1. Articles from Joseph M. Schmitt

    1-24 of 39 1 2 »
    1. Intravascular Measurement and Data Collection Systems, Apparatus and Methods

      Intravascular Measurement and Data Collection Systems, Apparatus and Methods

      A method and apparatus for determining properties of a tissue or tissues imaged by optical coherence tomography (OCT). In one embodiment the backscatter and attenuation of the OCT optical beam is measured and based on these measurements and indicium such as color is assigned for each portion of the image corresponding to the specific value of the backscatter and attenuation for that portion. The image is then displayed with the indicia and a user can then determine the tissue characteristics. In an alternative embodiment the tissue characteristics is classified automatically by a program given the combination of backscatter and attenuation ...

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      Mentions: St. Jude Medical
    2. Multimodal imaging system, apparatus, and methods

      Multimodal imaging system, apparatus, and methods

      In part, the invention relates to an image data collection system. The system can include an interferometer having a reference arm that includes a first optical fiber of length of L1 and a sample arm that includes a second optical fiber of length of L2 and a first rotary coupler configured to interface with an optical tomography imaging probe, wherein the rotary coupler is in optical communication with the sample arm. In one embodiment, L2 is greater than about 5 meters. The first optical fiber and the second optical fiber can both be disposed in a common protective sheath. In ...

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    3. Optical buffering methods, apparatus, and systems for increasing the repetition rate of tunable light sources

      Optical buffering methods, apparatus, and systems for increasing the repetition rate of tunable light sources

      In one embodiment, the invention relates to an apparatus for increasing the repetition rate in a light source. The apparatus includes a first optical coupler comprising a first arm, a second arm and a third arm; a first mirror in optical communication with the second arm of the first optical coupler; and a first optical delay line having a first end in optical communication with the third arm of the first optical coupler and a second end in optical communication with a second mirror, wherein light entering the first arm of the first optical coupler leaves the first arm of ...

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    4. Methods and apparatus for swept-source optical coherence tomography

      Methods and apparatus for swept-source optical coherence tomography

      A method and apparatus for tunable filter linearization of a Fourier-Domain Mode Locking (FDML) laser for a SS-OCT comprising the steps of: choosing a fundamental frequency that avoids the mechanical resonance frequencies of a tunable filter; summing two or three harmonically related sinusoids of the fundamental frequency; and tuning the amplitudes and phases of the summed sinusoids to compensate for nonuniformities in amplitude and phase responses of the tunable filter.

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    5. Intravascular Optical Coherence Tomography System with Pressure Monitoring Interface and Accessories

      Intravascular Optical Coherence Tomography System with Pressure Monitoring Interface and Accessories

      An optical coherence tomography system and method with integrated pressure measurement. In one embodiment the system includes an interferometer including: a wavelength swept laser; a source arm in communication with the wavelength swept laser; a reference arm in communication with a reference reflector; a first photodetector having a signal output; a detector arm in communication with the first photodetector, a probe interface; a sample arm in communication with a first optical connector of the probe interface; an acquisition and display system comprising: an A/D converter having a signal input in communication with the first photodetector signal output and a ...

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    6. Method of determining pressure in a vessel as measured by an optical pressure transducer in an optical coherence tomography system

      Method of determining pressure in a vessel as measured by an optical pressure transducer in an optical coherence tomography system

      An OCT system and method with integrated pressure measurement. In one embodiment, the system includes an interferometer; a wavelength swept laser; a source arm in communication with the wavelength swept laser; a reference arm in communication with a reference reflector; a first photoreceiver having a signal output; a detector arm in communication with the first photoreceiver, a probe interface; a sample arm in communication with a first optical connector of the probe interface; an acquisition and display system comprising: an A/D converter having a signal input in communication with the first photoreceiver signal output and a signal output; a ...

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    7. Swept mode-hopping laser system, methods, and devices for frequency-domain optical coherence tomography

      Swept mode-hopping laser system, methods, and devices for frequency-domain optical coherence tomography

      In part, the invention relates to frequency-domain optical coherence tomography system. The system includes a tunable laser comprising a laser output for transmitting laser light and a laser cavity having a length L, a gain element disposed within the laser cavity; a tunable wavelength selective element disposed within the laser cavity; a reference reflector disposed outside of the laser cavity; an interferometer in optical communication with the laser output and the reference reflector, wherein the interferometer is configured to transmit a portion of the laser light to a sample and combine light scattered from the sample with light scattered from ...

