The application of electric actuators in the multifunctional care service wheelchair bed

2026-02-28 11:50:19

At present, the number of people aged 60 and above worldwide has reached approximately 700 million, and population aging has become a major social issue worldwide. In China, the number of elderly people aged 60 and above has reached 178 million, and it continues to grow at an average annual rate of 3.32%. Additionally, there are approximately 60 million people with various disabilities in China, accounting for about 5% of the total population. The accelerated aging of the population has placed unprecedented pressure on the medical and social insurance systems. The self-care ability of the elderly is lacking, and they are mainly cared for by their families. The cost of care is high, the labor intensity is great, and the care conditions urgently need to be improved. Currently, "empty-nest families" have also become a social trend. Family-based care for the elderly is decreasing, and the objective conditions have increased the difficulty of caring for the elderly and disabled. The large number of people with various disabilities and those who are bedridden for a long time has made the issue of assisting the elderly and disabled an increasingly significant social problem. What kind of social health care methods can be used to solve the problems of family care and nursing for the elderly and disabled who are bedridden due to weakness or unable to take care of themselves due to illness, is a common problem faced by countries with an aging population. 

Based on this, this article designs a multifunctional wheelchair bed for the elderly, the disabled, and those with impaired lower limb mobility. This wheelchair bed is a combination of a wheelchair and a bed. It can be used as a nursing bed to assist the elderly and the disabled in performing functions such as back support, leg bending, and left-right turning. The middle part of the bed can also be converted into a wheelchair to help the elderly and the disabled complete their daily free activities. In addition, this wheelchair has the function of standing, enabling the user to freely switch between sitting and standing positions, helping patients with paralyzed lower limbs fulfill their desire to stand and walk. 

Based on human engineering principles, the modular concept was applied to complete the overall structure design of the multi-functional wheelchair bed. According to national standards, the specific parameters of the wheelchair bed body and each bed board were designed, the specific position of the wheelchair within the bed was determined, and the distribution of the space under the bed was carried out. Based on functional requirements and the requirement that no mutual interference occurs among various functional mechanisms, an appropriate mechanism configuration was selected. 

(2) Conducted an overall design for the bed. The structure of the interface between the wheelchair and the bed was designed, and the parameters and dimensions required for the realization of functions such as reclining, standing, side-overturning, and back-supporting were calculated. Based on this, the travel distance of the electric push rod was determined, and the type of the electric push rod was selected. A model diagram of the overall structure of the multi-functional wheelchair bed in a three-dimensional perspective was presented. 

(3) The kinematic models of the support-back mechanism and the standing mechanism were established, and the kinematic analysis of these mechanisms was conducted. The models were imported into the kinematic and dynamic analysis software ADAMS for functional verification analysis. The results showed that the mechanism could smoothly fulfill the expected functional requirements. 

(4) Using the ANSYS software, stress and strain analyses were conducted on some key force-bearing components such as the foot support rods, connecting parts, and bed frame. The results showed that these components all had high strength and stiffness, meeting the requirements of functionality and safety. 

Introduction: This project is an automated nursing product that features a nursing bed as its main component and also includes wheelchair mobility functionality. It has comprehensive functions and a high degree of automation, aligning with the development trend of intelligent nursing products. 

Detailed Introduction: This product is an automated nursing device that combines a nursing bed with wheelchair mobility functions. It can serve as a highly intelligent, small-scale transportation tool and also meet the diverse nursing needs in both home and hospital settings. It has two states: nursing bed state and wheelchair state. In the nursing bed state, it has various functions of a nursing bed, including automatic back elevation, turning over, changing leg sitting positions, leg therapy, intelligent toilet use, etc. In the wheelchair state, it can move within a small area (such as in the home or on the community floor) and has functions such as voice control and autonomous movement. Our product enables the free switching between the bed and the wheelchair, allowing long-term bedridden individuals to enjoy the fresh air outdoors without the hassle of transferring between the bed and the wheelchair. The main technical indicators of this product are as follows: 

1) Dimensions and specifications: Nursing bed in normal condition: Length * Width * Height = 2000 * 900 * 630; Wheelchair in normal condition: Length * Width * Height = 1385 * 900 * 1535; Turning radius = 120 

2) Load capacity: 170kg 

3) Position Adjustment Indicators  Indicator Item  Specific Value  Left Rolling Angle  0 - 45°  Right Rolling Angle  0 - 45°  Elevating Back Angle  0 - 80°  Thigh Board Rotation Angle  0 - 35°  Calf Board Rotation Angle  -61° - 35°  Leg Rehabilitation Function  Calf Board Rotation Angle  -20° - 35°  Pedal Elevating Travel Distance  140mm 

4) Stability Indicators  Indicator Item  Specific Value  Static Stability  Longitudinal  20°  Lateral  15° or when a load of 2250N is applied on the side, there is no imbalance  Dynamic Stability Uphill  8°  Downhill  5° 

5) Climbing ability: 6° 

6) Driving speed: 6 kilometers per hour 

7) Noise: < 65 dB 

8) Transmission angle γ γmin ≥ 22° 

9) Human-computer interaction methods: game controller, keyboard and voice. 

Scientificity, advancement 

Based on ergonomics, the overall design scheme for the multi-functional nursing service wheelchair bed was carried out. According to relevant standards and research results, the design principles, functional requirements and design indicators for the electric push rod of the wheelchair bed were formulated; the structural configurations of each functional module were selected, and the driving form and energy supply method were determined. 

② The kinematics and dynamics of the multi-functional nursing service wheelchair bed robot mechanism were analyzed in both Matlab and ADAMS environments. The rationality of the mechanism was proved and guiding data for detailed design was provided. 

③ The complete detailed design of the multi-functional nursing service wheelchair bed has been completed. From a systematic perspective, the sensing methods, the difficulty of control implementation, as well as details such as noise reduction and sealing have been comprehensively considered. 

④ Finite element analysis was conducted on the key components, and the stress distribution and deformation results were obtained. The analysis results indicated that the designed structure had considerable strength redundancy and high stiffness, and was fully capable of meeting the usage requirements.