DESIGN AND SIMULATION OF HIGH PRECISION SECOND-ORDER SIGMA-DELTA MODULATOR FOR BLUETOOTH APPLICATIONS

A second-order sigma-delta modulator is presented in this paper which, according to the considered standards, is suitable for bluetooth applications. The oversampling ratio and signal bandwidth of the proposed modulator is 128 and 1 MHz, respectively. The Signal to Noise and Distortion Ratio (SNDR) of the proposed structure is achieved 74 dB, equivalent to 12-bit accuracy, which is desirable precision for the aforementioned application. Utilizing highperformance blocks to implement the system at the circuit level, the sigma-delta modulator has obtained an overall desirable performance more specifically in terms of minimizing the power consumption. The modulator is simulated in 180 nm CMOS TSMC technology at cadence software applying 1.8 V supply voltage. The power consumption is obtained as low as 1.9 mW very suitable for portable modern ultra-low power applications

Development of a Modular Real-time Shared-control System for a Smart Wheelchair

In this paper, we propose a modular navigation system that can be mounted on a regular powered wheelchair to assist disabled children and the elderly with autonomous mobility and shared-control features. The lack of independent mobility drastically affects an individual's mental and physical health making them feel less self-reliant, especially children with Cerebral Palsy and limited cognitive skills. To address this problem, we propose a comparatively inexpensive and modular system that uses a stereo camera to perform tasks such as path planning, obstacle avoidance, and collision detection in environments with narrow corridors. We avoid any major changes to the hardware of the wheelchair for an easy installation by replacing wheel encoders with a stereo camera for visual odometry. An open source software package, the Real-Time Appearance Based Mapping package, running on top of the Robot Operating System (ROS) allows us to perform visual SLAM that allows mapping and localizing itself in the environment. The path planning is performed by the move base package provided by ROS, which quickly and efficiently computes the path trajectory for the wheelchair. In this work, we present the design and development of the system along with its significant functionalities. Further, we report experimental results from a Gazebo simulation and real-world scenarios to prove the effectiveness of our proposed system with a compact form factor and a single stereo camera

Determination of the relationship between Religious commitment and mental health among engineering students of Bonab University

For downloading the full-text of this article please click here.Background and Objectives: Religious beliefs play an important role in the social and psychological life, Students as the spiritual resources of society and Social capacities, are selective in terms of talent, creativity and perseverance. Having comfort and peace of mind in all aspects are essential for academic achievement and successful life, as well as attention to other interventions affecting the learning environment. This study from the psychological point of view has explored the relationship between religious beliefs and mental health of students.Materials and Methods: Method of this study was Descriptive-Correlation to examine the relationship between religious beliefs and mental health among students. The sample consisted of 183 students (88 men and 95 women) which were selected using random sampling among engineering students of Bonab University. Data collection techniques for Practical Commitment to Religious Beliefs and mental health are Golzari 2- Mabad Questionnaire and General Health questionnaire (GHQ- 28), respectively. Data using were analyzed using SPSS (Version 22) software and descriptive statistics (mean and standard deviation) and inferential statistics (Pearson correlation).Results: The data showed a negative significant correlation between Religious commitment and physical and mental disorders. Linear regression analysis was confirmed  predictive role of religious  commitment in mental health and its components (P<0.05), so that the practice of religious beliefs was explained 23% of the variance in mental health, and 23% of the variance in somatization, 19% of the variance in anxiety and insomnia, 27% of the variance in social dysfunction, and 2% of the variance in depression.Conclusion: Religious commitment result in promotion of mental health in students. With regard to the positive impact of religious beliefs and practices in mental health, the use of this capacities are recommended for planning mental health activities, particularly for the students.Keywords: Religious Commitment, Mental Health, StudentsFor downloading the full-text of this article please click here

Interrater reliability of quantitative ultrasound using force feedback among examiners with varied levels of experience

Background. Quantitative ultrasound measures are influenced by multiple external factors including examiner scanning force. Force feedback may foster the acquisition of reliable morphometry measures under a variety of scanning conditions. The purpose of this study was to determine the reliability of force-feedback image acquisition and morphometry over a range of examiner-generated forces using a muscle tissuemimicking ultrasound phantom. Methods. Sixty material thickness measures were acquired from a muscle tissue mimicking phantom using B-mode ultrasound scanning by six examiners with varied experience levels (i.e., experienced, intermediate, and novice). Estimates of interrater reliability and measurement error with force feedback scanning were determined for the examiners. In addition, criterion-based reliability was determined using material deformation values across a range of examiner scanning forces (1–10 Newtons) via automated and manually acquired image capture methods using force feedback. Results. All examiners demonstrated acceptable interrater reliability (intraclass correlation coefficient, ICC = .98, p \u3c .001) for material thickness measures obtained using force feedback. Individual examiners exhibited acceptable reliability with the criterion-based reference measures (ICC \u3e .90, p \u3c .001), independent of their level of experience. The measurement error among all examiners was 1.5%–2.9% across all applied stress conditions. Conclusion. Manual image capture with force feedback may aid the reliability of morphometry measures across a range of examiner scanning forces, and allow for consistent performance among examiners with differing levels of experience

