A Portable Soft Exosuit to Assist Stair Climbing with Hip Flexion

Round 1

Reviewer 1 Report

This paper presents the design and experimental evaluation of a soft exosuit for assisting stair climbing with hip flexion. The paper is well written, and the presented concept is also interesting. However, several issues should also be addressed to improve the quality of the manuscript. Below are some comments for the authors to consider:

 

1.     In the proposed exosuit, the Bowden cable is important for the force transmission. However, as is shown in Figure 1, the Bowden cables were directly connected to the knee wraps using cable knots. The reviewer wonders if such loose connection is stable and safe for the rehabilitation application. In addition, the authors should also provide the technical details of the used Bowden cable, such as the used material and the elastic stiffness, to demonstrate its mechanical feasibility and stability.

 

2.     The authors should add some labels to the figure in Figure 1 to explain different parts of the soft exosuit prototype.

 

3.     In Figure 3, the authors have used the unit Nm/kg to represent moment. However, the unit of moment should be Nm. Please clarify.

 

4.     In the last paragraph of the Introduction section, the authors mentioned that the purpose the proposed exosuit is to “address the increase of metabolic consumption and muscle fatigue in the elderly during walking upstairs”. However, in the experimental validation, all participants were young and healthy male adults, which is quite different from the situation of the older people. Please clarify.

 

5.     Please explain the meaning of the P values in Figure 6 because they are not mentioned in the paper.

 

6.     As already mentioned, the cable-driven mechanism used in the proposed exosuit can still be improved. In the current state of the art, there are also studies optimizing the mechanical performance of cable-driven soft robotic mechanisms. The authors are recommended to include those work in the literature review part of this paper. Below are several recommended references:

 

Suh, J. W. (2018). A novel cable actuation mechanism for 2-DOF hyper-redundant bending robot composed of pulleyless rolling joints. In 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (pp. 961-966). IEEE. DOI: 10.1109/IROS.2018.8593890.

 

Suh, J. W., & Kim, K. Y. (2018). Harmonious cable actuation mechanism for soft robot joints using a pair of noncircular pulleys. Journal of Mechanisms and Robotics, 10(6), 061002. DOI: 10.1115/1.4041055.

 

Sun, Y., Liu, Y., & Lueth, T. C. (2022). Optimization of stress distribution in tendon-driven continuum robots using fish-tail-inspired method. IEEE Robotics and Automation Letters, 7(2), 3380-3387. DOI: 10.1109/LRA.2022.3147456.

 

Sun, Y., & Lueth, T. C. (2023). Enhancing Torsional Stiffness of Continuum Robots Using 3-D Topology Optimized Flexure Joints. IEEE/ASME Transactions on Mechatronics. DOI: 10.1109/TMECH.2023.3266873.

Author Response

Response to Reviewer 1 Comments

 

Dear reviewer：

We appreciate for editors and reviewers’ warm work earnestly, and hope that the correction will meet with approval. The main corrections in the paper and the responds to the reviewers’ comments are as following:

 

Point 1: In the proposed exosuit, the Bowden cable is important for the force transmission. However, as is shown in Figure 1, the Bowden cables were directly connected to the knee wraps using cable knots. The reviewer wonders if such loose connection is stable and safe for the rehabilitation application. In addition, the authors should also provide the technical details of the used Bowden cable, such as the used material and the elastic stiffness, to demonstrate its mechanical feasibility and stability.

Response 1:

 According to your suggestions, we have made explain from the line 104 to 108 and the line 116 to 119. (in red)

 

 

Point 2: The authors should add some labels to the figure in Figure 1 to explain different parts of the soft exosuit prototype.

Response 2: Different labels have been added to Figure 1 to describe different parts of the exosuit prototype . 

 

 

Point 3: In Figure 3, the authors have used the unit Nm/kg to represent moment. However, the unit of moment should be Nm. Please clarify.

Response 3: According to your questions, The description has been highlighted in red which in the explanation section of Figure 3.(in red)

 

 

 

Point 4: In the last paragraph of the Introduction section, the authors mentioned that the purpose the proposed exosuit is to “address the increase of metabolic consumption and muscle fatigue in the elderly during walking upstairs”. However, in the experimental validation, all participants were young and healthy male adults, which is quite different from the situation of the older people. Please clarify.

 

Response 4: This paper is to verify the feasibility of the system. And In the Conclusion section, the current deficiencies of the system are explained and the system will be applied to the elderly in the future .The description has been highlighted in red which in line 319 to 320.  (in red)

 

 

 

Point 5: Please explain the meaning of the P values in Figure 6 because they are not mentioned in the paper.

