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Seraccess® Milestone 7a

Written by: D. Brunner; K. Tzikas; Dr. R. Rapold; Dr. med. vet. K. Klein; Dr. B. Schär

 

Continuous automated blood sampling based on an animal model

Securecell AG/Vetsuisse-Fakultät ZH, MSRU/CABMM, May 2022

Keywords: Seraccess, automated blood sampling, animal model

Background

Automated blood glucose monitoring with Securecell’s SeraMaster prototype was tested in a clinical setting as part of a feasibility study (see Milestone 6).

Several experiments on live sheep were defined to test automated blood sampling in vivo. In a first series of experiments, the automated sampling process, including dilution with NaCl, was compared with manual sampling.

Study design

The trial (national authorization number: 34196, cantonal: ZH215/2021) was conducted in collaboration with the Vetsuisse Faculty of the University of Zurich. It included two full-day trials. Blood samples were automatically collected with the SeraMaster prototype via central venous catheter (n=32) or arterial catheter (n=40) every 15 to 20 minutes. They were then compared with the manually collected reference samples by measuring the glucose concentration of each sample.

Results

To evaluate the automated method, the bias (=mean deviation from the reference method) was calculated. For samples from the central vein the bias was 1.9 mg/dl (n=32) and for samples from the peripheral artery it was 1.7 mg/dl (n=40). All 72 data points (100%) are within the margin of error of ± 6.5 mg/dl.

The following figure shows the regression analysis between SeraMaster glucose values (Y-axis) and manual sampling (X-axis). The correlation coefficient (R2) is 0.9667, which means that the two methods are equivalent and therefore interchangeable.

regression analysis between SeraMaster (Y-axis) and of Cobas C111 (X-axis)

The following images illustrate the experimental setup in the stables of the university. At the end of the day, the laboratory animals were allowed to return to the pasture.

Next steps

In the next series of experiments on sheep, automated blood sampling will be combined with automated glucose measurement.

Continuous automated blood sampling with the SeraMaster prototype is equivalent to the manual reference method. The bias, a measure of the accuracy of the method, is 1.9 mg/dl (venous) and 1.7 mg/dl (arterial) compared to the reference method. The regression analysis shows that the two methods are interchangeable. Therefore, it makes sense to tackle the next series of experiments.