3D打印 3D打印可负担和可编程的机器人假肢

菠菜plus 2020-05-25   4267

巴西研究人员Thiago A. do Carmo,Regina E. S. Cabette和Renato G. Gomes进一步研究了3D打印假体,并在最近发表的“低成本的上肢机器人机械假体原型”中发表了他们的发现。

Brazilian researchers Thiago A. do Carmo, Regina E. S. Cabette, and Renato G. Gomes delve further into 3D printed prosthetics, releasing their findings in the recently published ‘Prototype of robotic mechanical prosthesis of upper limb at low cost.’

随着3D打印的到来,以及随着技术和材料在世界范围内变得越来越容易获得,科学家在开发定制的医疗设备(例如假肢)方面取得了长足的进步。许多其他用户受到启发,也向需要帮助的人提供帮助,导致中学生在HandChallenge中帮助其他人,一名青少年为父亲印刷了义肢,e-NABLE等组织继续为各个年龄段需要肢体置换的个人提供帮助。

With the advent of 3D printing, and as the technology and materials have become more accessible around the world—scientists are making huge strides in creating customized medical devices like prosthetics. Many other users have been inspired to help those in need also, leading to middle schoolers helping others in HandChallenge, a teen printing a prosthetic for his father, and organizations like e-NABLE continuing to assist individuals of all ages in need of limb replacements.

这项研究的重点是提高机器人假肢的可负担性和复杂性,以及旨在增加残疾人生活功能的随附可编程解决方案。通过3D打印,EMG传感器和应变仪力传感器,作者的目标是通过肢体替代,更好的灵活性以及更好的整体生活质量来提供更好的社交互动。

This study focuses on greater affordability and complexity in robotic prosthetics, as well as accompanying programmable solutions meant to increase functionality in the lives of the disabled. With 3D printing, EMG sensors, and strain gauge force sensors, the authors aim to offer better social interaction via limb replacements, along with greater dexterity—and overall, better quality of life.

在AutoDesk中对设计进行建模,然后在AnetA8打印机上对零件进行3D打印,这是一种既流行又极低成本的套件;然而,研究人员被迫超越其局限性进行工作,增加了一个感应传感器来检测金属材料,更新和修改固件以及进行校准。

Designs were modeled in AutoDesk and then parts were 3D printed on an AnetA8 printer, a kit that is both popular and extremely low-cost; however, the researchers were forced to work beyond its limitations, adding an inductive sensor for detecting metallic materials, updating and modifying firmware, and calibration.

假体设计的结构旨在模仿由27条骨头组成的手的骨头结构:

The structure of the prosthetic design was meant to mimic the bone structure of the hand, made up of 27 bones:

“因此,在结构建模结束时,达到了等效的37件,所有这些件都经过结构化,因此可以通过内部电缆来执行动作中手指的移动。”

“Thus, at the end of the modeling of the structures, the equivalent of 37 pieces was reached, all of them structured so that it was possible to pass internal cables to perform the movement of the fingers during an action.”

真实模型之间的比较(左)和在此工作中开发的模型(右)

穿孔(每个直径2mm)用于尼龙单丝制成的电缆穿过。用钢螺钉固定手和手指的拳头,用硬铜连接手指的链环。

Perforations (diameter of 2mm each) were created for cables made of nylon monofilament to pass through. Steel screws were used to attach the fist by the hand and fingers, and hard copper was used for connecting finger links.

电缆布线结构

由于PLA的熔点约为190°C,并且粘合要求简单,因此是第一阶段的首选材料。研究团队使用Simplify3D V4.1设置了打印参数,并估计了它们需要多少细丝以及需要多长时间的3D打印。

PLA was the material of choice for the first phase due to its melting point of around 190°C and simple adhesion requirements. The research team used Simplify3D V4.1 to set parameters for printing, along with estimating how much filament they would need, and how long 3D printing would take.

当以4.8v供电且工作容量为4.8 – 7.2 V时,使用高扭矩13 kg / cm伺服电机。随附的金属齿轮减少了磨损,确保了手指的扭矩和运动的可靠性更高。

High torque 13 kg / cm servo motors were used when powered at 4.8v, with 4.8 – 7.2 V operating capacity. The accompanying gears made of metal allowed for less wear, ensuring better reliability in torque and movement of the digits.

