83 research outputs found
Analysis of a soft bio-Inspired active actuation model for the design of artificial vocal folds
Phonation results from the passively induced oscillation of the vocal folds in the larynx, creating sound waves that are then articulated by the mouth and nose. Patients undergoing laryngectomy have their vocal folds removed and thus must rely on alternative sources of achieving the desired vibration of artificial vocal folds. Existing solutions, such as voice prostheses and the Electrolarynx, are limited by producing sufficient voice quality, for instance. In this paper, we present a mathematical analysis of a physical model of an active vocal fold prosthesis. The inverse dynamical equation of the system will help to understand whether specific types of soft actuators can produce the required force to generate natural phonations. Hence, this is referred to as the active actuation model. We present the analysis to replicate the vowels /a/, /e/, /i/, and /u/ and voice qualities of vocal fry, modal, falsetto, breathy, pressed, and whispery. These characteristics would be required as a first step to design an artificial vocal folds system. Inverse dynamics is used to identify the required forces to change the glottis area and frequencies to achieve sufficient oscillation of artificial vocal folds. Two types of ionic polymer-metal composite (IPMC) actuators are used to assess their ability to produce these forces and the corresponding activation voltages required. The results of our proposed analysis will enable research into the effects of natural phonation and, further, provide the foundational work for the creation of advanced larynx prostheses
Meshless Simulation of Multi-site Radio Frequency Catheter Ablation through the Fragile Points Method
Computational models for radio frequency
catheter ablation (RFCA) of cardiac arrhythmia have been
developed and tested in conditions where a single ablation
site is considered. However, in reality arrhythmic events
are generated at multiple sites which are ablated during
treatment. Under such conditions, heat accumulation from
several ablations is expected and models should take this effect
into account. Moreover, such models are solved using the
Finite Element Method which requires a good quality mesh
to ensure numerical accuracy. Therefore, clinical application
is limited since heat accumulation effects are neglected and
numerical accuracy depends on mesh quality. In this work, we
propose a novel meshless computational model where tissue
heat accumulation from previously ablated sites is taken into
account. In this way, we aim to overcome the mesh quality
restriction of the Finite Element Method and enable realistic
multi-site ablation simulation. We consider a two ablation
sites protocol where tissue temperature at the end of the first
ablation is used as initial condition for the second ablation. The
effect of the time interval between the ablation of the two sites
is evaluated. The proposed method demonstrates that previous
models that do not account for heat accumulation between
ablations may underestimate the tissue heat distribution
Computational Analysis of Balloon Catheter Behaviour at Variable Inflation Levels
Aortic valvuloplasty is a minimally invasive procedure for the dilatation of stenotic aortic valves. Rapid ventricular pacing is an established technique for balloon stabilization during this procedure. However, low cardiac output due to the pacing is one of the inherent risks, which is also associated with several potential complications. This paper proposes a numerical modelling approach to understand the effect of different inflation levels of a valvuloplasty balloon catheter on the positional instability caused by a pulsating blood flow. An unstretched balloon catheter model was crimped into a tri-folded configuration and inflated to several levels. Ten different inflation levels were then tested, and a Fluid-Structure Interaction model was built to solve interactions between the balloon and the blood flow modelled in an idealised aortic arch. Our computational results show that the maximum displacement of the balloon catheter increases with the inflation level, with a small step at around 50% inflation and a sharp increase after reaching 85% inflation. This work represents a substantial progress towards the use of simulations to solve the interactions between a balloon catheter and pulsating blood flow
Soft, stiffness-controllable sensing tip for on-demand force range adjustment with angled force direction identification
Force sensors are essential for measuring and controlling robot-object interactions. However, current force sensors have limited usability in applications such as grasping and palpation, where the range of angled forces changes between tasks. To address this limitation this paper proposes a novel optical-based soft-tipped force sensor capable of adjusting its range and sensitivity through pneumatic modulation. This research describes the sensor’s design and examines the relationship between the internal pressure of the sensor and its sensing range, sensitivity, single-axis force-sensing accuracy, and capability of measuring the angle and magnitude of non-normal forces. Results indicate that by increasing the pressure in the sensor, the sensing range can be increased and the sensitivity decreased. These results demonstrate that the sensor can measure normal forces reliably at each pressure using 4th order fits with root-mean-square error (RMSE) ∈[0.032N0.110N] . Finally, it is also demonstrated that by using a neural network, the sensor can measure the angle and magnitude of non-normal forces with RMSEs on trained variables of 0.0120 Rad for Y-angle ( θY ) measurements, 0.0109 Rad for X-angle ( θX ) measurements, and 0.102 N for force measurements
Editorial: Translational research in medical robotics—challenges and opportunities
In the last few decades, emerging medical technologies and the growing number of
commercial robotic platforms have supported diagnosis and treatment of both acute
and chronic diseases of the human body, improving the clinical outcome, reducing
trauma, shortening the patient recovery time, and increasing postoperative survival rates
(Troccaz et al., 2019). Medical robots–including surgical robots, rehabilitation and assistive
robots, and hospital automation robots–with improved safety, efficacy and reduced costs,
robotic platforms will soon approach a tipping point, moving beyond early adopters to
become part of the mainstream clinical practice, defining the future of smart hospitals and
home-based patient care. Surgical robots promise to enhance minimally invasive surgery
with precise instrument control, intuitive hand-eye coordination, and superior dexterity
within tight spaces (Dupont et al., 2021). Rehabilitation robotics facilitates robot-assisted
therapy and automated recovery training (Xue et al., 2021). Assistive robots aid individuals
with physical limitations, either enhancing or compensating for functions, promoting
independence, and lessening the burden on caregivers (Trainum et al., 2023). Additionally,
robotic systems can automate hospital operations, spanning service robots aiding clinicians
to robots in labs for high-throughput testing (Kwon et al., 2022). These technologies aim to
revolutionize healthcare, offering improved patient care and operational efficiency
Soft Robot-Assisted Minimally Invasive Surgery and Interventions: Advances and Outlook
Since the emergence of soft robotics around two decades ago, research interest in the field has escalated at a pace. It is fuelled by the industry's appreciation of the wide range of soft materials available that can be used to create highly dexterous robots with adaptability characteristics far beyond that which can be achieved with rigid component devices. The ability, inherent in soft robots, to compliantly adapt to the environment, has significantly sparked interest from the surgical robotics community. This article provides an in-depth overview of recent progress and outlines the remaining challenges in the development of soft robotics for minimally invasive surgery
The PrHand: Functional Assessment of an Underactuated Soft-Robotic Prosthetic Hand
Functional tests aim to compare the functionality
of a prosthesis with a human hand. The main objective of
this work is to present and evaluate an affordable prosthesis
(PrHand) built with soft robotic technologies and novel joints
based on compliant mechanisms. Two functional tests have
been selected in this work. The first is the AHAP protocol,
which evaluates how the prosthesis performs eight different
grips; three variables are considered: grasping, maintaining,
and grasping ability score (GAS). The results were 69.03%
with 57.77% in grasping and 80.28% in maintaining. The
second test is the AM-ULA, which evaluates the prosthesis by
performing 23 Activities of Daily Living. PrHand prosthesis
had a score of 2.5 over 4.0. The functionality of the PrHand
prosthesis has similar results to other prostheses evaluated
in the literature. The comparison with the human hand was
69%. PrHand presents a promising solution for amputees in
developing countries regarding cost and functionalit
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