Showing papers in "Applied Bionics and Biomechanics in 2010"
TL;DR: The results of an experiment involving a pointing task to targets memorised through visual perception or through their auditory conversion by the Vibe are given, to demonstrate the validity and interest of this method of vision to audition conversion.
Abstract: We describe a sensory substitution scheme that converts a video stream into an audio stream in real-time. It was initially developed as a research tool for studying human ability to learn new ways of perceiving the world: the Vibe can give us the ability to learn a kind of 'vision' by audition. It converts a video stream into a continuous stereophonic audio signal that conveys information coded from the video stream. The conversion from the video stream to the audio stream uses a kind of retina with receptive fields. Each receptive field controls a sound source and the user listens to a sound that is a mixture of all these sound sources. Compared to other existing vision-to-audition sensory substitution devices, the Vibe is highly versatile in particular because it uses a set of configurable units working in parallel. In order to demonstrate the validity and interest of this method of vision to audition conversion, we give the results of an experiment involving a pointing task to targets memorised through visual perception or through their auditory conversion by the Vibe. This article is also an opportunity to precisely draw the general specifications of this scheme in order to prepare its implementation on an autonomous/mobile hardware.
58 citations
TL;DR: In this article, an analytical investigation of peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form is presented.
Abstract: The paper presents an analytical investigation of the peristaltic transport of a viscous fluid under the influence of a magnetic field through a tube of finite length in a dimensionless form. The expressions of pressure gradient, volume flow rate, average volume flow rate and local wall shear stress have been obtained. The effects of the transverse magnetic field and electrical conductivity i.e. the Hartmann number on the mechanical efficiency of a peristaltic pump have also been studied. The reflux phenomenon is also investigated. It is concluded, on the basis of the pressure distribution along the tubular length and pumping efficiency, that if the transverse magnetic field and the electric conductivity increase, the pumping machinery exerts more pressure for pushing the fluid forward. There is a linear relation between the averaged flow rate and the pressure applied across one wavelength that can restrain the flow due to peristalsis. It is found that there is a particular value of the averaged flow rate corresponding to a particular pressure that does not depend on the Hartmann number. Naming these values 'critical values', it is concluded that the pressure required for checking the flow increases with the Hartmann number above the critical value and decreases with it below the critical value. It is also inferred that magneto-hydrodynamic parameters make the fluid more prone to flow reversal. The conclusion applied to oesophageal swallowing reveals that normal water is easier to swallow than saline water. The latter is more prone to flow reversal. A significant difference between the propagation of the integral and non-integral number of waves along the tube is that pressure peaks are identical in the former and different in the latter cases.
32 citations
TL;DR: This work hypothesises that the skin's intermediate ridges may help explain, in part, the sensitivity of slowly adapting type I SA-I mechanoreceptors to edge stimuli, and seeks to inform the positioning of force sensors in robotic skin substrates.
Abstract: Background: The skin plays a role in conditioning mechanical indentation into distributions of stress/strain that mechanoreceptors convert into neural signals. Solid mechanics methods have modelled the skin to predict the in vivo neural response from mechanoreceptors. Despite their promise, current models cannot explain the role that anatomical positioning and receptor organ morphology play in producing differences in neural response. This work hypothesises that the skin's intermediate ridges may help explain, in part, the sensitivity of slowly adapting type I SA-I mechanoreceptors to edge stimuli. Method: Two finite-element models of the fingertip were built, validated and used to analyse the functionality of the intermediate ridges. One of the two-dimensional, cross-sectional models included intermediate ridges, while the other did not. The analysis sought to determine if intermediate ridges 1 increase the magnitude of strain energy density SED near the SA-I location and 2 help differentiate one 2.0-mm indenter from two 0.5-mm wide indenters with a 1.0-mm gap. Results: Higher concentrations of SED were found near the tips of the intermediate ridges, the anatomical location that coincides with the SA-I receptors. This first result suggested that the location of the SA-Is in the stiffer epidermal tissue helps magnify their response to edge stimuli. The second result was that both models were equally capable of predicting the spatial structure within the in vivo neural responses, and therefore the addition of intermediate ridges did not help in differentiating the indenters. Conclusion: The finding, a 15%--35% increase in response when the sampling point lies within the stiffer tissue at the same depth, seeks to inform the positioning of force sensors in robotic skin substrates.
