scholarly journals Haptic Manipulation of 3D Scans for Geometric Feature Enhancement

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2716
Author(s):  
Sri Harsha Turlapati ◽  
Dino Accoto ◽  
Domenico Campolo

Localisation of geometric features like holes, edges, slots, etc. is vital to robotic planning in industrial automation settings. Low-cost 3D scanners are crucial in terms of improving accessibility, but pose a practical challenge to feature localisation because of poorer resolution and consequently affect robotic planning. In this work, we address the possibility of enhancing the quality of a 3D scan by a manual ’touch-up’ of task-relevant features, to ensure their automatic detection prior to automation. We propose a framework whereby the operator (i) has access to both the actual work-piece and its 3D scan; (ii) evaluates the missing salient features from the scan; (iii) uses a haptic stylus to physically interact with the actual work-piece, around such specific features; (iv) interactively updates the scan using the position and force information from the haptic stylus. The contribution of this work is the use of haptic mismatch for geometric update. Specifically, the geometry from the 3D scan is used to predict haptic feedback at a point on the work-piece surface. The haptic mismatch is derived as a measure of error between this prediction and the real interaction forces from physical contact at that point on the work-piece. The geometric update is driven until the haptic mismatch is minimised. Convergence of the proposed algorithm is first numerically verified on an analytical surface with simulated physical interaction. Error analysis of the surface position and orientations were also plotted. Experiments were conducted using a motion capture system providing sub-mm accuracy in position and a 6 axis F/T sensor. Missing features are successfully detected after the update of the scan using the proposed method in an experiment.

2021 ◽  
pp. 1-12
Author(s):  
Hamilton Hernandez ◽  
Isabelle Poitras ◽  
Linda Fay ◽  
Ajmal Khan ◽  
Jean-Sébastien Roy ◽  
...  

BACKGROUND: Video games can be used to motivate repetitive movements in paediatric rehabilitation. Most upper limb videogaming therapies do not however include haptic feedback which can limit their impact. OBJECTIVE: To explore the effectiveness of interactive computer play with haptic feedback for improving arm function in children with cerebral palsy (CP). METHODS: Eleven children with hemiplegic CP attended 12 therapist-guided sessions in which they used a gaming station composed of the Novint Falcon, custom-built handles, physical supports for the child’s arm, games, and an application to manage and calibrate therapeutic settings. Outcome measures included Quality of Upper Extremity Skills Test (QUEST) and Canadian Occupational Performance Measure (COPM). The study protocol is registered on clinicaltrials.gov (NCT04298411). RESULTS: Participants completed a mean of 3858 wrist extensions and 6665 elbow/shoulder movements during the therapist-guided sessions. Clinically important improvements were observed on the dissociated and grasp dimensions on the QUEST and the performance and satisfaction scales of the COPM (all p< 0.05). CONCLUSION: This study suggests that computer play with haptic feedback could be a useful and playful option to help improve the hand/arm capacities of children with CP and warrants further study. The opportunities and challenges of using low-cost, mainstream gaming software and hardware for therapeutic applications are discussed.


2020 ◽  
Author(s):  
Megan Kiely Mueller ◽  
Eric C Anderson ◽  
Erin K. King ◽  
Heather L. Urry

Animal-assisted interventions (AAIs) are increasingly popular as treatments to reduce anxiety. However, there is little empirical evidence testing the mechanisms of action in AAIs, especially among adolescents. We examined whether two possible mechanisms, social interaction and/or physical contact with a therapy dog, might reduce anxiety during a social stressor. To test these mechanisms, we randomly assigned 75 adolescents with low, middle, and high levels of social anxiety to complete a laboratory-based social evaluative stressor in one of three conditions: social interaction with a therapy dog (no physical interaction), social plus physical interaction with a therapy dog, or no interaction with a therapy dog. We found no evidence that the presence of a real dog, with or without the opportunity to touch it, reduced anxiety or autonomic reactivity or improved cognitive performance relative to the presence of a stuffed dog in the control condition, regardless of levels of preexisting social anxiety.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Audet-Gilbert Émie ◽  
Sylvain François-Étienne ◽  
Bouslama Sidki ◽  
Derome Nicolas

