In-line optical monitoring of oxygen saturation and hematocrit for cardiopulmonary bypass: Adjustment-free and bloodless calibration
-
Uwe J. Netz
,
Moritz Friebel
Abstract
Background and objective:
This article describes a new sensor for monitoring oxygen saturation (sO2) and hematocrit (Hct) of blood during cardiopulmonary bypass. The sensor is calibrated without blood and does not need to be adjusted by laboratory blood parameter analysis when in operation.
Materials and methods:
The optical sensor presented here uses near-infrared spatially resolved reflectance spectroscopy. The primary calibration model for a master sensor is derived from the measurement of circulating human blood from a number of different patients with references taken from standard laboratory analysis of blood parameters. Transfer of the calibration model from the master sensor to new sensors is performed by measurement of an optical standard made of artificial material with defined and controlled optical properties.
Results:
The predicted values of sO2 and Hct exhibit an accuracy of 1.2% for sO2 and 1.1% for Hct compared to the reference values. The optical standard yields optical signals similar to the measurement of blood. After calibration transfer, the mean accuracy of the measurement of 10 sensors is 1.3% for sO2 and 1.2% for Hct.
Conclusion:
A new sensor with high degree of accuracy for sO2 and Hct compared to commercially available sensor systems is presented. The calibration transfer using optical standards gives a comparable degree of accuracy. The method could be adapted for use with existing sensors. No animal blood needs to be used in calibration process anymore.
Zusammenfassung
Hintergrund und Zielsetzung:
Dieser Artikel beschreibt einen neuen Sensor für die Überwachung der Sauerstoffsättigung (sO2) und des Hämatokrits (Hct) von Blut am extrakorporalen Kreislauf. Der Sensor wird ohne Blut kalibriert und erfordert im Einsatz keinen Abgleich mittels Laboranalyse der Blutparameter.
Materialien und Methoden:
Der vorgestellte Sensor verwendet das Verfahren der ortsaufgelösten Rückstreuspektroskopie im Nahinfrarotbereich. Das Kalibriermodell für einen Mastersensor wird zunächst aus der Messung an zirkulierendem menschlichem Blut von mehreren Patienten sowie der Referenzmessung durch Laboranalyse der Blutparameter gewonnen. Die Übertragung des Kalibriermodells vom Mastersensor auf neue Sensoren erfolgt mit Hilfe der Messung an einem optischen Standard aus künstlichen Materialien mit definierten optischen Eigenschaften.
Ergebnisse:
Die Vorhersagewerte für sO2 und Hct erreichen eine Genauigkeit gegenüber den Referenzwerten von 1.2% für sO2 und 1.1% für Hct. Der optische Standard erzeugt ähnliche Sensorsignale wie bei Messungen an Blut. Die Genauigkeit der Messung nach der Kalibrierübertragung liegt im Mittel von 10 Sensoren bei 1.3% für sO2 und 1.2% für Hct.
Fazit:
Es wird ein neuer Sensor zur Messung von sO2 und Hct präsentiert, der eine hohe Genauigkeit im Vergleich zu den am Markt befindlichen Sensoren aufweist. Die Kalibrierübertragung mittels optischer Standards liefert eine vergleichbare Genauigkeit. Die Methode lässt sich auch für bestehende Sensoren anwenden. Für die Kalibrierung ist damit kein Tierblut mehr nötig.
Acknowledgments
Financial support is gratefully acknowledged from the Berlin Senate Department of Commerce, Technology and Research (IBB, ProFIT 10147774), and co-financed by the European Fund for Regional Development (EFRE). Our thanks go to Enno Ott for the operation of the cardiopulmonary bypass and the sensor measurements, to Lesley Hirst for blood management and the blood parameter reference measurements, and to the DRK-Blutspendedienst Nord-Ost for their help in supplying us with blood products.
Conflict of interest statement: There is no conflict of interest to declare.
References
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©2015 Walter de Gruyter GmbH, Berlin/Boston
Artikel in diesem Heft
- Frontmatter
- Editorial
- Sensors in diagnostics and monitoring
- Magazine section
- Snapshots
- Reviews
- Recent advances in SPR and SERS for sensitive translational medical diagnostics
- Raman spectroscopy for the discrimination of cancerous and normal skin
- Original contribution
- Fluorescence-optical handheld non-contact sensor for rapid cleaning validation of surfaces
- Preliminary research reports
- Evaluation of a novel skin tone meter and the correlation between Fitzpatrick skin type and skin color
- In-line optical monitoring of oxygen saturation and hematocrit for cardiopulmonary bypass: Adjustment-free and bloodless calibration
- Short communications
- Non-invasive detection of free hemoglobin in red blood cell concentrates for quality assurance
- Development of an in-vivo sensor for monitoring of water content in skin
- Congress announcements
- LASER World of PHOTONICS – DGLM Application Panel: Laser-advanced new methods for diagnostics and therapeutics
- Congresses 2015/2016
Artikel in diesem Heft
- Frontmatter
- Editorial
- Sensors in diagnostics and monitoring
- Magazine section
- Snapshots
- Reviews
- Recent advances in SPR and SERS for sensitive translational medical diagnostics
- Raman spectroscopy for the discrimination of cancerous and normal skin
- Original contribution
- Fluorescence-optical handheld non-contact sensor for rapid cleaning validation of surfaces
- Preliminary research reports
- Evaluation of a novel skin tone meter and the correlation between Fitzpatrick skin type and skin color
- In-line optical monitoring of oxygen saturation and hematocrit for cardiopulmonary bypass: Adjustment-free and bloodless calibration
- Short communications
- Non-invasive detection of free hemoglobin in red blood cell concentrates for quality assurance
- Development of an in-vivo sensor for monitoring of water content in skin
- Congress announcements
- LASER World of PHOTONICS – DGLM Application Panel: Laser-advanced new methods for diagnostics and therapeutics
- Congresses 2015/2016