Body-Mounted Robotic System for MRI-Guided Shoulder Arthrography: Cadaver and Clinical Workflow Studies

This paper presents an intraoperative MRI-guided, patient-mounted robotic system for shoulder arthrography procedures in pediatric patients. The robot is designed to be compact and lightweight and is constructed with nonmagnetic materials for MRI safety. Our goal is to transform the current two-step arthrography procedure (CT/x-ray-guided needle insertion followed by diagnostic MRI) into a streamlined single-step ionizing radiation-free procedure under MRI guidance. The MR-conditional robot was evaluated in a Thiel embalmed cadaver study and healthy volunteer studies. The robot was attached to the shoulder using straps and ten locations in the shoulder joint space were selected as targets. For the first target, contrast agent (saline) was injected to complete the clinical workflow. After each targeting attempt, a confirmation scan was acquired to analyze the needle placement accuracy. During the volunteer studies, a more comfortable and ergonomic shoulder brace was used, and the complete clinical workflow was followed to measure the total procedure time. In the cadaver study, the needle was successfully placed in the shoulder joint space in all the targeting attempts with translational and rotational accuracy of 2.07 ± 1.22mm and 1.46 ± 1.06 degrees, respectively. The total time for the entire procedure was 94 min and the average time for each targeting attempt was 20 min in the cadaver study, while the average time for the entire workflow for the volunteer studies was 36 min. No image quality degradation due to the presence of the robot was detected. This Thiel-embalmed cadaver study along with the clinical workflow studies on human volunteers demonstrated the feasibility of using an MR-conditional, patient-mounted robotic system for MRI-guided shoulder arthrography procedure. Future work will be focused on moving the technology to clinical practice

MRI Robots for Needle-Based Interventions: Systems and Technology.

© 2018, Biomedical Engineering Society. Magnetic resonance imaging (MRI) provides high-quality soft-tissue images of anatomical structures and radiation free imaging. The research community has focused on establishing new workflows, developing new technology, and creating robotic devices to change an MRI room from a solely diagnostic room to an interventional suite, where diagnosis and intervention can both be done in the same room. Closed bore MRI scanners provide limited access for interventional procedures using intraoperative imaging. MRI robots could improve access and procedure accuracy. Different research groups have focused on different technology aspects and anatomical structures. This paper presents the results of a systematic search of MRI robots for needle-based interventions. We report the most recent advances in the field, present relevant technologies, and discuss possible future advances. This survey shows that robotic-assisted MRI-guided prostate biopsy has received the most interest from the research community to date. Multiple successful clinical experiments have been reported in recent years that show great promise. However, in general the field of MRI robotic systems is still in the early stage. The continued development of these systems, along with partnerships with commercial vendors to bring this technology to market, is encouraged to create new and improved treatment opportunities for future patients

MRI Robots for Needle-Based Interventions: Systems and Technology

© 2018, Biomedical Engineering Society. Magnetic resonance imaging (MRI) provides high-quality soft-tissue images of anatomical structures and radiation free imaging. The research community has focused on establishing new workflows, developing new technology, and creating robotic devices to change an MRI room from a solely diagnostic room to an interventional suite, where diagnosis and intervention can both be done in the same room. Closed bore MRI scanners provide limited access for interventional procedures using intraoperative imaging. MRI robots could improve access and procedure accuracy. Different research groups have focused on different technology aspects and anatomical structures. This paper presents the results of a systematic search of MRI robots for needle-based interventions. We report the most recent advances in the field, present relevant technologies, and discuss possible future advances. This survey shows that robotic-assisted MRI-guided prostate biopsy has received the most interest from the research community to date. Multiple successful clinical experiments have been reported in recent years that show great promise. However, in general the field of MRI robotic systems is still in the early stage. The continued development of these systems, along with partnerships with commercial vendors to bring this technology to market, is encouraged to create new and improved treatment opportunities for future patients

A New Indicator for Gain-Switching Control of Position Error-based Teleoperation System

Abstract – Some adaptive control schemes was suggested for Teleoperation systems. These schemes are based on environment impedance estimation which has abrupt changes. In this paper, estimation loop is applied to identify just gradual variations in the slave robot dynamic. Then the required data for compensating environment changes are explored through accurate slave dynamic. Experimental results for both negligible time delay and 150ms time delay in the communication channel are included to show the effectiveness of the proposed controller. Also, stability analysis for the designed controller is presented. Index Terms – Teleoperation, Transparency, gain switching controller