@article {4318, title = {Comparison between rigid and soft poly-articulated prosthetic hands in non-expert myo-electric users shows advantages of soft robotics.}, journal = {Scientific Reports}, volume = {11}, year = {2021}, month = {12/2021}, chapter = {1}, abstract = {

Notwithstanding the advancement of modern bionic hands and the large variety of prosthetic hands in the market, commercial devices still present limited acceptance and percentage of daily use. While commercial prostheses present rigid mechanical structures, emerging trends in the design of robotic hands are moving towards soft technologies. Although this approach is inspired by nature and could be promising for prosthetic applications, there is scant literature concerning its benefits for end-users and in real-life scenarios. In this work, we evaluate and assess the role and the benefits of soft robotic technologies in the field of prosthetics. We propose a thorough comparison between rigid and soft characteristics of two poly-articulated hands in 5 non-expert myo-electric prosthesis users in pre- and post-therapeutic training conditions. The protocol includes two standard functional assessments, three surveys for user-perception, and three customized tests to evaluate the sense of embodiment. Results highlight that rigid hands provide a more precise grasp, while soft properties show higher functionalities thanks to their adaptability to different requirements, intuitive use and more natural execution of activities of daily living. This comprehensive evaluation suggests that softness could also promote a quick integration of the system in non-expert users.

}, isbn = {ISSN 2045-2322}, doi = {https://doi.org/10.1038/s41598-021-02562-y}, url = {https://www.nature.com/articles/s41598-021-02562-y}, author = {Capsi-Morales, Patricia and Piazza, Cristina and Catalano, Manuel G. and Grioli, Giorgio and Schiavon, Lisa and Fiaschi, Elena and Bicchi, Antonio} } @article {4079, title = {Exploring Stiffness Modulation in Prosthetic Hands and Its Perceived Function in Manipulation and Social Interaction.}, journal = {Frontiers in Neurorobotics}, volume = {14}, year = {2020}, month = {06/2020}, abstract = {

To physically interact with a rich variety of environments and to match situation-dependent requirements, humans adapt both the force and stiffness of their limbs. Reflecting this behavior in prostheses may promote a more natural and intuitive control and, consequently, improve prostheses acceptance in everyday life. This pilot study proposes a method to control a prosthetic robot hand and its impedance, and explores the utility of variable stiffness when performing activities of daily living and physical social interactions. The proposed method is capable of a simultaneous and proportional decoding of position and stiffness intentions from two surface electro-myographic sensors placed over a pair of antagonistic muscles. The feasibility of our approach is validated and compared to existing control modalities in a preliminary study involving one prosthesis user. The algorithm is implemented in a soft under-actuated prosthetic hand (SoftHand Pro). Then, we evaluate the usability of the proposed approach while executing a variety of tasks. Among these tasks, the user interacts with other 12 able-bodied subjects, whose experiences were also assessed. Several statistically significant aspects from the System Usability Scale indicate user{\textquoteright}s preference of variable stiffness control over low or high constant stiffness due to its reactivity and adaptability. Feedback reported by able-bodied subjects reveal a general tendency to favor soft interaction, i.e., low stiffness, which is perceived more human-like and comfortable. These combined results suggest the use of variable stiffness as a viable compromise between firm control and safe interaction which is worth investigating further.

}, keywords = {human-robot social interaction, impedance control, prosthetics, Soft robotics, task adaptability}, doi = {10.3389/fnbot.2020.00033}, url = {https://www.frontiersin.org/articles/10.3389/fnbot.2020.00033/full?\&utm_source=Email_to_authors_\&utm_medium=Email\&utm_content=T1_11.5e1_author\&utm_campaign=Email_publication\&field=\&journalName=Frontiers_in_Neurorobotics\&id=503842}, author = {Capsi-Morales, Patricia and C. Piazza and M. G. Catalano and A. Bicchi and G. Grioli} } @article {4081, title = {Exploring the Role of Palm Concavity and Adaptability in Soft Synergistic Robotic Hands}, journal = { IEEE Robotics and Automation Letters }, volume = {5}, year = {2020}, month = {17 June 2020}, pages = {4703 - 4710}, chapter = {4703}, abstract = {

Robotic hand engineers usually focus on finger capabilities, often disregarding the palm contribution. Inspired by human anatomy, this paper explores the advantages of including a flexible concave palm into the design of a robotic hand actuated by soft synergies. We analyse how the inclusion of an articulated palm improves finger workspace and manipulability. We propose a mechanical design of a modular palm with two elastic rolling-contact palmar joints, that can be integrated on the Pisa/IIT SoftHand, without introducing additional motors. With this prototype, we evaluate experimentally the grasping capabilities of a robotic palm. We compare its performance to that of the same robotic hand with the palm fixed, and to that of a human hand. To assess the effective grasp quality achieved by the three systems, we measure the contact area using paint-transfer patterns in different grasping actions. Preliminary grasping experiments show a closer resemblance of the soft-palm robotic hand to the human hand. Results evidence a higher adaptive capability and a larger involvement of all fingers in grasping.