28 citations
TL;DR: The survey found that respondents were very interested in the robotic guide having a number of different functions and being useful in a wide range of circumstances and considered the robot's appearance to be very important but did not like any of the proposed designs.
Abstract: This paper reports the results of a multi-national survey in several different countries on the attitudes, requirements and preferences of blind and visually impaired people for a robotic guide. The survey is introduced by a brief overview of existing work on robotic travel aids and other mobile robotic devices. The questionnaire comprises three sections on personal information about respondents, existing use of mobility and navigation devices and the functions and other features of a robotic guide. The survey found that respondents were very interested in the robotic guide having a number of different functions and being useful in a wide range of circumstances. They considered the robot's appearance to be very important but did not like any of the proposed designs. From their comments, respondents wanted the robot to be discreet and inconspicuous, small, light weight and portable, easy to use, robust to damage, require minimal maintenance, have a long life and a long battery life.
25 citations
TL;DR: A bio-robotic fin has been developed that models the pectoral fin of the bluegill sunfish as the fish turned to avoid an obstacle and produced the forces and flows that drove the manoeuvre and had a sufficiently high number of degrees of freedom to create a variety of non-biologically derived motions.
Abstract: A bio-robotic fin has been developed that models the pectoral fin of the bluegill sunfish as the fish turned to avoid an obstacle. This work involved biological studies of the sunfish fin, the development of kinematic models of the motions of the fin's rays, CFD based predictions of the 3D forces and flows created by the fin, and the implementation of simplified models of the fin's kinematics and mechanical properties in a physical model. The resulting robotic fin produced the forces and flows that drove the manoeuvre and had a sufficiently high number of degrees of freedom to create a variety of non-biologically derived motions. The results indicate that for robotic fins to produce a level of performance on par with biological fins, both the kinematics and the mechanical properties of the biological fin must be modelled well.
24 citations
TL;DR: Results show that feedback conditions, including force feedback, significantly improve task performance independently of the operator's suturing experience, and it is deduced that force feedback in translations improves subject's dexterity, while torque feedback might not further benefit such a task.
Abstract: The introduction of Minimally Invasive Surgery MIS has revolutionised surgical care, considerably improving the quality of many surgical procedures. Technological advances, particularly in robotic surgery systems, have reduced the complexity of such an approach, paving the way for even less invasive surgical trends. However, the fact that haptic feedback has been progressively lost through this transition is an issue that to date has not been solved. Whereas traditional open surgery provides full haptic feedback, the introduction of MIS has eliminated the possibility of direct palpation and tactile exploration. Nevertheless, these procedures still provide a certain amount of force feedback through the rigid laparoscopic tool. Many of the current telemanipulated robotic surgical systems in return do not provide full haptic feedback, which to a certain extent can be explained by the requirement of force sensors integrated into the tools of the slave robot and actuators in the surgeon's master console. In view of the increased complexity and cost, the benefit of haptic feedback is open to dispute. Nevertheless, studies have shown the importance of haptic feedback, especially when visual feedback is unreliable or absent. In order to explore the importance of haptic feedback for the surgeon's master console of a novel teleoperated robotic surgical system, we have identified a typical surgical task where performance could potentially be improved by haptic feedback, and investigate performance with and without this feedback. Two rounds of experiments are performed with 10 subjects, six of them with a medical background. Results show that feedback conditions, including force feedback, significantly improve task performance independently of the operator's suturing experience. There is, however, no further significant improvement when torque feedback is added. Consequently, it is deduced that force feedback in translations improves subject's dexterity, while torque feedback might not further benefit such a task.
24 citations
TL;DR: These studies indicate that it is feasible to fabricate an electronic nervous system controller integrating both aVLSI CPGs and layered DTM exteroceptive reflexes, and will illustrate aspects of controllers for ambulatory biomimetic robots.
