Mechanical Design and Analysis of Multi-Functional Portable Patient Bed

Siah, Jian How (2021) Mechanical Design and Analysis of Multi-Functional Portable Patient Bed. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

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Abstract

Patient bed or hospital bed is a specially designed bed that designed with the ergonomic consideration for the patients who need special health care. Currently, patient bed is playing a vital role in the society as the aging population is increasing drastically all over the world. Besides, the Covid-19 has resulted a big impact on the whole world as the bedridden population is getting even more. However, there are some weakness on the current patient bed design such as the low portability of the patient bed due to its big sizing, lack of storage space, insufficient total lifetime and so on as the transportation of bed is needed frequently in the hospital for a new patient bed assignment. Hence, new design of patient bed with multiple functions such as portable, storage space and simple posture changing and longer lifetime will be researched in this project. The literatures of designs and mechanism of current patient bed were being reviewed in this project and there were some conceptual designs being proposed. A final design which was designed based on the foldable patient bed concept from the literature review was chosen after the evaluation of every conceptual designs proposed. The selected mechanism in the final design such as caster wheel mechanism, main frame structure and the posture changing mechanism as well were being simulated and tested with new materials chosen to compare the total lifetime of the current materials used in the particular mechanism. After the simulation, the new materials chosen for the caster wheel mechanism was AISI 347 Stainless Steel, showed that it has no much difference in the static test simulation but in the fatigue test, the total life cycles of AISI 347 Stainless Steel can withstand about 47.36% higher than the original material used which is the 1023 low carbon steel. While for the body posture changing mechanism, the new material chosen (AISI 4340 Steel) showed that the safety factor is increased by about 40% compared to the existing material used (SAE 1015 Steel), while the fatigue test for the posture changing mechanism, it shows that the new material has an increment of 103.21 % in terms of the total lifetime of the mechanism compared to the existing material. Last but not least, for the main frame structure, the new material used (AISI 1010 steel) has a lower safety factor than the existing material (7075-T6 Aluminium Alloy) used in the static test, however, the safety factor is still in the acceptable range. While in the fatigue test, the new material has an increment of 189.81% than the existing material in term of the total life cycle. These simulation results showed that the new material chosen for the selected mechanism in the patient bed designed have longer lifetime and more durable.