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    8. Phase-lock loop-based clocking system, methods and apparatus

      Phase-lock loop-based clocking system, methods and apparatus

      In part, the invention relates to an optical coherence tomography system that includes one or more phased-locked loop circuits. In one embodiment, the phased-locked loop circuit includes a phase detector, a loop filter, and a voltage controlled oscillator wherein the phased-locked loop circuit is configured to generate a sample clock. The optical coherence tomography system can include an analog to digital converter having a sample clock input, an interferometric signal input, and a sample data output, the analog to digital converter configured to receive the sample clock and sample OCT data in response thereto. In one embodiment, the phased-locked loop ...

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    9. Intravascular optical coherence tomography system with pressure monitoring interface and accessories

      Intravascular optical coherence tomography system with pressure monitoring interface and accessories

      An optical coherence tomography system and method with integrated pressure measurement. In one embodiment the system includes an interferometer including: a wavelength swept laser; a source arm in communication with the wavelength swept laser; a reference arm in communication with a reference reflector; a first photodetector having a signal output; a detector arm in communication with the first photodetector, a probe interface; a sample arm in communication with a first optical connector of the probe interface; an acquisition and display system comprising: an A/D converter having a signal input in communication with the first photodetector signal output and a ...

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    10. Volumetric assessment of lesion severity with optical coherence tomography: relationship with fractional flow reserve

      Volumetric assessment of lesion severity with optical coherence tomography: relationship with fractional flow reserve

      Aims: Frequency-domain optical coherence tomography (FD-OCT) provides a rapid tomographic scan of a coronary vessel, with an accurate reconstruction of its lumen profile. An FD-OCT-based metric that corresponds more closely with physiological significance of lesions may enable more precise guidance of interventional procedures. The aim of this feasibility study was to evaluate a new method for quantifying coronary lesion severity that estimates hyperaemic flow resistance of branched vessel segments imaged by FD-OCT. Methods and results: An analytical flow model was developed that relates fractional flow reserve (FFR) to the vascular resistance ratio (VRR), a measure of blood flow resistance derived ...

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    11. Extended coherence length megahertz FDML and its application for anterior segment imaging

      Extended coherence length megahertz FDML and its application for anterior segment imaging
      We present a 1300 nm Fourier domain mode locked (FDML) laser for optical coherence tomography (OCT) that combines both, a high 1.6 MHz wavelength sweep rate and an ultra-long instantaneous coherence length for rapid volumetric deep field imaging. By reducing the dispersion in the fiber delay line of the FDML laser, the instantaneous coherence length and hence the available imaging range is approximately quadrupled compared to previously published MHz-FDML setups, the imaging speed is increased by a factor of 16 compared to previous extended coherence length results. We present a detailed characterization of the FDML laser performance. We demonstrate ...
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    12. Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos)

      Structural markers observed with endoscopic 3-dimensional optical coherence tomography correlating with Barrett's esophagus radiofrequency ablation treatment response (with videos)

      Background Radiofrequency ablation (RFA) is effective for treating Barrett's esophagus (BE) but often involves multiple endoscopy sessions over several months to achieve complete response. Objective Identify structural markers that correlate with treatment response by using 3-dimensional (3-D) optical coherence tomography (OCT; 3-D OCT). Design Cross-sectional. Setting Single teaching hospital. Patients Thirty-three patients, 32 male and 1 female, with short-segment (<3 cm) BE undergoing RFA treatment. Intervention Patients were treated with focal RFA, and 3-D OCT was performed at the gastroesophageal junction before and immediately after the RFA treatment. Patients were re-examined with standard endoscopy 6 to 8 weeks later ...

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    13. Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

      Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography

      Two main nonsurgical endoscopic approaches for ablating dysplastic and early cancer lesions in the esophagus have gained popularity, namely, radiofrequency ablation (RFA) and cryospray ablation (CSA). We report a uniquely suited endoscopic and near-microscopic imaging modality, three-dimensional (3D) optical coherence tomography (OCT), to assess and compare the esophagus immediately after RFA and CSA. The maximum depths of architectural changes were measured and compared between the two treatment groups. RFA was observed to induce 230~260 

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    14. Cervical inlet patch-optical coherence tomography imaging and clinical significance

      Cervical inlet patch-optical coherence tomography imaging and clinical significance

      AIM: To demonstrate the feasibility of optical coherence tomography (OCT) imaging in differentiating cervical inlet patch (CIP) from normal esophagus, Barrett’s esophagus (BE), normal stomach and duodenum. METHODS: This study was conducted at the Veterans Affairs Boston Healthcare System (VABHS). Patients undergoing standard esophagogastroduodenoscopy at VABHS, including one patient with CIP, one representative patient with BE and three representative normal subjects were included. White light video endoscopy was performed and endoscopic 3D-OCT images were obtained in each patient using a prototype OCT system. The OCT imaging probe passes through the working channel of the endoscope to enable simultaneous video ...