Abstract: We are developing robot controllers based on biomimetic design principles. The goal is to realise the adaptive capabilities of the animal models in natural environments. We report feasibility studies of a hybrid architecture that instantiates a command and coordinating level with computed discrete-time map-based DTM neuronal networks and the central pattern generators with analogue VLSI Very Large Scale Integration electronic neuron aVLSI networks. DTM networks are realised using neurons based on a 1-D or 2-D Map with two additional parameters that define silent, spiking and bursting regimes. Electronic neurons ENs based on Hindmarsh--Rose HR dynamics can be instantiated in analogue VLSI and exhibit similar behaviour to those based on discrete components. We have constructed locomotor central pattern generators CPGs with aVLSI networks that can be modulated to select different behaviours on the basis of selective command input. The two technologies can be fused by interfacing the signals from the DTM circuits directly to the aVLSI CPGs. Using DTMs, we have been able to simulate complex sensory fusion for rheotaxic behaviour based on both hydrodynamic and optical flow senses. We will illustrate aspects of controllers for ambulatory biomimetic robots. These studies indicate that it is feasible to fabricate an electronic nervous system controller integrating both aVLSI CPGs and layered DTM exteroceptive reflexes.
22 citations
TL;DR: Algorithms for identifying the odour source of a chemical plume with significant filament intermittency and meander developed in fluid-advected environments are presented and Monte Carlo methods are used to optimise the proposed algorithms.
Abstract: This paper presents algorithms for identifying the odour source of a chemical plume with significant filament intermittency and meander developed in fluid-advected environments. The algorithms are abstracted from moth-inspired chemical plume tracing strategies in two steps. First, we introduce the concept of the last chemical detection points that leads to construction of a source identification zone and development of two variations in the source identification algorithms. Second, we use Monte Carlo methods to optimise the proposed algorithms in a simulated environment. The evaluation results demonstrate that the optimised algorithm achieves a success rate of over 90% in identifying the source location, the average identification time is 3--4 min and the average error is 1--2 m surrounding the source location.
16 citations
TL;DR: A reconfigurable four-cable-based parallel manipulator has been proposed as a motion assisting and guiding device to help people to accomplish a number of tasks, such as an aiding or guiding system to move the upper and lower limbs or the whole body.
Abstract: This paper presents results on the modelling, simulation and experimental tests of a cable-based parallel manipulator to be used as an aiding or guiding system for people with motion disabilities. There is a high level of motivation for people with a motion disability or the elderly to perform basic daily-living activities independently. Therefore, it is of great interest to design and implement safe and reliable motion assisting and guiding devices that are able to help end-users. In general, a robot for a medical application should be able to interact with a patient in safety conditions, i.e. it must not damage people or surroundings; it must be designed to guarantee high accuracy and low acceleration during the operation. Furthermore, it should not be too bulky and it should exert limited wrenches after close interaction with people. It can be advisable to have a portable system which can be easily brought into and assembled in a hospital or a domestic environment. Cable-based robotic structures can fulfil those requirements because of their main characteristics that make them light and intrinsically safe. In this paper, a reconfigurable four-cable-based parallel manipulator has been proposed as a motion assisting and guiding device to help people to accomplish a number of tasks, such as an aiding or guiding system to move the upper and lower limbs or the whole body. Modelling and simulation are presented in the ADAMS environment. Moreover, experimental tests are reported as based on an available laboratory prototype.
16 citations
TL;DR: A technique based on electrooculography to control a robot arm by measuring the movement of the eyes, measuring the difference of potential between the cornea and the retina by placing electrodes around the ocular area is described.
Abstract: This paper describes a technique based on electrooculography to control a robot arm. This technique detects the movement of the eyes, measuring the difference of potential between the cornea and the retina by placing electrodes around the ocular area. The processing algorithm developed to obtain the position of the eye at the blink of the user is explained. The output of the processing algorithm offers, apart from the direction, four different values zero to three to control the velocity of the robot arm according to how much the user is looking in one direction. This allows controlling two degrees of freedom of a robot arm with the eyes movement. The blink has been used to mark some targets in tests. In this paper, the experimental results obtained with a real robot arm are shown.
14 citations
TL;DR: A model of smooth pursuit based on prediction and learning is presented, starting from amodel of the neuro-physiological system proposed by Shibata and Schaal Shibata et al., Neural Networks, vol.
