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OBJECT TRACKING DEVICE

Foreign code F190009831
File No. S2017-0464-C0
Posted date Jul 24, 2019
Country WIPO
International application number 2018JP007873
International publication number WO 2018159775
Date of international filing Mar 1, 2018
Date of international publication Sep 7, 2018
Priority data
  • P2017-041111 (Mar 3, 2017) JP
Title OBJECT TRACKING DEVICE
Abstract Provided is an object tracking device that comprises: a superimposed image creation unit (C6) that creates a plurality of superimposed images (26) in which each of a plurality of images of untracked objects not including tracking object image characteristics is superimposed on a tracking object section image (23) that includes tracking object image characteristics (21); a discriminator creation unit (C9) that creates a discriminator by learning at least the image characteristics of the tracking object or the position thereof on the basis of the plurality of superimposed images (26); and a tracking object identification unit (C12) that, on the basis of the discriminator and a tracked image (28) that includes the image characteristics of the tracking object and of an obstacle, identifies at least the image characteristics of the tracking object or the position thereof in the tracked image (28). As a result of the foregoing, the object tracking device makes it possible for the location of the tracking object to be identified more easily without being affected by obstacles, as compared to the image tracking methods based on the template matching of the prior art.
Outline of related art and contending technology BACKGROUND ART
In the case of performing treatment such as radiation therapy, the subject's respiration or heart beat (patient) and the like, the position of the treatment of the target object is moved (such as a tumor), radiation in the portion other than the target object is not irradiated (normal tissues) in order to, X-ray fluoroscopic image is captured in real-time tracking of the target object and its position is determined, the radiation of the target object as the irradiation position is moved only when the radiation needs to be irradiated. In addition, the captured image of the target object identifying and tracking the position of the irradiation position of the radiation induced technique, induced by the object tracking technique is a so-called image, X-ray fluoroscopic image is typically used, but are not limited to this. For example, X-ray fluoroscopic image as well, ultrasonic image, MRI(Magnetic Resonance Imaging: nuclear magnetic resonance imaging) image, image CT (Computed Tomography), PET(Positron Emission Tomography: positron emission tomography) image can also be used. The position of the target object as a technique for tracking, is known the following techniques.
Patent Document 1 (Patent Publication 5610441) is, by the X-ray fluoroscopy is assumed at the time of tracking the marker-less tracking performance degradation, the complementary information of the outside of the described technology. That is, a lesion such as cancer treatment including a target object based on the template image, at the time of treatment of a therapeutic target for detecting the position of the X-ray image in each frame by the perspective processing of pattern matching, as a therapeutic target position from the preset irradiation position within the predetermined error range, and, due to respiration or the like (pseudo-periodic) motion of the substantially periodic irradiation in order to minimize the deviation, suitable as the application timing (the surface which is set based on the movement of) the time (phase) within a window of the therapeutic radiation irradiated to the target tracking technique. In addition, in Patent Document 1, in order to improve the accuracy of the determination of the position of a therapeutic target, such as a bone or a different therapeutic target for the diaphragm as position information in reference to the non-tracking object, as described in the pattern matching may be performed.
Patent Document 2 (Patent Publication 3053389) is, a metal marker is inserted into the patient's body in the vicinity of the X-ray fluoroscopy technique to increase the tracking accuracy of the tracking of the tumor has been described. That is, embedded in the vicinity of the target tumor therapeutic target for treatment of the tumor marker from a plurality of directions in the X-ray perspective view of the solid-state imaging device, the tracking target (tumor) registered in advance in the template image and a grayscale of the marker is subjected to template matching by the normalized cross-correlation, the position of the tumor marker 3 specified by the two-dimensional technique are described.
Patent Document 3 (Patent Publication 4505639) is, in the same manner as Patent Document 2 is subjected to template matching by the gray-scale normalized correlation between the position of the tumor marker, the time-series position data may be acquired in advance, from the data acquired in advance, to estimate the location of a tumor marker at the current time is a technique.
Patent Document 4 (International Publication No. JP-2015/125600) is, obtained by continuous X-ray image, created for different respiratory phases by executing the template matching, the position of the treatment target portion in each breathing phase specific to the technology. In the technique described in Patent Document 4, the treatment target portion and the position of the reference respiratory phase, respiratory phase of a plurality of consecutive three-dimensional treatment target site in the X-ray image data 3, respiratory phase different between the X-ray image of the treatment target portion and the deformation amount, the treatment target portion in each respiratory phase and acquires the position of the template was created.
Scope of claims (In Japanese)[請求項1]
 追跡対象の画像特徴を含む追跡対象部画像に、前記画像特徴を含まない複数からなる非追跡対象画像のそれぞれを重ねた複数の重畳画像を作成する重畳画像作成部と、
 前記複数の重畳画像に基づいて、前記追跡対象の画像特徴および位置情報の少なくとも一方を学習して識別器を作成する識別器作成部と、
 前記識別器と、前記追跡対象の画像特徴を含む被追跡画像とに基づいて、前記被追跡画像における前記追跡対象の画像特徴および位置情報の少なくとも一方を特定する追跡対象特定部と、
 を備えたことを特徴とする対象追跡装置。