使用力范围为100克至约10千克的力传感器,其探测范围为15mm,呈圆形。应变仪传感器也放置在假体的手掌中:

A force sensor with a measuring range between 100 grams to approximately 10kg was used, featuring a detection area of 15mm, in a circular format. Strain gauge sensors were also placed in the palm of the prosthesis:

研究人员说:“这种传感器的目的是防止在手指的闭合运动过程中检测到结构,并且在接触过程中,它可以防止手指不规则地闭合,从而损坏结构。” “传感器呈圆形,直径约10厘米,位于假体的手掌上。”

“The purpose of this sensor was to prevent structures from being detected during the closing movement of the fingers, and during contact, it prevents the fingers from closing irregularly, causing damage to the structure,” stated the researchers. “The sensor has a circular shape with approximately 10 cm in diameter and is located on the palm of the prosthesis.”

传感器应变计

EMG传感器也存在局限性,主要在于仅测量一种肌肉的EMG刺激,噪声和设定值调整,从而导致研究人员修改目标肌肉的位置。

EMG sensors also presented limitations, mainly in measuring only one muscle EMG stimulus, noise, and setpoint adjustments—leading the researchers to modify the position of the target musculature.

传感器EMG Advancer V3

研究人员说:“结果表明,基于所执行的实施,感觉应用是令人满意的,因为它可以测量假体与目标肌肉之间的测量结果,并将其转换为设备的运动。”

“The results showed that, based on the implementations performed, the sensory application proved to be satisfactory in view that the results measured between the prosthesis and the target musculature, were measured and converted into movements for the equipment,” stated the researchers.

“因此,力传感器能够停止运动,从而防止手指闭合,从而损坏了假体的关节结构。考虑到它们在按压手指的过程中能够承受相当于13kg的伺服电机施加的力,因此在组装步骤中也充分控制了用PLA灯丝印刷的结构。”

“Thus, the force sensor was able to stop the movement, preventing the fingers from closing in such a way as to damage the joint structure of the prosthesis. The structures printed in PLA filament are also sufficiently controlled during the assembly steps, considering that they were able to withstand a force exerted by the servo motor equivalent to 13kg in the process of pressing the fingers.”

在评估整个项目的发展时,研究人员表示,“该项目的最终收购价值”约为2,000.00雷亚尔(折合365美元)。

On assessing overall project development, the researchers stated that ‘final acquisition value of the project’ was around R$ 2,000.00 (translating to around $365 US).

“针对涉及机械假体改进项目的未来研究,可以提供可模拟类似于人类皮肤的表面触摸的传感器,并提供新的力和EMG传感器,以更好地处理耗散在人体中的刺激信号。肌室。通过这种方式,该项目应通过新的结构尺寸,例如对新零件进行建模和印刷,以减少当前结构的局限性,例如,手指在笛卡尔x轴上的不移位。

“Aiming at future studies involving the improvement project of mechanical prostheses, sensors that may simulate the touch of a surface similar to human skin may be provided, as well as the insertion of new force and EMG sensors to better treat the stimulus signals dissipated in the muscle ventricle. In this way, the project should pass through new structural dimensions such as modeling and printing of new parts that can reduce limitations of the current structure, for example, the non-displacement of the fingers on the Cartesian x axis,” concluded the researchers.

“作为通过假体的印刷结构提供更大柔韧性的一种手段,对于可能需要多方向性行为(例如手指的预旋转)的物品,估计全部或部分使用诸如TPU(聚氨酯热塑性塑料)之类的细丝。 手臂结构中使用的伺服马达占用了太多空间,无法满足实际需要,目的是仅用于肢体截肢的人,因此有必要使用更小的马达,以及在假体结构中分配它们所需的空间 。”

“As a means of providing greater flexibility through the printed structures of the prostheses, the use of filaments such as TPU (polyurethane thermoplastic), total or partial, is estimated for items that may require multidirectional behaviors, such as prerotation of the fingers. The servo motors used in the arm structure take up too much space to the real needs, aiming at the use for people with only hand amputations, it will be necessary to use smaller motors, and also the space needed for their allocation in the prosthesis structure.”



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