Abstract: Smooth pursuit is one of the five main eye movements in humans, consisting of tracking a steadily moving visual target. Smooth pursuit is a good example of a sensory-motor task that is deeply based on prediction: tracking a visual target is not possible by correcting the error between the eye and the target position or velocity with a feedback loop, but it is only possible by predicting the trajectory of the target. This paper presents a model of smooth pursuit based on prediction and learning. It starts from amodel of the neuro-physiological system proposed by Shibata and Schaal Shibata et al., Neural Networks, vol. 18, pp. 213-224, 2005. The learning component added here decreases the prediction time in the case of target dynamics already experienced by the system. In the implementation described here, the convergence time is, after the learning phase, 0.8 s.
TL;DR: Both inhomogeneous CSF content and anisotropy in permeability have a great influence on the CSF flow pattern through the parenchyma under an imposed pressure gradient between the ventricles and the subarachnoid spaces.
Abstract: Hydrocephalus is a cerebral disease where brain ventricles enlarge and compress the brain parenchyma towards the skull leading to symptoms like dementia, walking disorder and incontinence. The origin of normal pressure hydrocephalus is still obscure. In order to study this disease, a finite element model is built using the geometries of the ventricles and the skull measured by magnetic resonance imaging. The brain parenchyma is modelled as a porous medium fully saturated with cerebrospinal fluid CSF using Biot's theory of consolidation 1941. Owing to the existence of bundles of axons, the brain parenchyma shows locally anisotropic behaviour. Indeed, permeability is higher along the fibre tracts in the white matter region. In contrast, grey matter is isotropic. Diffusion tensor imaging is used to establish the local CSF content and the fibre tracts direction together with the associated local frame where the permeability coefficients are given by dedicated formulas. The present study shows that both inhomogeneous CSF content and anisotropy in permeability have a great influence on the CSF flow pattern through the parenchyma under an imposed pressure gradient between the ventricles and the subarachnoid spaces.
TL;DR: It is shown that when adhered to a lightweight object resting on a water surface the plasmodium can propel the object by oscillating its protoplasmic pseudopodia.
Abstract: Plasmodium of Physarum polycephalum is a single huge visible by naked eye cell with a myriad of nuclei. The plasmodium is a promising substrate for non-classical, nature-inspired computing devices. It is capable of approximation of the shortest path in a maze, computation of planar proximity graphs and plane tessellations, primitive memory and decision making. The unique properties of the plasmodium make it an ideal candidate for a role of amorphous biological robots with massive parallel information processing and distributed inputs and outputs. We show that when adhered to a lightweight object resting on a water surface the plasmodium can propel the object by oscillating its protoplasmic pseudopodia. In experimental laboratory conditions and computational experiments we study phenomenology of the plasmodium-floater system, and possible mechanisms of controlling motion of objects propelled by on-board plasmodium.
TL;DR: The results of biological studies on spider locomotion and mobility are generalised, including the major movement and the position constraints set by the dry adhesion system, and the overall kinematics of the legs both in flight and in contact with the surface are studied.
Abstract: In the space environment the absence of gravity calls for constant safe attachment of any loose object, but the low-pressure conditions prohibit the use of glue-type adhesives. The attachment system of freely hunting spiders, e.g. Evarcha arcuata, employs van der Waals forces and mechanical interlocking. Furthermore, detachment is achieved passively and requires little force. Hence, the spider serves as a model for a versatile legged robot for space applications, e.g. on the outer surface of a space station. In this paper, we analyse the dry attachment systems of E. arcuata and geckos as well as the kinematics of freely hunting spiders. We generalise the results of biological studies on spider locomotion and mobility, including the major movement and the position constraints set by the dry adhesion system. From these results, we define a simplified spider model and study the overall kinematics of the legs both in flight and in contact with the surface. The kinematic model, the data on spider gait characteristics and the adhesion constraints are implemented in a kinematic simulator. The simulator results confirm the principal functionality of our concept.
TL;DR: In this paper, the effects of slip boundary condition on peristaltic transport of incompressible Newtonian viscous fluid in an asymmetric channel is investigated, under the conditions of low Reynolds number and long wavelength.
Abstract: The effects of slip boundary condition on peristaltic transport of incompressible Newtonian viscous fluid in an asymmetric channel is investigated, under the conditions of low Reynolds number and long wavelength. The pumping characteristics, trapping and reflux limits are studied for different values of the dimensionless slip parameter β.
