TY - JOUR

T1 - Contactless and continuous sodium concentration monitoring during continuous renal replacement therapy

AU - Berger, Marc

AU - Zygmanowski, Anne

AU - Sellering, Flora

AU - Röhrich, Hannes

AU - Perl, Thorsten

AU - Mansour, Hussam

AU - Zimmermann, Stefan

N1 - Funding Information: Supported by the German Federal Ministry of Education and Research (BMBF) under the grant 13GW0085B .

PY - 2020/10/1

Y1 - 2020/10/1

N2 - A frequent complication of critically ill patients in intensive care units suffering from acute kidney injury is a severe dysnatremia requiring a continuous renal replacement therapy. For such patients, an individual dialysis treatment with an individual composition of the dialysate to limit the rate of serum sodium normalization has a positive effect on patients’ recovery. However, a precise control of the serum sodium concentration change requires continuous sodium monitoring. Drawing blood samples and analyzing such samples with a blood gas analyzer gives the serum sodium concentration with an absolute accuracy of about 2 mmol/L and a precision of 0.6 mmol/L. Nevertheless, blood gas analyzers do not allow for continuous serum sodium monitoring. Therefore, we present a new sensing concept based on a differential transformer consisting of printed circuit board coils for contactless and noninvasive monitoring of the serum sodium concentration during continuous renal replacement therapy to enable an individual sodium management. This sensing concept covers a linear operating range from 100 mmol/L to 170 mmol/L, comparable to commercially available blood gas analyzers. In a preclinical investigation using reconfigured human packed red blood cells as test medium, we could continuously measure the serum sodium concentration with an absolute accuracy of 4 mmol/L compared to the reference and a precision of 0.3 mmol/L. Moreover, we have established an analytical expression to optimize the differential transformer coils, resulting in a high sensitivity of 192 mV/mol/L.

AB - A frequent complication of critically ill patients in intensive care units suffering from acute kidney injury is a severe dysnatremia requiring a continuous renal replacement therapy. For such patients, an individual dialysis treatment with an individual composition of the dialysate to limit the rate of serum sodium normalization has a positive effect on patients’ recovery. However, a precise control of the serum sodium concentration change requires continuous sodium monitoring. Drawing blood samples and analyzing such samples with a blood gas analyzer gives the serum sodium concentration with an absolute accuracy of about 2 mmol/L and a precision of 0.6 mmol/L. Nevertheless, blood gas analyzers do not allow for continuous serum sodium monitoring. Therefore, we present a new sensing concept based on a differential transformer consisting of printed circuit board coils for contactless and noninvasive monitoring of the serum sodium concentration during continuous renal replacement therapy to enable an individual sodium management. This sensing concept covers a linear operating range from 100 mmol/L to 170 mmol/L, comparable to commercially available blood gas analyzers. In a preclinical investigation using reconfigured human packed red blood cells as test medium, we could continuously measure the serum sodium concentration with an absolute accuracy of 4 mmol/L compared to the reference and a precision of 0.3 mmol/L. Moreover, we have established an analytical expression to optimize the differential transformer coils, resulting in a high sensitivity of 192 mV/mol/L.

KW - Contactless sodium monitoring

KW - Differential transformer

KW - Individualized dialysis treatment

KW - Measuring blood parameters

UR - http://www.scopus.com/inward/record.url?scp=85086362097&partnerID=8YFLogxK

U2 - 10.1016/j.snb.2020.128372

DO - 10.1016/j.snb.2020.128372

M3 - Article

AN - SCOPUS:85086362097

VL - 320

JO - Sensors and Actuators, B: Chemical

JF - Sensors and Actuators, B: Chemical

SN - 0925-4005

M1 - 128372

ER -