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    15. Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

      Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos)

      Background: Radiofrequency ablation (RFA) is an endoscopic technique used to eradicate Barrett's esophagus (BE). However, such ablation can commonly lead to neosquamous epithelium overlying residual BE glands not visible by conventional endoscopy and may evade detection on random biopsy samples.Objective: To demonstrate the capability of endoscopic 3-dimensional optical coherence tomography (3D-OCT) for the identification and characterization of buried glands before and after RFA therapy.Design: Cross-sectional study.Setting: Single teaching hospital.Patients: Twenty-six male and 1 female white patients with BE undergoing RFA treatment.Interventions: 3D-OCT was performed at the gastroesophageal junction in 18 patients before attaining complete ...

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    16. Extended coherence length Fourier domain mode locked lasers at 1310 nm

      Extended coherence length Fourier domain mode locked lasers at 1310 nm
      Fourier domain mode locked (FDML) lasers are excellent tunable laser sources for frequency domain optical coherence tomography (FD-OCT) systems due to their combination of high sweep rates, large tuning ranges, and high output powers. However, conventional FDML lasers provide coherence lengths of only 4–10 mm, limiting their use in demanding applications such as intravascular OCT where coherence lengths of >20 mm are required for optimal imaging of large blood vessels. Furthermore, like most swept lasers, conventional FDML lasers produce only one useable sweep direction per tunable filter drive cycle, halving the effective sweep rate of the laser compared to ...
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    17. Automatic detection of stent struts with thick neointimal growth in intravascular optical coherence tomography image sequences

      Automatic detection of stent struts with thick neointimal growth in intravascular optical coherence tomography image sequences
      To assist cardiologists investigating neointimal tissue growth on stents during follow-up with optical coherence tomography (OCT), we developed an automatic algorithm to locate deeply buried stent struts and to quantify the restenosis burden. The technique is based on an improved steerable filter for computing the local ridge strength and orientation. It also uses an ellipsoid fitting algorithm and continuity criteria to obtain globally optimal stent localization. The restenosis burden calculations were compared to manual assessment of OCT coronary artery image data obtained from in vivo human clinical studies. Compared to manual assessment by expert readers, the algorithm operated with > 97 ...
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    18. Intravascular Optical Coherence Tomography System With Pressure Monitoring Interface And Accessories

      Intravascular Optical Coherence Tomography System With Pressure Monitoring Interface And Accessories
      An optical coherence tomography system and method with integrated pressure measurement. In one embodiment the system includes an interferometer including: a wavelength swept laser; a source arm in communication with the wavelength swept laser; a reference arm in communication with a reference reflector; a first photodetector having a signal output; a detector arm in communication with the first photodetector, a probe interface; a sample arm in communication with a first optical connector of the probe interface; an acquisition and display system comprising: an A/D converter having a signal input in communication with the first photodetector signal output and a ...
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    19. Opto-acoustic imaging devices and methods

      Opto-acoustic imaging devices and methods
      In one aspect, the invention relates to a probe. The probe includes a sheath, a flexible, bi-directionally rotatable, optical subsystem positioned within the sheath, the optical subsystem comprising a transmission fiber, the optical subsystem capable of transmitting and collecting light of a predetermined range of wavelengths along a first beam having a predetermined beam size. The probe also includes an ultrasound subsystem, the ultrasound subsystem positioned within the sheath and adapted to propagate energy of a predetermined range of frequencies along a second beam having a second predetermined beam size, wherein a portion of the first and second beams overlap ...
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    20. Methods and apparatus for swept-source optical coherence tomography

      Methods and apparatus for swept-source optical coherence tomography
      In one embodiment of the invention, a semiconductor optical amplifier (SOA) in a laser ring is chosen to provide low polarization-dependent gain (PDG) and a booster semiconductor optical amplifier, outside of the ring, is chosen to provide high polarization-dependent gain. The use of a semiconductor optical amplifier with low polarization-dependent gain nearly eliminates variations in the polarization state of the light at the output of the laser, but does not eliminate the intra-sweep variations in the polarization state at the output of the laser, which can degrade the performance of the SS-OCT system.
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    21. Optical coherence tomography apparatus and methods

