1
|
Gao Y, Zhang J, Zou C, Bi L, Huang C, Nie J, Yan Y, Yu X, Zhang F, Yao F, Ding L. A method for calculating vector forces at human-mattress interface during sleeping positions utilizing image registration. Sci Rep 2024; 14:15238. [PMID: 38956282 PMCID: PMC11220148 DOI: 10.1038/s41598-024-66035-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 06/26/2024] [Indexed: 07/04/2024] Open
Abstract
The vector forces at the human-mattress interface are not only crucial for understanding the distribution of vertical and shear forces exerted on the human body during sleep but also serves as a significant input for biomechanical models of sleeping positions, whose accuracy determines the credibility of predicting musculoskeletal system loads. In this study, we introduce a novel method for calculating the interface vector forces. By recording indentations after supine and lateral positions using a vacuum mattress and 3D scanner, we utilize image registration techniques to align body pressure distribution with the mattress deformation scanning images, thereby calculating the vector force values for each unit area (36.25 mm × 36.25 mm). This method was validated through five participants attendance from two perspectives, revealing that (1) the mean summation of the vertical force components is 98.67% ± 7.21% body weight, exhibiting good consistency, and mean ratio of horizontal component force to body weight is 2.18% ± 1.77%. (2) the predicted muscle activity using the vector forces as input to the sleep position model aligns with the measured muscle activity (%MVC), with correlation coefficient over 0.7. The proposed method contributes to the vector force distribution understanding and the analysis of musculoskeletal loads during sleep, providing valuable insights for mattress design and evaluation.
Collapse
Affiliation(s)
- Ying Gao
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Jing Zhang
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Chengzhao Zou
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Liwen Bi
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Chengzhen Huang
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Jiachen Nie
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Yongli Yan
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Xinli Yu
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China
| | - Fujun Zhang
- De Rucci Healthy Sleep Co., Ltd, Dongguan, 523960, Guangdong, China
| | - Fanglai Yao
- De Rucci Healthy Sleep Co., Ltd, Dongguan, 523960, Guangdong, China
| | - Li Ding
- Beijing Advanced Innovation Center for Biomedical Engineering, Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, 100191, China.
| |
Collapse
|
2
|
Bogard F, Polidori G, Murer S, Maalouf C, Blancheteau Y, Quinart H, Beaumont F. Hygro-thermo-mechanical performance of wheelchair cushion technologies in the prevention of pressure ulcers and moisture-associated skin damages. Assist Technol 2023; 35:64-73. [PMID: 34185618 DOI: 10.1080/10400435.2021.1949406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
This study aims at investigating the effects of three different wheelchair cushion technologies at the patient-wheelchair interface. To this end, eight participants were recruited to remain in an unrelieved seated position on a wheelchair successively equipped with three different cushions (foam, air-cell-based and gel), for a duration of 45 min. Interface pressure, temperature (measured with infrared thermography) and relative humidity were measured at the seat interface, at different timestamps. Experimental results show that foam cushion is significantly more efficient in reducing contact peak pressure (p < .01), while the gel cushion displays higher heat evacuation capabilities. In terms of relative humidity, no significant difference is observed among the three technologies (p > .29): all of them evacuate around only 10% of the total humidity compared to the reference situation (i.e., without cushion). Besides, a complementary numerical simulation corresponding to the steady state of the patient-wheelchair structure clearly highlights the temperature volume field at the underside of the seat, which acts like a thermal barrier and contributes to heat accumulation. Besides, an air flow at the underside of the chair in motion is shown to significantly reduce heat accumulation.
Collapse
Affiliation(s)
- Fabien Bogard
- MATIM Laboratory, University of Reims Champagne Ardenne, Reims, France
- Pôle de Recherche Châlonnais, University of Reims Champagne Ardenne, Reims, France
| | | | - Sébastien Murer
- MATIM Laboratory, University of Reims Champagne Ardenne, Reims, France
| | - Chadi Maalouf
- MATIM Laboratory, University of Reims Champagne Ardenne, Reims, France
| | | | | | - Fabien Beaumont
- MATIM Laboratory, University of Reims Champagne Ardenne, Reims, France
| |
Collapse
|
3
|
Kim SG, Ko CY, Kim DH, Song YE, Kang TU, Ahn S, Lim D, Kim HS. Development of a shear force measurement dummy for seat comfort. PLoS One 2017; 12:e0187918. [PMID: 29186136 PMCID: PMC5706699 DOI: 10.1371/journal.pone.0187918] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 10/27/2017] [Indexed: 11/18/2022] Open
Abstract
Seat comfort is one of the main factors that consumers consider when purchasing a car. In this study, we develop a dummy with a shear-force sensor to evaluate seat comfort. The sensor has dimensions of 25 mm × 25 mm × 26 mm and is made of S45C. Electroless nickel plating is employed to coat its surface in order to prevent corrosion and oxidation. The proposed sensor is validated using a qualified load cell and shows high accuracy and precision (measurement range: -30-30 N; sensitivity: 0.1 N; linear relationship: R = 0.999; transverse sensitivity: <1%). The dummy is manufactured in compliance with the SAE standards (SAE J826) and incorporates shear sensors into its design. We measure the shear force under four driving conditions and at five different speeds using a sedan; results showed that the shear force increases with speed under all driving conditions. In the case of acceleration and deceleration, shear force significantly changes in the lower body of the dummy. During right and left turns, it significantly changes in the upper body of the dummy.
Collapse
Affiliation(s)
- Seong Guk Kim
- Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon, Republic of Korea
| | - Chang-Yong Ko
- Korea Orthopedics & Rehabilitation Engineering Center, Incheon, Republic of Korea
| | - Dong Hyun Kim
- Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon, Republic of Korea
| | - Ye Eun Song
- Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon, Republic of Korea
| | - Tae Uk Kang
- Body & trim development team, Hyundai Motor Group, Uiwang, Republic of Korea
| | - Sungwoo Ahn
- Cozy international Co., Ltd, Ansan, Republic of Korea
| | - Dohyung Lim
- Department of Mechanical Engineering, Faculty of Mechanical and Aerospace Engineering, College of Engineering, Sejong University, Seoul, Republic of Korea
| | - Han Sung Kim
- Department of Biomedical Engineering and Research Institute for Medical Instruments & Rehabilitation Engineering, Yonsei University, Wonju, Gangwon, Republic of Korea
| |
Collapse
|