Die invasive Messung der Blutalkoholkonzentration (BAK) stellt eine zeit- und kostenaufwaendige P... more Die invasive Messung der Blutalkoholkonzentration (BAK) stellt eine zeit- und kostenaufwaendige Prozedur dar. Daher wurden neben der Ermittlung der Atemalkoholkonzentration (AAK) diverse Ansaetze zur nichtinvasiven transdermalen Messung der Alkoholbeeinflussung (TBAK: transdermale Alkoholkonzentration) entwickelt. Es werden die bisher existierenden unterschiedlichen Systeme vorgestellt und diskutiert. Die nichtinvasive Messung der Alkoholkonzentration im Blut ist eine sehr nuetzliche und vielversprechende Massnahme, die technisch allerdings ausserordentlich schwierig ist. Es bleibt abzuwarten, ob eine zuverlaessige und exakte Bestimmung mit verbesserten spektroskopisch basierten Ansaetzen zu erreichen ist. (A) ABSTRACT IN ENGLISH: Invasive measurement of blood alcohol concentration (BAC) is a time-consuming and an expensive procedure. That is the reason why new approaches for a non-invasive transdermal blood alcohol concentration (TBAC) measurement in addition to the breath alcohol ...
Die invasive Messung der Blutalkoholkonzentration (BAK) ist eine zeit- und kostenaufwendige Proze... more Die invasive Messung der Blutalkoholkonzentration (BAK) ist eine zeit- und kostenaufwendige Prozedur. Jede Blutentnahme muss richterlich angeordnet und von einem Arzt durchgefuehrt werden. Daher wurden neben der Ermittlung der Atemalkoholkonzentration (AAK) diverse Ansaetze zur nichtinvasiven transdermalen Messung der Alkoholkonzentration (TAK: transdermale Alkoholkonzentration) entwickelt. Es werden auf Spektroskopie basierende Voruntersuchungen vorgestellt, die zeigen, dass eine nichtinvasive Messung von Gewebealkoholkonzentrationen im physiologischen Konzentrationsbereich und in vitro Versuchsanordnungen ein hohes Potenzial dieser Methode verspricht. (A) ABSTRACT IN ENGLISH: Invasive measurement of blood alcohol concentration (BAC) is a well-known, but time-consuming and expensive procedure. The measurement of the BAC requires authorized approval based on the personal rights. Every involuntary taking of a blood sample from a person has to be legalized by a judge or state attorney...
Background: Hyperspectral Imaging (HSI) has a strong potential to be established as a new contact... more Background: Hyperspectral Imaging (HSI) has a strong potential to be established as a new contact-free measuring method in medicine. Hyperspectral cameras and data processing have to fulfill requirements concerning practicability and validity to be integrated in clinical routine processes. Methods: Calculating physiological parameters which are of significant clinical value from recorded remission spectra is a complex challenge. We present a data processing method for HSI remission spectra based on a five-layer model of perfused tissue that generates perfusion parameters for every layer and presents them as depth profiles. The modeling of the radiation transport and the solution of the inverse problem are based on familiar approximations, but use partially heuristic methods for efficiency and to fulfill practical clinical requirements. Results: The parameter determination process is consistent, as the measured spectrum is practically completely reproducible by the modeling sequence;...
Worldwide, chronic wounds are still a major and increasing problem area in medicine with protract... more Worldwide, chronic wounds are still a major and increasing problem area in medicine with protracted suffering of patients and enormous costs. Beside conventional wound treatment, for instance kinds of oxygen therapy and cold plasma technology have been tested, providing an improvement in the perfusion of wounds and their healing potential, but these methods are unfortunately not sufficiently validated and accepted for clinical practice to date. Using hyperspectral imaging technology in the visible (VIS) and near infrared (NIR) region with high spectral and spatial resolution, perfusion parameters of tissue and wounds can be determined. We present a new compact hyperspectral camera which can be used in clinical practice. From hyperspectral data the hemoglobin oxygenation (StO2), the relative concentration of hemoglobin [tissue hemoglobin index (THI)] and the so-called NIR-perfusion index can be determined. The first two parameters are calculated from the VIS-part of the spectrum and ...