TL;DR: The aim of this study is to investigate the impact of a chest support on lower back muscle activity during forward bending and to establish a possible relation between supporting force and the kind of balancing strategy a person adopts.
Abstract: The present study is based on previous research on the poor body posture of surgeons and their experienced discomfort during surgical procedures. Since surgeons have head-bent and back-bent posture during open surgical procedures, a chest support is a viable supporting principle. This support is meant to reduce lower back pain by minimising lower back muscle activity. The aim of this study is to investigate the impact of a chest support on lower back muscle activity during forward bending and to establish a possible relation between supporting force and the kind of balancing strategy a person adopts. Use of the chest support shows a significant reduction of muscle activity in the lower back and leg muscles. Within the participants three user groups are identified as “sceptical users”, “non-trusters” and “fully trusters”, each following a different balancing strategy. Since there are different kinds of users, the designed body support should offer the possibility for altering the posture and should not constrain the user to take a certain body posture.
TL;DR: In this paper, a fast numerical solution for the inverse kinematics of a serial manipulator is presented, which is implemented on the C-arm, a manipulator designed for use in robotic surgery.
Abstract: This paper presents a fast numerical solution for the inverse kinematics of a serial manipulator. The method is implemented on the C-arm, a manipulator designed for use in robotic surgery. The inverse kinematics solution provides all possible solutions for any six degree-of-freedom serial manipulator, assuming that the forward kinematics are known and that it is possible to solve for the remaining joint angles if one joint angle's value is known. With a fast numerical method and the current levels of computing power, designing a manipulator with closed-form inverse kinematics is no longer necessary. When designing the C-arm, we therefore chose to weigh other factors, such as actuator size and patient safety, more heavily than the ability to find a closed-form inverse kinematics solution.
TL;DR: A cerebral disease where brain ventricles enlarge and compress the brain parenchyma towards the skull leading to symptoms like dementia, walking disorder and incontinence was identified in this paper.
Abstract: Hydrocephalus is a cerebral disease where brain ventricles enlarge and compress the brain parenchyma towards the skull leading to symptoms like dementia, walking disorder and incontinence. The orig...
TL;DR: Th thumb motion on pushing the keys of the cellular phone was produced mainly by the MP and the CM joints, and the ability to reach keys in different areas of the Cellular phone keypad is regulated by changing the flexion angle of the CM joint.
Abstract: The thumb motion of 10 normal subjects during cellular phone use was measured using a reflective marker detection system to compare the maximum, minimum and range of flexion angles of the interphalangeal IP, metacarpophalangeal MP and carpometacarpal CM joints. Two micro-reflective markers 3 mm in diameter were each placed on the dorsal surface of the distal phalanx, basal phalanx and metacarpal bone of the thumb. Three markers were placed on the dorsal hand in order to define the dorsal hand plane. Each subject pushed the 12 keys of a folding cellular phone with an 85-mm-long and 40-mm-wide keypad, sequentially from '1' to '#', and the pushing motion was recorded by six infrared video cameras for 12 seconds, using the VICON 612 system. The mean maximum flexion angle of the MP joint was significantly p <.05 larger than the CM joint, and the mean minimum flexion angle of the CM joint was significantly p <.01 smaller than the IP and MP joints. The mean range of motion of the IP joint was significantly p <.05 larger than the MP and the CM joints. In a comparison of different key-pushing motions, only the CM joint was significantly p <.05 larger in its range of motion. In conclusion, thumb motion on pushing the keys of the cellular phone was produced mainly by the MP and the CM joints. In addition, the ability to reach keys in different areas of the cellular phone keypad is regulated by changing the flexion angle of the CM joint.
TL;DR: Simulation results are presented which show that the servo regulator accomplishes accurate depth control despite uncertainties in the model parameters, shown that in the closed-loop system, all the harmonic components of order up to k of the tracking error are suppressed.
