Validation of non-invasive point of care blood content analysis using the TensorTip™ MTX device: a method comparison study.

Abstract

The TensorTip™ MTX is a non-invasive device designed to determine several physiological parameters with additional analysis of haemoglobin, haematocrit and blood gas analysis by interpreting blood diffusion colour of the finger skin based on spectral analysis. The aim of our study was to investigate the accuracy and precision of the TensorTip MTX in a clinical setting in comparison with routine analysis of blood samples. Forty-six patients, scheduled for elective surgery, were enrolled in this study. Placement of an arterial catheter had to be part of the standard of care. Measurements were performed during the perioperative period. The measurements obtained with the TensorTip MTX were compared with the results of routine analysis of the blood samples as areference using correlation, Bland-Altman analysis and mountain plots. No significant correlation was present in the measurements. Measurement of haemoglobin with the TensorTip MTX had a mean bias of 0.4 mmol/L, haematocrit's bias was 3.0 %. Bias of partial pressure of carbon dioxide and oxygen was 3.6 and 66.6 mmHg, respectively. Calculated percentage errors were 48.2 , 48.9, 39.9 and 109.0 %. Proportional bias was present in all Bland-Altman analyses. Less than 95 % of the differences fell within the pre-set limits of allowable error. Non-invasive blood content analysis with the TensorTip MTX device is not equivalent to and did not correlate sufficiently with conventional laboratory analysis. None of the parameters measured showed results within the limits of allowable error. Therefore, the use of the TensorTip MTX is not recommended for perioperative care.