彈簧式動態減壓座墊對於脊髓損傷患者臀部壓力分佈之影響

The effect of dynamic cushion system with spring elements on buttock pressure distribution in patients with spinal cord injury

蔡豐隆(Feng-Long Cai)

指導教授 ： ARRAY(0xc8d4228)

中原大學/工學院/醫學工程研究所/碩士(2009年)

https://doi.org/10.6840/CYCU.2009.00897

摘要

多數脊髓損傷患者由於脊髓神經組織遭受到嚴重破壞，使得由大腦發出的運動控制訊息無法順利傳遞，造成活動能力下降而需長時間仰賴輪椅活動，導致臀部壓瘡形成機率大為提高。本研究改良過往所開發之彈簧式動態減壓座墊系統重量過重之缺失，改採剛性較高之塑膠材料製成，並針對脊髓損傷病患進行臀部壓力量測，以評估動態減壓座墊系統對於壓瘡生成預防之效益。
本研究徵召30位脊髓損傷患者(實驗組)與20位健康受測試者(控制組)進行臀部壓力量測，並且比較不同勁度之彈簧(剛體、6.37 N/mm及10.37 N/mm)對於臀部壓力分佈之影響。此外，以自行開發之軟組織力量位移量測儀所獲得之臀部組織材料特性，配合三維動作分析系統取得之板座移動軌跡作為邊界條件，進行臀部有限元素分析及結果驗證，探討乘坐彈簧式動態減壓座墊系統臀部皮膚、脂肪及肌肉組織之所承受之負載。
臀部壓力量測實驗結果顯示，脊髓損傷患者乘坐於低勁度彈簧座墊系統相較於剛體支撐，可降低坐骨結節下方皮膚表層之最大平均壓力13.77 %、壓力峰值28.01 %以及壓力-時間積分值14.58 %。而由有限元素分析之結果可以發現，臀部脂肪與肌肉組織之壓力、剪應力及蒙麥斯應力分佈亦會隨著座墊系統的擺動而產生高低起伏之週期變化。因此，搭配低勁度彈簧之動態減壓座墊系統不僅可以降低臀部坐骨結節下方皮膚表層之壓力與減少壓力負載累積，並且可能改變深層組織之應力分佈，而降低壓瘡之形成之機率。

關鍵字

脊髓損傷 ； 壓瘡 ； 動態減壓座墊 ； 臀部 ； 有限元素模型

並列摘要

Patients with paraplegic spinal cord injuries (SCI) need to spend long hours each day sitting on their wheelchair cushions. However, long-term sitting on the wheelchair may raise the probability of pressure sore formation. Many conventional cushion systems are also heavy in weight. As a result, we have developed a rigid plastic dynamic cushion system that is lighter in weight and designed for the purpose of pressure sore prevention. In addition, the efficacy of pressure sore prevention of this cushion system was also evaluated by measuring the buttock pressures in spinal cord injury patients.
Thirty SCI patients (experimental group) and 20 age matched healthy subjects (control group) were recruited to compare the effect of different cushion stiffness (rigid, 6.37 N/mm and 10.37 N/mm) on the buttock pressure distribution. For the finite element analysis of the buttock, the material property was determined by the soft tissue loading-displacement measuring device, and the boundary condition was considered as the sway trajectory of cushion system. The results of finite element analysis were validated and could be used to investigate the loading sustained by the skin, fat and muscle tissues of the buttock.
Results of buttock pressure measurements showed that the reduction of maximum mean pressure, peak pressure and pressure-time integral beneath the ischial tuberosity were 13.77 %, 28.01 % and 14.58 % when sitting on our newly dynamic cushion system of low stiffness as compared to the conventional rigid support seat cushion. Results of finite element analysis showed that the pressure, shear stress and von Mises stress of fat and muscle were altered cyclically by the sway of the dynamic cushion system. So, the dynamic cushion system with low spring stiffness could reduce not only the skin pressure and the cumulative loading beneath ischial tuberosities, but also alter the stress distribution of deep tissues. Therefore, this device may be used to decrease the occurrence of buttock pressure ulcer formation in patients with paraplegic spinal cord injuries.

並列關鍵字

Spinal cord injury ； Pressure sores ； Dynamic cushion system ； Buttock ； Finite element model

參考文獻

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