Response 5: P means statistical significance. A parameter used to determine the result of a hypothesis test. The description has been highlighted in red which in the explanation section of Figure 6.(in red)

 

 

 

Point 6: As already mentioned, the cable-driven mechanism used in the proposed exosuit can still be improved. In the current state of the art, there are also studies optimizing the mechanical performance of cable-driven soft robotic mechanisms. The authors are recommended to include those work in the literature review part of this paper. Below are several recommended references:

 

Suh, J. W. (2018). A novel cable actuation mechanism for 2-DOF hyper-redundant bending robot composed of pulleyless rolling joints. In 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS) (pp. 961-966). IEEE. DOI: 10.1109/IROS.2018.8593890.

 

Suh, J. W., & Kim, K. Y. (2018). Harmonious cable actuation mechanism for soft robot joints using a pair of noncircular pulleys. Journal of Mechanisms and Robotics, 10(6), 061002. DOI: 10.1115/1.4041055.

 

Sun, Y., Liu, Y., & Lueth, T. C. (2022). Optimization of stress distribution in tendon-driven continuum robots using fish-tail-inspired method. IEEE Robotics and Automation Letters, 7(2), 3380-3387. DOI: 10.1109/LRA.2022.3147456.

 

Sun, Y., & Lueth, T. C. (2023). Enhancing Torsional Stiffness of Continuum Robots Using 3-D Topology Optimized Flexure Joints. IEEE/ASME Transactions on Mechatronics. DOI: 10.1109/TMECH.2023.3266873.

Response 6: According to your suggestion, we have made some changes from the line 25 to 31 . (in red)

 

 

 

Thank you very much for taking the time to review this paper during your busy schedule. I wish you good health, successful scientific research and a happy life. Thank you very much.

Best wishes.

 

​

 

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript describes a proposed flexible exosuit for stair climbing assistance. The developed device is validated based on its use by four people using an electric stair machine, both from a metabolic cost perspective and by measuring dynamic variation of surface electromyographic signal. The results are slightly satisfactory. The main advantage of the proposed system over other similar systems lies in its greater usability (due to its flexibility and lower weight).

The work is interesting and significant and, in addition, it is well planned and validated. It should be improved by:

1. incorporate a disaggregated analysis of the results by each of the participants (since there are only 4).

2. Improve the narrative and correct typos and formatting errors.

The manuscript should be thoroughly reviewed, preferably by a native English speaker.

Author Response

Response to Reviewer 2 Comments

Dear reviewer：

We appreciate for editors and reviewers’ warm work earnestly, and hope that the correction will meet with approval. The main corrections in the paper and the responds to the reviewers’ comments are as following:

 

Point 1: incorporate a disaggregated analysis of the results by each of the participants (since there are only 4).

Response 1: According to your suggestion, we have made some changes from the line 220 to 225. (The sentence marked in red).

 

Point 2: Improve the narrative and correct typos and formatting errors.

Response 2: Thank you for your valuable and thoughtful comments. We have carefully checked and improved the English writing in the revised manuscript.

 

Thank you very much for taking the time to review this paper during your busy schedule. I wish you good health, successful scientific research and a happy life. Thank you very much.

Best wishes.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

The paper considers a waste wearable soft exosuit that assists hip flexion to aid stair climbing in older adults. The importance of  assistance of hip flexion prоved by experiments shows a lower metabolism when climbing stairs, a reduction in muscle fatigue for the rectus femoris, lateral femoris and gastrocnemius muscle. The article is clearly written and theses are well reasoned and defended.

I have only one remark to the authors of the paper. Is it possible for Figure 1, where the system overview of the soft exosuit is shown, to explain the motor§drive group in more detail.

Author Response

Response to Reviewer 3 Comments

 

Dear reviewer：

We appreciate for editors and reviewers’ warm work earnestly, and hope that the correction will meet with approval. The main corrections in the paper and the responds to the reviewers’ comments are as following:

 

Point 1: I have only one remark to the authors of the paper. Is it possible for Figure 1, where the system overview of the soft exosuit is shown, to explain the motor§drive group in more detail.

 

Response 1: According to your suggestion, we have made some explanation from the line 112 to 114 . (in red)

 

Thank you very much for taking the time to review this paper during your busy schedule. I wish you good health, successful scientific research and a happy life. Thank you very much.

Best wishes.

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors have carefully revised the manuscript according to my comments. Therefore, I recommend to publish this paper in this journal.