Abstract Background One of the most charismatic, and yet not completely resolved example of mutualistic interaction is the partnership of clownfish and its symbiotic sea anemone. The mechanism explaining this tolerance currently relies on the molecular mimicry of clownfish epithelial mucus, which could serve as camouflage, preventing the anemone's nematocysts' discharge. Resident bacteria are known as key drivers of epithelial mucus chemical signature in vertebrates. A recent study has proposed a restructuration of the skin microbiota in a generalist clown fish when first contacting its symbiotic anemone. We explored a novel hypothesis by testing the effect of remote interaction on epithelial microbiota restructuration in both partners. Methods With metataxonomics, we investigated the epithelial microbiota dynamic of 18 pairs of percula clownfish (Amphiprion percula) and their symbiotic anemone Heteractis magnifica in remote interaction, physical interaction and control groups for both partners during a 4-week trial. Results The Physical and Remote Interaction groups’ results evidence gradual epithelial microbiota convergence between both partners when fish and anemone were placed in the same water system. This convergence occurred preceding any physical contact between partners, and was maintained during the 2-week interaction period in both contact groups. After the interaction period, community structure of both fish and anemone’s epthelial community structures maintained the interaction signature 2 weeks after fish–anemone pairs’ separation. Furthermore, the interaction signature persistence was observed both in the Physical and Remote Interaction groups, thus suggesting that water-mediated chemical communication between symbiotic partners was strong enough to shift the skin microbiota durably, even after the separation of fish–anemone pairs. Finally, our results suggest that fish–anemone convergent microbiota restructuration was increasingly associated with the parallel recruitment of three Flavobacteriaceae strains closely related to a tyrosinase-producing Cellulophaga tyrosinoxydans. Conclusions Our study shows that bacterial community restructuration, in the acclimation process, does not only rely on direct physical contact. Furthermore, our results challenge, for the first time, the traditional unidirectional chemical camouflage hypothesis, as we argue that convergence of the epithelial microbiota of both partners may play essential roles in establishing mutual acceptance.


Author(s):  
Robert N. Dean ◽  
Lauren E. Beckingham

Printed circuit board (PCB) sensors are a sensor technology where the layout of traces on a PCB has been optimized so that the traces electromagnetically interact with the surrounding environment. These types of sensors can be manufactured at very low cost using standard commercially available low-cost printed circuit board fabrication. Exposed conductive electrodes on the circuit board are useful for measuring the electrical conductivity of the surrounding environment, and these sensors have been used in applications such as salinity measurement and dissolved ion content measurement of aqueous solutions. Insulated interdigitated electrode sensors are useful for capacitively analyzing the surrounding environment, and these sensors have been used to detect the presence of liquid water and to measure the moisture content of substances in physical contact with the sensor. Additionally, by measuring the complex impedance of the capacitive sensor over a wide frequency range, information concerning the chemical composition of the substance in contact with the sensor can be determined. In addition to conducive and capacitive PCB sensors, the third type of PCB sensor would be an inductive sensor. Although it is challenging to realize 3D coils in PCB technology, planar inductors can be realized in a single Cu layer on a PCB, and insulated from the environment using a cover layer of polymeric solder mask. This type of electrode structure can inductively couple with magnetic materials in close proximity to the sensor. A variety of magnetic materials exist, including iron, nickel and cobalt. Additionally, many alloys of these elements are also magnetic. Of particular interest are corrosion products with magnetic properties, such as iron(III) oxide, Fe3O2, also known as common rust. A thin layer of iron(III) oxide powder deposited on the sensor's active area results in a measureable increase in the sensor's inductance. As such, an inductive PCB sensor could be a low-cost option for detecting the presence of some corrosion products in its operating environment.


Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3783 ◽  
Author(s):  
Petsiuk ◽  
Pearce

Nineteen million Americans have significant vision loss. Over 70% of these are not employed full-time, and more than a quarter live below the poverty line. Globally, there are 36 million blind people, but less than half use white canes or more costly commercial sensory substitutions. The quality of life for visually impaired people is hampered by the resultant lack of independence. To help alleviate these challenges this study reports on the development of a low-cost, open-source ultrasound-based navigational support system in the form of a wearable bracelet to allow people with the lost vision to navigate, orient themselves in their surroundings and avoid obstacles when moving. The system can be largely made with digitally distributed manufacturing using low-cost 3-D printing/milling. It conveys point-distance information by utilizing the natural active sensing approach and modulates measurements into haptic feedback with various vibration patterns within the four-meter range. It does not require complex calibrations and training, consists of the small number of available and inexpensive components, and can be used as an independent addition to traditional tools. Sighted blindfolded participants successfully demonstrated the device for nine primary everyday navigation and guidance tasks including indoor and outdoor navigation and avoiding collisions with other pedestrians.


Author(s):  
Samir Benbelkacem ◽  
Abdelkader Bellarbi ◽  
Nadia Zenati-Henda ◽  
Ahmed Bentaleb ◽  
Ahmed Nazim Bellabaci ◽  
...  

2020 ◽  
Vol 6 (34) ◽  
pp. eabb9083 ◽  
Author(s):  
Yang Wang ◽  
Heting Wu ◽  
Lin Xu ◽  
Hainan Zhang ◽  
Ya Yang ◽  
...  

Flexible sensors are highly desirable for tactile sensing and wearable devices. Previous researches of smart elements have focused on flexible pressure or temperature sensors. However, realizing material identification remains a challenge. Here, we report a multifunctional sensor composed of hydrophobic films and graphene/polydimethylsiloxane sponges. By engineering and optimizing sponges, the fabricated sensor exhibits a high-pressure sensitivity of >15.22 per kilopascal, a fast response time of <74 millisecond, and a high stability over >3000 cycles. In the case of temperature stimulus, the sensor exhibits a temperature-sensing resolution of 1 kelvin via the thermoelectric effect. The sensor can generate output voltage signals after physical contact with different flat materials based on contact-induced electrification. The corresponding signals can be, in turn, used to infer material properties. This multifunctional sensor is excellent in its low cost and material identification, which provides a design concept for meeting the challenges in functional electronics.


Sensor Review ◽  
2016 ◽  
Vol 36 (2) ◽  
pp. 158-168 ◽  
Author(s):  
Drew van der Riet ◽  
Riaan Stopforth ◽  
Glen Bright ◽  
Olaf Diegel

Purpose This paper aims to explore the electronic design of the Touch Hand: a low-cost electrically powered prosthetic hand. The hand is equipped with an array of sensors allowing for position control and haptic sensation. Pressure sensors are used on the fingertips to detect grip force. A temperature sensor placed in the fingertip is used to measure the contact temperature of objects. Investigations are made into the use of cantilever vibration sensors to detect surface texture and object slippage. The hand is capable of performing a lateral grip of 3.7 N, a power grip of 19.5 N and to passively hold a weight of up to 8 kg with a hook grip. The hand is also tested on an amputee and used to perform basic tasks. The amputee took 30 min to learn how to operate the hands basic gripping functions. Design/methodology/approach Problems of previous prosthetic hands were investigated, followed by ways to improve or have similar capabilities, yet keeping in mind to reduce the price. The hand was then designed, simulated, developed and then tested. The hand was then displayed to public and tested with an amputee. Findings The Touch Hand’s capabilities with the usage of the low-cost materials, components and sensory system was obtained in the tests that were conducted. The results are shown in this paper to identify the appropriateness of the sensors for a usage while the costs are reduced. Furthermore, models were developed from the results obtained to take into account factors such as the non-slip material. Research limitations/implications The research was restricted to a US$1,000 budget to allow the availability of a low-cost prosthetic hand. Practical implications The Touch Hand had to have the ability to supply the amputee with haptic feedback while allowing the basic grasping of objects. The commercial value is the availability of an affordable prosthetic hand that can be used by amputees in Africa and other Lower-Income countries, yet allowing a more advanced control system compared to the pure mechanical systems currently available. Social implications The Touch Hand has the ability to give amputees affected in war situations the ability to grasp objects in a more affordable manner compared to the current available options. Feedback from amputees about the current features of the Touch Hand was very positive and it proves to be a way to improve society in Lower-Income countries in the near future. A sponsorship program is being developed to assist amputees with the costs of the Touch Hand. Originality/value The contributions of this research is a low-cost prototype system than can be commercialized to allow amputees in the Lower-Income countries to have the ability of a prosthetic hand. A sensory system in the hand is also explained which other low-cost prosthetic hands do not have, which includes temperature, force and vibration. Models of the sensors used that are developed and calibrated to the design of the hand are also described.


