The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Michael J Vellekoop - One of the best experts on this subject based on the ideXlab platform.
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CH2-Symmetric/CH2-Antisymmetric Stretch Ratio Sensor for Cell Analysis
IFMBE Proceedings, 2020Co-Authors: S Van Den Driesche, Wojciech Witarski, Michael J VellekoopAbstract:Here we report on a novel infrared sensor system for measuring the CH2-symmetric/CH2-antisymmetric Stretch Ratio of cell samples. Based on IR absorbance spectra of healthy and malignant breast [1], blood [2] and brain [3] cells found in literature we hypothesized the possibility of disease stage cell discrimination by only comparing a few absorbance peaks in the lipid absorbance wavelength region between 3 and 4 μm. By comparing the lipid CH2-symmetric and CH2-antisymmetric Stretch Ratios (with baseline correction and normalization) of three defined epithelial kidney cell lines, healthy MDCK and carcinoma A-498 and Caki-1 with the developed sensor, significant Stretch Ratio differences have been found between healthy and tumor cell types (and even between the two tumor types). The developed LED-photodiode based infrared absorbance sensor could be used for quick pre-screening of biopsy samples which, compared to labeling and staining techniques, does not require highly trained personnel and is much cheaper than liquid nitrogen cooled FTIR spectroscopes.
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A biopsymeter to support the diagnostic procedure of skin samples
Bio-MEMS and Medical Microdevices II, 2015Co-Authors: Valeria Fioravanti, Sander Van Den Driesche, Heimo Breiteneder, Christine Hafner, Shailendra Chandrashekar, Lukas Brandhoff, Daniela Pucciarelli, Michael J VellekoopAbstract:We present an infrared biopsymeter to assist pathologists in the diagnosis of melanoma presence in skin biopsies. The designed and realized system combines the features of visual inspection and physical sensing to reduce false positives and false negatives occurring during standard histopathological analyses. The biopsymeter determines the CH2-Stretch Ratio by infrared absorbance measurements of skin biopsies. Investigations conducted with the biopsymeter shows that malignant melanomas and melanoma metastases have higher CH2-Stretch Ratio values compared to healthy skin tissues.
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a label free indicator for tumor cells based on the ch2 Stretch Ratio
Analyst, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Silvia Pastorekova, Heimo Breiteneder, Christine Hafner, Michael J VellekoopAbstract:In this paper, we assess the potential of a label-free infrared absorbance based measurement method for determination of the CH2-symmetric to CH2-antisymmetric Stretch Ratio, to aid in the detection of the presence of cancer cells and to differentiate between various cancer cells. For this study a normal epithelial kidney cell line, two carcinoma epithelial kidney cell lines, an adult primary human melanocyte cell line, and three human melanoma cell lines were investigated. For the measurements we used a self-designed IR sensor which has the potential to be further developed in a point-of-care instrument. To investigate the mechanism influencing the CH2-Stretch Ratio of mammalian cell membranes, a normal epithelial kidney cell line was exposed to the plasma membrane bound cholesterol reducing agent methyl-β-cyclodextrin. This methodology yielded statistically significant CH2-Stretch Ratio differences between the individual cell lines, normal and tumorous, of both epithelial kidney and melanocyte origin. Measurement results of normal epithelial kidney cells exposed to methyl-β-cyclodextrin indicate that an increase in the CH2-Stretch Ratio arises when there is a decrease in, or redistribution of, the membrane stabilizing agent cholesterol. This study proves that the proposed cell type discrimination method, based on the CH2-symmetric to CH2-antisymmetric Stretch Ratio, allows the discrimination between normal and tumor cells. In addition, the method shows high potential for improvement of staging of suspicious tissues.
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mid infrared ch2 Stretch Ratio sensor for suspended mammalian cells
Smart Sensors Actuators and MEMS V, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Christoph Haiden, Michael J VellekoopAbstract:In this contribution we present a sensor system to measure the CH 2 -Stretch Ratio of suspended mammalian cells. To overcome the strong infrared absorbance of water our sensor system comprises a sample chip with three equal chambers with an inner height of only 20 μm.
