Design of optimised linear quadratic regulator for capsule endoscopes based on artificial bee colony tuning algorithm

Wireless Capsule Endoscope (WCE) is a new medical device that can be used for examining the whole digestive tract if effectively actuated. In this paper, a new three-coil actuator is proposed for the capsule endoscope navigation system. The proposed system, which is based on the currentcontrolled magnetic levitation concept, utilises a small permanent magnet within the capsule body and an arrangement of controlled electromagnet actuator placed on a movable frame. The dynamics of the proposed control system is modelled mathematically and then formulated in state space form. In this research, the Linear Quadratic Regulator (LQR) technique is used for designing a 3DOF controller for the capsule actuation system. Artificial Bee Colony (ABC) tuning algorithm is used for obtaining optimum values for controller gain parameters. The optimised LQR controller is simulated by using the Matlab/Simulink tool, and its performance is then evaluated based on the stability and control effort parameters to validate the proposed system. Finally, the simulation results suggest that the LQR controller based on the ABC optimisation method can be adopted to synthesise an effective capsule actuation system

Design and implementation of DSP-based magnetic control system for capsule endoscope

PhD ThesisEarly detection methods are key to reducing morbidity rates from digestive tract cancer which is currently one of the fastest growing cancers in the World. Capsule endoscopes (CEs) are a new technology that can be used to improve early detection of the gastrointestinal (GI) tract disorder. The device integrates the technologies such as image processing, optoelectronic engineering, information communication, and biomedical engineering. The capsule is the size and shape of a pill and contains an optoelectronic camera, antenna, transmitter, battery and optoelectronic illuminating light emitting diodes (LEDs). The small size of these devices enables them to offer many advantages over conventional endoscopes such as accessibility to the entire intestine and minimising the risk of perforation, particularly for patients with difficult anatomy (e.g. post-operative scar tissue). Currently used devices are passive and can only follow the natural transit of the intestines, and hence there is considerable interest in methods of controlled actuation for these devices. In this thesis, a novel actuation system based on magnetic levitation is designed, developed and implemented, utilizing a small permanent magnet embedded within the capsule and an arrangement of digitally controlled electromagnets outside the body. The proposed approach is that the magnet can be moved and oriented by DC magnetic force and torque produced by coils placed outside of the human body, with a suitable position feedback sensor enabling closed-loop control. Theoretical analyses of the proposed actuation system are presented which model the magnetic field, force and torque exerted by electromagnetic coil on the embedded magnet. Based on the distribution of the magnetic field, an optimal geometry for the coils is proposed in order to achieve a levitation distance which is realistic for the inspection of the GI tract. Two types of systems are investigated in the thesis, namely single-input single-output (SISO) and multi-input multi-output (MIMO), and the dynamics of these systems are modelled in state space form and hence linear controllers are designed for capsule actuation. The controllers are simulated using Matlab/ Simulink tools to realize the mathematical analysis of the system, and then implemented digitally in real-time using Texas Instruments (TI) TMS320F2812 Digital Signal Processor (DSP) to validate the proposed actuation system. In the SISO system, a linear one degree of freedom (1DOF) proportionalintegral- derivative (PID) controller is designed to move the inserted magnet in the vertical dimension within an area around the operating point and to maintain it at a desired position. A realistic simulation model is designed and implemented to evaluate the proposed controller. Simulation results have shown that the controller is able to successfully hold the embedded magnet in the desired position. For practical validation, the PID controller is implemented in real-time on the DSP system, where pulse width modulation (PWM) is generated to control the coil current, and Hall effect sensors are used for position feedback. Experimental results are obtained under step and square wave input demand. In the proposed system, high frequency noise on the position sensor is initially rejected by hardware implementation of resistor capacitor-low pass filter (RC-LPF) circuit. The accuracy of the position feedback is increased by calibrating the DSP’s on-chip analogue-digital converter (ADC) in order to reduce conversion error due to inherent gain and offset errors. To further reduce the influence of the position feedback noise, an average of ten repeated samples based on mean filter is implemented by the DSP in order to reduce the influctuation of the sensor reading. The tracking performance of the actuation system based on two Hall effect sensors on the opposite coil’s poles is investigated under step trajectory input. In an improved actuation system, position feedback is provided by using an AC magnetic field to obtain the capsule position information, decoupling this from the DC actuation field. The noise of the position feedback in the improved system is reduced by replacing the PWM current drive with a linear power amplifier driven from a digital to analogue converter (DAC), hence reducing AC interference. Positioning sensor noise was found to be further reduced by implementing digital filtering based on a coherent detector using the DSP, without increasing response time. The performance of the actuation system using these position sensors is compared based on settling time, overshoot, steady-state error, and control input parameters in order to validate the proposed improvement in the position feedback. The experimental results have shown that the controller based on both sensing strategies satisfactory control of the magnet’s position. However, the response of the system based on AC position sensing has the shortest settling time, smallest overshoot value and steady-state error. In the MIMO system, several linear controllers such as pole placement (PP), Entire Eigenstructure Assignment (EEA), and linear Quadratic regulator (LQR) techniques are designed and their tracking performances are compared. Simulation results have shown that, based on acceptable control inputs, the LQR controller has the fastest response with minimal overshoot value and steady state error. However, the LQR controller based on 2DOF is unable to maintain stable control of the magnet due to the insufficient position feedback from the two coil sensors. Specifically, it is not possible to achieve a stable 2D system since the orientation angle of the magnet is not resolvable. Therefore, the position feedback is improved by obtaining the device position and orientation information from a pair of 3-axis orthogonal coils. A realistic simulation model for the 3DOF LQR controller is designed and implemented to evaluate the developed system. Simulation results have shown that this controller is can achieve the necessary stability. In conclusion, based on the results from the 1D control system, the thesis shows that the DC magnetic field, which is used for capsule movement, can be also used to provide the controller acceptable position feedback. However, the use of AC magnetic field for positioning purpose provides more accurate position information. In order to implement 2DOF control system successfully, two 3-axis orthogonal coil sensors are considered which are used to provide the actuation algorithm with more accurate feedback of position and orientation information.Ministry of Higher Education, Iraq

