Measurement, Evaluation, and Control of Active Intelligent Gait Training Systems—Analysis of the Current State of the Art

Round 1

Reviewer 1 Report

This paper gives an overview of research in gait measurement, movement intention detection, gait evaluation and gait training systems. This literature review can be of potential interest to readers working in this area. The structure of the paper is clear and easy to follow. I have following comments which I think would enhance the manuscript.

Define what ‘active intelligent gait training systems’ are at the beginning of the paper. Definitions of several key technical terms are missing. Please add the description for clarity. Describe what is human-machine cooperative motion/ human-machine cooperation in RF signal-based motion capture systems?

Sufficient technical insights are not given from the research studies being reviewed here and some description appears to be too vague to draw some technical understanding of methods/techniques being reviewed.  Overall, the paper needs more technical depth and discussion of methods used by these studies to be an impactful review of the field such that readers can make scientific decisions based on this review.  

Table 1 can be more descriptive. This description doesn’t give critical depth into each of these technologies beyond what is said in the preceding text. It would be useful to mention in the table what techniques each of the papers is using to capture movement from the sensing technologies. High accuracy, no privacy issues are very high-level descriptors for advantages. Please also give more specific advantages. I didn’t quite understand what you mean by decoupling of radio frequency signal with human-machine cooperative motion.

Figure 2 is not informative enough. It does not show which studies you are talking about. You have not discussed IF and IMU based techniques to detect movement intention in this section and yet included these in the figure. I feel that a table with more information would be more appropriate here instead of this figure.

Line 171 - What ‘several gait parameters’ were estimated? Please be more specific with technical details

Line 174 - What does it mean by incomplete assessing system?

Please also include research studies on functional electrical stimulation (FES) based systems for rehabilitation and gait correction in section 3 and 4. FES based systems are commonly studied for lower limb rehabilitation.

Line 205 - What does it mean by minimizing physiological consumption goals?

Table 2 can be more informative. Gait evaluation methods – gait parameters/ muscle activity etc are very general descriptors.  Say what gait parameters are evaluated by each of the studies and what specific evaluation methods they have used.

Line 241 -Say what is the problem of marker point loss

Line 243 - explain what is vibrotactile control

Not sufficient information of devices and their control strategies is given in the table 3. Please describe shortly what is Pure force/position control, Impedance/admittance control, Novel Human-in-the-loop control? Each device should have its own description of the control strategy used as these higher-level strategies are very general and do not give enough understanding to readers.

Specify the exact challenges in the current systems with examples in section 5. What types of breakthroughs are needed? Give examples of specific limitations instead of generalised statements such as ‘breakthroughs are needed’ or ‘need further studying’ in line 257, 258. Overall, the limitations discussed in this section 5 seem very general, specifically in 1^st and 3^rd paragraph, try to give more specific limitations from the technical point of view.

Line 269 - What do you mean by mobilize the enthusiasm of the users?

Line 298 - What is vital signs motion signals of the lower limbs?

In the last paragraph starting in line 305, you simply mention extremely common methods such as PCA, regression, neural network etc. It is not clear to me how any of these simple methods can generate personalised gait training strategies. These are again very general statements. Writing throughout the paper, especially in section 5 and 6 should be more specific.

Please pay more attention to the sentence structure and grammar in the paper. The paper needs thorough proofreading and a rewrite to correct sentence structure and grammar. Current sentence structuring is not quite correct. It makes it very difficult to parse sentences which do not flow well. For example, line 114 should be “Clinical studies have shown that more active involvement of patients in the rehabilitation training is effective in the neurological reconstruction and motor function recovery”. Similarly, sentences in line 116 and 141 do not read well. There are several grammatical errors, especially singular form has been used instead of plural or vice a versa (e.g., line 216 ‘devices interacts’ should be ‘devices interact’, line 161 – ‘shows numbers of’ should be ‘shows number of’, line 153- ‘are an important method’ should be ‘are important methods’, etc). Many sentences are very long and conjoined with several ands and commas. Please break them up into multiple sentences. e.g., line 157.

Minor comments:

Line 113 – certain athletic ability – do you mean more or less athletic ability?

Line 127 – ‘brain nerves’ is not correct, just say in brain or neurons

Line 127 – best rapidity, do you mean have very latency?

Line 127 - what are high requirements? Replace with more suitable phrase

Line 128 - what do you mean by intensity of EMG? do you mean increase in amplitude?

Line 137 – should be Artificial Neural Network

Line 142 – do you mean closed-loop control systems with feedback is required?

Word researches is not correct. Use research studies instead.

Line 197 - Use lack of ability instead of disability.

Line 210 - each of the includes studied – do you mean each of the included studies?

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The paper is a proposal of solutions supporting the rehabilitation of gait, which on the one hand is extremely important and up-to-date, but on the other hand does not include - in the description - the recognized and successfully used rehabilitation systems, which undoubtedly include the Lokomat Pro.

