Biomedical subjects

Yud-Ren Chen

Publications and source records attributed to Yud-Ren Chen.

10 recordsLinked to original sources

PubMed2006

Three-color mixing for classifying agricultural products for safety and quality.

A three-color mixing application for food safety inspection is presented. It is shown that the chromaticness of the visual signal resulting from the three-color mixing achieved through our device is directly related to the three-band ratio of light intensity at three selected wavebands. An optical visual device using three-color mixing to implement the three-band ratio criterion is presented. Inspection through human vision assisted by an optical device that implements the three-band ratio criterion would offer flexibility and significant cost savings as compared to inspection with a multispectral machine vision system that implements the same criterion. Example applications of this optical three-color mixing technique are given for the inspection of chicken carcasses with various diseases and for apples with fecal contamination. With proper selection of the three narrow wavebands, discrimination by chromaticness that has a direct relation with the three-band ratio can work very well. In particular, compared with the previously presented two-color mixing application, the conditions of chicken carcasses were more easily identified using the three-color mixing application. The novel three-color mixing technique for visual inspection can be implemented on visual devices for a variety of applications, ranging from target detection to food safety inspection.

Agriculture↗

PubMed2006

Two-color mixing for classifying agricultural products for safety and quality.

We show that the chromaticness of the visual signal that results from the two-color mixing achieved through an optically enhanced binocular device is directly related to the band ratio of light intensity at the two selected wavebands. A technique that implements the band-ratio criterion in a visual device by using two-color mixing is presented here. The device will allow inspectors to identify targets visually in accordance with a two-wavelength band ratio. It is a method of inspection by human vision assisted by an optical device, which offers greater flexibility and better cost savings than a multispectral machine vision system that implements the band-ratio criterion. With proper selection of the two narrow wavebands, discrimination by chromaticness that is directly related to the band ratio can work well. An example application of this technique for the inspection of carcasses chickens of afficted with various diseases is given. An optimal pair of wavelengths of 454 and 578 nm was selected to optimize differences in saturation and hue in CIE LUV color space among different types of target. Another example application, for the detection of chilling injury in cucumbers, is given, here the selected wavelength pair was 504 and 652 nm. The novel two-color mixing technique for visual inspection can be included in visual devices for various applications, ranging from target detection to food safety inspection.

Journal Article↗

PubMed2006

Fluorescence characteristics of wholesome and unwholesome chicken carcasses.

Each chicken carcass intended for U.S. consumers is mandated to be inspected by Food Safety and Inspection Service (FSIS) inspectors for its wholesomeness at the processing plants. Fluorescence responses of wholesome and unwholesome chicken carcasses were characterized and further evaluated for potential on-line applications for detection and classification of wholesome and unwholesome chicken carcasses. For this study, unwholesome chicken carcasses included cadaver and those with disease conditions such as airsacculitis and septicemia. Fluorescence characteristics from the epidermal layers in the breast areas of chicken carcasses were dynamic in nature. Emission peaks and ridges (maxima) were observed at 386, 444, 472, 512, and 554 nm and valleys (minima) were observed at 410, 460, 484, and 538 nm. One of the major factors affecting the line shapes of fluorescence responses from chicken carcass skin layers was absorption by hemoglobin. With the use of the normalized ratio spectra (NRS) approach, oxyhemoglobin was shown to be a major constituent in chicken carcasses affecting the fluorescence emission line shapes. Subtle line shape changes in the NRS also provided a qualitative means by which to assess the minute differences in oxy- and deoxyhemoglobin compositions perturbed by poultry diseases such as septicemia and airsacculitis. With the use of simple fluorescence band ratios as a multivariate model, wholesome and unwholesome chicken carcasses were correctly classified with 97.1% and 94.8% accuracies, respectively. On-line implementation of fluorescence techniques for the assessment of chicken carcass wholesomeness appears promising.

Animals↗

PubMed2005

Two-wave-band color-mixing binoculars for the detection of wholesome and unwholesome chicken carcasses: a simulation.

Visual inspection of wholesome and unwholesome chicken carcasses with a novel two-narrowband color-mixing technique for optically enhanced binoculars is simulated. From mean spectra of wholesome, airsacculitis (air-sac), cadaver, inflammatory process (IP), septicemia-toxemia (septox), and tumor chicken samples, 10 nm wave-band pairs are selected using color difference and chromaticness difference indices for simulation of multitarget and single-target detection. The color appearance simulation uses the CIECAM97s color appearance model. Results show that for multitarget detection, the wave-band pair of (454 nm, 578 nm) is able to differentiate all six chicken conditions. For single-target detection of wholesome, air-sac, cadaver, and tumor, the wave-band pairs of (449 nm, 571 nm), (441 nm, 576 nm), (458 nm, 576 nm), and (431 nm, 501 nm), respectively, easily distinguish the target condition from the other five conditions. For single-target detection of IP and septox, the wave-band pairs of (454 nm, 591 nm) and (454 nm, 590 nm), respectively, are able to differentiate the target conditions from wholesome and tumor conditions but have difficulty with the other chicken conditions. The two-color-mixing technique shows promise for use in small-scale processing plant environments to improve the visual inspection process.

Animals↗

PubMed2005

Detection of fecal contamination on apples with nanosecond-scale time-resolved imaging of laser-induced fluorescence.