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A label-free sensor system for chemotherapeutic drug screening
SENSORS 2011 IEEE, 2011Co-Authors: Sander Van Den Driesche, Heimo Breiteneder, Michael J Vellekoop, Filippo Iuliano, Christine HafnerAbstract:Here we report on the design and realisation of a measurement method and sensor system for the label-free determination of chemotherapeutic drug effectiveness. The measurement method is based on the CH2-symmetric and CH2-antisymmetric Stretches of tumour cells. These CH2-Stretches in cells can visualize the formation of tight packed phospholipid, which are formed while the cells are being in apoptosis. The sensor system records IR absorbance of the CH2-symmetric and CH2-antisymmetric Stretch at wavelengths 3.51μm and 3.42 μm, respectively. In addition, the IR absorbance at two reference wavelengths is determined to compensate for variations in the sample thickness and water content. By taken the Ratio of the two Stretches the CH2-Stretch Ratio is obtained independent on sample thickness and confluency. The main components of the sensor system are mid-IR emitting LEDs, a photodiode, and narrow band-pass filters. Experiments on melanoma cell lines exposed to cisplatin show a significant decrease in CH2-Stretch Ratio indicating that the proposed label-free sensing system has great potential for investigating the effectiveness of chemotherapeutic drugs on tumour cells.
Wojciech Witarski - One of the best experts on this subject based on the ideXlab platform.
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CH2-Symmetric/CH2-Antisymmetric Stretch Ratio Sensor for Cell Analysis
IFMBE Proceedings, 2020Co-Authors: S Van Den Driesche, Wojciech Witarski, Michael J VellekoopAbstract:Here we report on a novel infrared sensor system for measuring the CH2-symmetric/CH2-antisymmetric Stretch Ratio of cell samples. Based on IR absorbance spectra of healthy and malignant breast [1], blood [2] and brain [3] cells found in literature we hypothesized the possibility of disease stage cell discrimination by only comparing a few absorbance peaks in the lipid absorbance wavelength region between 3 and 4 μm. By comparing the lipid CH2-symmetric and CH2-antisymmetric Stretch Ratios (with baseline correction and normalization) of three defined epithelial kidney cell lines, healthy MDCK and carcinoma A-498 and Caki-1 with the developed sensor, significant Stretch Ratio differences have been found between healthy and tumor cell types (and even between the two tumor types). The developed LED-photodiode based infrared absorbance sensor could be used for quick pre-screening of biopsy samples which, compared to labeling and staining techniques, does not require highly trained personnel and is much cheaper than liquid nitrogen cooled FTIR spectroscopes.
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a label free indicator for tumor cells based on the ch2 Stretch Ratio
Analyst, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Silvia Pastorekova, Heimo Breiteneder, Christine Hafner, Michael J VellekoopAbstract:In this paper, we assess the potential of a label-free infrared absorbance based measurement method for determination of the CH2-symmetric to CH2-antisymmetric Stretch Ratio, to aid in the detection of the presence of cancer cells and to differentiate between various cancer cells. For this study a normal epithelial kidney cell line, two carcinoma epithelial kidney cell lines, an adult primary human melanocyte cell line, and three human melanoma cell lines were investigated. For the measurements we used a self-designed IR sensor which has the potential to be further developed in a point-of-care instrument. To investigate the mechanism influencing the CH2-Stretch Ratio of mammalian cell membranes, a normal epithelial kidney cell line was exposed to the plasma membrane bound cholesterol reducing agent methyl-β-cyclodextrin. This methodology yielded statistically significant CH2-Stretch Ratio differences between the individual cell lines, normal and tumorous, of both epithelial kidney and melanocyte origin. Measurement results of normal epithelial kidney cells exposed to methyl-β-cyclodextrin indicate that an increase in the CH2-Stretch Ratio arises when there is a decrease in, or redistribution of, the membrane stabilizing agent cholesterol. This study proves that the proposed cell type discrimination method, based on the CH2-symmetric to CH2-antisymmetric Stretch Ratio, allows the discrimination between normal and tumor cells. In addition, the method shows high potential for improvement of staging of suspicious tissues.
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mid infrared ch2 Stretch Ratio sensor for suspended mammalian cells
Smart Sensors Actuators and MEMS V, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Christoph Haiden, Michael J VellekoopAbstract:In this contribution we present a sensor system to measure the CH 2 -Stretch Ratio of suspended mammalian cells. To overcome the strong infrared absorbance of water our sensor system comprises a sample chip with three equal chambers with an inner height of only 20 μm.
