Design, Fabrication, and Characterization of Inkjet-Printed Organic Piezoresistive Tactile Sensor on Flexible Substrate.

In this paper, we propose a novel tactile sensor with a "fingerprint" design, named due to its spiral shape and dimensions of 3.80 mm × 3.80 mm. The sensor is duplicated in a four-by-four array containing 16 tactile sensors to form a "SkinCell" pad of approximately 45 mm by 29 mm. The SkinCell was fabricated using a custom-built microfabrication platform called the NeXus which contains additive deposition tools and several robotic systems. We used the NeXus' six-degrees-of-freedom robotic platform with two different inkjet printers to deposit a conductive silver ink sensor electrode as well as the organic piezoresistive polymer PEDOT:PSS-Poly (3,4-ethylene dioxythiophene)-poly(styrene sulfonate) of our tactile sensor. Printing deposition profiles of 100-micron- and 250-micron-thick layers were measured using microscopy. The resulting structure was sintered in an oven and laminated. The lamination consisted of two different sensor sheets placed back-to-back to create a half-Wheatstone-bridge configuration, doubling the sensitivity and accomplishing temperature compensation. The resulting sensor array was then sandwiched between two layers of silicone elastomer that had protrusions and inner cavities to concentrate stresses and strains and increase the detection resolution. Furthermore, the tactile sensor was characterized under static and dynamic force loading. Over 180,000 cycles of indentation were conducted to establish its durability and repeatability. The results demonstrate that the SkinCell has an average spatial resolution of 0.827 mm, an average sensitivity of 0.328 mΩ/Ω/N, expressed as the change in resistance per force in Newtons, an average sensitivity of 1.795 µV/N at a loading pressure of 2.365 PSI, and a dynamic response time constant of 63 ms which make it suitable for both large area skins and fingertip human-robot interaction applications.

Motor differences in autism during a human-robot imitative gesturing task.

BACKGROUND: Difficulty with imitative gesturing is frequently observed as a clinical feature of autism. Current practices for assessment of imitative gesturing ability-behavioral observation and parent report-do not allow precise measurement of specific components of imitative gesturing performance, instead relying on subjective judgments. Advances in technology allow researchers to objectively quantify the nature of these movement differences, and to use less socially stressful interaction partners (e.g., robots). In this study, we aimed to quantify differences in imitative gesturing between autistic and neurotypical development during human-robot interaction. METHODS: Thirty-five autistic (n = 19) and neurotypical (n = 16) participants imitated social gestures of an interactive robot (e.g., wave). The movements of the participants and the robot were recorded using an infrared motion-capture system with reflective markers on corresponding head and body locations. We used dynamic time warping to quantify the degree to which the participant's and robot's movement were aligned across the movement cycle and work contribution to determine how each joint angle was producing the movements. FINDINGS: Results revealed differences between autistic and neurotypical participants in imitative accuracy and work contribution, primarily in the movements requiring unilateral extension of the arm. Autistic individuals imitated the robot less accurately and used less work at the shoulder compared to neurotypical individuals. INTERPRETATION: These findings indicate differences in autistic participants' ability to imitate an interactive robot. These findings build on our understanding of the underlying motor control and sensorimotor integration mechanisms that support imitative gesturing in autism which may aid in identifying appropriate intervention targets.

In-Process Orbiting Laser-Assisted Technique for the Surface Finish in Material Extrusion-Based 3D Printing.

Material extrusion-based polymer 3D printing, one of the most commonly used additive manufacturing processes for thermoplastics and composites, has drawn extensive attention due to its capability and cost effectiveness. However, the low surface finish quality of the printed parts remains a drawback due to the nature of stacking successive layers along one direction and the nature of rastering of the extruded tracks of material. In this work, an in-process thermal radiation-assisted, surface reflow method is demonstrated that significantly improves the surface finish of the sidewalls of printed parts. It is observed that the surface finish of the printed part is drastically improved for both flat and curved surfaces. The effect of surface reflow on roughness reduction was characterized using optical profilometry and scanning electron microscopy (SEM), while the local heated spot temperature was quantified using a thermal camera.

Augmented Reality in Surgical Oncology. A Literature Review.

