Imaging fiber

Figure 8. Seventy-six sensor beads (Jupiter C4/Nile Red) monitored to show that the average responses for three consecutive 0.38-s exposures of 50% saturated vapor levels result in reproducible and high-speed response profiles. The sensors are positioned on the distal tip of an optical imaging fiber and relative analyte concentrations are 0.5 and 18700 ppm for 1,3-DNB and toluene, respectively. Reprinted with permission from ref 12a. Copyright 2000 American Chemical Society.

I. Biran and D. R. Walt, Optical Imaging Fiber-Based Single Live Cell Arrays, And Chem. 2002, 74, 3046. 

Similarly, SEM is a well known method of examining and imaging fibers and particles (47). Many papers report the use of this technique in the study of archaeological materials (e.g., 48-50). 

Due to recent advancements in instrumentation, Raman spectroscopy has become one of the most powerful tools in medical research. Such advancements include development of new lasers, FT-Raman spectroscopy, CCD detectors, confocal Raman microscopy, Raman imaging, fiber optic probes, and computer software. In the following, the utility of Raman spectroscopy in medical science is demonstrated by using selected examples. A more complete coverage of the field is found in review articles by Ozaki (32) and Levin et al. (33). 

Acetylcholineesterase A 350 pM diameter coherent imaging fiber coated on the distal surface with a planar layer of analyte-sensitive polymer that was thin enough not to affect the fiber s imaging capabilities. It was applied to a pH sensor array and an ACh biosensor array (each contain 6000 optical sensor). Fibers were coated with an immobilized layer of poly (hydroxyethylmethacrylate)-N-flurosceinylacrylamide and AChE-fluorescein isothiocyanate isomer poly (acryloamide-co-N-acryl oxysuccinimide), respectively. The response time of the pH sensor was 2 s for a 0.5 unit increase in pH. The biosensor had a detection limit of 35 pM ACh and a linear response in the range 0.1 mM. [90]... 

Since in the images used in this study, objects (fibers) are white on a black background, the images first need to be complemented. In the complement of a binary image, zeros become ones and ones become zeros black and white are reversed. Thus in the complement of the image, fibers are black and background is white. Afterwards, the distance between each pixel and its nearest nonzero pixel is found by using Euclidean distance transform. 

A dual-analyte fiber optic biosensor for O2 and glucose was developed by Li and Walt [22] based on O2 quenching of a phosphorescent ruthenium dye. Excitation was at X = 480 nm, with fluorescent emission captured by a CCD camera. A relatively large (350 (U,m diameter) imaging fiber with 6000 elements was modified by attaching two separate drops of ruthenium dye encapsulated in poly(hydroxyethyl methacrylate) polymer (HEMA). The ruthenium dye allowed measurements of O2 in both encapsulated drops, which were approximately 50 ixm in diameter. A two-site Stern-Volmer quenching model (equation (4.32) with n — 2) was used to determine O2 concentration from measurements of fluorescence intensity. One of the drops had the enzyme glucose oxidase (EC... 

Healey B G, Foran S E and Walt D R 1995 Photodeposition of micrometer-scale polymer patterns on optical imaging fibers Science 269 1078-80 Tsien R Y 1983 Intracellular measurements of ion activities Annu. Rev. Bioeng. 12 91-116... 

Optical Imaging Fibers King electrodes around... 

Figure 10.17 Microelectrodes array formed through chemical etching. (Al) SEM of an 1141-electrode titanium alloy electrode array, (A2) SEM image of a parylene-coated assembly of platinum-coated electrodes (181), (Bl) SEM of an etched optical imaging fiber bundle, and (B2) SEM of a with gold covered and with electrophoretic paint insulated microelectrode array (with permission from reference (34)).

An example of a light-reflection-type space filter system is shown in Fig. 22a. The light from halogen lamps is focused by a lens and guided by an optical image fiber bundle into the measuring space (bundle... 

Kamiwano M, Saito F. Measurement method of flow velocity of liquid and irregular solid particles using an image sensor with an image fiber. AIChE S5mip Ser 80(241) 122-128, 1984. 

Imaging fiber Bundle of coherently ordered individual optical fibers through which an image can be transmitted from one side to the other. 

FIGURE 20 Multianalyte fiber-optic chemical sensor with different indicators immobilized in polymers attached to an imaging fiber. COa-sensitive matrices (A and B), pH-sensitive matrix (C), and Oa-sensitive matrices (D and E). [Reprinted with permission from Ferguson, J. A., Healey, B. G., Bronk, K. S., Barnard, S. M., and Walt, D. R. (1997). Anal. Chim. Acta 340, 123-131.]... 

FIGURE 22 Combined imaging and chemical sensing concept. The technique provides the ability to both view a sample and measure surface chemical changes using a single optical imaging fiber. 

Videoscope A special endoscope that contains a miniature electronic imaging device (e.g., charge-coupled device) instead of an ordered imaging fiber bundle. 

Point scan Line imaging Fiber arrays Interference filters LCTFs... 

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