The monitoring of free flaps, free transplants or organs for transplantation still poses a proble... more The monitoring of free flaps, free transplants or organs for transplantation still poses a problem in medicine. Available systems for the measurement of perfusion and oxygenation can only perform localized measurements and usually need contact with the tissue. Contact free hyperspectral imaging and near-infrared spectroscopy (NIRS) for the analysis of tissue oxygenation and perfusion have been used in many scientific studies with good results. But up to now the clinical and scientific application of this technology has been hindered by the lack of hyperspectral measurement systems usable in clinical practice. We will introduce the application of a new hyperspectral camera system for the quick and robust recording of remission spectra in the combined VIS and NIR spectral range with high spectral and spatial resolution. This new system can be applied for the clinical monitoring of free flaps and organs providing high quality oxygenation and perfusion images.
The development of improved preservation techniques and the reliable assessment of donor grafts a... more The development of improved preservation techniques and the reliable assessment of donor grafts are main fields of research in transplantation medicine. Normothermic machine perfusion (NMP) is a promising alternative to static cold storage of organs, maintaining physiological conditions during preservation. In combination with NMP, we introduce hyperspectral imaging (HSI) as a novel approach for the monitoring of physiological kidney parameters. A line-scan HSI camera system was used to record images of porcine kidneys during NMP. Based on a dual-wavelength algorithm, the oxygen saturation levels were calculated from HSI recordings. Furthermore, we observed HSI images in the near-infrared (NIR) range in order to detect water characteristics of the kidney tissue. We found increasing levels of oxygenation during NMP and could discriminate between perfused and non-perfused areas. Cysts at the renal capsula were characterized by an absorption increase in the NIR band. Within this work, we showed that HSI is able to detect relevant chemical changes during NMP and allows the identification of pathologic variations.
BACKGROUND: Pulse spectroscopy is a new noninvasive technology involving hundreds of wavelengths ... more BACKGROUND: Pulse spectroscopy is a new noninvasive technology involving hundreds of wavelengths of visible and infrared light, enabling the simultaneous quantitation of multiple types of normal and dysfunctional hemoglobin. We evaluated the accuracy of a first-generation pulse spectroscopy system (V-Spec™ Monitoring System, Senspec, Germany) in measuring oxygen saturation (Spo 2) and detecting carboxyhemoglobin (COHb) or methemoglobin (MetHb), alone or simultaneously, with hypoxemia. METHODS: Nineteen volunteers were fitted with V-Spec probes on the forehead and fingers. A radial arterial catheter was placed for blood sampling during (1) hypoxemia with arterial oxygen saturations (Sao 2) of 100% to 58.5%; (2) normoxia with MetHb and COHb increased to approximately 10%; (3) 10% COHb or MetHb combined with hypoxemia with Sao 2 of 100% to 80%. Standard measures of pulse-oximetry performance were calculated: bias (pulse spectroscopy measured value − arterial measured value) mean ± SD a...
Abstract Hyperspectral imaging and near infrared spectroscopy (NIRS) for wound analysis have been... more Abstract Hyperspectral imaging and near infrared spectroscopy (NIRS) for wound analysis have been used in many scientific studies with good results for the chemical analysis of wounds and have the potential to raise objective measurement and assessment of wounds to a new level with considerable higher clinical informative value. Up to now the clinical and scientific use of this technology has been hindered by the lack of a hyperspectral measurement system usable in clinical practice. We present the first hyperspectral camera for quick and robust acquisition of hyperspectral data in the combined VIS and NIR spectral range with high spectral and spatial resolution from wounds. First case studies and evaluations of chemometric parameters like the oxygenation of hemoglobin and perfusion quality are presented and exhibit the high quality and potential of this new wound measurement system.