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ch2 symmetric ch2 antisymmetric Stretch Ratio sensor for cell analysis
2009Co-Authors: S Van Den Driesche, Wojciech Witarski, Michael J VellekoopAbstract:Here we report on a novel infrared sensor system for measuring the CH2-symmetric/CH2-antisymmetric Stretch Ratio of cell samples. Based on IR absorbance spectra of healthy and malignant breast [1], blood [2] and brain [3] cells found in literature we hypothesized the possibility of disease stage cell discrimination by only comparing a few absorbance peaks in the lipid absorbance wavelength region between 3 and 4 μm. By comparing the lipid CH2-symmetric and CH2-antisymmetric Stretch Ratios (with baseline correction and normalization) of three defined epithelial kidney cell lines, healthy MDCK and carcinoma A-498 and Caki-1 with the developed sensor, significant Stretch Ratio differences have been found between healthy and tumor cell types (and even between the two tumor types). The developed LED-photodiode based infrared absorbance sensor could be used for quick pre-screening of biopsy samples which, compared to labeling and staining techniques, does not require highly trained personnel and is much cheaper than liquid nitrogen cooled FTIR spectroscopes.
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A mid infrared LED-photodiode based sensor for cell analysis
SENSORS 2009 IEEE, 2009Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Christine Hafner, Michael J Vellekoop, Harald KittlerAbstract:We report on the development of a novel LED-photodiode based mid-infrared absorbance sensor system for label-free cell analysis. Compared to common techniques to distinguish healthy from malignant cells our sensor system does not require specific labeling or staining, or the use of expensive liquid nitrogen cooled IR spectrometers. The detection principle comprises a four-wavelength based absorbance measurement to determine the lipid CH2-symmetric/CH2-antisymmetric Stretch Ratio (3.51 and 3.42 ¿m, respectively). The other two wavelengths (3.33 and 3.57 ¿m) are used as reference points to derive a baseline for determination of the functional absorbance values at 3.51 and 3.42 ¿m. Our sensor experiments show significant differences in CH2 Stretch Ratio of healthy and malignant epithelial kidney cells. The developed sensor has the potential for fast, low cost and label-free screening of suspicious biopsy samples.
Sander Van Den Driesche - One of the best experts on this subject based on the ideXlab platform.
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A biopsymeter to support the diagnostic procedure of skin samples
Bio-MEMS and Medical Microdevices II, 2015Co-Authors: Valeria Fioravanti, Sander Van Den Driesche, Heimo Breiteneder, Christine Hafner, Shailendra Chandrashekar, Lukas Brandhoff, Daniela Pucciarelli, Michael J VellekoopAbstract:We present an infrared biopsymeter to assist pathologists in the diagnosis of melanoma presence in skin biopsies. The designed and realized system combines the features of visual inspection and physical sensing to reduce false positives and false negatives occurring during standard histopathological analyses. The biopsymeter determines the CH2-Stretch Ratio by infrared absorbance measurements of skin biopsies. Investigations conducted with the biopsymeter shows that malignant melanomas and melanoma metastases have higher CH2-Stretch Ratio values compared to healthy skin tissues.
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a label free indicator for tumor cells based on the ch2 Stretch Ratio
Analyst, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Silvia Pastorekova, Heimo Breiteneder, Christine Hafner, Michael J VellekoopAbstract:In this paper, we assess the potential of a label-free infrared absorbance based measurement method for determination of the CH2-symmetric to CH2-antisymmetric Stretch Ratio, to aid in the detection of the presence of cancer cells and to differentiate between various cancer cells. For this study a normal epithelial kidney cell line, two carcinoma epithelial kidney cell lines, an adult primary human melanocyte cell line, and three human melanoma cell lines were investigated. For the measurements we used a self-designed IR sensor which has the potential to be further developed in a point-of-care instrument. To investigate the mechanism influencing the CH2-Stretch Ratio of mammalian cell membranes, a normal epithelial kidney cell line was exposed to the plasma membrane bound cholesterol reducing agent methyl-β-cyclodextrin. This methodology yielded statistically significant CH2-Stretch Ratio differences between the individual cell lines, normal and tumorous, of both epithelial kidney and melanocyte origin. Measurement results of normal epithelial kidney cells exposed to methyl-β-cyclodextrin indicate that an increase in the CH2-Stretch Ratio arises when there is a decrease in, or redistribution of, the membrane stabilizing agent cholesterol. This study proves that the proposed cell type discrimination method, based on the CH2-symmetric to CH2-antisymmetric Stretch Ratio, allows the discrimination between normal and tumor cells. In addition, the method shows high potential for improvement of staging of suspicious tissues.
