Tomografi keselarasan optik

Revisi sejak 8 Juli 2017 01.04 oleh JohnThorne (bicara | kontrib) (Perbaikan)

Optical coherence tomography (OCT) adalah sebuah teknik pencitraan medis yang menggunakan cahaya untuk menangkap gambar tiga dimensi beresolusi mikrometer dari dalam media hamburan optik (misalnya, jaringan biologis). Optical coherence tomography didasarkan pada Interferometri koherensi rendah, biasanya menggunakan cahaya inframerah dekat. Penggunaan yang cahaya dengan panjang gelombang relatif panjang memungkinkan untuk menembus ke dalam media hamburan. Confocal microscopy, teknik optik yang lain, biasanya menembus kurang dalam ke dalam sampel tetapi dengan resolusi yang lebih tinggi.

Optical coherence tomography
Intervensi
Optical Coherence Tomography (OCT) menghasilkan gambar suatu sarkoma
Kode OPS-3013-300

Tergantung pada sifat dari sumber cahaya (superluminescent dioda, ultrashort pulsed laser, dan supercontinuum laser sudah pernah digunakan), optical coherence tomography telah mencapai resolusi sub-mikrometer (dengan sumber spektrum sangat lebar memancarkan kisaran panjang gelombang lebih dari ~100 nm).

Pendahuluan

 
Optical coherence tomogram dari ujung jari. Meungkinkan untuk mengamati kelenjar keringat, yang memiliki "penampilan seperti uliran pembuka botol"

Mulai dari cahaya putih interferometri untuk in vivo okular mata pengukuran pencitraan dari jaringan biologis, terutama dari mata manusia, diselidiki oleh beberapa kelompok di seluruh dunia. Pertama dua dimensi di vivo penggambaran manusia fundus mata sepanjang meridian horizontal berdasarkan cahaya putih interferometric kedalaman scan disajikan di ICO-15 DUDUK konferensi pada tahun 1990. Selanjutnya dikembangkan pada tahun 1990 oleh Naohiro Tanno, kemudian seorang profesor di Yamagata University, dan khususnya sejak tahun 1991 oleh Huang et al., di Prof. James Fujimoto laboratorium di Institut Teknologi Massachusetts, optical coherence tomography (OCT) dengan mikrometer resolusi dan cross-sectional kemampuan pencitraan telah menjadi menonjol biomedis jaringan-teknik pencitraan; hal ini sangat cocok untuk aplikasi mata dan jaringan lain pencitraan yang membutuhkan mikrometer resolusi milimeter dan kedalaman penetrasi. Pertama di vivo OKT gambar – menampilkan retina struktur – diterbitkan pada tahun 1993, dan pertama endoskopi gambar pada tahun 1997. OCT juga telah digunakan untuk berbagai seni konservasi proyek, di mana ia digunakan untuk menganalisis lapisan yang berbeda dalam sebuah lukisan. OCT telah menarik keuntungan lain dari sistem pencitraan medis.

 
OCT scan retina di 800nm dengan resolusi aksial dari 3µm.

Kelebihan utama OCT adalah:

  • Gambar di bawah permukaan hidup-hidup dengan resolusi mendekati mikroskopik
  • Pencitraan segera dan langsung dari morfologi jaringan
  • Tanpa penyiapan sampel atau subyek
  • Tanpa radiasi yang menyebabkan ionisasi
 
Fig. 2 Typical optical setup of single point OCT. Scanning the light beam on the sample enables non-invasive cross-sectional imaging up to 3 mm in depth with micrometer resolution.
 
Fig. 1 Full-field OCT optical setup. Components include: super-luminescent diode (SLD), convex lens (L1), 50/50 beamsplitter (BS), camera objective (CO), CMOS-DSP camera (CAM), reference (REF), and sample (SMP). The camera functions as a two-dimensional detector array, and with the OCT technique facilitating scanning in depth, a non-invasive three dimensional imaging device is achieved.
 
Fig. 4 Spectral discrimination by fourier-domain OCT. Components include: low coherence source (LCS), beamsplitter (BS), reference mirror (REF), sample (SMP), diffraction grating (DG) and full-field detector (CAM) acting as a spectrometer, and digital signal processing (DSP)
 
Fig. 3 Spectral discrimination by swept-source OCT. Components include: swept source or tunable laser (SS), beamsplitter (BS), reference mirror (REF), sample (SMP), photodetector (PD), and digital signal processing (DSP)
|lay-date=September 4, 2013 |lay-source=Los Angeles Times }}</ref> Optical coherence tomography is also applicable and increasingly used in industrial applications, such as nondestructive testing (NDT), material thickness measurements,[1] and in particular thin silicon wafers[2][3] and compound semiconductor wafers thickness measurements[4][5] surface roughness characterization, surface and cross-section imaging[6][7] and volume loss measurements. OCT systems with feedback can be used to control manufacturing processes.

