There are many persons in the world affected by amputation. Upper limb amputations require high cost prosthetic devices in order to provide significant motor recovery. We propose a sustainable design and control of a new anthropomorphic prosthetic hand: all components are modular and exchangeable and they can be assembled by non-expert users. Phalanges & articulations of the fingers and the palm are manufactured via a 3D printing process in Acrylonitrile Butadiene Styrene (ABS) or Polyactic Acid (PLA) materials. The design is optimized in order to provide human-like motion and grasping taxonomy through linear actuators and flexion tendon mechanisms, which are embedded within the palm. HardWare (HW) and Software (SW) open sourced units for ElectroMyography (EMG) input and control can be combined with a user-friendly and intuitive Graphical User Interface (GUI) to enable amputees handling the prosthesis. To reduce the environmental impact of the device lifetime cycle, the material and energy consumption were optimized by adopting: simple design & manufacturing, high dexterity, open source HW and SW, low cost components, anthropomorphic design

Agidew, Tayachew

Moutschen, Cedric

Nagar, Atulya K.

Secco, Emanuele Lindo

Hope's Institutional Research Archive

EAI Endorsed Transactions on Pervasive Health and Technology Research Article 1 A Sustainable & Biologically Inspired Prosthetic Hand for Healthcare  E.L. Secco1,*, C. Moutschen1, T.F. Agidew1 and A.K. Nagar1 1Robotic Laboratory, Department of Mathematics & Computer Science, Liverpool Hope University, Hope Park L16 9JD, UK Abstract There are many persons in the world affected by amputation. Upper limb amputations require high cost prosthetic devices in order to provide significant motor recovery. We propose a sustainable design and control of a new anthropomorphic prosthetic hand: all components are modular and exchangeable and they can be assembled by non-expert users. Phalanges & articulations of the fingers and the palm are manufactured via a 3D printing process in Acrylonitrile Butadiene Styrene (ABS) or Polyactic Acid (PLA) materials.  The design is optimized in order to provide human-like motion and grasping taxonomy through linear actuators and flexion tendon mechanisms, which are embedded within the palm. HardWare (HW) and Software (SW) open sourced units for ElectroMyography (EMG) input and control can be combined with a user-friendly and intuitive Graphical User Interface (GUI) to enable amputees handling the prosthesis.  To reduce the environmental impact of the device lifetime cycle, the material and energy consumption were optimized by adopting: simple design & manufacturing, high dexterity, open source HW and SW, low cost components, anthropomorphic design. Keywords: smart prosthetics, human-centred healthcare, sustainability, bio-mimetic. Received on 13 March 2018, accepted on 13 May 2018, published on 23 July 2018Copyright © 2018 E.L. Secco et al., licensed to EAI. This is an open access article distributed under the terms of theCreative Commons Attribution licence (http://creativecommons.org/licenses/by/3.0/), which permits unlimited use, distribution and reproduction in any medium so long as the original work is properly cited. doi: 10.4108/eai.13-7-2018.1550801. IntroductionNowadays limb loss and amputations can be a devastating phenomenon with functional limitations and dramatic implications. One of the primary cause of upper limb and hand amputations are traumatic events, poor vascularity and neoplasia [1]. From a medical viewpoint, an association between the age of the patient and the cause of the amputation has been found as a result of higher morbidity in the older population. Moreover, especially in the western countries, vascular disease and diabetes accounted for a significant percentage of all the amputations [2]. In current developing countries, traumatic events have a main role on the amputation surgical procedures. Vascular diseases are also responsible of even high level of amputations as well [3]. *Corresponding author. Email:seccoe@hope.ac.ukFocusing on upper limb amputation and, specifically, on hand amputation, it is clearly a challenging task to provide artificial devices, which inherently replace the dexterity and functionality of the human hand [4]. Human hand, in fact, is a marvellous system performing optimized task with an integrated approach: this applies (a) to the biomechanical design of the hand, (b) to the set of superficial and inner available sensors which are embedded - either for the monitoring of the movement or the interaction with the external world - as well as (c) to the synergic control techniques, allowing the manipulation, micro-manipulation and performance of an enormous variety of daily life tasks [5, 6]. Significant progresses in prosthetics have been done, even if current devices and especially those with high dexterity are quite expensive. Moreover, most of these devices require professional technicians with high EAI Endorsed Transactionson Pervasive Health and Technology02 2018 - 07 2018 | Volume 4 | Issue 14 | e3E.L. Secco, C. Moutschen, T.F. Agidew and A.K. Nagar 2 expertise to be customised to the patient and to be fixed and repaired.  Here we propose a low-cost functional robotic hand, which is inherently simple from a mechanical and integration point of view. The device is low cost, can be easily assembled and its design has been inspired by a biomimetic approach. In this context, the device is also sustainable and environmentally compatible.  2. RequirementsThe main requirements and specifications behind this study are the design and the prototyping of a (i) fully integrated and (ii) environmentally compatible, (iii) low cost and (iv) anthropomorphic robotic and prosthetic hand. Namely the device should achieve the following targets, performing:  Pd-Distal phalanx Pm-medial  phalanx Pp-proximal  phalanx [mm] 21.67 ±1.6 31.57 ±3.13 15.82 ±2.26 22.38 ±2.51 39.78 ±4.94 17.4 ±1.85 26.33 ±3.00 44.63 ±3.81 17.3 ±2.22 25.65 ±3.29 41.37 ±1.6 15.96 ±2.45 22.38 ±1.6 32.74 ±2.77 Table 1. Average and std of phalanges lengths [1].  Simple design & manufacturing: the manufacturingprocess of the hand should be easy and accessible toinexpert end-users requiring a short assembly time. High dexterity (i.e. inherently human-like andsustainable): the hand should be able to mimic thehuman grasping taxonomy. It should express sixunder-actuated degrees of freedom (d.o.f.) with twod.o.f. at the thumb, i.e. two rotational axes performingthe adduction and abduction of the finger [4]. Open source HardWare (HW) and SoftWare (SW):sustainability will be enhanced by adopting a SW)and HW design implemented with open source toolsand programming languages, respectively. Low cost HW & SW: the project should have a loweconomic impact in terms of the cost of the materials,the manufacturing integration and the assemblyprocess. Anthropomorphic design: the finger design,kinematics and grasping configurations should beoptimized in order to replicate human hand features[5].Figure 1. 3D model of finger phalanges and joints. These requirements derive from the observation that currently prosthetic hands have many structural and functional constraints:  Expensive cost: most amputees cannot afford thesehigh costs. Complex design: complex mechanical structures -such as pulley and tendon mechanisms with numberof gears and articulations - results in complexity ofthe motion strategies and of the repairing [6]. Complex & high cost manufacturing processes. Lack of open source HW & SW resources: theavailability of open sources tools enable easycustomization of the device vs. the end-user needs.Figure 2. Joint motion 3. Anthropomorphic modelDimensions and shape of the phalanges of the fingers and of the mechanism of the joints articulation were designed at first stage. During this stage, the design of the patterns of the tendons, of the thumb and of the palm of the hand were defined as well. Particularly, the size of the fingers were taken from the effective dimensions of  the human phalanges (Table 1) A 3D model of the hand was design by means of the Solid Works (from the Dassault Systèmes Solidworks Corp) 3D CAD product engineering software. Then a set of STereo Lithography (STL) files was exported to an HP Designjet 3D printer. EAI Endorsed Transactionson Pervasive Health and Technology02 2018 - 07 2018 | Volume 4 | Issue 14 | e3A Sustainable & Biologically Inspired Prosthetic Hand for Healthcare  3 Figure 3. Thumb extension and flexion. We design the anthropomorphic kinematics of the hand to be similar as its human counterpart in terms of similar arrangement, length, proportion and range of motion of the fingers, of the thumb and of the articulations [5, 7]. The design of every parts of the hand was then implemented into 3D models of the parts (Figures 2-6). Figure 4. Actuators set-up within the palm. 3.1 Joints and phalanges design Using the reference dimensions of the human hand, fingers and joints (Figure1), tendon patterns and kinematics (Figure 2), were designed in view of a complete hand design (Figure 3).  