Rosenthal M J, Felton R M, Hileman D L, Lee M, Friedman M, Navach J H
Geriatric Research, Education and Clinical Center, Physical Medicine and Rehabilitation Service, VA Medical Center, Sepulveda, CA 91343, USA.
Arch Phys Med Rehabil. 1996 Mar;77(3):278-82. doi: 10.1016/s0003-9993(96)90112-4.
Despite the diversity of wheelchair cushions currently in clinical use, pressure on bony prominences continues to be a major problem for wheelchair-bound patients, and the incidence of pressure ulcers remains high. No static surface has been reported to reduce resting pressure under the ischial tuberosities to below that of capillary pressure, which may well be the threshold for inducing tissue damage. An entirely new form of seating was designed to decrease absolute pressure using a prosthetic fitting technique analogous to a below-the-knee prosthesis.
A repeated measures randomized design was used to test differences between the experimental (TCS) and three other standard cushions.
A Veterans Medical Center outpatient service.
Wheelchair-bound volunteer subjects, n = 47, were selected who weighed more than 60kg.
Pressures were measured by a standard air pressure pad and also by a computer-linked array of pressure transducers. The grid was standardized and used to generate topographic maps for each site over time. These data were used to measure the seating interface pressures.
There was a significant main effect of cushion over site, F = 131 for left ischial tuberosity. Pressure were lowest while patients sat on the experimental seat and differences were significant at all time points. Using 1psi as presumed capillary pressure, frequency of success at achieving this pressure threshold was greatest for the experimental seat, p < .001. This difference persisted throughout the 30 minutes of testing.
A computerized pressure grid was developed that allowed evaluation of anatomically localized pressures. The prosthetically designed TCS displays lower seating pressures than any other cushion tested. Consistent and sustained pressures were below the postulated threshold for tissue damage.
尽管目前临床使用的轮椅坐垫种类多样，但对于依赖轮椅的患者来说，骨隆突处的压力仍然是一个主要问题，压疮的发生率依然很高。尚无静态表面能将坐骨结节下方的静息压力降低至毛细血管压力以下，而毛细血管压力很可能是诱发组织损伤的阈值。一种全新的座椅形式被设计出来，采用类似于膝下假肢的假肢装配技术来降低绝对压力。
采用重复测量随机设计来测试实验性坐垫（TCS）与其他三种标准坐垫之间的差异。
一家退伍军人医疗中心门诊部。
选取了体重超过60千克、依赖轮椅的47名志愿者作为研究对象。
通过标准气压垫以及与计算机相连的压力传感器阵列来测量压力。网格进行了标准化处理，并用于生成每个部位随时间变化的地形图。这些数据用于测量座椅界面压力。
坐垫在不同部位存在显著的主效应，左侧坐骨结节处的F值为131。患者坐在实验性座椅上时压力最低，且在所有时间点差异均具有统计学意义。以1磅力/平方英寸作为假定的毛细血管压力，实验性座椅达到该压力阈值的成功率最高，p <.001。在整个30分钟的测试过程中，这种差异一直存在。
开发了一种计算机化压力网格，可用于评估解剖学局部压力。经假肢设计的TCS所显示的座椅压力低于所测试的任何其他坐垫。持续且稳定的压力低于假定的组织损伤阈值。
