Harnessing Mechanical Instabilities in the Development of an Efficient Soft Pump for an Artificial Heart Ventricle Simulator

While mechanical instabilities were traditionally considered as failure events, triggering them in a controlled fashion recently paved the way to novel functionalities and improved performance, especially in systems made of soft materials. In this article, we present a novel cable-driven compliant mechanism whose pumping function is based on mechanical instabilities. Specifically, the cables are arranged in helices wrapped around a soft shell chamber that hosts the fluid, and upon pulling, they cause its dramatic volumetric reduction by inducing a torsional instability that maximizes the pumping action. We introduce a geometrical model to describe the deformation kinematics of the soft pump and a finite element model to investigate the detailed postbuckling behavior of the shell. Both models show very good agreement with the experiments. The computational model allowed us to perform a parametric study of the behavior of the soft pump as a function of the number of turns of the cables and their displacement upon pulling. Finally, we demonstrate experimentally the applicability of our soft pump as an artificial ventricle simulator, since the pumped volumes at physiologically relevant afterload pressures approach those found in left and right human ventricles

Soft Smart Interfaces for Bilateral Teleoperation with Distributed Tactile Haptic Feedback in Remote Medical Palpation

Robotics and teleoperated robotics have been increasingly implemented in the healthcare system in the last two decades. From robotic-assisted minimally invasive surgery to neurosurgery, endoscopy, and remote monitoring of patients at risk, robotic systems have showcased a beyond-human performance, allowing medical procedures to be performed at a distance, in hard-to-reach environments, and with strongly increased accuracy and speed. However, areas like primary care are still to be permeated by the ongoing growth of robotics. In particular, the routine test of physical examination, and especially the task of palpation, cannot be performed remotely, despite several research groups having attempted to develop teleoperated systems to enable remote palpation. This thesis proposes soft smart interfaces for distributed tactile haptic feedback, trying to exploit recent advancements in soft robotics to develop interfaces able to mimic the feeling of hand-to-skin palpation while providing the necessary information to enable the user to rapidly perform the correct diagnosis during remote palpation. Moreover, the focus is centered on both of the human-machine interfaces: the one between doctor and robot and the one between robot and patient. For the sake of safety, the patient is simulated using silicone phantoms of different shapes. Part I is centered around the development of a custom-made teleoperated architecture and the integration of shared control as a tool to augment the user experience while performing remote palpation. A combination of shared control and predictive models can be used to avoid indirect instabilities, normally created by the human operator's overcompensation of the delayed tactile recorded signal. Part II concerns the doctor-robot interface. Such an interface should act as a bilateral physical twin of the patient in the remote environment. It should not only reproduce the morphology of the tissues in contact with the robotic end-effector but also allow the doctor to control the robot's trajectory by just palpating the interface itself. This is achieved thanks to the embodied intelligence of the implemented device due to the smart position of sensors able to exploit the non-linearities introduced by the soft silicones used during manufacturing. All elements of such an interface are tested individually in unilateral teleoperation and are then integrated to achieve a fully functioning bilateral architecture. Part III focuses on the robot-patient interface. In order to ensure contact with the environment through a soft material and avoid mechanical constraints imposed by the sensing technology, this thesis exploits the approach of filtered tactile sensing. However, the presence of a mechanical filter between the sensing unit and the remote environment affects the quality of the recorded data. Hereby, I analyze the requirements of the selected filter in relation to the environment, as the guidelines to achieve the ideal filter cannot be defined without taking into consideration the surroundings and the contact interaction. Moreover, in order to bypass the trade-off between compliance and mechanical filtering, magnetorheological materials have been used to implement online tunable stiffness filters. Furthermore, a self-sensing 3D printable magnetorheological elastomer has been developed, paving the way for closed-loop stiffness control. Lastly, Part IV goes beyond haptics and investigates the importance of secondary modalities. In particular, facial expressions are proven to deliver important information for the diagnosis. Moreover, they showcase good performance without any other feedback modality. In summary, the work in this thesis focuses on the introduction of soft interfaces for remote palpation. By utilizing soft materials it is possible to obtain interfaces that feel like soft tissues while achieving the functionality needed by the teleoperated system. Thanks to a bilateral physical twin as a doctor-robot interface and filtered tactile sensing on the robot-patient interface, this thesis showcases how to record and deliver distributed tactile haptic feedback, thus paving the way for the development of teleoperated remote palpation systems.This work was supported by the SMART project, European Union's Horizon 2020 research and innovation under the Marie Sklodowska-Curie (grant agreement ID 860108)