Finally, the hand has 5 fingers. Each finger has three phalanges, namely the proximal phalange, the middle phalange and the distal one, respectively.  The corresponding artificial joints are the MetaCarpal joint (MC), the Proximal IntePhalangeal joint (PIP) and the Distal InterPhalangeal joints (DIP), respectively [8].  The range of motion of each joint is set between 0 and 90 and the flexion is performed by means of a single tendon mechanism. A flexor tendon or wire is attached to the DIP: pulling the flexor results in a force torque applied to each finger joint. The extension is performed via a passive mechanism consisting on a low cost rubber band (Figure 2). Figure 5. The robotic hand human-like grasping performance. 3.2 Thumb and palm design The human thumb has a primary role on grasping capability. Because of that, a particular attention has been devoted to the design of this component of the hand.  There are about six movements of the thumb; these ones are the abduction, adduction, extension, flexion, opposition and reposition. The proposed unique hand design enables us to accomplish the flexion and extension movements of the thumb, which offer the benefit of being able to perform a lot of different types of grasping (Figures 3, 5).  Moreover, the final design of thumb allows embedding five linear actuators for the 5 fingers of the end just within the palm of the hand itself (Figure 4).  EAI Endorsed Transactionson Pervasive Health and Technology02 2018 - 07 2018 | Volume 4 | Issue 14 | e3E.L. Secco, C. Moutschen, T.F. Agidew and A.K. Nagar 4 Figure 6. The 3D printed finger Phalanges and Joint articulations 3.3 Hand assembly & printing After designing the individual components of the hand – i.e. the phalanges, fingers, joints and tunnels for the motion of the extensor and flexor tendons – the assembly of all the components is accomplished. The final result is an artificial hand with human like grasping capability: a 3D rendering of it is reported in Figure 5.  Figure 7. – Hand assembly (1). After optimizing the 3D model and the hand kinematic [9], the device and its parts have been manufactured using the 3D printing facility.   At this stage Acrylonitrile Butadiene Styrene (ABS) has been used to print the hand components. ABS is most widely used as a 3D printing material, whose mechanical properties are shown in Table 2 [10]. In a future stage, PolyLactic Acid (PLA) filament may be used in order to reduce the environmental impact of the prototype. A partial assembly of the palm and of the artificial hand vs. the human hand is shown in the Figure 7 and Figure 8, respectively. These figures also illustrate the anthropomorphic design of the hand.  3.4 Hand actuation & control To actuate the fingers, different technical solutions were considered. The hand should contain a minimum set of independent actuators providing independent movements and postures [11]. A motor with compact size, fast speed and linear actuation was selected: PQ12-P Firgelli linear actuator has a maximal force, speed and stroke of 30 N, 12 mm/s and 20 mm, respectively. Five of these motors were embedded in the palm. The motors’ hand were controlled via an open source HW and SW architecture, namely an low cost Arduino board combined with its Integrated Development Environment (IDE) software.  This architecture allows the hand to be controlled via ElectroMyoGraphy (EMG) input signals: by capturing EMG signals generated from the muscular contraction of the end-user were captured by means of a MyoWare muscle sensor [12].  Figure 8. – Hand assembly (2). This set up reporting the integration of the aforementioned components is shown in Figure 9.  Thanks to this architecture, different control algorithms may be implemented, such as Principal Components Analysis (PCA) based controller or systems adopting Neural Network and imitation of the natural human movements [13-16]. EAI Endorsed Transactionson Pervasive Health and Technology02 2018 - 07 2018 | Volume 4 | Issue 14 | e35 Property Value Units Elastic Modulus 2000 N/mm2Poisson’s Ratio 0.35 - Shear Modulus 318.9 N/mm2 Mass Density 1020 Kg/m3Tensile Strength 40 N/mm2 Compressive Strength 42 N/mm2 Table 2. Mechanical properties of the Acrylonitrile Butadiene Styrene (ABS). 