · CPC title

• A61B5/0095 Primary

  by applying light and detecting acoustic waves, i.e. photoacoustic measurements · CPC title

• A61B8/4416 Primary

  related to combined acquisition of different diagnostic modalities, e.g. combination of ultrasound and X-ray acquisitions · CPC title

• A61B5/0261

  using optical means, e.g. infrared light · CPC title

• A61B8/5207

  involving processing of raw data to produce diagnostic data, e.g. for generating an image · CPC title