Large-scale laser projection systems used in industrial environment, e.g. for the projection of C... more Large-scale laser projection systems used in industrial environment, e.g. for the projection of CAD drawings onto large work pieces, require external calibration to ensure constant precision and hence quality. Basically, each different projected pattern has to be calibrated at least once, to account for temperature-induced variations in the laser scanning systems, relative displacements due to variable distances and shifts between projector and projection target. The calibration system consists of 4 to 10 standard machine vision B/W cameras or alternatively less expensive modified USB or 1394 cameras, depending on the specific requirements of the factory. Specific calibration patterns are projected at given positions, acquired by spatially calibrated cameras, image processed and compared with the default coordinates. Evaluation algorithms perform error minimisations between the actual data and the set point data, involving different parameter models accounting for offset, rotation, ...
Turquoises (CuAl6[(OH)2/PO4]4⋅4H2O) are highly prized as gem stones, but easy to counterfeit. Thu... more Turquoises (CuAl6[(OH)2/PO4]4⋅4H2O) are highly prized as gem stones, but easy to counterfeit. Thus, simple and reliable methods to detect fraudulent jewellery would be of high interest. One possible solution is to use an imaging spectrometer system for the visible and near infrared. This method, in combination with a software toolbox for computer-aided classification, complements the expensive standard methods currently employed to investigate minerals. The aim of the experiments was to develop a method to distinguish between true turquoises and (potential) fakes. The mineralogical collection of the Vienna Museum of Natural History (NHM Wien) provided referenced samples of (i) natural turquoise, (ii) treated turquoise, e.g. pressed turquoise powder, (iii) artificial, industrial turquoise (Gilson) and (iv) samples of other minerals that are frequently mistaken for turquoises. Spectrally resolved reflectance images of the mineralogical samples were acquired using a hyperspectral imagi...
12th Symposium and School on High-Resolution Molecular Spectroscopy, 1997
ABSTRACT The aim of the present paper is to collect the spectroscopic data assembled so far on sm... more ABSTRACT The aim of the present paper is to collect the spectroscopic data assembled so far on small water polymers in the gas phase as well as on host clusters and in cryogenic matrices and to compare them with each other. In addition it is shown that the whole set of data can be regarded as highly consistent if the frequency shifts are analyzed in terms of a correlation with the square root of the critical temperature of the gas constituting the matrix or host cluster.
Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH ra... more Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH radicals has been used to study O3/OH(v = 0)/HO2 chain reaction kinetics at 298 K, (i.e.,(k(sub 1) is OH + 03 yields H02 + 02 and (k(sub 2) is H02 + 03 yields OH + 202). From time-resolved detection of OH radicals with high-resolution near IR laser absorption methods, the chain induction kinetics have been measured at up to an order of magnitude higher ozone concentrations ([03] less than or equal to 10(exp 17) molecules/cu cm) than accessible in previous studies. This greater dynamic range permits the full evolution of the chain induction, propagation, and termination process to be temporally isolated and measured in real time. An exact solution for time-dependent OH evolution under pseudo- first-order chain reaction conditions is presented, which correctly predicts new kinetic signatures not included in previous OH + 03 kinetic analyses. Specifically, the solutions predict an initial exponential loss (chain "induction") of the OH radical to a steady-state level ([OH](sub ss)), with this fast initial decay determined by the sum of both chain rate constants, k(sub ind) = k(sub 1) + k(sub 2). By monitoring the chain induction feature, this sum of the rate constants is determined to be k(sub ind) = 8.4(8) x 10(exp -14) cu cm/molecule/s for room temperature reagents. This is significantly higher than the values currently recommended for use in atmospheric models, but in excellent agreement with previous results from Ravishankara et al.
