Japan (JA)
国・地域を選択してください。
補償光学技術と眼底イメージング
補償光学（Adaptive Optics; AO）は、観察対象や光学機器内部などで発生した波面収差を波面センサで計測し、それを動的に補正することで得られる画質を直接的に改善させる技術です。この補正には光路長を直接的に変えるデフォーマブルミラーなどの利用がありますが、当社はより高精細に補正するために、屈折率変化により光の位相を局所的かつ精細にシフトさせられる空間光位相変調器（LCOS-SLM）を用いた技術を研究しています。現在の主要な補償光学アプリケーションは、眼底イメージングの分野にあり、人間の網膜の高解像度画像を得ることができます。
LCOS-SLMを用いた補償光学技術を眼底観察に適用し、眼底を数ミクロンの空間分解能で（視細胞が見える程度）の計測が可能になります。図1は補償光学眼底イメージング装置の概要を示します。レーザ安全基準を十分にクリアした弱い光を人眼に照射し、眼底から散乱されて戻ってくる光はLCOS-SLMを経て、波面センサに入射されます。波面センサはマイクロレンズアレイと高感度なビジョンカメラから構成されています。この波面センサは眼球光学系とイメージング機器により生じた波面の歪みを計測します。負帰還制御は波面センサで計測された波面歪みを基に、出力波面が平面波（或いは所望の曲率の球面波）になるようにLCOS-SLMへの入力信号をコントロールします。
撮像結果
図2は収差補正の効果を示す例です。歪み補正が動作しない場合はボケた像しか得られませんでした（左のWithout AO Correction）。これでは観察に使える有用な情報を得ることができません。しかし、歪み補正を動作すると、視細胞（明るい輝点）が鮮明に見えるようになります（右のWith AO Correction）。人眼の最も小さい視細胞は2 µm～3 µmしかないため、視細胞を観察するには補償光学の適用が必須であることが分かります。
図2.撮像結果
網膜は多層構造であることが知られています。焦点深さ位置を制御することにより、網膜の各層の組織を描出することが可能となります。図3はLCOS-SLMで視細胞、血管、神経線維の層に焦点位置制御も同時に行い得られた撮像例です。左の視細胞像は明るい輝点が光を感知する視細胞を示します。視細胞の像から、例えば視細胞の分布密度・配列の異常や欠損の有無などを検出することが可能となります。真ん中の血管・血球の像では2分岐の血管が見られ、また、血管壁（黒い線状のもの）と血管中の血球（2つの黒い線状間にある明るい部分）の観察や、連続の動画記録による血流の計測も可能となります。右側の神経線維の像では左上から右下へはしる神経線維の束が見られます。観察される高分解能の眼底像を分析することにより、高度医療技術への展開が期待されています。
図3.深さ方向の撮像結果
参考文献
- H. Huang, T. Inoue and H. Tanaka, “Stabilized high-accuracy correlation of ocular aberrations with liquid crystal on silicon spatial light modulator in adaptive optics retinal imaging system,” Optics Express 19(16), 15026-15040 (2011).
- H. Huang, T. Inoue, H. Toyota, and H. Tsutomu, “Long-term stable and high performance adaptive optics system using liquid crystal on silicon spatial light modulator for high resolution retinal imaging,” Proc. SPIE, 8200, 820002(2011).
- H. Huang, et. al., “Adaptive optics scanning laser ophthalmoscope using liquid crystal on silicon spatial light modulator: Performance study with involuntary eye movement,” Japanese Journal of Applied Physics, 56(9S), 09NB02(2017).
- Confirmation
-
It looks like you're in the . If this is not your location, please select the correct region or country below.
You're headed to Hamamatsu Photonics website for JP (Japanese). If you want to view an other country's site, the optimized information will be provided by selecting options below.
In order to use this website comfortably, we use cookies. For cookie details please see our cookie policy.
- Cookie Policy
-
This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in this cookie policy. By closing the cookie warning banner, scrolling the page, clicking a link or continuing to browse otherwise, you agree to the use of cookies.
Hamamatsu uses cookies in order to enhance your experience on our website and ensure that our website functions.
You can visit this page at any time to learn more about cookies, get the most up to date information on how we use cookies and manage your cookie settings. We will not use cookies for any purpose other than the ones stated, but please note that we reserve the right to update our cookies.