The Impact of Website Quality on Online Purchase Intention: The Mediating Effect of e-WOM, Jordan Context

Purpose: The objective of the study is to investigate how the quality of a website impacts the intent to purchase, as assessed by factors such as usability, quality of information, service interaction quality, eWOM, trust, and satisfaction.   Theoretical framework: This research has provided empirical evidence of the factors that influence the online shopping behavior of consumers.   Design/methodology/approach: The research was conducted using a quantitative approach, with SPSS statistical methods applied. An online survey was administered to 303 customers in Amman, the capital of Jordan.   Findings: The results suggest that website quality, customer trust, and satisfaction significantly and positively impact eWOM, thereby increasing the intent to purchase among consumers in Jordan's e-commerce sector.   Research, Practical & Social implications: This research offers valuable managerial principles to assist e-commerce businesses in improving their performance. It also provides valuable insights into the evaluation of eWOM and purchases intent in Jordan, serving as a foundation for future research in this area in Jordan and other countries.   Originality/value: this study provides a foundation for future research to investigate the complex and multifaceted nature of online customer behaviour in the e-commerce contex

Role of Stem Cells in Orthopaedic Surgery: Theoretical Survey

This study aims at analyzing the Stem cell application is a burgeoning field of medicine that is likely to influence the future of orthopaedic surgery. Stem cells are associated with great promise and great controversy. For the orthopaedic surgeon, stem cells may change the way that orthopaedic surgery is practiced and the overall approach of the treatment of musculoskeletal disease. Stem cells may change the field of orthopaedics from a field dominated by surgical replacements and reconstructions to a field of regeneration and prevention. This review will introduce the basic concepts of stem cells pertinent to the orthopaedic surgeon and proceed with a more in depth discussion of current developments in the study of stem cells in orthopaedic surgery. Keywords: Stem cell, orthopaedic, surgery

Generation of open metatarsal fracture in rats: a model for secondary fracture healing

A fracture model in rats for the study of secondary bone healing was described. Standard open midshaft transverse metatarsal fracture was produced with bone cutting forceps in 28 rats. The commonly open and close fracture models utilized for bone and mineral researches are associated with varying degree of complications ranging from a high degree of fracture comminution to severe associated soft tissue injury which interferes with the healing process. We hypothesized that fracture model in rat third metatarsal bone could be associated with low -post-surgical complications and could be a reproducible model. To test this, open mid-shaft transverse fractures were created on the metatarsals of 28 rats. The objectives of the study were to evaluate the fracture complications, to determine the nature of fracture produced, evaluate the fracture consolidation during healing periods, and to assess the histological and radiographic healing of the fracture. The fracture produced in the mid metatarsal shaft of all rats was 100% transverse, 73% located at the midshaft. Minimal fracture angulations were recorded (0.48 ± 0.09o; 0.78 ± 0.17o) for anterior-posterior and lateral views respectively. Minimal soft tissue injury was recorded immediately post-surgery, but no infection and the delayed union was observed. Varying degrees of weight-bearing lameness was also recorded but seized at day six onward post-operative. Callus index observed was peaked at week 2 and 3 (2.02 ± 0.1, 1.99 ± 0.13) respectively but declined to 1.10 ± 0.04 at week 7 during the consolidation period. The fracture line disappeared completely at week 7. The histological and radiographic healing scores were (3.5 ± 0.13 and 3.75 ± 0.25) respectively (out of the maximum healing score of 4) at week 7 post-operative. There was a positive correlation between the histological and radiographic healing scores. The metatarsal fracture model is considered to be a suitable model for in vivo study of secondary fracture healing