Therefore, I consider it necessary to provide reliable information about this system, and then to perform a comparative analysis between the authors' propositions and the solutions offered in systems such as Lokomat Pro.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Review of paper:

Measurement, Evaluation and Control of Active Intelligent Gait Training Systems

Authors:

Yi Han, Chenhao Liu, Bin Zhang, Ning Zhang, Shuoyu Wang, Meimei Han, João P. Ferreira, Tao Liu, Xiufeng Zhang

 

Comments:

In my opinion, the paper can be a source of basic information about measurement techniques, evaluation, and control techniques used in gait training systems. However, the text should be improved by adding more engineering information in several places in order to increase its substantive value.

 

List of critical comments below:

1. Considering such a large number of authors and the volume of the paper, I am puzzled by the real personal contribution of each author to the work presented for review. One would expect a more extensive and detailed review of work and analysis based on the analysis of literature.
2. Line 45 - …aging level has reached 17.17% in 2020… - the article was submitted to Electronics Journal in April 2022, so the data shown is unlikely to be current. Please correct the posted statistics and provide the actual status for 2022.
3. A review paper cannot include a list of sources in the form [4-12] line 55, [26-34] line 97, [56-92] line 164, etc. without indicating the results and actual contributions of these works. Please correct these places in the text and indicate the actual contributions of the literature cited.
4. Fig. 2-what do numbers 2, 3, 4, and 6 in the figure mean? Is it the number of works discovered on a specific subject?
5. The list of cited and analyzed literature sources in most cases refers to the papers of Chinese authors. In the case of a review article, the list should be supplemented with additional papers from authors from Europe, America, etc.
6. Sections 5 and 6 should be more precise and wider, describing the actual needs and validity of scientific work in the given scopes. In the Reviewer's opinion, these sections should be restructured and broadened so that after reading them, the Reader can actually determine in which direction it is worthwhile to conduct future scientific research.

Author Response

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Author Response File: Author Response.pdf

Reviewer 4 Report

The authors have tried to give a review of the limitations, challenges and future direction for gait measurement and intention recognition, gait rehabilitation evaluation and gait control. Possible future research directions are discussed. They suggest the need for a different sensing methods for the decoding of human movement intention. The requirement of the human walking ability evaluation is pointed out. They also mention the necessity of a personalized gait training strategy for collaborative control of human-machine systems which should be implemented through clinical applications.

I think that this review is good but is not complete. I also have some comments which I include in the following:

1. Line 45: what does the ’aging level has reached 17.17%’ mean?
2. Line 62: Important basic scientific problems are discussed. You may number the three to make it clear.
3. Line 71 to Line 75: The contents are repeated in previous paragraphs.
4. Line 80: The sentence sounds like there are not systems that monitor patient’s movement in real-time which is not the case. For example, the following article is one that does simultaneous analysis of the gait. ‘Development of an abnormal gait analysis system in gait exercise assist robot 'Welwalk' for hemiplegic stroke patients, Nakashima et al., 2020’. There should be more system that monitor patients’ movements in real-time, whether the movement is upper limb or lower limb.
5. Line 155: At the end of the sentence, it is written ‘… in this research’. Is it ‘… in this review’.
6. Figure 3. The text ‘Information’ is not completely visible.
7. Line 256: Part of the sentence ‘the fusion interpretation based on physical models’ is not clear.
8. Line 279: Radio frequency is discussed as a potential future research. What is the advantage of radio frequency for gait research? How does it improve the assessment of the gait? Does it make the real-time assessment easier for the medical professions or more complicated?
9. Line 285: Why do we need a non-contact motion sensing? Is it possible from physiological point of view to have such a system? How may researchers develop a non-contact motion sensing?
10. Line 298: How does the frequency component of the analysis of the gait may help researcher and especially medial professions?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors referred to the most important comments made in my review.

Author Response

We appreciate for your time and patience.

Reviewer 3 Report

Review of paper: second round

Measurement, Evaluation and Control of Active Intelligent Gait Training Systems

Authors:

Yi Han, Chenhao Liu, Bin Zhang, Ning Zhang, Shuoyu Wang, Meimei Han, João P. Ferreira, Tao Liu, Xiufeng Zhang

 

Comments:

The authors have improved the text of the article according to the reviewer's suggestions. They also sent a response to the formulated critical comments. The reviewer confirms the validity of the changes made, which raised the substantive content of the paper.

After re-reading and analyzing the text, it should be stated that it would be worthwhile to supplement the title of the paper with information that the work is a review, adding after the title e.g. - analysis of the current state of the art. Such an expanded title would reflect the actual scope and content of the article.

Author Response

We appreciate for your critical comments and your patience. We added a few words as you suggested after the title: '- Analysis of the Current State of the Art' and now the title has been revised to: "Measurement,s Evaluation and Control of Active Intelligent Gait Training Systems - Analysis of the Current State of the Art".

Reviewer 4 Report

I think that the authors have addressed the feedback and corrected the manuscript accordingly and it should be fine for publication.

Author Response

We appreciate for your patience and time.