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Shadfan A, Darwiche H, Blanco J, Gillenwater A, Richards-Kortum R, Tkaczyk TS. Development of a multimodal foveated endomicroscope for the detection of oral cancer. Biomed Opt Express 2017; 8:1525-1535. [PMID: 28663847 PMCID: PMC5480562 DOI: 10.1364/boe.8.001525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 02/06/2017] [Accepted: 02/06/2017] [Indexed: 05/11/2023]
Abstract
A multimodal endomicroscope was developed for cancer detection that combines hyperspectral and confocal imaging through a single foveated objective and a vibrating optical fiber bundle. Standard clinical examination has a limited ability to identify early stage oral cancer. Optical detection methods are typically restricted by either achievable resolution or a small field-of-view. By combining high resolution and widefield spectral imaging into a single probe, a device was developed that provides spectral and spatial information over a 5 mm field to locate suspicious lesions that can then be inspected in high resolution mode. The device was evaluated on ex vivo biopsies of human oral tumors.
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Affiliation(s)
- Adam Shadfan
- Rice University, Bioengineering Department, 6100 Main Street, Houston, TX 77005, USA
| | - Hawraa Darwiche
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
| | - Jesus Blanco
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
| | - Ann Gillenwater
- Department of Head and Neck Surgery, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA
| | | | - Tomasz S. Tkaczyk
- Rice University, Bioengineering Department, 6100 Main Street, Houston, TX 77005, USA
- Rice University, Electrical and Computer Engineering, 6100 Main Street, Houston, TX 77005, USA
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Subramanian K, Gabay I, Ferhanoğlu O, Shadfan A, Pawlowski M, Wang Y, Tkaczyk T, Ben-Yakar A. Kagome fiber based ultrafast laser microsurgery probe delivering micro-Joule pulse energies. Biomed Opt Express 2016; 7:4639-4653. [PMID: 27896003 PMCID: PMC5119603 DOI: 10.1364/boe.7.004639] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/12/2016] [Accepted: 10/13/2016] [Indexed: 05/22/2023]
Abstract
We present the development of a 5 mm, piezo-actuated, ultrafast laser scalpel for fast tissue microsurgery. Delivery of micro-Joules level energies to the tissue was made possible by a large, 31 μm, air-cored inhibited-coupling Kagome fiber. We overcome the fiber's low NA by using lenses made of high refractive index ZnS, which produced an optimal focusing condition with 0.23 NA objective. The optical design achieved a focused laser spot size of 4.5 μm diameter covering a 75 × 75 μm2 scan area in a miniaturized setting. The probe could deliver the maximum available laser power, achieving an average fluence of 7.8 J/cm2 on the tissue surface at 62% transmission efficiency. Such fluences could produce uninterrupted, 40 μm deep cuts at translational speeds of up to 5 mm/s along the tissue. We predicted that the best combination of speed and coverage exists at 8 mm/s for our conditions. The onset of nonlinear absorption in ZnS, however, limited the probe's energy delivery capabilities to 1.4 μJ for linear operation at 1.5 picosecond pulse-widths of our fiber laser. Alternatives like broadband CaF2 crystals should mitigate such nonlinear limiting behavior. Improved opto-mechanical design and appropriate material selection should allow substantially higher fluence delivery and propel such Kagome fiber-based scalpels towards clinical translation.
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Affiliation(s)
- Kaushik Subramanian
- Department of Mechanical Engineering, The University of Texas at Austin, Texas 78712, USA
- These authors contributed equally to this work
| | - Ilan Gabay
- Department of Mechanical Engineering, The University of Texas at Austin, Texas 78712, USA
- These authors contributed equally to this work
| | - Onur Ferhanoğlu
- Department of Mechanical Engineering, The University of Texas at Austin, Texas 78712, USA
| | - Adam Shadfan
- Department of Bioengineering, Rice University, Houston 77005, USA
| | - Michal Pawlowski
- Department of Bioengineering, Rice University, Houston 77005, USA
| | - Ye Wang
- Department of Bioengineering, Rice University, Houston 77005, USA
| | - Tomasz Tkaczyk
- Department of Bioengineering, Rice University, Houston 77005, USA
| | - Adela Ben-Yakar
- Department of Mechanical Engineering, The University of Texas at Austin, Texas 78712, USA
- Department of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA
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Shadfan A, Pawlowski M, Wang Y, Subramanian K, Gabay I, Ben-Yakar A, Tkaczyk T. Design and fabrication of a miniature objective consisting of high refractive index zinc sulfide lenses for laser surgery. Opt Eng 2016; 55:025107. [PMID: 28579656 PMCID: PMC5450972 DOI: 10.1117/1.oe.55.2.025107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A miniature laser ablation probe relying on an optical fiber to deliver light requires a high coupling efficiency objective with sufficient magnification in order to provide adequate power and field for surgery. A diffraction-limited optical design is presented that utilizes high refractive index zinc sulfide to meet specifications while reducing the miniature objective down to two lenses. The design has a hypercentric conjugate plane on the fiber side and is telecentric on the tissue end. Two versions of the objective were built on a diamond lathe-a traditional cylindrical design and a custom-tapered mount. Both received an antireflective coating. The objectives performed as designed in terms of observable resolution and field of view as measured by imaging a 1951 USAF resolution target. The slanted edge technique was used to find Strehl ratios of 0.75 and 0.78, respectively, indicating nearly diffraction-limited performance. Finally, preliminary ablation experiments indicated threshold fluence of gold film was comparable to similar reported probes.
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Affiliation(s)
- Adam Shadfan
- Rice University, Tkaczyk Group, Department of Bioengineering, 6100 Main Street, Houston, Texas 77005, United States
| | - Michal Pawlowski
- Rice University, Tkaczyk Group, Department of Bioengineering, 6100 Main Street, Houston, Texas 77005, United States
| | - Ye Wang
- Rice University, Tkaczyk Group, Department of Bioengineering, 6100 Main Street, Houston, Texas 77005, United States
| | - Kaushik Subramanian
- University of Texas at Austin, Ben-Yakar Group, Mechanical Engineering Department, 1 University Station C2200, Austin, Texas 78712, United States
| | - Ilan Gabay
- University of Texas at Austin, Ben-Yakar Group, Mechanical Engineering Department, 1 University Station C2200, Austin, Texas 78712, United States
| | - Adela Ben-Yakar
- University of Texas at Austin, Ben-Yakar Group, Mechanical Engineering Department, 1 University Station C2200, Austin, Texas 78712, United States
- University of Texas at Austin, Ben-Yakar Group, Biomedical Engineering Department, 1 University Station C0800, Austin, Texas 78712, United States
| | - Tomasz Tkaczyk
- Rice University, Tkaczyk Group, Department of Bioengineering, 6100 Main Street, Houston, Texas 77005, United States
- Rice University, Electrical and Computer Engineering Department, 6100 Main Street, Houston, Texas 77005-1892, United States
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Abstract
By mimicking the variable resolution of the human eye, a newly designed foveated endomicroscopic objective shows the potential to improve current endoscopic based techniques of identifying abnormal tissue in the esophagus and colon. The prototype miniature foveated objective is imaged with a confocal microscope to provide large field of view images combined with a high resolution central region to rapidly observe morphological structures associated with cancer development in a mouse model.
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