Introduction: Augmented reality (AR) devices enable doctors to associate visualizing diagnostic data, to establish therapeutic procedures in order to improve work efficiency and safety and to develop the surgical training of young doctors. This new approach may contribute to an increase in the quality of medical training and a decrease in the costs of surgeries. This paper assesses whether augmented reality can improve the results of surgical procedures as well as its possible progress in the future. Methods and results: The intra-operative use of augmented reality by using Google Glass glasses, on which we projected MRI/CT images of the anatomical areas invaded by tumors and/or images of normal anatomy, helps us to perform surgeries, as well as to present them as teaching material. We have also performed a review of the available literature, beginning with 2011 and ending with November 2021, by looking up the terms "augmented reality" and "surgical oncology" in PubMed. The results of the search were 308 studies in this field which prove the utility of the method. Many papers show that the performance of the augmented reality systems is superior and compatible with traditional imaging techniques. Conclusions: The specialty literature reveals a growing interest on the part of surgeons regarding the use of augmented reality during surgery. This procedure enables the improvement of the safety and efficiency of surgical techniques, as well as their presentation to students and residents alike. The method is innovative and has to be carefully approached before being introduced into routine practice.

Clinical-Pathological Correlations in the Acute Surgical Abdomen in the Pre and Post-Pandemic Period Covid-19.

Background: In the case of patients admitted with acute abdomen at the emergency department, interstitial pulmonary pathology (Covid-19 infections) represents a significant operative risk for the patients. The rate of postoperative complications is high with increased morbidity and mortality, a real challenge for the medical staff and surgical/intensive care unit teams. In emergency settings, patients were examined with targeted clinical and paraclinical parameters that assure a fast diagnosis to optimize a rapid medical and surgical treatment. Methods: We conducted a retrospective comparative study that included patients enrolled and diagnosed with an acute surgical abdomen in Surgical Clinic 1 Tg. Mures Emergency County Hospital. Patients were examined and analyzed at the emergency department UPU-SMURD. We included patients admitted over the two years (2019 and 2020) and divided them into two groups. Results: The total number of patients admitted in the UPU-Smurd emergency department Surgical Clinic I over the two years was 1033. There was a significant reduction in total cases diagnosed with the acute surgical abdomen in the pandemic period (p=0.033). The average time from the admission to the surgical procedure was significantly higher in the pandemic period 380Ã+-2 min in comparison with 222+-3 min (p=0.001) and also with an increased average operative time 223+-3 min versus 145+-2 min (p=0.002). Average hospitalization time was higher in the pandemic period 10+-1 (p=0.031) with no significant difference between the groups regarding Intensive Care Unit (ICU) admission (p=0.122). Overall mortality has more than doubled, with 31 cases (19%) in the pandemic and 28 (9%) in the non-pandemic. (p=0.001). Conclusions: The COVID-19 pandemic has played an essential role in treating acute surgical abdomen cases. The high solicitation rate of the emergency department delayed the diagnosis and treatment of severe surgical cases. As the scale of this pandemic is unprecedented, standard protocols with minor changes do not provide adequate results.

Acceptability of Using a Robotic Nursing Assistant in Health Care Environments: Experimental Pilot Study.

BACKGROUND: According to the US Bureau of Labor Statistics, nurses will be the largest labor pool in the United States by 2022, and more than 1.1 million nursing positions have to be filled by then in order to avoid a nursing shortage. In addition, the incidence rate of musculoskeletal disorders in nurses is above average in comparison with other occupations. Robot-assisted health care has the potential to alleviate the nursing shortage by automating mundane and routine nursing tasks. Furthermore, robots in health care environments may assist with safe patient mobility and handling and may thereby reduce the likelihood of musculoskeletal disorders. OBJECTIVE: This pilot study investigates the perceived ease of use and perceived usefulness (acceptability) of a customized service robot as determined by nursing students (as proxies for nursing staff in health care environments). This service robot, referred to as the Adaptive Robotic Nurse Assistant (ARNA), was developed to enhance the productivity of nurses through cooperation during physical tasks (eg, patient walking, item fetching, object delivery) as well as nonphysical tasks (eg, patient observation and feedback). This pilot study evaluated the acceptability of ARNA to provide ambulatory assistance to patients. METHODS: We conducted a trial with 24 participants to collect data and address the following research question: Is the use of ARNA as an ambulatory assistive device for patients acceptable to nurses? The experiments were conducted in a simulated hospital environment. Nursing students (as proxies for nursing staff) were grouped in dyads, with one participant serving as a nurse and the other acting as a patient. Two questionnaires were developed and administrated to the participants based on the Technology Acceptance Model with respect to the two subscales of perceived usefulness and perceived ease of use metrics. In order to evaluate the internal consistency/reliability of the questionnaires, we calculated Cronbach alpha coefficients. Furthermore, statistical analyses were conducted to evaluate the relation of each variable in the questionnaires with the overall perceived usefulness and perceived ease of use metrics. RESULTS: Both Cronbach alpha values were acceptably high (.93 and .82 for perceived usefulness and perceived ease of use questionnaires, respectively), indicating high internal consistency of the questionnaires. The correlation between the variables and the overall perceived usefulness and perceived ease of use metrics was moderate. The average perceived usefulness and perceived ease of use metrics among the participants were 4.13 and 5.42, respectively, out of possible score of 7, indicating a higher-than-average acceptability of this service robot. CONCLUSIONS: The results served to identify factors that could affect nurses' acceptance of ARNA and aspects needing improvement (eg, flexibility, ease of operation, and autonomy level).