Die invasive Messung der Blutalkoholkonzentration (BAK) stellt eine zeit- und kostenaufwaendige P... more Die invasive Messung der Blutalkoholkonzentration (BAK) stellt eine zeit- und kostenaufwaendige Prozedur dar. Daher wurden neben der Ermittlung der Atemalkoholkonzentration (AAK) diverse Ansaetze zur nichtinvasiven transdermalen Messung der Alkoholbeeinflussung (TBAK: transdermale Alkoholkonzentration) entwickelt. Es werden die bisher existierenden unterschiedlichen Systeme vorgestellt und diskutiert. Die nichtinvasive Messung der Alkoholkonzentration im Blut ist eine sehr nuetzliche und vielversprechende Massnahme, die technisch allerdings ausserordentlich schwierig ist. Es bleibt abzuwarten, ob eine zuverlaessige und exakte Bestimmung mit verbesserten spektroskopisch basierten Ansaetzen zu erreichen ist. (A) ABSTRACT IN ENGLISH: Invasive measurement of blood alcohol concentration (BAC) is a time-consuming and an expensive procedure. That is the reason why new approaches for a non-invasive transdermal blood alcohol concentration (TBAC) measurement in addition to the breath alcohol ...
Die invasive Messung der Blutalkoholkonzentration (BAK) ist eine zeit- und kostenaufwendige Proze... more Die invasive Messung der Blutalkoholkonzentration (BAK) ist eine zeit- und kostenaufwendige Prozedur. Jede Blutentnahme muss richterlich angeordnet und von einem Arzt durchgefuehrt werden. Daher wurden neben der Ermittlung der Atemalkoholkonzentration (AAK) diverse Ansaetze zur nichtinvasiven transdermalen Messung der Alkoholkonzentration (TAK: transdermale Alkoholkonzentration) entwickelt. Es werden auf Spektroskopie basierende Voruntersuchungen vorgestellt, die zeigen, dass eine nichtinvasive Messung von Gewebealkoholkonzentrationen im physiologischen Konzentrationsbereich und in vitro Versuchsanordnungen ein hohes Potenzial dieser Methode verspricht. (A) ABSTRACT IN ENGLISH: Invasive measurement of blood alcohol concentration (BAC) is a well-known, but time-consuming and expensive procedure. The measurement of the BAC requires authorized approval based on the personal rights. Every involuntary taking of a blood sample from a person has to be legalized by a judge or state attorney...
Background: Hyperspectral Imaging (HSI) has a strong potential to be established as a new contact... more Background: Hyperspectral Imaging (HSI) has a strong potential to be established as a new contact-free measuring method in medicine. Hyperspectral cameras and data processing have to fulfill requirements concerning practicability and validity to be integrated in clinical routine processes. Methods: Calculating physiological parameters which are of significant clinical value from recorded remission spectra is a complex challenge. We present a data processing method for HSI remission spectra based on a five-layer model of perfused tissue that generates perfusion parameters for every layer and presents them as depth profiles. The modeling of the radiation transport and the solution of the inverse problem are based on familiar approximations, but use partially heuristic methods for efficiency and to fulfill practical clinical requirements. Results: The parameter determination process is consistent, as the measured spectrum is practically completely reproducible by the modeling sequence;...
Worldwide, chronic wounds are still a major and increasing problem area in medicine with protract... more Worldwide, chronic wounds are still a major and increasing problem area in medicine with protracted suffering of patients and enormous costs. Beside conventional wound treatment, for instance kinds of oxygen therapy and cold plasma technology have been tested, providing an improvement in the perfusion of wounds and their healing potential, but these methods are unfortunately not sufficiently validated and accepted for clinical practice to date. Using hyperspectral imaging technology in the visible (VIS) and near infrared (NIR) region with high spectral and spatial resolution, perfusion parameters of tissue and wounds can be determined. We present a new compact hyperspectral camera which can be used in clinical practice. From hyperspectral data the hemoglobin oxygenation (StO2), the relative concentration of hemoglobin [tissue hemoglobin index (THI)] and the so-called NIR-perfusion index can be determined. The first two parameters are calculated from the VIS-part of the spectrum and ...