All the data produced during Leone Costi's research on remote palpation

<p>This dataset contains all the data created while researching the topic of remote palpation.</p><p>This contains the data used in the following papers:</p><p>'Comparative Analysis of Model-Based Predictive Shared Control for Delayed Operation in Object Reaching and Recognition Tasks With Tactile Sensing'</p><p>'Soft Morphing Interface for Tactile Feedback in Remote Palpation'</p><p>'Magneto-Active Elastomer Filter for Tactile Sensing Augmentation Through Online Adaptive Stiffening'</p><p>'Soft Control Interface for Highly Dexterous Unilateral Remote Palpation'</p><p>'Comparative Study of Hand-Tracking and Traditional Control Interfaces for Remote Palpation'</p><p>'How the Environment Shapes Tactile Sensing: Understanding the Relationship Between Tactile Filters and Surrounding Environment'</p><p>'Barometric Soft Tactile Sensor for Depth Independent Contact Localization'</p><p>and the pre-print:</p><p>'Multi-silicone Bilateral Soft Physical Twin as an Alternative to Traditional User Interfaces for Remote Palpation: a Comparative Study'</p&gt

FEM-driven design and development of a bioinspired soft robotic artificial ventricle based on mechanical instabilities.

Cardiovascular diseases, which could often be the determining factor of heart failure, are the first cause of death worldwide. The gold standard in such cases is the transplant, but45%of the patients die while waiting. For this reason, the development of a Total Artificial Heart (TAH) is of extreme medical importance. At present, there is only one clinically adopted TAH: the CardioWest. Many TAHs are under research, but they all suffer from device-related complications, such as thrombosis and hemolysis, mainly addressed to the compliance mismatch between the natural tissues and the device. In the last decades, soft robotic technologies have been pinpointed as possible approaches to solve the aforementioned problems, but soft TAHs cannot yet reach physiological requirements. This master thesis proposes a soft robotic artificial ventricle, composed by a ventricular chamber and an actuation layer of artificial muscles that is able to reach physiological values of pumped blood volume and generated blood pressure. The aim of this work is to study the deformation of the ventricular chamber, relative to different geometries and contractile capabilities of the actuation layer. Firstly, a geometrical model of the system was developed. A FEM study was then used to study the ventricle contraction, also simulating physiological blood pressure conditions. Finally, the FEM model was experimentally validated. The described models allowed the design of the device, for what concerns its dimensions, constitutive materials, and requirements for the artificial muscles, both in terms of stroke and force generation capabilities

Multi-silicone bilateral soft physical twin as an alternative to traditional user interfaces for remote palpation: a comparative study

Abstract Teleoperated medical technologies are a fundamental part of the healthcare system. From telemedicine to remote surgery, they allow remote diagnosis and treatment. However, the absence of any interface able to effectively reproduce the sense of touch and interaction with the patient prevents the implementation of teleoperated systems for primary care examinations, such as palpation. In this paper, we propose the first reported case of a soft robotic bilateral physical twin for remote palpation. By creating an entirely soft interface that can be used both to control the robot and receive feedback, the proposed device allows the user to achieve remote palpation by simply palpating the soft physical twin. This is achieved through a compact design showcasing 9 pneumatic chambers and exploiting multi-silicone casting to minimize cross-noise and allow teleoperation. A comparative study has been run against a traditional setup, and both the control and feedback of the physical twin are carefully analyzed. Despite distributed tactile feedback not achieving the same performance as the visual map, the soft control and visual feedback combination showcases a 5.1% higher accuracy. Moreover, the bilateral soft physical twin results always in a less invasive procedure, with 41% lower mechanical work exchanged with the remote phantom

How to define the correct guidelines for enhanced telepresence and task embodiment in remote palpation.