4. ConclusionIn this work the design and prototyping of an anthropomorphic prosthetic hand has been proposed. The design of the parts mainly consists on the 3D modelling preparation with an appropriate selection of the material, the 3D printing process and the assembly of the hand. Following the 3D printing, an integration of the controller and actuators has been defined.  This approach integrates an Arduino board and the IDE software as ac central controller to manipulate senor signal and to command the motor and actuate the fingers.   This work showed the possibility of developing and controlling a simplified, low-cost and anthropomorphic hand via EMG.  The proposed biomimetic design may be further improved by incorporating fundamental features of the biological hand, either in terms of imitation of its biomechanics and motor control. For example, using more flexible material and covering the hand surface with soft skin materials an highly flexible and human-like hand may be further developed. Figure 9. – Overall layout of the system. Acknowledgements This work was presented in thesis form in fulfilment of the requirements for the MSC in Computer Science for the student Cedric Moutschen under the supervision of E.L. Secco from the Robotics Laboratory, Department of Mathematics & Computer Science, Liverpool Hope University.  References [1] Clement RGE, Bugler KE et al, Bionic Prosthetic Hands: A review of Present Technology and Future Aspirations, The surgeon 6(9), 336-340, 2011. [2] Sinha R, Adjustments to amputation & artificial limb, and quality of life in lower limb amputees, University of Groningen, 2013. [3] Desmond DM et al, Limb Amputation, The Oxford Handbook of Rehabilitation Psychology, 351, 2012. [4] Secco EL, Magenes G, Bio-mimetic Finger - Human like morphology, control & motion planning for intelligent robot & prosthesis, Mobile Robotics, Moving Intelligence, 325-348, 2006. [5] Zhe X, Todorov E, Design of a Highly Biomimetic Anthropomorphic Robotic Hand towards Artificial Limb Regeneration, 2016 IEEE International Conference on Robotics and Automation (ICRA), 3485-3492, 2016. [6] Scarcia U, Design and Control of Robotic Hands, PhD Thesis, University of Bologna, 2015. [7] Buryanov A,  Kotiuk V, Proportions of Hand Segments, International Journal of Morphology, 28(3), 755-758, 2010 [8] Lynette JA, Lederman SJ, Human hand function, Oxford University Press, 2006. [9] Chen CF, Favetto A et al, Human Hand: Kinematics, Statics and Dynamics, 41st International Conference on Environmental Systems (ICES), 5249, 17-21, 2011. [10] Cantrell J, Rohde S et al, Experimental Characterization of the Mechanical Properties of 3D Printed ABS and Polycarbonate Parts, Advancement of Optical Methods in Experimental Mechanics, 3, 89-105, Springer, 2017. [11] Skyler AD, Wiste TE et al, Design of a Multifunctional Anthropomorphic Prosthetic Hand with Extrinsic Actuation, IEEE/ASME Transactions on Mechatronics, 14(6), 699-706, 2009. [12] Amft O, Holger J et al, Sensing muscle activities with body-worn sensors, International Workshop on Wearable and Implantable Body Sensor Networks (BSN), 4, 2006. [13] Matrone C, Cipriani C, Secco EL et al, A biomimetic Approach based on Principal Components Analysis for multi-d.o.f. Prosthetic Hand Control, Corner Workshop, 2009. [14] Secco EL, Magenes G, A Feedforward Neural Network Controlling a 3 d.o.f. Finger, 5th International Conference on Cognitive & Neural Systems, 2001. [15] Secco EL, Magenes G, Control of a 3 dof  Artificial Finger by a Multi-Layer Perceptron, International Federation of Medical and Biological Engineering (IFMBE) Proceedings Medicon, 927-930, 2001. [16] Magenes G, Secco EL, Teaching a robot with human natural movements’, XI Winter Universiads Conference on Biomechanics and Sports, 135-144, 2003. A Sustainable & Biologically Inspired Prosthetic Hand for Healthcare  EAI Endorsed Transactionson Pervasive Health and Technology02 2018 - 07 2018 | Volume 4 | Issue 14 | e3

A Sustainable & Biologically Inspired Prosthetic Hand for Healthcare

Crossref

http://hira.hope.ac.uk/id/eprint/2585/1/eai.13-7-2018.155080.pdf

A Sustainable & Biologically Inspired Prosthetic Hand for Healthcare

Abstract

Similar works

Full text

Available Versions

Hope's Institutional Research Archive

Crossref