Development of a novel visuomotor integration paradigm by integrating a virtual environment with mobile eye-tracking and motion-capture systems.

Visuomotor integration (VMI), the use of visual information to guide motor planning, execution, and modification, is necessary for a wide range of functional tasks. To comprehensively, quantitatively assess VMI, we developed a paradigm integrating virtual environments, motion-capture, and mobile eye-tracking. Virtual environments enable tasks to be repeatable, naturalistic, and varied in complexity. Mobile eye-tracking and minimally-restricted movement enable observation of natural strategies for interacting with the environment. This paradigm yields a rich dataset that may inform our understanding of VMI in typical and atypical development.

Concurrent surface electromyography and force myography classification during times of prosthetic socket shift and user fatigue.

OBJECTIVE: Surface electromyography has been a long-standing source of signals for control of powered prosthetic devices. By contrast, force myography is a more recent alternative to surface electromyography that has the potential to enhance reliability and avoid operational challenges of surface electromyography during use. In this paper, we report on experiments conducted to assess improvements in classification of surface electromyography signals through the addition of collocated force myography consisting of piezo-resistive sensors. METHODS: Force sensors detect intrasocket pressure changes upon muscle activation due to changes in muscle volume during activities of daily living. A heterogeneous sensor configuration with four surface electromyography-force myography pairs was investigated as a control input for a powered upper limb prosthetic. Training of two different multilevel neural perceptron networks was employed during classification and trained on data gathered during experiments simulating socket shift and muscle fatigue. RESULTS: Results indicate that intrasocket pressure data used in conjunction with surface EMG data can improve classification of human intent and control of a powered prosthetic device compared to traditional, surface electromyography only systems. SIGNIFICANCE: Additional sensors lead to significantly better signal classification during times of user fatigue, poor socket fit, as well as radial and ulnar wrist deviation. Results from experimentally obtained training data sets are presented.

Optimized Assistive Human-Robot Interaction Using Reinforcement Learning.

An intelligent human-robot interaction (HRI) system with adjustable robot behavior is presented. The proposed HRI system assists the human operator to perform a given task with minimum workload demands and optimizes the overall human-robot system performance. Motivated by human factor studies, the presented control structure consists of two control loops. First, a robot-specific neuro-adaptive controller is designed in the inner loop to make the unknown nonlinear robot behave like a prescribed robot impedance model as perceived by a human operator. In contrast to existing neural network and adaptive impedance-based control methods, no information of the task performance or the prescribed robot impedance model parameters is required in the inner loop. Then, a task-specific outer-loop controller is designed to find the optimal parameters of the prescribed robot impedance model to adjust the robot's dynamics to the operator skills and minimize the tracking error. The outer loop includes the human operator, the robot, and the task performance details. The problem of finding the optimal parameters of the prescribed robot impedance model is transformed into a linear quadratic regulator (LQR) problem which minimizes the human effort and optimizes the closed-loop behavior of the HRI system for a given task. To obviate the requirement of the knowledge of the human model, integral reinforcement learning is used to solve the given LQR problem. Simulation results on an x - y table and a robot arm, and experimental implementation results on a PR2 robot confirm the suitability of the proposed method.

Human-like object tracking and gaze estimation with PKD android.

