Compliance of a microstructured, soft sampling device for transcutaneous blood gas monitoring

Abstract

Replacing rigid transcutaneous blood gas monitoring sensors with microstructured silicone patches, makes the proof of concept system developed and evaluated here a viable first step towards truly continuous measurement on premature neonates.

Partial least squares modelling of spectroscopic data from microplasma emissions for determination of CO2 concentration

“…The employed TBM setup is thoroughly described in Ref. [6]. Using these and other measurements on samples with known CO2 concentration, the precision, accuracy and stability of the modelled responses were calculated and compared, both to each other and to the previously reported analytical method.…”

Modeling and Evaluation of a Rate-Based Transcutaneous Blood Gas Monitor

“…The gas collector and sensor are connected with fluidics that flow gas from the former to the latter with the help of a pump. These fluidics contain a thin fused silica capillary that acts as a choke and defines the flow through the system to a few µl/s [16].…”

“…The emitted light is then studied with a spectrometer, and the individual species (in this case CO2) are quantified by investigating relevant parts of the recorded spectra. The technique was initially developed for space applications, more precisely to look for past or present life on Mars, [14], but its ability to handle extremely small sample sizes, [15], has proved useful for quantifying the minute transcutaneous gas flux [16]. Like the recirculation example above, it is rate-based and works on unheated skin, but it does not require repeated purging, enabling continuous monitoring.…”

“…Like the recirculation example above, it is rate-based and works on unheated skin, but it does not require repeated purging, enabling continuous monitoring. Additionally, it uses a small (10 mm), soft skin interface that does not have to be attached to flat surfaces, which makes it easier to use on preterm infants [16]- [18]. In this study, a theoretical model for the relationship between the measured spectroscopic signal and the partial CO2 tension in the blood is derived and evaluated with respect to empirical results.…”

PDMS-polyimide transcutaneous blood gas collector with self-folding out-of-plane heater elements

“…A previous study [5], presented a novel transcutaneous blood gas collector made from soft and flexible polydimethylsiloxane (PDMS), which enabled attachment to curved surfaces on the skin and hence made it easier to use for a caregiver. However, this first prototype did not contain a heater and hence did not enable monitoring of arterialized gas levels.…”