Abstract: The development of a control system for the dive plane control of non-linear biorobotic autonomous underwater vehicles, equipped with pectoral-like fins, is the subject of this paper. Marine animals use pectoral fins for swimming smoothly. The fins are assumed to be oscillating with a combined pitch and heave motion and therefore produce unsteady control forces. The objective is to control the depth of the vehicle. The mean angle of pitch motion of the fin is used as a control variable. A computational-fluid-dynamics-based parameterisation of the fin forces is used for control system design. A robust servo regulator for the control of the depth of the vehicle, based on the non-linear internal model principle, is derived. For the control law derivation, an exosystem of third order is introduced, and the non-linear time-varying biorobotic autonomous underwater vehicle model, including the fin forces, is represented as a non-linear autonomous system in an extended state space. The control system includes the internal model of a k-fold exosystem, where k is a positive integer chosen by the designer. It is shown that in the closed-loop system, all the harmonic components of order up to k of the tracking error are suppressed. Simulation results are presented which show that the servo regulator accomplishes accurate depth control despite uncertainties in the model parameters.
TL;DR: In this paper, the authors used existing pattern recognition methods to evaluate the effect of age on performance of a specific motion, reaching to a target by moving the end-effector of a robot an X-Y table.
Abstract: New movement assessment and data analysis methods are developed to quantify human arm motion patterns during physical interaction with robotic devices for rehabilitation. These methods provide metrics for future use in diagnosis, assessment and rehabilitation of subjects with affected arm movements. Specifically, the current study uses existing pattern recognition methods to evaluate the effect of age on performance of a specific motion, reaching to a target by moving the end-effector of a robot an X-Y table. Differences in the arm motion patterns of younger and older subjects are evaluated using two measures: the principal component analysis similarity factor SPCA to compare path shape and the number of Fourier modes representing 98% of the path 'energy' to compare the smoothness of movement, a particularly important variable for assessment of pathologic movement. Both measures are less sensitive to noise than others previously reported in the literature and preserve information that is often lost through other analysis techniques. Data from the SPCA analysis indicate that age is a significant factor affecting the shapes of target reaching paths, followed by reaching movement type crossing body midline/not crossing and reaching side left/right; hand dominance and trial repetition are not significant factors. Data from the Fourier-based analysis likewise indicate that age is a significant factor affecting smoothness of movement, and movements become smoother with increasing trial number in both younger and older subjects, although more rapidly so in younger subjects. These results using the proposed data analysis methods confirm current practice that age-matched subjects should be used for comparison to quantify recovery of arm movement during rehabilitation. The results also highlight the advantages that these methods offer relative to other reported measures.
TL;DR: While lumbar bracing reduces the sEMG activity on average, these data suggest the existence of an infrequent paradoxical response that may provide a possible explanation for the discordant results observed in previous bracing investigations.
Abstract: Lumbar bracing is prescribed frequently for disability caused by low back pain; however, investigations into this practice demonstrate a range of patient outcomes. This inconsistency may arise from the practice of employing voluntary, single-axis trunk movements when investigating braces. Alternatively, this study employed a parallel robot to create a standardised, multi-axis testing environment. Surface electromyographic sEMG data were collected from the trunk of 24 asymptomatic participants, who were seated on the robot, tilted to 15°, then circumducted while attempting to maintain an upright posture. Multiple trials were performed for three randomised conditions: non-braced, soft-material brace and stiff-material brace. As expected, the sEMG activity was significantly reduced in the majority of muscle responses 201/240. Unexpectedly, a paradoxical increase in the sEMG activity was observed in 39/240 responses. While lumbar bracing reduces the sEMG activity on average, these data suggest the existence of an infrequent paradoxical response that may provide a possible explanation for the discordant results observed in previous bracing investigations.
TL;DR: In this paper, a pneumatically actuated, one-legged hopping machine with a simple actuator has been developed to mimic the biomechanics of jumping in Homo sapiens, which can be used as an educational tool for teaching real-time control of hybrid and nonlinear systems.
Abstract: Hopping is a complicated dynamic behaviour in the animal kingdom. Development of a hopping machine that can mimic the biomechanics of jumping in Homo sapiens is envisioned. In this context, the design, development and control of a cost-effective, pneumatically actuated, one-legged hopping machine were initiated at the University ofRegina in 2005. The pneumatic actuator has a simple design that employs an off-the-shelf on/off control valve which regulates the air pressure supplied to the hopper's body using a pulse width modulated PWM signal. The objective is to maintain a constant jumping height in the hopper after going through a finite number of hopping cycles. The mechanistic model of the system was investigated in full detail. This model facilitates: 1 the design of the actuating system, and 2 the synthesis and verification of different control strategies in a simulation environment prior to implementation in the real world. The movement of the hopper is supported by a vertical slide; therefore, the hopper can only jump in place. However, the proposed control strategy and the propulsion unit can be further utilised for stable hopping in a 3-D environment. A model-free Neuro-PD controller was then designed, trained and implemented on a real system. Simulation and experimentation showed promising results. This system can be used as an educational tool for teaching real-time control of hybrid and non-linear systems. It can be also used as a biomechatronics test bed to simulate the effect of different timings in firing action potentials in jump-causing leg muscles on achieving a desired jumping height in the animal kingdom.
