Large phase II trials of fluorescence and reflectance spectroscopy using a fiber optic probe in the screening and diagnostic settings for detecting cervical neoplasia have been conducted. We present accrual and histopathology data, instrumentation, data processing, and the preliminary results of interdevice consistencies throughout the progression of a trial. Patients were recruited for either a screening trial (no history of abnormal Papanicolaou smears) or a diagnostic trial (a history of abnormal Papanicolaou smears). Colposcopy identified normal and abnormal squamous, columnar, and transformation zone areas that were subsequently measured with the fiber probe and biopsied. In the course of the clinical trial, two generations of spectrometers (FastEEM2 and FastEEM3) were designed and utilized as optical instrumentation for in vivo spectroscopic fluorescence and reflectance measurements. Data processing of fluorescence and reflectance data is explained in detail and a preliminary analysis of the variability across each device and probe combination is explored. One thousand patients were recruited in the screening trial and 850 patients were recruited in the diagnostic trial. Three clinical sites attracted a diverse range of patients of different ages, ethnicities, and menopausal status. The fully processed results clearly show that consistencies exist across all device and probe combinations throughout the diagnostic trial. Based on the stratification of the data, the results also show identifiable differences in mean intensity between normal and high-grade tissue diagnosis, pre- and postmenopausal status, and squamous and columnar tissue type. The mean intensity values of stratified data show consistent separation across each of the device and probe combinations. By analyzing trial spectra, we provide more evidence that biographical variables such as menopausal status as well as tissue type and diagnosis significantly affect the data. Understanding these effects will lead to better modeling parameters when analyzing the performance of fluorescence and reflectance spectroscopy.
We report on a study designed to assess variability among three different fluorescence spectroscopy devices, four fiber optic probes, and three sets of optical calibration standards to better understand the reproducibility of measurements and interdevice comparisons of fluorescence spectroscopic data intended for clinical diagnostic use. Multiple measurements are acquired from all sets of standards using each combination of spectrometer, fiber optic probe, and optical standard. Data are processed using standard calibration methods to remove instrument-dependant responses. Processed spectra are analyzed using an analysis of variance to assess the percent variance explained by each factor that was statistically significant. Analysis of processed data confirms statistically significant differences among the spectrometers and fiber optic probes. However, no differences are found when varying calibration standards or measurement date and time. The spectrometers and fiber optic probes are significant sources of variability, but appropriate data processing substantially reduces these effects. Studies of inter- and intradevice variability are important methodological issues for optical device trials and must be included in the quality assurance studies for the clinical trial design.
Introduction-A study was designed to assess variability between different fluorescence spectroscopy devices. Measurements were made with all combinations of three devices, four probes, and thee sets of standards trays. Additionally, we made three measurements on the same day over two days for the same combination of device, probe, and standards tray to assess reproducibility over a day and across days.Material and Methods-The devices consisted of light sources, fiber optics, and cameras. We measured thirteen standards and present the data from: the frosted cuvette, water, and rhodamine standards. A preliminary analysis was performed with the data that was wavelength calibrated and background subtracted however the system has not been corrected for systematic intensity variations caused by the devices. Two analyses were performed on the rhodamine, water, and frosted cuvette standards data. The first one is based on first clustering the measurements and then looking for association between the 5 factors (device, probe, standards tray, day, measurement number) using chi-squared tests on the cross tabulation of cluster and factor level. This showed that only device and probe were significant. We then did an analysis of variance to assess the percent variance explained by each factor that was significant from the chi-squared analysis.Results-The data were remarkably similar across the different combinations of factors. The analysis based on the clusters showed that sometimes devices alone, probes alone, but most often combinations of device and probe caused significant differences in measurements. The analysis showed that time of day, location of device, and standards trays do not vary significantly; whereas the devices and probes account for differences in measurement. We expected this type of significance Correspondence to:
We report results from a proof-of-principle study investigating a technique for highresolution imaging of large fields of view (FOV). This is achieved through structured illumination of the sample from a laterally replicated spatial light modulator (SLM). By incorporating the SLM into the illumination path of an otherwise conventional microscopy imaging system, we can perform the sampling by using our illumination source instead of our areal detector (camera). The increased resolution is achieved through anti-binning or splitting of the charge-coupled device (CCD) pixels, and the extended FOV is obtained by a lateral replication technique applied to the whole illumination field. With anti-binning, we effectively exceed the sampling resolution limit set by the Nyquist theorem. Also, our lateral replication technique enables us to maintain the same FOV for the increased resolution without the need for adaptive optics or highly corrected lenses far from the optical axis. The two techniques of resolution enhancement and lateral replication of the illumination field could be employed independently, hence offering increased versatility and adaptability for specialized imaging applications. Different imaging modes can be accessed digitally, without the need to change objectives, stitch together individual frames, or move the sample. The resulting imaging modality of this system is quasi-confocal.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.