Detection of apples contaminated with feces is a public health concern. We found that time-resolved imaging of apples artificially contaminated with feces allowed optimization of timing parameters for detection. Dairy feces were applied to Red Delicious and Golden Delicious apples. Laser-induced fluorescence responses were imaged by use of a gated intensified camera. We developed algorithms to automatically detect contamination iteratively by using one half of the apples and validated them by applying the optimized algorithms to the remaining apples. Results show that consideration of the timing of fluorescence responses to pulsed-laser excitation can enhance detection of feces on apples.

Algorithms↗

PubMed2005

Development of a simple algorithm for the detection of chilling injury in cucumbers from visible/near-infrared hyperspectral imaging.

Hyperspectral images of cucumbers under a variety of conditions were acquired to explore the potential for the detection of chilling-induced damage in whole cucumbers. Region of interest (ROI) spectral features of chilling injured areas, resulting from chilling treatment at 0 degrees C, showed the reduction of reflectance intensity over the period at post-chilling room temperature (RT) storage. A large spectral difference between good, smooth skins and chilling-injured skins occurred in the 700-850 nm visible/near-infrared (NIR) region. Both simple band ratio algorithms and principal component analysis (PCA) were attempted to discriminate the ROI spectra of good cucumber skins from those of chilling injured ones. Results revealed that both the dual-band ratio algorithm (R(811nm)/R(756nm)) and a PCA model from a narrow spectral region of 733-848 nm can detect chilling-injured skins with a success rate of over 90%. The results also suggested that chilling injury is relatively difficult to detect at the initial post-chilling RT stage, especially during the first 0-2 days in storage, due to insignificant manifestation of chilling induced symptoms.

Algorithms↗

PubMed2004

Analysis of hyperspectral fluorescence images for poultry skin tumor inspection.

We present a hyperspectral fluorescence imaging system with a fuzzy inference scheme for detecting skin tumors on poultry carcasses. Hyperspectral images reveal spatial and spectral information useful for finding pathological lesions or contaminants on agricultural products. Skin tumors are not obvious because the visual signature appears as a shape distortion rather than a discoloration. Fluorescence imaging allows the visualization of poultry skin tumors more easily than reflectance. The hyperspectral image samples obtained for this poultry tumor inspection contain 65 spectral bands of fluorescence in the visible region of the spectrum at wavelengths ranging from 425 to 711 nm. The large amount of hyperspectral image data is compressed by use of a discrete wavelet transform in the spatial domain. Principal-component analysis provides an effective compressed representation of the spectral signal of each pixel in the spectral domain. A small number of significant features are extracted from two major spectral peaks of relative fluorescence intensity that have been identified as meaningful spectral bands for detecting tumors. A fuzzy inference scheme that uses a small number of fuzzy rules and Gaussian membership functions successfully detects skin tumors on poultry carcasses. Spatial-filtering techniques are used to significantly reduce false positives.

Animals↗

PubMed2003

Multispectral laser-induced fluorescence imaging system for large biological samples.

A laser-induced fluorescence imaging system developed to capture multispectral fluorescence emission images simultaneously from a relatively large target object is described. With an expanded, 355-nm Nd:YAG laser as the excitation source, the system captures fluorescence emission images in the blue, green, red, and far-red regions of the spectrum centered at 450, 550, 678, and 730 nm, respectively, from a 30-cm-diameter target area in ambient light. Images of apples and of pork meat artificially contaminated with diluted animal feces have demonstrated the versatility of fluorescence imaging techniques for potential applications in food safety inspection. Regions of contamination, including sites that were not readily visible to the human eye, could easily be identified from the images.

Animals↗

PubMed2003

Automated detection of fecal contamination of apples by multispectral laser-induced fluorescence imaging.

Animal feces are a suspected source of contamination of apples by disease-causing organisms such as Echerichia coli O157. Laser-induced fluorescence was used to detect different amounts of feces from dairy cows, deer, and a dairy pasture applied to Red Delicious apples. One day after application, detection for 1:2 and 1:20 dilutions was nearly 100%, and for 1:200 dilutions (<15 ng of dry matter) detection was >80%. Detection after apples had been washed and brushed was lowest for pasture feces; detection for 1:2, 1:20, and 1:200 dilutions of feces was 100%, 30%, and 0%, respectively. This technology may encourage development of commercial systems for detecting fecal contamination of apples.

Animals↗

PubMed2003

Optimal fluorescence excitation and emission bands for detection of fecal contamination.

Fecal contamination of food products is a critical health issue. To test the feasibility of the use fluorescent techniques to detect fecal contamination, fluorescence excitation and emission characteristics of fecal matter from cows, deer, swine, chickens, and turkeys in the UV to far-red regions of the spectrum were evaluated. To allow the optimization of the detection of fecal contamination on animal carcasses and cut meats, emission-excitation spectra of the feces were compared with spectra for animal meats. The feedstuffs for the swine, chickens, and turkeys were also analyzed. Excitation at approximately 410 to 420 nm yielded the highest level of fluorescence for both feces and feedstuffs. Emission maxima were in the red region (at 632 nm for chicken feces and at 675 nm for the feces of the other species). The major constituent responsible for emission at 632 nm was tentatively identified as protoporphyrin IX; emission at 675 nm most likely emanates from chlorophyll a or its metabolites. Animal meats emitted strong fluorescence in the blue-green regions, but no emission peaks were observed in the red region for these meats. These results suggest that fluorescence emissions from naturally occurring chlorophyll a and its metabolites are good markers for fecal contamination and that with excitation at 410 to 420 nm, the responses of fecal matter can easily be differentiated from the responses of animal meats. We suggest that the detection of fecal contamination can be enhanced by requiring a minimum chlorophyll a content in the finishing diets of all farm animals.

Animal Feed↗