With high speed data acquisition,[8] and sub-micron resolution, OCT is adaptable to perform both inline and off-line.[9] Due to the high volume of produced pills, an interesting field of application is in the pharmaceutical industry to control the coating of tablets.[10] Fiber-based OCT systems are particularly adaptable to industrial environments.[11] These can access and scan interiors of hard-to-reach spaces,[12] and are able to operate in hostile environments—whether radioactive, cryogenic, or very hot.[13] Novel optical biomedical diagnostic and imaging technologies are currently being developed to solve problems in biology and medicine.[14] As of 2014, attempts have been made to use optical coherence tomography to identify root canals in teeth, specifically canal in the maxillary molar, however, there's no difference with the current methods of dental operatory microscope.[15][butuh sumber nonprimer] Research conducted in 2015 was successful in utilizing a smartphone as an OCT platform, although much work remains to be done before such a platform would be commercially viable.[16]

See also

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Referensi

  1. ^ B1 US patent 7116429 B1, Walecki, Wojciech J. & Van, Phuc, "Determining thickness of slabs of materials", dikeluarkan tanggal 2006-10-03, diberikan kepada Walecki, Wojciech J. dan Van, Phuc .
  2. ^ Walecki, Wojtek J.; Szondy, Fanny (2008). "Integrated quantum efficiency, reflectance, topography and stress metrology for solar cell manufacturing". Proc. SPIE. 7064: 70640A. doi:10.1117/12.797541. 
  3. ^ Walecki, Wojciech J.; Lai, Kevin; Pravdivtsev, Alexander; Souchkov, Vitali; Van, Phuc; Azfar, Talal; Wong, Tim; Lau, S.H.; Koo, Ann (2005). "Low-coherence interferometric absolute distance gauge for study of MEMS structures". Proc. SPIE. 5716: 182. doi:10.1117/12.590013. 
  4. ^ Walecki, W.J.; Lai, K.; Souchkov, V.; Van, P.; Lau, S.; Koo, A. (2005). "Novel noncontact thickness metrology for backend manufacturing of wide bandgap light emitting devices". Physica status solidi (c). 2: 984–989. doi:10.1002/pssc.200460606. 
  5. ^ Walecki, Wojciech; Wei, Frank; Van, Phuc; Lai, Kevin; Lee, Tim; Lau, S.H.; Koo, Ann (2004). "Novel low coherence metrology for nondestructive characterization of high-aspect-ratio microfabricated and micromachined structures". Proc. SPIE. 5343: 55. doi:10.1117/12.530749. 
  6. ^ Guss, G.; Bass, I.; Hackel, R.; Demos, S.G. (November 6, 2007). High-resolution 3-D imaging of surface damage sites in fused silica with Optical Coherence Tomography (PDF) (Laporan). Lawrence Livermore National Laboratory. UCRL-PROC-236270. Diakses tanggal December 14, 2010. 
  7. ^ Walecki, W; Wei, F; Van, P; Lai, K; Lee, T (2004). Interferometric Metrology for Thin and Ultra-Thin Compound Semiconductor Structures Mounted on Insulating Carriers (PDF). CS Mantech Conference. 
  8. ^ Walecki, Wojciech J.; Pravdivtsev, Alexander; Santos, Manuel, II; Koo,, Ann (August 2006). "High-speed high-accuracy fiber optic low-coherence interferometry for in situ grinding and etching process monitoring". Proc. SPIE. 6293: 62930D. doi:10.1117/12.675592. 
  9. ^ See, for example: "ZebraOptical Optoprofiler: Interferometric Probe". 
  10. ^ EP application 2799842, Markl, Daniel; Hannesschläger, Günther & Leitner, Michael et al., "A device and a method for monitoring a property of a coating of a solid dosage form during a coating process forming the coating of the solid dosage form", diterbitkan tanggal 2014-11-05 ; GB application 2513581 ; A1 US application 20140322429 A1 .
  11. ^ Walecki, Wojtek J.; Szondy, Fanny (30 April 2009). "Fiber optics low-coherence IR interferometry for defense sensors manufacturing" (PDF). Proc. SPIE. 7322: 73220K. doi:10.1117/12.818381. 
  12. ^ Dufour, Marc; Lamouche, Guy; Gauthier, Bruno; Padioleau, Christian; Monchalin, Jean-Pierre (13 December 2006). "Inspection of hard-to-reach industrial parts using small diameter probes" (PDF). SPIE - The International Society for Optical Engineering. doi:10.1117/2.1200610.0467. Diakses tanggal December 15, 2010. 
  13. ^ Dufour, M. L.; Lamouche, G.; Detalle, V.; Gauthier, B.; Sammut, P. (April 2005). "Low-Coherence Interferometry, an Advanced Technique for Optical Metrology in Industry". Insight - Non-Destructive Testing and Condition Monitoring. 47 (4): 216–219. doi:10.1784/insi.47.4.216.63149. ISSN 1354-2575. 
  14. ^ Boppart, Stephen (11 June 2014). "Developing new optical imaging techniques for clinical use". SPIE. doi:10.1117/2.3201406.03. 
  15. ^ Iino, Y; Ebihara, A; Yoshioka, T; Kawamura, J; Watanabe, S; Hanada, T; Nakano, K; Sumi, Y; Suda, H (November 2014). "Detection of a second mesiobuccal canal in maxillary molars by swept-source optical coherence tomography". Journal of Endodontics. 40 (11): 1865–1868. doi:10.1016/j.joen.2014.07.012. PMID 25266471. 
  16. ^ Subhash, Hrebesh M.; Hogan, Josh N.; Leahy, Martin J. (May 2015). "Multiple-reference optical coherence tomography for smartphone applications". SPIE. doi:10.1117/2.1201503.005807.