Biology ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 328
Author(s):  
Yihe Zhang ◽  
Bingjie Jiang ◽  
Meng Huee Lee

Stromal fibroblasts surrounding cancer cells are a major and important constituent of the tumor microenvironment not least because they contain cancer-associated fibroblasts, a unique fibroblastic cell type that promotes tumorigenicity through extracellular matrix remodeling and secretion of soluble factors that stimulate cell differentiation and invasion. Despite much progress made in understanding the molecular mechanisms that underpin fibroblast–tumor cross-talk, relatively little is known about the way the two cell types interact from a physical contact perspective. In this study, we report a novel three-dimensional dumbbell model that would allow the physical interaction between the fibroblasts and cancer cells to be visualized and monitored by microscopy. To achieve the effect, the fibroblasts and cancer cells in 50% Matrigel suspension were seeded as independent droplets in separation from each other. To allow for cell migration and interaction, a narrow passage of Matrigel causeway was constructed in between the droplets, effectively molding the gel into the shape of a dumbbell. Under time-lapse microscopy, we were able to visualize and image the entire process of fibroblast-guided cancer cell migration event, from initial vessel-like structure formation by the fibroblasts to their subsequent invasion across the causeway, attracting and trapping the cancer cells in the process. Upon prolonged culture, the entire population of fibroblasts eventually infiltrated across the passage and condensed into a spheroid-like cell mass, encapsulating the bulk of the cancer cell population within. Suitable for almost every cell type, our model has the potential for a wider application as it can be adapted for use in drug screening and the study of cellular factors involved in cell–cell attraction.


2019 ◽  
Vol 38 (4) ◽  
pp. 403-421 ◽  
Author(s):  
Burak Yüksel ◽  
Cristian Secchi ◽  
Heinrich H. Bülthoff ◽  
Antonio Franchi

This paper proposes the use of a novel control method based on interconnection and damping assignment–passivity-based control (IDA-PBC) in order to address the aerial physical interaction (APhI) problem for a quadrotor unmanned aerial vehicle (UAV). The apparent physical properties of the quadrotor are reshaped in order to achieve better APhI performances, while ensuring the stability of the interaction through passivity preservation. The robustness of the IDA-PBC method with respect to sensor noise is also analyzed. The direct measurement of the external wrench, needed to implement the control method, is compared with the use of a nonlinear Lyapunov-based wrench observer and advantages/disadvantages of both methods are discussed. The validity and practicability of the proposed APhI method is evaluated through experiments, where for the first time in the literature, a lightweight all-in-one low-cost force/torque (F/T) sensor is used onboard of a quadrotor. Two main scenarios are shown: a quadrotor responding to external disturbances while hovering (physical human–quadrotor interaction), and the same quadrotor sliding with a rigid tool along an uneven ceiling surface (inspection/painting-like task).


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