Very Short-Term Photoplethysmography-Based Heart Rate Variability for Continuous Autoregulation Assessment

Round 1

Reviewer 1 Report

Dear Authors,

thank you for submitting this paper. The presented study is interesting and clinically relevant.

1.     Title: the title is clear and sufficiently summarizes the research topic.

2.     Abstract: ts is short and clear.

3.     Introduction:

a.      Line 73-75. Sentences about fever and infection need to be rewritten. Example: Fever is one of the early signs of infection and need to be systematically monitored in intensive care unit (IUC).

b. Line 76 – omit in daily life.

c. Line 77 – grammatically incorrect sentence – necessary is repeated! Example: Therefore, temperature monitoring is necessary with this patient.  

d. part from line 78 – 85 needs to be rewritten as it is not clear and medically sense.

4.     Materials and methods:

a.      Line 95 – ...and were diagnosed with fever...

b.  Example: »The previous study showed that iPRV can be performed using short-term PPG [20], a total of 15 seconds stable signal of the the middle of total PPG signal was used in this study. It can also decrease the computation time cost of the advance EMD method and the SampEn algorithm.«

Do not discuss during this section. This belongs to de discussion section. Methods should be clear and should include only description of step by step procedures used in the experiment.

Check the whole section for similar.

c. Line 100-103 – I recommend that you put this part at the beginning of methods section.

5.     Results:

a.    are clearly presented.  

6.     Discussion:

a.      Part from line 228 – 244 need revision as it is grammatically very poorly written.

b.       288- correct this sentence and omit terms germs. Fiver can be sign of multiple causes. Infection is the most common.

c. line 290 – thermographic

7. References:

 Reference 1 – authors are missing?

a.       There are inconsistencies in references. Please check guidelines for authors.

I would suggest English spell checking and prof reading by English native speaker. The number of errors in substantial.

Thank you for your article and I am looking forward to the revised manuscript.

Best regards.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This paper starts by presenting state-of-the-art techniques for heart rate variability (HRV) monitoring. The authors proposed the HRV analysis for fever detection and autoregulation assessment by short-term photoplethysmography (PPG).
This work is interesting and presents good scientific quality and could be relevant. It is well presented from point of view of the Materials and Method. Its publication is recommended.
Just some aspects of improvement that the authors could consider:
It would be helpful to the reader if some details could be included concerning the results that were briefly described in Section 3 "Results".
The bibliography is scarce and should be reviewed and updated to improve the quality and interest of readers and researchers
Once these considerations have been made as a recommendation, the work could be published with the approval of the editors.
1 )There are many abbreviations and several markers, for this reason, I suggest to the authors report a short table with a short description of each parameter.
2) In section 1 (Introduction) the authors should extend the description of HRV and PRV. I think that is necessary for this paper that the authors quote the prior works. Moreover, in row 35 the authors write "SDNN, pNN50" without specifying what means.
3) Which type of PPG sampling device has been used? Add details. Which kind of pipeline has been used to stabilize/filter the raw PPG signals with respect to artefacts (body movements, etc..) or electronic noise? Add more details about the above questions if the authors consider it would be useful.
4) The figures must be described appropriately, (some are written with different dimensions, Figure 8 is written in bold style.) as well as improve the quality. Moreover, is sufficient to write Figure 8 and not Figure.8 the same thing for the tables.
5) The following typographical error was detected
•    Line 98: the the, is a repetition
•    Line 154: “The Figure. 2” is more correct “Figure 2”
•    Line 171: “normalized power of each band were calculated as follows” I suggest was
•    Line: 232, maybe is necessary a point between fever and One.
•    Line 303: the influence in age, I suggest the influence of age

Author Response

Please see the attachment.

Author Response File: Author Response.docx