The monitoring of free flaps, free transplants or organs for transplantation still poses a proble... more The monitoring of free flaps, free transplants or organs for transplantation still poses a problem in medicine. Available systems for the measurement of perfusion and oxygenation can only perform localized measurements and usually need contact with the tissue. Contact free hyperspectral imaging and near-infrared spectroscopy (NIRS) for the analysis of tissue oxygenation and perfusion have been used in many scientific studies with good results. But up to now the clinical and scientific application of this technology has been hindered by the lack of hyperspectral measurement systems usable in clinical practice. We will introduce the application of a new hyperspectral camera system for the quick and robust recording of remission spectra in the combined VIS and NIR spectral range with high spectral and spatial resolution. This new system can be applied for the clinical monitoring of free flaps and organs providing high quality oxygenation and perfusion images.
The development of improved preservation techniques and the reliable assessment of donor grafts a... more The development of improved preservation techniques and the reliable assessment of donor grafts are main fields of research in transplantation medicine. Normothermic machine perfusion (NMP) is a promising alternative to static cold storage of organs, maintaining physiological conditions during preservation. In combination with NMP, we introduce hyperspectral imaging (HSI) as a novel approach for the monitoring of physiological kidney parameters. A line-scan HSI camera system was used to record images of porcine kidneys during NMP. Based on a dual-wavelength algorithm, the oxygen saturation levels were calculated from HSI recordings. Furthermore, we observed HSI images in the near-infrared (NIR) range in order to detect water characteristics of the kidney tissue. We found increasing levels of oxygenation during NMP and could discriminate between perfused and non-perfused areas. Cysts at the renal capsula were characterized by an absorption increase in the NIR band. Within this work, we showed that HSI is able to detect relevant chemical changes during NMP and allows the identification of pathologic variations.
BACKGROUND: Pulse spectroscopy is a new noninvasive technology involving hundreds of wavelengths ... more BACKGROUND: Pulse spectroscopy is a new noninvasive technology involving hundreds of wavelengths of visible and infrared light, enabling the simultaneous quantitation of multiple types of normal and dysfunctional hemoglobin. We evaluated the accuracy of a first-generation pulse spectroscopy system (V-Spec™ Monitoring System, Senspec, Germany) in measuring oxygen saturation (Spo 2) and detecting carboxyhemoglobin (COHb) or methemoglobin (MetHb), alone or simultaneously, with hypoxemia. METHODS: Nineteen volunteers were fitted with V-Spec probes on the forehead and fingers. A radial arterial catheter was placed for blood sampling during (1) hypoxemia with arterial oxygen saturations (Sao 2) of 100% to 58.5%; (2) normoxia with MetHb and COHb increased to approximately 10%; (3) 10% COHb or MetHb combined with hypoxemia with Sao 2 of 100% to 80%. Standard measures of pulse-oximetry performance were calculated: bias (pulse spectroscopy measured value − arterial measured value) mean ± SD a...
Abstract Hyperspectral imaging and near infrared spectroscopy (NIRS) for wound analysis have been... more Abstract Hyperspectral imaging and near infrared spectroscopy (NIRS) for wound analysis have been used in many scientific studies with good results for the chemical analysis of wounds and have the potential to raise objective measurement and assessment of wounds to a new level with considerable higher clinical informative value. Up to now the clinical and scientific use of this technology has been hindered by the lack of a hyperspectral measurement system usable in clinical practice. We present the first hyperspectral camera for quick and robust acquisition of hyperspectral data in the combined VIS and NIR spectral range with high spectral and spatial resolution from wounds. First case studies and evaluations of chemometric parameters like the oxygenation of hemoglobin and perfusion quality are presented and exhibit the high quality and potential of this new wound measurement system.