Abstract Teleoperated robots have been widely accepted in several fields of medical practice, enhancing human abilities and allowing remote operation. However, such technology has not been able yet to permeate areas such as primary care and physical examination. Such applications strongly rely on the quality of the interaction between doctor and patient, and on its multimodal nature. In order to achieve remote physical examination is thus mandatory to have a good doctor-robot interface, but what does good mean? Ultimately, the goal is for the user to achieve task embodiment, making the remote task feel like the in-person one. Several research groups have proposed a wide variety of interfaces, showcasing largely different methods of control and feedback, because of the absence of design guidelines. In this work, we argue that the ideal interface for a remote task should resemble as close as possible the experience provided by the in-person equivalent, keeping in consideration the nature of the target users. To support our claims, we analyze many remote interfaces and compare them with the respective in-person task. This analysis is not limited to the medical sector, with examples such as remote abdominal surgery, but it expands to all forms of teleoperation, up to nuclear waste handling and avionics.</jats:p

Multi-silicone bilateral soft physical twin as an alternative to traditional user interfaces for remote palpation: a comparative study

AbstractTeleoperated medical technologies are a fundamental part of the healthcare system. From telemedicine to remote surgery, they allow remote diagnosis and treatment. However, the absence of any interface able to effectively reproduce the sense of touch and interaction with the patient prevents the implementation of teleoperated systems for primary care examinations, such as palpation. In this paper, we propose the first reported case of a soft robotic bilateral physical twin for remote palpation. By creating an entirely soft interface that can be used both to control the robot and receive feedback, the proposed device allows the user to achieve remote palpation by simply palpating the soft physical twin. This is achieved through a compact design showcasing 9 pneumatic chambers and exploiting multi-silicone casting to minimize cross-noise and allow teleoperation. A comparative study has been run against a traditional setup, and both the control and feedback of the physical twin are carefully analyzed. Despite distributed tactile feedback not achieving the same performance as the visual map, the soft control and visual feedback combination showcases a 5.1% higher accuracy. Moreover, the bilateral soft physical twin results always in a less invasive procedure, with 41% lower mechanical work exchanged with the remote phantom.</jats:p

Multi-silicone bilateral soft physical twin as an alternative to traditional user interfaces for remote palpation: a comparative study.

Teleoperated medical technologies are a fundamental part of the healthcare system. From telemedicine to remote surgery, they allow remote diagnosis and treatment. However, the absence of any interface able to effectively reproduce the sense of touch and interaction with the patient prevents the implementation of teleoperated systems for primary care examinations, such as palpation. In this paper, we propose the first reported case of a soft robotic bilateral physical twin for remote palpation. By creating an entirely soft interface that can be used both to control the robot and receive feedback, the proposed device allows the user to achieve remote palpation by simply palpating the soft physical twin. This is achieved through a compact design showcasing 9 pneumatic chambers and exploiting multi-silicone casting to minimize cross-noise and allow teleoperation. A comparative study has been run against a traditional setup, and both the control and feedback of the physical twin are carefully analyzed. Despite distributed tactile feedback not achieving the same performance as the visual map, the soft control and visual feedback combination showcases a 5.1% higher accuracy. Moreover, the bilateral soft physical twin results always in a less invasive procedure, with 41% lower mechanical work exchanged with the remote phantom.This work was supported by the SMART project, European Union's Horizon 2020 research and innovation under the Marie Sklodowska-Curie (grant agreement ID 860108)

How the Environment Shapes Tactile Sensing: Understanding the Relationship Between Tactile Filters and Surrounding Environment

The mechanical properties of a sensor strongly affect its tactile sensing capabilities. By exploiting tactile filters, mechanical structures between the sensing unit and the environment, it is possible to tune the interaction dynamics with the surrounding environment. But how can we design a good tactile filter? Previously, the role of filters’ geometry and stiffness on the quality of the tactile data has been the subject of several studies, both implementing static filters and adaptable filters. State-of-the-art works on online adaptive stiffness highlight a crucial role of the filters’ mechanical behavior in the structure of the recorded tactile data. However, the relationship between the filter’s and the environment’s characteristics is still largely unknown. We want to show the effect of the environment’s mechanical properties on the structure of the acquired tactile data and the performance of a classification task while testing a wide range of static tactile filters. Moreover, we fabricated the filters using four materials commonly exploited in soft robotics, to merge the gap between tactile sensing and robotic applications. We collected data from the interaction with a standard set of twelve objects of different materials, shapes, and textures, and we analyzed the effect of the filter’s material on the structure of such data and the performance of nine common machine learning classifiers, both considering the overall test set and the three individual subsets made by all objects of the same material. We showed that depending on the material of the test objects, there is a drastic change in the performance of the four tested filters, and that the filter that matches the mechanical properties of the environment always outperforms the others.</jats:p