[請求項2]
 前記追跡対象の画像特徴を特定する教師画像を予め入力する入力部と、
 前記複数の重畳画像と前記教師画像に基づいて、前記追跡対象の画像特徴および位置情報の少なくとも一方を学習して識別器を作成する前記識別器作成部と、
 を備えたことを特徴とする請求項1に記載の対象追跡装置。

[請求項3]
 前記追跡対象の画像特徴の大きさと、画像の分解能と、予め設定された追跡精度とに基づいて、前記非追跡対象画像の枚数を導出して、導出された枚数に応じた前記非追跡対象画像を作成する非追跡対象画像編集部、
 を備えたことを特徴とする請求項1または2に記載の対象追跡装置。

[請求項4]
 前記追跡対象の画像特徴を含む学習用の元画像から、前記追跡対象の画像特徴を含む追跡対象部画像と、前記追跡対象の画像特徴を含まない分離非追跡対象画像とに分離抽出する画像分離部と、
 前記分離非追跡対象画像を編集して複数からなる前記非追跡対象画像を編集作成する非追跡対象画像編集部と、
 前記追跡対象部画像と前記非追跡対象画像とに基づいて前記重畳画像を作成する前記重畳画像作成部と 
 を備えたことを特徴とする請求項1ないし3のいずれかに記載の対象追跡装置。

[請求項5]
 前記追跡対象の画像特徴を含む元画像から、前記追跡対象の画像特徴を含む追跡対象部画像と、前記追跡対象の画像特徴を含まない分離非追跡対象画像とに分離する画像分離部と、
 前記元画像に含まれず且つ前記被追跡画像に含まれる障害物の画像を取得する障害物画像取得部と、
 前記分離非追跡対象画像と前記障害物の画像との少なくとも1つを編集して複数からなる前記非追跡対象画像を編集作成する非追跡対象画像編集部と、
 前記追跡対象部画像と前記非追跡対象画像とに基づいて前記重畳画像を作成する前記重畳画像作成部と、
 を備えたことを特徴とする請求項1ないし3のいずれかに記載の対象追跡装置。

[請求項6]
 前記追跡対象の画像特徴を含む学習用の元画像から、前記追跡対象の画像特徴の画像コントラスト情報に基づき、前記追跡対象部画像と前記分離非追跡対象画像とに分離抽出する前記画像分離部と、
 を備えたことを特徴とする請求項4または5に記載の対象追跡装置。

[請求項7]
 追跡対象の画像特徴および位置情報の少なくとも一方が予め設定された評価用の画像と、前記識別器とに基づいて、追跡対象の追跡の精度を評価する追跡精度評価部、
 を備えたことを特徴とする請求項1ないし6のいずれかに記載の対象追跡装置。

[請求項8]
 前記追跡精度評価部による追跡の精度が、予め設定された精度に達しない場合に、前記非追跡対象画像の枚数を増やして前記識別器を再作成する前記識別器作成部、
 を備えたことを特徴とする請求項7に記載の対象追跡装置。

  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • UNIVERSITY OF TSUKUBA
  • Inventor
  • TERUNUMA Toshiyuki
  • SAKAE Takeji
IPC(International Patent Classification)
Specified countries National States: AE AG AL AM AO AT AU AZ BA BB BG BH BN BR BW BY BZ CA CH CL CN CO CR CU CZ DE DJ DK DM DO DZ EC EE EG ES FI GB GD GE GH GM GT HN HR HU ID IL IN IR IS JO JP KE KG KH KN KP KR KW KZ LA LC LK LR LS LU LY MA MD ME MG MK MN MW MX MY MZ NA NG NI NO NZ OM PA PE PG PH PL PT QA RO RS RU RW SA SC SD SE SG SK SL SM ST SV SY TH TJ TM TN TR TT TZ UA UG US UZ VC VN ZA ZM ZW
ARIPO: BW GH GM KE LR LS MW MZ NA RW SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ RU TJ TM
EPO: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW KM ML MR NE SN ST TD TG
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