Postnatal ex vivo rat model for longitudinal bone growth investigations

Background: Chondrocytes in the growth plate (GP) undergo increases in volume during different cascades of cell differentiation during longitudinal bone growth. The volume increase is reported to be the most significant variable in understanding the mechanism of long bone growth. Methods: Forty‐five postnatal Sprague‐Dawley rat pups, 7‐15 days old were divided into nine age groups (P7‐P15). Five pups were allocated to each group. The rats were sacrificed and tibia and metatarsal bones were harvested. Bone lengths were measured after 0, 24, 48, and 72 hours of ex vivo incubation. Histology of bones was carried out, and GP lengths and chondrocyte densities were determined. Results: There were significant differences in bone length among the age groups after 0 and 72 hours of incubation. Histological sectioning was possible in metatarsal bone from all age groups, and in tibia from 7‐to 13‐day‐old rats. No significant differences in tibia and metatarsal GP lengths were seen among different age groups at 0 and 72 hours of incubation. Significant differences in chondrocyte densities along the epiphyseal GP of the bones between 0 and 72 hours of incubation were observed in most of the age groups. Conclusion: Ex vivo growth of tibia and metatarsal bones of rats aged 7‐15 days old is possible, with percentage growth rates of 23.87 ± 0.80% and 40.38 ± 0.95%measured in tibia and metatarsal bone, respectively. Histological sectioning of bones was carried out without the need for decalcification in P7‐P13 tibia and P7‐P15metatarsal bone. Increases in chondrocyte density along the GP influence overall bone elongation

Impostor phenomenon among urologists in Saudi Arabia

Impostor phenomenon (IP) is the persistent inability to believe that one’s success is deserved or has been legitimately achieved due to one’s efforts or skills. It is associated with burnout, anxiety and depression and can negatively impact the lives of the affected individuals. This study aimed to determine the prevalence of IP among urologists in Saudi Arabia. A cross-sectional study was conducted among practicing urologists and urologists-in-training in Saudi Arabia between November and December 2022. A self-administered questionnaire comprising questions on the sociodemographic characteristics and the Clance impostor phenomenon scale (CIPS) was distributed through email to all registered urologists in the Saudi Commission for Health Specialties database. A total of 155 urologists (143 men and 12 women) were enrolled in this study. The majority of the urologists (44.5%) were consultants, and the prevalence of the impostor phenomenon in this study was 27.7%. Nearly half of the urologists (49.7%) presented moderate levels of the phenomenon, 23.9% of the urologists demonstrated high levels, and 20.6% presented low levels. Only 5.8% of the urologists showed intense levels of the phenomenon. The phenomenon was significantly more prevalent among those in training (p = 0.010) and less prevalent among those with a subspecialty in endourology (p = 0.016). The prevalence of the impostor phenomenon among urologists was 27.7%. It was more commonly seen in resident urologists, and those with a subspecialty in endourology were less likely to be affected by this phenomenon

COVID-19 specialized diabetes clinic model for excellence in diabetes care: scientific perspective

While diabetes centers are well established by the Ministry of Health, there is no separate specialized diabetes clinics for COVID-19 patients (SDCs). There are several clinical diabetes centers throughout the Kingdom of Saudi Arabia, several of which have been developed through philanthropy funding; nevertheless, it is not obvious what distinguishes SDCs from a therapeutic viewpoint and what the potential would be for such centers. Through this context, we suggest a structure to direct the progress of SDCs. Defining protocols for wider adoption of SDCs as a means to enhance public safety and COVID-19 patient care efficiency (including consistency and satisfaction) and minimize health care expenses becomes increasingly essential when moving towards value-based sales and reimbursements away from service charges. It is wise to introduce innovative financial mechanisms to pay for diabetes that cannot be covered by fiscally limited private and university medical centers. We foresee potential clinical SDCs to be made up of a well-defined framework and six areas or foundations that act as basic guiding principles for the advancement of diabetes treatment skills that can be easily illustrated by stakeholders, including insurance facilities, consumers, payers and government departments

Role of L- glutamine and crizanlizumab in sickle cell anaemia painful crisis reduction

BackgroundPatients with sickle cell disease, frequently ‎ suffer from intense painful episodes. Till recently hydroxyurea was the only available medical therapy that approved for reduction of painful episodes.AimsTo summarize the available data from randomized controlled trials that aim to evaluate the efficacy of newly approved L-‎glutamine‎ (alters redox state of red blood cells ‎‎[RBCs]) ‎and ‎crizanlizumab (‎(anti-P-selectin)‎)‎ ‎on vaso-occlusive episodes in Sickle cell disease ‎ patients.Methods PubMed, ‎Google Scholar, and EBSCO ‎ databases were ‎‎systematically search for relevant articles. The terms ‎ ‎ ‎ L-glutamine, sickle cell disease, sickle cell ‎anaemia,‎ ‎‎crizanlizumab ‎and vaso-occlusive episodes‎ were used.Results Out of Four-hundred seventy-two records, only three fulfilled the inclusion criteria. Two trials were aimed to evaluate the efficacy of L-glutamine therapy on the frequency of painful crises in sickle cell anaemia patients. Both studies showed that L-glutamine therapy significantly reduce the frequency of VOEs. Only one trial examined the ability of crizanlizumab on VOEs reduction, and showed crizanlizumab successful reduce the occurrence of VOEs.‎ConclusionNewer agent ‎with different mechanism of action, such as ‎L-glutamine, ‎and crizanlizumab may consider if ‎hydroxyurea not effective or not ‎tolerable

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020