TL;DR: The experimental results of photoelasticity for determining the magnitude and distribution of stresses on the polyethylene insert of the knee prostheses designed for high/deep knee flexion conclude that the design and the configuration of CFK is acceptable at deep kneeflexion from a load-bearing viewpoint.
Abstract: This paper presents the experimental results of photoelasticity for determining the magnitude and distribution of stresses on the polyethylene insert of the knee prostheses designed for high/deep knee flexion. The prostheses used in our experiment were a conventional posterior stabiliser knee, Scorpio NRG Non-Restricted Geometry, Stryker Co., USA and CFK Complete Flexion Knee, Japan Medical Material Co., Japan, which we have developed to enable the patient to make a complete knee flexion i.e. seiza in Japanese. Prior to the photoelastic experiment, we had introduced the forces exerted on the knee joint during ascending from deep knee flexion. Here we took squatting as an example of deep knee flexion instead of seiza because ascending from seiza contains complex modalities. The introduced data in terms of knee angles and joint forces were applied to the photoelastic models. The results demonstrated that after the knee angle became larger than 90°, the shear stresses on the post and cam of NRG were higher than those on the ball and socket of CFK. We conclude that the design and the configuration of CFK is acceptable at deep knee flexion from a load-bearing viewpoint.
TL;DR: In this article, the mobility of a horse in the standing position with its hooves fixed to the ground is investigated to assist designing a minimally obstructing system for restraining large animals.
Abstract: The mobility of a horse in the standing position with its hooves fixed to the ground is investigated to assist designing a minimally obstructing system for restraining large animals. The horse is modelled as a mechanical linkage driven by muscle forces. The linkage's configuration patterns, active joints and the forces associated with motion initiation are studied by reducing it to a mechanism with a low number of degrees of freedom. A restraint system blocking the motion of active joints with ropes is proposed as an alternative to massive mechanical devices restraining the whole body. The system has been verified experimentally on a sheep.
TL;DR: A method to render brain tumours from endoneurosonography using conformal geometric algebra to compute the geometric transformations that yield the 3D position of the tumour, which was segmented in the ultrasound image using morphological operators.
Abstract: We have developed a method to render brain tumours from endoneurosonography. We propose to track an ultrasound probe in successive endoscopic images without relying on an external optic or magnetic tracking system. The probe is tracked using two different methods: one of them based on a generalised Hough transform and the other one based on particle filters. By estimating the pose of the ultrasound probe in several contiguous images, we use conformal geometric algebra to compute the geometric transformations that yield the 3D position of the tumour, which was segmented in the ultrasound image using morphological operators. We use images from brain phantoms to evaluate the performance of the proposed methods, and our results show that they are robust.
TL;DR: This work describes a robotic experimental workstation composed of robots and specific measuring devices, together with their corresponding control and monitoring strategies for orthopaedic surgery and shows the possibilities of having a test bed available for repetitive and quantifiable trials, which make a reliable scientific comparison between different surgical strategies possible.
Abstract: Robotics has shown its potential not only in assisting the surgeon during an intervention but also as a tool for training and for surgical procedure's evaluation. Thus, robotics can constitute an extension of simulators that are based on the high capabilities of computer graphics. In addition, haptics has taken a first step in increasing the performance of current virtual reality systems based uniquely on computer simulation and their corresponding interface devices. As a further step in the field of training and learning in surgery, this work describes a robotic experimental workstation composed of robots and specific measuring devices, together with their corresponding control and monitoring strategies for orthopaedic surgery. Through a case study, humerus arthroplasty, experimental evaluation shows the possibilities of having a test bed available for repetitive and quantifiable trials, which make a reliable scientific comparison between different surgical strategies possible.