Final Report Summary - MOSAIC (Middle-Infrared Optical Spectroscopy for Anaesthetic Agent and Carbon Isotope Analysis)
The MOSAIC project employs ultra-sensitive optical cavity ring-down spectroscopy (CRDS) in the middle-infrared (mid-IR) spectral range to develop new analytical instrumentation for two high impact applications: medical exhaled breath analytics and carbon-14 isotope measurement. Every year over 100 million people undergo surgery, mostly performed under general anaesthesia. The majority of operations are performed using inhaled anaesthetic agents. However, more and more patients are anaesthetised using intravenously administered drugs, such as propofol, because there is growing evidence that intravenously administered drugs have several advantages over inhaled ones: shorter recovery times and less frequent adverse side effects. Compatibility with other drugs is also better, which is crucial for balanced anaesthesia. The increasing clinical use of intravenous anaesthetics is accompanied by the alarming fact that no viable instruments exist for monitoring their blood plasma concentration.
In this project an optical cavity ring-down (CRD) spectrometer operating around 3 micrometer wavelength has been designed for propofol studies. In a CRD spectrometer light bounces back and forth between two highly reflectivity mirrors to yield long, kilometer scale absorption length. State of the art distributed feedback (DFB) semiconductor laser operating at 3 µm at room temperature is used as the light source. No commercial room temperature quantum cascade laser can reach this wavelength region, and difference frequency generation is experimentally more complex than the DFB diode laser. DFB lasers are also beneficial due to their compact size and low power consumption. Their operating temperature can be controlled through thermoelectric cooling, and the laser intensity and wavelength can be electrically tuned. Full electronic control over the laser system will be possible allowing for an entire set up that is readily computer controlled. The spectrometer is being constructed at the host institute.
The second application, analysis of carbon 14-C/12-C isotope ratio from CO2 samples, responds to the emerging need to monitor the fossil to modern carbon ratio and to detect leakages in Carbon Capture and Storage (CCS) systems. The EU Emissions Trading Scheme, together with the proposed CCS Directive, is expected to keep the EU on track to meet its target to cut greenhouse gas emissions in Europe by 20% by 2020 compared to 1990 levels. CCS is emerging technology concept and currently there is no established state of the art, particularly with regards to monitoring of CO2 leakages in the storage strata. A CRD spectrometer operating at 4.5 micrometer mid-IR spectral range has been designed and the first test set-up has been constructed. The set-up has been tested using a laser light source based on difference frequency generation. The first tests successfully demonstrated that the targeted sensitivity level can be achieved for enriched 14C samples. A quantum cascade semiconductor laser is currently being implemented to the set up to make the spectrometer more compact.
An important contribution to this field has been made by an Italian research group [I. Galli et al, Opt. Lett. 35, 3616 (2010)]. They have demonstrated a new significant improvement to the CRD technique, called saturated-CRD or SCAR. SCAR has been shown to allow 14C measurement at ambient, sub-parts-per-trillion level mixing ratios. There is thus proven technical potential for a breakthrough in all-optical radiocarbon dating. The approach proposed within MOSAIC, that is, using a compact QCL light source for CRD radiocarbon dating is thus very topical.
The MOSAIC project was terminated early as the researcher left the host institute before the end date of the project. The researcher accepted an offer for a permanent research position in a private company. His new role is to head the research analytics group of the company. However, research on the topics proposed in the MOSAIC project continues at the host institute. The host organization is in a very good position to reach the targeted research goals both in the field of exhaled breath diagnostics and 14C isotope measurements. During the MOSAIC project the researcher was active in disseminating the results by presenting the achievements in established scientific conferences. The researcher significantly contributed to increasing research collaborations of the host at European level.
In this project an optical cavity ring-down (CRD) spectrometer operating around 3 micrometer wavelength has been designed for propofol studies. In a CRD spectrometer light bounces back and forth between two highly reflectivity mirrors to yield long, kilometer scale absorption length. State of the art distributed feedback (DFB) semiconductor laser operating at 3 µm at room temperature is used as the light source. No commercial room temperature quantum cascade laser can reach this wavelength region, and difference frequency generation is experimentally more complex than the DFB diode laser. DFB lasers are also beneficial due to their compact size and low power consumption. Their operating temperature can be controlled through thermoelectric cooling, and the laser intensity and wavelength can be electrically tuned. Full electronic control over the laser system will be possible allowing for an entire set up that is readily computer controlled. The spectrometer is being constructed at the host institute.
The second application, analysis of carbon 14-C/12-C isotope ratio from CO2 samples, responds to the emerging need to monitor the fossil to modern carbon ratio and to detect leakages in Carbon Capture and Storage (CCS) systems. The EU Emissions Trading Scheme, together with the proposed CCS Directive, is expected to keep the EU on track to meet its target to cut greenhouse gas emissions in Europe by 20% by 2020 compared to 1990 levels. CCS is emerging technology concept and currently there is no established state of the art, particularly with regards to monitoring of CO2 leakages in the storage strata. A CRD spectrometer operating at 4.5 micrometer mid-IR spectral range has been designed and the first test set-up has been constructed. The set-up has been tested using a laser light source based on difference frequency generation. The first tests successfully demonstrated that the targeted sensitivity level can be achieved for enriched 14C samples. A quantum cascade semiconductor laser is currently being implemented to the set up to make the spectrometer more compact.
An important contribution to this field has been made by an Italian research group [I. Galli et al, Opt. Lett. 35, 3616 (2010)]. They have demonstrated a new significant improvement to the CRD technique, called saturated-CRD or SCAR. SCAR has been shown to allow 14C measurement at ambient, sub-parts-per-trillion level mixing ratios. There is thus proven technical potential for a breakthrough in all-optical radiocarbon dating. The approach proposed within MOSAIC, that is, using a compact QCL light source for CRD radiocarbon dating is thus very topical.
The MOSAIC project was terminated early as the researcher left the host institute before the end date of the project. The researcher accepted an offer for a permanent research position in a private company. His new role is to head the research analytics group of the company. However, research on the topics proposed in the MOSAIC project continues at the host institute. The host organization is in a very good position to reach the targeted research goals both in the field of exhaled breath diagnostics and 14C isotope measurements. During the MOSAIC project the researcher was active in disseminating the results by presenting the achievements in established scientific conferences. The researcher significantly contributed to increasing research collaborations of the host at European level.