1. What are cookies?
For modern websites to work according to visitor’s expectations, they need to collect certain basic information about visitors. To do this, a site will create small text files which are placed on visitor’s devices (computer or mobile) - these files are known as cookies when you access a website. Cookies are used in order to make websites function and work efficiently. Cookies are uniquely assigned to each visitor and can only be read by a web server in the domain that issued the cookie to the visitor. Cookies cannot be used to run programs or deliver viruses to a visitor’s device.
Cookies do various jobs which make the visitor’s experience of the internet much smoother and more interactive. For instance, cookies are used to remember the visitor’s preferences on sites they visit often, to remember language preference and to help navigate between pages more efficiently. Much, though not all, of the data collected is anonymous, though some of it is designed to detect browsing patterns and approximate geographical location to improve the visitor experience.
Certain type of cookies may require the data subject’s consent before storing them on the computer.
2. What are the different types of cookies?
This website uses two types of cookies:
- First party cookies. For our website, the first party cookies are controlled and maintained by Hamamatsu. No other parties have access to these cookies.
- Third party cookies. These cookies are implemented by organizations outside Hamamatsu. We do not have access to the data in these cookies, but we use these cookies to improve the overall website experience.
3. How do we use cookies?
This website uses cookies for following purposes:
- Certain cookies are necessary for our website to function. These are strictly necessary cookies and are required to enable website access, support navigation or provide relevant content. These cookies direct you to the correct region or country, and support security and ecommerce. Strictly necessary cookies also enforce your privacy preferences. Without these strictly necessary cookies, much of our website will not function.
- Analytics cookies are used to track website usage. This data enables us to improve our website usability, performance and website administration. In our analytics cookies, we do not store any personal identifying information.
- Functionality cookies. These are used to recognize you when you return to our website. This enables us to personalize our content for you, greet you by name and remember your preferences (for example, your choice of language or region).
- These cookies record your visit to our website, the pages you have visited and the links you have followed. We will use this information to make our website and the advertising displayed on it more relevant to your interests. We may also share this information with third parties for this purpose.
Cookies help us help you. Through the use of cookies, we learn what is important to our visitors and we develop and enhance website content and functionality to support your experience. Much of our website can be accessed if cookies are disabled, however certain website functions may not work. And, we believe your current and future visits will be enhanced if cookies are enabled.
4. Which cookies do we use?
There are two ways to manage cookie preferences.
- You can set your cookie preferences on your device or in your browser.
- You can set your cookie preferences at the website level.
If you don’t want to receive cookies, you can modify your browser so that it notifies you when cookies are sent to it or you can refuse cookies altogether. You can also delete cookies that have already been set.
If you wish to restrict or block web browser cookies which are set on your device then you can do this through your browser settings; the Help function within your browser should tell you how. Alternatively, you may wish to visit www.aboutcookies.org, which contains comprehensive information on how to do this on a wide variety of desktop browsers.
5. What are Internet tags and how do we use them with cookies?
Occasionally, we may use internet tags (also known as action tags, single-pixel GIFs, clear GIFs, invisible GIFs and 1-by-1 GIFs) at this site and may deploy these tags/cookies through a third-party advertising partner or a web analytical service partner which may be located and store the respective information (including your IP-address) in a foreign country. These tags/cookies are placed on both online advertisements that bring users to this site and on different pages of this site. We use this technology to measure the visitors' responses to our sites and the effectiveness of our advertising campaigns (including how many times a page is opened and which information is consulted) as well as to evaluate your use of this website. The third-party partner or the web analytical service partner may be able to collect data about visitors to our and other sites because of these internet tags/cookies, may compose reports regarding the website’s activity for us and may provide further services which are related to the use of the website and the internet. They may provide such information to other parties if there is a legal requirement that they do so, or if they hire the other parties to process information on their behalf.
If you would like more information about web tags and cookies associated with on-line advertising or to opt-out of third-party collection of this information, please visit the Network Advertising Initiative website http://www.networkadvertising.org.
6. Analytics and Advertisement Cookies
We use third-party cookies (such as Google Analytics) to track visitors on our website, to get reports about how visitors use the website and to inform, optimize and serve ads based on someone's past visits to our website.
You may opt-out of Google Analytics cookies by the websites provided by Google:
https://tools.google.com/dlpage/gaoptout?hl=en
As provided in this Privacy Policy (Article 5), you can learn more about opt-out cookies by the website provided by Network Advertising Initiative:
http://www.networkadvertising.org
We inform you that in such case you will not be able to wholly use all functions of our website.
Close