      Optical coherence tomography apparatus and methods
      In one aspect, the invention relates to an imaging probe. The imaging probe includes an elongate body having a proximal end and distal end, the elongate body adapted to enclose a portion of a slidable optical fiber, the optical fiber having a longitudinal axis; and a first optical assembly attached to a distal end of the fiber. The first optical assembly includes a beam director adapted to direct light emitted from the fiber to a plane at a predetermined angle to the longitudinal axis, a linear actuator disposed at the proximal portion of the elongated body, the actuator adapted to ...
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    22. Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images

      Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images
      Coronary calcified plaque (CP) is both an important marker of atherosclerosis and major determinant of the success of coronary stenting. Intracoronary optical coherence tomography (OCT) with high spatial resolution can provide detailed volumetric characterization of CP. We present a semiautomatic method for segmentation and quantification of CP in OCT images. Following segmentation of the lumen, guide wire, and arterial wall, the CP was localized by edge detection and traced using a combined intensity and gradient-based level-set model. From the segmentation regions, quantification of the depth, area, angle fill fraction, and thickness of the CP was demonstrated. Validation by comparing the ...
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    23. Imaging catheter with integrated reference reflector

      Imaging catheter with integrated reference reflector
      In part, the invention relates to a lens assembly. The lens assembly includes a micro-lens; a beam director in optical communication with the micro-lens; and a substantially transparent film. The substantially transparent film is capable of bi-directionally transmitting light, and generating a controlled amount of backscatter. In addition, the film surrounds a portion of the beam director.
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    24. Features of Sub-Epithelial Glandular Structures on Three-Dimensional Endoscopic Optical Coherence Tomography (3D-EOCT) After Endoscopic Mucosal Ablation

      Features of Sub-Epithelial Glandular Structures on Three-Dimensional Endoscopic Optical Coherence Tomography (3D-EOCT) After Endoscopic Mucosal Ablation

      Abstracts submitted to ASGE 2010. Endoscopic mucosal ablative therapies are becoming accepted as a treatment for Barrett's esophagus (BE) with high-grade dysplasia. Radiofrequency ablation (RFA) has been shown to be effective in achieving broad and superficial BE ablation and replacement with normal-appearing squamous epithelium. Endoscopic optical coherence tomography (EOCT) is an imaging technique that uniquely allows visualization of sub-surface structures. The new three-dimensional EOCT (3D-EOCT) provides both cross-sectional and en face images of examined structures. 3D-EOCT may represent a novel method for post-ablation BE surveillance by revealing different glandular structures underneath the post-ablative surface epithelium.

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    1-24 of 39 1 2 »
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  2. Topics in the News

    1. (38 articles) Joseph M. Schmitt
    2. (37 articles) St. Jude Medical
    3. (11 articles) Desmond C. Adler
    4. (8 articles) Massachusetts Institute of Technology
    5. (8 articles) James G. Fujimoto
    6. (7 articles) Chao Zhou
    7. (7 articles) Tsung-Han Tsai
    8. (7 articles) Hiroshi Mashimo
    9. (6 articles) Harvard University
    10. (6 articles) Chris L. Petersen
    11. (1 articles) University of Lübeck
    12. (1 articles) University of Western Australia
    13. (1 articles) Erasmus University
    14. (1 articles) Robert A. Huber
    15. (1 articles) Gijs van Soest
    16. (1 articles) Fred K. Chen
    17. (1 articles) Corrado Tamburino
    18. (1 articles) Anton F. W. van der Steen
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    Scanning miniature optical probes with optical distortion correction and rotational control Effects of axial resolution improvement on optical coherence tomography (OCT) imaging of gastrointestinal tissues Current and future developments in intracoronary optical coherence tomography imaging Endoscopic 3D-OCT reveals buried glands following radiofrequency ablation of Barrett's esophagus Features of Sub-Epithelial Glandular Structures on Three-Dimensional Endoscopic Optical Coherence Tomography (3D-EOCT) After Endoscopic Mucosal Ablation Semiautomatic segmentation and quantification of calcified plaques in intracoronary optical coherence tomography images Characterization of buried glands before and after radiofrequency ablation by using 3-dimensional optical coherence tomography (with videos) Comparison of Tissue Architectural Changes between Radiofrequency Ablation and Cryospray Ablation in Barrett’s Esophagus Using Endoscopic Three-Dimensional Optical Coherence Tomography Intravitreal Ranibizumab Monotherapy or Combined with Laser for Diabetic Macular Edema (OCT guided study) Prospective evaluation of drug eluting self‐apposing stent for the treatment of unprotected left main coronary artery disease: 1‐year results of the TRUNC study Clinical validation of the RTVue optical coherence tomography angiography image quality indicators Intraoperative OCT-Assisted Retinal Detachment Repair in the DISCOVER Study: Impact and Outcomes