Mechanical load applied by Intraosseous Transcutaneous Amputation Prosthesis (ITAP)

Walking on level and sloped treadmill M, N and P data sets. Also included are data from Sitting and rising from stool (Q) and Step over block (R). Data collected from one participant: The participant was a 50 year old male with a left transfemoral amputation (residuum = 181 mm measured from greater trochanter proximal ridge) as a result of trauma in 1984, he provided full informed consent for this study. He had used a prosthetic socket until he received an ITAP in 2012 as part of a clinical trial (Identifier = NCT02491424). The ITAP spigot (the percutaneous part of the POI) connected to a failsafe release device, which protects the bone from overload (now withdrawn Fail-Safe Attachment for Prosthetic Limb, patent GB2479532A, Stanmore Implants Worldwide, Hertfordshire, UK). The failsafe connected to a microprocessor controlled Genium knee, which connected to a mechanical carbon fibre Taleo foot (both Ottobock, Duderstadt, Germany) using standard prosthetic fittings. He was 1.89 m tall and weighed 102.8 kg (including the 1.4 kg artificial leg and all prosthetic components) with a K3 prosthetic activity level. Kinetic data collection: Uphill, level and downhill gait data was collected on a treadmill (GRAIL Motek, Amsterdam, The Netherlands) at a self-selected speed and gradient. The uphill and downhill gradients were 8.5 ° and 7.0 ° respectively. Level and downhill walking was at 1.0 m/s; uphill walking was at 0.8 m/s. The participant walked untethered without the use of handrails in level walking and intermittently on the slopes, and after fitting the load cell, acclimatised to the treadmill conditions for 20 minutes prior to measurement. Load cell construction: A prosthetic tube connecting the participant’s artificial knee to a failsafe device was replaced with an instrumented tube (load cell). The load cell contained 20 thin film strain gauges oriented such as to be sensitive to the DOF to be measured, having five thin film strain gauges located on each of four sides. Gauges (20 kOhms) were wire bonded to a flexible printed circuit which interconnected the four quadrants. Electrically, these formed six half bridges of gauges wired for primary sensitivity to axial compression, AP bending and ML bending. Four gauges at 45 ° to the long axis were wired into four channels of quarter bridge action only, for primary sensitivity to shear force and torque. It was accepted that there would be cross-talk between channels wired primarily for one DOF, as is usually the case where gauges are shared between DOF’s, and the matrix method of calibration was therefore used to identify and appropriately combine channels sensitive to more than one applied load type. Each channel was wired to a printed circuit for amplification, A-D conversion, serial data streaming and radio transmission

包含平地与坡度跑步机行走的M、N、P数据集，同时涵盖从座椅起身（Q）以及跨越障碍物（R）的相关数据。本数据集仅采集自1名受试者：该受试者为50岁男性，1984年因外伤接受左侧经股骨截肢（残肢长度为181mm，测量基准为大转子近端嵴），并为本研究签署了完整的知情同意书。其此前一直使用传统假肢接受腔，2012年作为临床试验（试验编号：NCT02491424）的一部分植入了经皮骨整合假肢接受腔（ITAP）。该ITAP的连接端（即经皮骨整合假体（POI）的经皮部分）连接至过载保护释放装置，该装置可避免骨骼承受过载载荷（相关产品现已退市：假肢肢体失效安全固定装置，专利号GB2479532A，制造商：英国赫特福德郡Stanmore Implants Worldwide公司）。该失效安全装置连接至搭载微处理器的Genium膝关节，再通过标准假肢连接件与碳纤维机械结构的Taleo假肢足连接（两款产品均产自德国杜德施塔特的Ottobock公司）。受试者身高1.89m，体重102.8kg（含1.4kg的人工假肢及所有假肢组件），假肢活动等级为K3级。动力学数据采集：在荷兰阿姆斯特丹Motek公司GRAIL跑步机上采集上坡、平地及下坡步态数据，采集参数为受试者自主选择的速度与坡度：上坡与下坡坡度分别为8.5°和7.0°，平地与下坡行走速度为1.0m/s，上坡行走速度为0.8m/s。平地行走时受试者未受束缚且未借助扶手，坡道行走时仅间歇性使用扶手；安装测力传感器后，受试者需在正式测量前适应跑步机环境20分钟。测力传感器结构：将连接受试者人工膝关节与失效安全装置的假肢导管替换为带传感器的导管（即测力传感器）。该测力传感器包含20片薄膜应变片，用于采集目标自由度（Degree of Freedom，DOF）下的信号，四个侧面各布置5片薄膜应变片。20kΩ的应变片通过引线键合连接至柔性印刷电路板，实现四个象限的信号互联。电路上，6组半桥由应变片组成，主要用于采集轴向压缩、前后向（AP）弯曲及内外侧（ML）弯曲信号；另有4片与长轴成45°布置的应变片，仅接入4个通道组成半桥，主要用于采集剪切力与扭矩信号。由于不同自由度共享应变片时，通道间通常存在串扰，本研究接受该现象，并采用矩阵校准法识别并合理合并对多种载荷类型敏感的通道。每个通道均连接至印刷电路板，用于信号放大、模数转换、串行数据流传输及无线信号发射。