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mid infrared ch2 Stretch Ratio sensor for suspended mammalian cells
Smart Sensors Actuators and MEMS V, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Christoph Haiden, Michael J VellekoopAbstract:In this contribution we present a sensor system to measure the CH 2 -Stretch Ratio of suspended mammalian cells. To overcome the strong infrared absorbance of water our sensor system comprises a sample chip with three equal chambers with an inner height of only 20 μm.
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A label-free sensor system for chemotherapeutic drug screening
SENSORS 2011 IEEE, 2011Co-Authors: Sander Van Den Driesche, Heimo Breiteneder, Michael J Vellekoop, Filippo Iuliano, Christine HafnerAbstract:Here we report on the design and realisation of a measurement method and sensor system for the label-free determination of chemotherapeutic drug effectiveness. The measurement method is based on the CH2-symmetric and CH2-antisymmetric Stretches of tumour cells. These CH2-Stretches in cells can visualize the formation of tight packed phospholipid, which are formed while the cells are being in apoptosis. The sensor system records IR absorbance of the CH2-symmetric and CH2-antisymmetric Stretch at wavelengths 3.51μm and 3.42 μm, respectively. In addition, the IR absorbance at two reference wavelengths is determined to compensate for variations in the sample thickness and water content. By taken the Ratio of the two Stretches the CH2-Stretch Ratio is obtained independent on sample thickness and confluency. The main components of the sensor system are mid-IR emitting LEDs, a photodiode, and narrow band-pass filters. Experiments on melanoma cell lines exposed to cisplatin show a significant decrease in CH2-Stretch Ratio indicating that the proposed label-free sensing system has great potential for investigating the effectiveness of chemotherapeutic drugs on tumour cells.
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A mid infrared LED-photodiode based sensor for cell analysis
SENSORS 2009 IEEE, 2009Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Christine Hafner, Michael J Vellekoop, Harald KittlerAbstract:We report on the development of a novel LED-photodiode based mid-infrared absorbance sensor system for label-free cell analysis. Compared to common techniques to distinguish healthy from malignant cells our sensor system does not require specific labeling or staining, or the use of expensive liquid nitrogen cooled IR spectrometers. The detection principle comprises a four-wavelength based absorbance measurement to determine the lipid CH2-symmetric/CH2-antisymmetric Stretch Ratio (3.51 and 3.42 ¿m, respectively). The other two wavelengths (3.33 and 3.57 ¿m) are used as reference points to derive a baseline for determination of the functional absorbance values at 3.51 and 3.42 ¿m. Our sensor experiments show significant differences in CH2 Stretch Ratio of healthy and malignant epithelial kidney cells. The developed sensor has the potential for fast, low cost and label-free screening of suspicious biopsy samples.
Christine Hafner - One of the best experts on this subject based on the ideXlab platform.
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A biopsymeter to support the diagnostic procedure of skin samples
Bio-MEMS and Medical Microdevices II, 2015Co-Authors: Valeria Fioravanti, Sander Van Den Driesche, Heimo Breiteneder, Christine Hafner, Shailendra Chandrashekar, Lukas Brandhoff, Daniela Pucciarelli, Michael J VellekoopAbstract:We present an infrared biopsymeter to assist pathologists in the diagnosis of melanoma presence in skin biopsies. The designed and realized system combines the features of visual inspection and physical sensing to reduce false positives and false negatives occurring during standard histopathological analyses. The biopsymeter determines the CH2-Stretch Ratio by infrared absorbance measurements of skin biopsies. Investigations conducted with the biopsymeter shows that malignant melanomas and melanoma metastases have higher CH2-Stretch Ratio values compared to healthy skin tissues.
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a label free indicator for tumor cells based on the ch2 Stretch Ratio
Analyst, 2011Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Silvia Pastorekova, Heimo Breiteneder, Christine Hafner, Michael J VellekoopAbstract:In this paper, we assess the potential of a label-free infrared absorbance based measurement method for determination of the CH2-symmetric to CH2-antisymmetric Stretch Ratio, to aid in the detection of the presence of cancer cells and to differentiate between various cancer cells. For this study a normal epithelial kidney cell line, two carcinoma epithelial kidney cell lines, an adult primary human melanocyte cell line, and three human melanoma cell lines were investigated. For the measurements we used a self-designed IR sensor which has the potential to be further developed in a point-of-care instrument. To investigate the mechanism influencing the CH2-Stretch Ratio of mammalian cell membranes, a normal epithelial kidney cell line was exposed to the plasma membrane bound cholesterol reducing agent methyl-β-cyclodextrin. This methodology yielded statistically significant CH2-Stretch Ratio differences between the individual cell lines, normal and tumorous, of both epithelial kidney and melanocyte origin. Measurement results of normal epithelial kidney cells exposed to methyl-β-cyclodextrin indicate that an increase in the CH2-Stretch Ratio arises when there is a decrease in, or redistribution of, the membrane stabilizing agent cholesterol. This study proves that the proposed cell type discrimination method, based on the CH2-symmetric to CH2-antisymmetric Stretch Ratio, allows the discrimination between normal and tumor cells. In addition, the method shows high potential for improvement of staging of suspicious tissues.
