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Non-invasive monitoring of pH and oxygen using miniaturized electrochemical sensors

The Original Article was published on 04 February 2021

Dear Editor,

We read with great interest a recent published article by Pla et al. [1] in Journal of Translational Medicine. In this study, the authors investigated some variables including partial pressure of oxygen, pH, lactate, bicarbonate, and potassium in different time-points of hypoxia induction (i.e., basal, hypoxia-acidosis, and recovery periods). Therefore, they compared these variables between different time-points of measurement in one sample of 27 New Zealand White male rabbits. Since their comparisons were within-group, they were dependent to each others. However, they stated in abstract and statistical analysis section of the methods that one-way analysis of variance (ANOVA) was used to compare variables between different time-points of measurement. One-way ANOVA is used to compare numerical variables with normal distribution between more than two independent groups [2,3,4,5,6]. Because the comparisons in this study was performed between different time-points of measurements in one group of animals, the authors must assess normal distribution of numerical variables and then use repeated measures ANOVA or Friedman test [7,8,9,10]. Furthermore, they used student’s t-test for comparison of numerical variables between each two time-points of measurement, while they must use paired t-test or Wilcoxon for comparison of numerical variables between two time-points of measurement.

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  1. Pla L, Berdún S, Mir M, Rivas L, Miserere S, Dulay S, Samitier J, Eixarch E, Illa M, Gratacós E. Non-invasive monitoring of pH and oxygen using miniaturized electrochemical sensors in an animal model of acute hypoxia. J Transl Med. 2021;19:1–11.

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Authors and Affiliations



MF: study design, writing draft of the study. SPM: study design, writing draft of the study. FT: study design, writing draft of the study. All authors read and approved the final manuscript.

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Correspondence to Mehrdad Farrokhi.

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Farrokhi, M., Manavi, S.P. & Taheri, F. Non-invasive monitoring of pH and oxygen using miniaturized electrochemical sensors. J Transl Med 19, 252 (2021).

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