Large-scale laser projection systems used in industrial environment, e.g. for the projection of C... more Large-scale laser projection systems used in industrial environment, e.g. for the projection of CAD drawings onto large work pieces, require external calibration to ensure constant precision and hence quality. Basically, each different projected pattern has to be calibrated at least once, to account for temperature-induced variations in the laser scanning systems, relative displacements due to variable distances and shifts between projector and projection target. The calibration system consists of 4 to 10 standard machine vision B/W cameras or alternatively less expensive modified USB or 1394 cameras, depending on the specific requirements of the factory. Specific calibration patterns are projected at given positions, acquired by spatially calibrated cameras, image processed and compared with the default coordinates. Evaluation algorithms perform error minimisations between the actual data and the set point data, involving different parameter models accounting for offset, rotation, ...
Turquoises (CuAl6[(OH)2/PO4]4⋅4H2O) are highly prized as gem stones, but easy to counterfeit. Thu... more Turquoises (CuAl6[(OH)2/PO4]4⋅4H2O) are highly prized as gem stones, but easy to counterfeit. Thus, simple and reliable methods to detect fraudulent jewellery would be of high interest. One possible solution is to use an imaging spectrometer system for the visible and near infrared. This method, in combination with a software toolbox for computer-aided classification, complements the expensive standard methods currently employed to investigate minerals. The aim of the experiments was to develop a method to distinguish between true turquoises and (potential) fakes. The mineralogical collection of the Vienna Museum of Natural History (NHM Wien) provided referenced samples of (i) natural turquoise, (ii) treated turquoise, e.g. pressed turquoise powder, (iii) artificial, industrial turquoise (Gilson) and (iv) samples of other minerals that are frequently mistaken for turquoises. Spectrally resolved reflectance images of the mineralogical samples were acquired using a hyperspectral imagi...
12th Symposium and School on High-Resolution Molecular Spectroscopy, 1997
ABSTRACT The aim of the present paper is to collect the spectroscopic data assembled so far on sm... more ABSTRACT The aim of the present paper is to collect the spectroscopic data assembled so far on small water polymers in the gas phase as well as on host clusters and in cryogenic matrices and to compare them with each other. In addition it is shown that the whole set of data can be regarded as highly consistent if the frequency shifts are analyzed in terms of a correlation with the square root of the critical temperature of the gas constituting the matrix or host cluster.
Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH ra... more Excimer laser photolysis in combination with time-resolved IR laser absorption detection of OH radicals has been used to study O3/OH(v = 0)/HO2 chain reaction kinetics at 298 K, (i.e.,(k(sub 1) is OH + 03 yields H02 + 02 and (k(sub 2) is H02 + 03 yields OH + 202). From time-resolved detection of OH radicals with high-resolution near IR laser absorption methods, the chain induction kinetics have been measured at up to an order of magnitude higher ozone concentrations ([03] less than or equal to 10(exp 17) molecules/cu cm) than accessible in previous studies. This greater dynamic range permits the full evolution of the chain induction, propagation, and termination process to be temporally isolated and measured in real time. An exact solution for time-dependent OH evolution under pseudo- first-order chain reaction conditions is presented, which correctly predicts new kinetic signatures not included in previous OH + 03 kinetic analyses. Specifically, the solutions predict an initial exponential loss (chain "induction") of the OH radical to a steady-state level ([OH](sub ss)), with this fast initial decay determined by the sum of both chain rate constants, k(sub ind) = k(sub 1) + k(sub 2). By monitoring the chain induction feature, this sum of the rate constants is determined to be k(sub ind) = 8.4(8) x 10(exp -14) cu cm/molecule/s for room temperature reagents. This is significantly higher than the values currently recommended for use in atmospheric models, but in excellent agreement with previous results from Ravishankara et al.
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Papers by Axel Kulcke