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A label-free sensor system for chemotherapeutic drug screening
SENSORS 2011 IEEE, 2011Co-Authors: Sander Van Den Driesche, Heimo Breiteneder, Michael J Vellekoop, Filippo Iuliano, Christine HafnerAbstract:Here we report on the design and realisation of a measurement method and sensor system for the label-free determination of chemotherapeutic drug effectiveness. The measurement method is based on the CH2-symmetric and CH2-antisymmetric Stretches of tumour cells. These CH2-Stretches in cells can visualize the formation of tight packed phospholipid, which are formed while the cells are being in apoptosis. The sensor system records IR absorbance of the CH2-symmetric and CH2-antisymmetric Stretch at wavelengths 3.51μm and 3.42 μm, respectively. In addition, the IR absorbance at two reference wavelengths is determined to compensate for variations in the sample thickness and water content. By taken the Ratio of the two Stretches the CH2-Stretch Ratio is obtained independent on sample thickness and confluency. The main components of the sensor system are mid-IR emitting LEDs, a photodiode, and narrow band-pass filters. Experiments on melanoma cell lines exposed to cisplatin show a significant decrease in CH2-Stretch Ratio indicating that the proposed label-free sensing system has great potential for investigating the effectiveness of chemotherapeutic drugs on tumour cells.
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A mid infrared LED-photodiode based sensor for cell analysis
SENSORS 2009 IEEE, 2009Co-Authors: Sander Van Den Driesche, Wojciech Witarski, Christine Hafner, Michael J Vellekoop, Harald KittlerAbstract:We report on the development of a novel LED-photodiode based mid-infrared absorbance sensor system for label-free cell analysis. Compared to common techniques to distinguish healthy from malignant cells our sensor system does not require specific labeling or staining, or the use of expensive liquid nitrogen cooled IR spectrometers. The detection principle comprises a four-wavelength based absorbance measurement to determine the lipid CH2-symmetric/CH2-antisymmetric Stretch Ratio (3.51 and 3.42 ¿m, respectively). The other two wavelengths (3.33 and 3.57 ¿m) are used as reference points to derive a baseline for determination of the functional absorbance values at 3.51 and 3.42 ¿m. Our sensor experiments show significant differences in CH2 Stretch Ratio of healthy and malignant epithelial kidney cells. The developed sensor has the potential for fast, low cost and label-free screening of suspicious biopsy samples.
G. C. Valley - One of the best experts on this subject based on the ideXlab platform.
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demonstRation of a large Stretch Ratio rm m 41 photonic analog to digital converter with 8 enob for an input signal bandwidth of 10 ghz
IEEE Photonics Technology Letters, 2012Co-Authors: Willie W Ng, T. D. Rockwood, G. A. Sefler, G. C. ValleyAbstract:We report the demonstRation of a time-Stretch photonic analog-to-digital conversion (ADC) system with a Stretch Ratio of . By Stretching a 10-GHz modulation envelope to 242 MHz via optical dispersion, we demonstrated, for the first time, an ADC resolution that is better than 8 effective number of bits for a 10-GHz input-signal bandwidth.
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DemonstRation of a Large Stretch-Ratio $({\rm M}=41)$ Photonic Analog-to-Digital Converter With 8 ENOB for an Input Signal Bandwidth of 10 GHz
IEEE Photonics Technology Letters, 2012Co-Authors: W. Ng, T. D. Rockwood, G. A. Sefler, G. C. ValleyAbstract:We report the demonstRation of a time-Stretch photonic analog-to-digital conversion (ADC) system with a Stretch Ratio of . By Stretching a 10-GHz modulation envelope to 242 MHz via optical dispersion, we demonstrated, for the first time, an ADC resolution that is better than 8 effective number of bits for a 10-GHz input-signal bandwidth.