As the use of robots increases for tasks that require human-robot interactions, it is vital that robots exhibit and understand human-like cues for effective communication. In this paper, we describe the implementation of object tracking capability on Philip K. Dick (PKD) android and a gaze tracking algorithm, both of which further robot capabilities with regard to human communication. PKD's ability to track objects with human-like head postures is achieved with visual feedback from a Kinect system and an eye camera. The goal of object tracking with human-like gestures is twofold : to facilitate better human-robot interactions and to enable PKD as a human gaze emulator for future studies. The gaze tracking system employs a mobile eye tracking system (ETG; SensoMotoric Instruments) and a motion capture system (Cortex; Motion Analysis Corp.) for tracking the head orientations. Objects to be tracked are displayed by a virtual reality system, the Computer Assisted Rehabilitation Environment (CAREN; MotekForce Link). The gaze tracking algorithm converts eye tracking data and head orientations to gaze information facilitating two objectives: to evaluate the performance of the object tracking system for PKD and to use the gaze information to predict the intentions of the user, enabling the robot to understand physical cues by humans.

Saliva characteristics, diet and carioreceptivity in dental students.

BACKGROUND AND AIMS: The use of sugar by dental plaque microorganisms leads to acid formation from the bacteria metabolism, which determines a decrease of pH onto teeth surfaces. The value of the critical pH is 5.2-5.5. We aimed to evaluate the capacity of patients to change their diet towards caries prevention after acknowledging the values of saliva parameters (pH, buffer capacity). MATERIAL AND METHODS: A group of 52 subjects were clinically examined according to the International Caries Assessment and Detection System protocol. They were required to complete a diet questionnaire and salivary tests were made for the oral mucosa hydration level, pH, buffer capacity, salivary flow rate at rest and upon stimulation. 4 pre-calibrated 6th year students and 2 dentists performed the tests and the ICDAS examination. One week after the tests, the subjects were asked to complete the diet questionnaire again. The studied group consisted of students aged between 23-26 years, randomly selected among 6(th) year students of the Faculty of Dentistry from Cluj-Napoca. RESULTS AND DISCUSSION: The mean DMF-S index was 18.39. Most of the patients (65%) had a DMF-S index between 9 and 21. Just 2.5% had an index of 3, which was the lowest value recorded. 5% of the patients had a DMFS of 35, which was the maximal value recorded. The distribution of DMF-S was normal. 50% of the patients had no active caries. Even though most subjects (19.23%) had a pH within the normal interval, most of them were at the bottom value of the interval (6.8). Most subjects had a pH of 6.4, which is moderately acid. The mean pH was 6.7, therefore, a moderately acid one. The Pearson correlation coefficient between DMFS and pH was 0.255. A mild negative correlation (-0.275) was found between the cariogenic food and buffer capacity. A week later we noticed a statistically significant decrease of cariogenic foods and drinks in students with acid pH and with low buffer capacity. CONCLUSIONS: A regular intake of cakes, bonbons and chocolate was reported by subjects who had a high DMF-S value and a low saliva buffer capacity. Only after the patients were aware of their caries risk, did they change their diet towards a non-cariogenic one, even though they had had the theoretical knowledge regarding caries prevention for at least 3 years. We conclude that the use of the chair-side salivary test should be highly recommended for cario-receptive patients.

Ibuprofen blocks time-dependent increases in hypoxic ventilation in rats.

Recently, inflammatory processes have been shown to increase O(2)-sensitivity of the carotid body during chronic sustained hypoxia [Liu, X., He, L., Stensaas, L., Dinger, B., Fidone, S., 2009. Adaptation to chronic hypoxia involves immune cell invasion and increased expression of inflammatory cytokines in rat carotid body. Am. J. Physiol. Lung Cell Mol. Physiol. 296, L158-L166]. We hypothesized that blocking inflammation with ibuprofen would reduce ventilatory acclimatization to hypoxia by blocking such increases in carotid body O(2) sensitivity. We tested this in conscious rats treated with ibuprofen (4mg/kg IP daily) or saline during acclimatization to hypoxia ( [Formula: see text] for 7 days). Ibuprofen blocked the increase in hypoxic ventilation observed in chronically hypoxic rats treated with saline; ibuprofen had no effects on ventilation in normoxic control rats. Ibuprofen blocked increases in inflammatory cytokines (IL-1ß, IL-6) in the brainstem with chronic hypoxia. The data supports our hypothesis and further analysis indicates that ibuprofen also blocks inflammatory processes in the central nervous system contributing to ventilatory acclimatization to hypoxia. Possible mechanisms linking inflammatory and hypoxic signaling are reviewed.