Horizontal Test Stand for Bone Screw Insertion

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

the content of the text is very interesting, however from the point of view of research methodology it definitely needs to be improved in order to validate your work.

The introduction is clearly and precisely written.

The methodology should be corrected on the basis of the following reflections:

1. the text should be divided into: introduction, materials and methods, discussion, conclusion

2. there is no discussion

3. a significant and substantial section discussing the usefulness of the study is missing (I suggest including it in the discussion):

- what is the problem being solved?

- what are the possible clinical implications of the work you have done?

I remain at your disposal for further clarification.

 

Best regards

 

Author Response

Comments 1: The text should be divided into: introduction, materials and methods, discussion, conclusion
Response 1: Normally I would agree, however the Author guidelines for this jounal prescribe a different structure. The can be found at https://www.mdpi.com/journal/hardware/instructions. 
To quote:

# Manuscript Preparation
## General Considerations
- Research manuscripts should comprise:
      - Front matter: Title, Author list, Affiliations, Abstract, Keywords.
>>    - Research manuscript sections: Introduction, Design, Build Instructions, Operating Instructions, Validation, Conclusions.   <<
      - Back matter: Supplementary Materials, Acknowledgments, Author Contributions, Conflicts of Interest, References.

Comments 2: there is no discussion
Response 2: Please see response 1.

Comments 3: a significant and substantial section discussing the usefulness of the study is missing (I suggest including it in the discussion):

- what is the problem being solved?

- what are the possible clinical implications of the work you have done?
Response 3: The problem/necessity of developing the test rig is descibed/motivated as background information the Introduction, with background on what research it will be/was used for and relating it to clinical outcomes/implications. Additional explanation of the clinical implications was added to the conclusion.

 

Reviewer 2 Report

Comments and Suggestions for Authors

This paper explains about development of a horizontal test stand for bone screw insertion. The manuscript is well-written and also provide details of the device. Low cost is considered to be the advantage of the device. Some additions and modifications may improve the quality of the manuscript. Please consider the following comments.

 

1.       Please provide dimensions of the device for example in Figure 1. It should be better if there is a comparison with existing device in terms of dimensions.

2.       Could you provide a control block diagram of the control system? Is there any feedback mechanism in the control system?

3.       It should help readers to easily understand, if explanations (arrows and text boxes) regarding the parts is added on each figure (Figure 4 to Figure 17).

4.       It is very hard to understand the operating instructions. Could you provide a flow chart that explain the process?

5.       Regarding Figure 26, could you add the picture of the device with attached torque sensor?

6.       Regarding Figure 27 and 28, the errors are non-linear. For example, in Figure 27, the differences decrease at 2 and 3.5 Nm. Could you give an explanation regarding the reasons of this phenomenon?

Author Response

Comments 1:     Please provide dimensions of the device for example in Figure 1. It should be better if there is a comparison with existing device in terms of dimensions.
Response 1:    Added dimensions to the Figure caption and added a paragraph comparing size and weight to the previously mentioned alternative designs

Comments 2:     Could you provide a control block diagram of the control system? Is there any feedback mechanism in the control system?
Response 2:    The motor driver provides a black-box feedback control for the stepper motor. Commands to the driver are effectively open-loop, so there is no additional control system that was designed that we can discuss.

Comments 3:     It should help readers to easily understand, if explanations (arrows and text boxes) regarding the parts is added on each figure (Figure 4 to Figure 17).
Response 3:    Added annotations to Figures 5a, 12,  13a, 13b for important/unclear parts.

Comments 4:     It is very hard to understand the operating instructions. Could you provide a flow chart that explain the process?
Response 4:    Added summarised bullet point lists at end of instruction sections.

Comments 5:     Regarding Figure 26, could you add the picture of the device with attached torque sensor?
Response 5:    Added figure.

Comments 6:     Regarding Figure 27 and 28, the errors are non-linear. For example, in Figure 27, the differences decrease at 2 and 3.5 Nm. Could you give an explanation regarding the reasons of this phenomenon?
Response 6:    Many things could cause this, however as both sensors are proprietary we have no real way to know exactly. We have added an explanation but because of the above reason it is very brief and nonspecific; we would prefer not to specualte as we believe it would have minimal value to the reader.

Reviewer 3 Report

Comments and Suggestions for Authors

Review comments for manuscript ID: hardware-3022750

 1.     Too many figures. The authors may consider deleting some similar diagrams such as Fig.4, Fig.5, Fig.6 and Fig.22, which are similar.

2.     If Figure 12 is unimportant, it may be considered removed.

3.     The authors should well describe Figure 27, and note what is “Max Spacing”; “Mid Spacing” “Min Spacing”, and what is “1:1 Line”?

4.     In section 5.3, why were 4 different conditions (No load, 80, 240, 600 g/cm3) run? Why 20 revolutions? Are they based on the test specifications? Or what test specification was followed?

5.     In Figure 27, the legend shows “No Load, 80, 240, 600 g/cm3” The unit may be wrong. Three different densities of PU foam were used in this study. However, their densities are so great (ex: the density of iron is only 7.9 g/cm3), that Figure 27 shows that the density of PU is as high as 600 g/cm3. Please check the densities of the PU foams.

 

6.     Please check that Figures 5 (a) and 5(b) are revised.

Author Response

Comments 1:     Too many figures. The authors may consider deleting some similar diagrams such as Fig.4, Fig.5, Fig.6 and Fig.22, which are similar.
Response 1:    In most cases these are used to show a specific part of the assembly with minimal clutter, however Figure 22 is indeed not really necessary/helpful, and was removed.

Comments 2:     If Figure 12 is unimportant, it may be considered removed.
Response 2:    We believe it is important to provide a reference for how these parts are to be prepared.

Comments 3:     The authors should well describe Figure 27, and note what is “Max Spacing”; “Mid Spacing” “Min Spacing”, and what is “1:1 Line”?
Response 3:    Additional explanation was added to clarify this point.

Comments 4:     In section 5.3, why were 4 different conditions (No load, 80, 240, 600 g/cm3) run? Why 20 revolutions? Are they based on the test specifications? Or what test specification was followed?
Response 4:    More explanation was added.

Comments 5:     In Figure 27, the legend shows “No Load, 80, 240, 600 g/cm3” The unit may be wrong. Three different densities of PU foam were used in this study. However, their densities are so great (ex: the density of iron is only 7.9 g/cm3), that Figure 27 shows that the density of PU is as high as 600 g/cm3. Please check the densities of the PU foams.
Response 5:    Thank you for pointing out this oversight. The units have been fixed.

Comments 6:     Please check that Figures 5 (a) and 5(b) are revised.
Response 6:    The captions were corrected.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for your response. Nice work. I can be accepted for publication.

Author Response

Comment: Thank you for your response. Nice work. I can be accepted for publication.

Response: Thank you for participating in the review and giving constructive feedback to improve the paper.

Reviewer 3 Report

Comments and Suggestions for Authors

Please check the reference and figure numbers in the full text, they are shown as "[?]" or "(Fig??)".

 

Author Response

Comment: Please check the reference and figure numbers in the full text, they are shown as "[?]" or "(Fig??)".

 

Response: I see the issue in the uploaded pdf paper and could not reproduce it when compiling the latex source. I must have made an error and uploaded the wrong file, or an incompletely compiled pdf file. I will try uploading again more carefully. If the issue is not resolved I can only assume there is an issue with the MDPI submission system not being able to compile the file correctly, and it should be fixed during the finalisation of the publication. I have attached the corrected file for reference in case the issue occurs again.

Otherwise thank you for your constructive feedback on the paper.

Author Response File: Author Response.pdf