}, keywords = {Ellipsoids, Grasping, Indexes, Kinematics, Robots, Shape, Thumb}, issn = { 2377-3766}, doi = {10.1109/LRA.2020.3003257}, url = {https://ieeexplore.ieee.org/document/9119822?source=authoralert}, author = {Capsi-Morales, Patricia and G. Grioli and C. Piazza and A. Bicchi and M. G. Catalano} } @proceedings {4106, title = {SIMULTANEOUS AND PROPORTIONAL DECODING OF STIFFNESS AND POSITION INTENTIONS FROM TWO SEMG CHANNELS FOR UL PROSTHETICS}, year = {2020}, month = {07/2020}, abstract = {

To physically interact with a rich variety of environments and situation-oriented requirements, humans continuously adapt both the stiffness and the force of their limbs through antagonistic muscle coactivation. Reflecting this behaviour in prostheses may promote control naturalness and intuitiveness and, consequently, their acceptance in everyday life. We propose a method capable of a simultaneous and proportional decoding of position and stiffness intentions from two surface electro-myographic sensors placed over a pair of antagonistic muscles. First, the algorithm is validated and compared to existing control modalities. Then, the algorithm is implemented in a soft under-actuated prosthetic hand (SoftHand Pro). We investigated the feasibility of our approach in a preliminary study involving one prosthetic user. Our future goal is to evaluate the usability of the proposed approach executing a variety of tasks including physical social interaction with other subjects (see Figure 1). Our hypothesis is that variable stiffness could be a compromise between firm control and safe interaction.

}, url = {https://conferences.lib.unb.ca/index.php/mec/article/view/35}, author = {Capsi-Morales, Patricia and C. Piazza and M. G. Catalano and A. Bicchi and G. Grioli} } @conference {4320, title = {Towards a Myoelectric Prosthetic Wrist with Rigid and Compliant Behaviour}, booktitle = {International Conference on NeuroRehabilitation}, year = {2020}, month = {10/2020}, pages = {489-493}, abstract = {

The simple kinematics of commercial prosthetic wrists limits the individuals in performing a wide range of tasks and restore natural motor functions. We propose a functional prosthesis that improves grasping capabilities through the addition of a simple yet useful 3 DoF myoelectric wrist joint with compliant and rigid properties. Its locking capability enables the adjustment of hand configuration in pre-grasping phases and separates the hand motion from the wrist motion. The proposed wrist, combined with a prosthetic hand, was tested with 8 able-bodied subjects and 1 subject with limb loss. It was compared to a common commercial rotational wrist and to subjects{\textquoteright} natural wrist. Results evidence the feasibility of the prototype, improved performance capabilities, and the subjects{\textquoteright} first impression about the proposed system. Finally, a prosthesis user tested and compared systems during Activities of Daily Living (ADL).

}, doi = {https://doi.org/10.1007/978-3-030-70316-5_78}, url = {https://link.springer.com/chapter/10.1007/978-3-030-70316-5_78}, author = {Capsi-Morales, Patricia and Piazza, Cristina and Grioli, Giorgio and Bicchi, Antonio and Catalano, Manuel G.} } @conference {4319, title = {Towards More Natural Transradial Bionic Limbs}, booktitle = {I-RIM}, year = {2020}, month = {12/2020}, abstract = {

Based on previous experience with prosthesis users and literature, this paper introduces three important aspects to further develop functional transradial myoelectric prostheses: stiffness modulation, grasp reliability and limb dexterity. In particular, we propose three possible solutions and discuss on the insights observed about the exploration of impedance control in prosthetic hands during Activities of Daily Living and social interaction, the introduction of an articulated palm to increase all hand parts contribution in grasping, and a compact 3 DoF myoelectric wrist capable to switch from compliant to rigid properties during pre-grasping phase to decrease compensatory movements and favour more natural body postures in prosthesis users.

}, keywords = {Bionic Limbs, Myoelectric control, Soft-robotics, Upper-limb prostheses}, url = {https://i-rim.it/wp-content/uploads/2020/12/I-RIM_2020_paper_144.pdf}, author = {Capsi-Morales, Patricia and Catalano, Manuel G. and Grioli, Giorgio and Piazza, Cristina and Bicchi, Antonio} }