Application of artificial intelligence in pancreas endoscopic ultrasound imaging- A systematic review.

The pancreas is a vital organ in digestive system which has significant health implications. It is imperative to evaluate and identify malignant pancreatic lesions promptly in light of the high mortality rate linked to such malignancies. Endoscopic Ultrasound (EUS) is a non-invasive precise technique to detect pancreas disorders, but it is highly operator dependent. Artificial intelligence (AI), including traditional machine learning (ML) and deep learning (DL) techniques can play a pivotal role to enhancing the performance of EUS regardless of operator. AI performs a critical function in the detection, classification, and segmentation of medical images. The utilization of AI-assisted systems has improved the accuracy and productivity of pancreatic analysis, including the detection of diverse pancreatic disorders (e.g., pancreatitis, masses, and cysts) as well as landmarks and parenchyma. This systematic review examines the rapidly developing domain of AI-assisted system in EUS of the pancreas. Its objective is to present a thorough study of the present research status and developments in this area. This paper explores the significant challenges of AI-assisted system in pancreas EUS imaging, highlights the potential of AI techniques in addressing these challenges, and suggests the scope for future research in domain of AI-assisted EUS systems.

Pattern Classification of Hand Movement Tremor in MS Patients with DBS ON and OFF.

BACKGROUND: Hand tremor is one of the consequences of MS disease degrading quality of patient's life. Recently DBS is used as a prominent treatment to reduce this effect. Evaluation of this approach has significant importance because of the prevalence rate of disease. OBJECTIVE: The purpose of this study was the nonlinear analysis of tremor signal in order to evaluate the quantitative effect of DBS on reducing MS tremor and differentiating between them using pattern recognition algorithms. MATERIAL AND METHODS: In this analytical study, nine features were extracted from the tremor signal. Through statistical analysis, the significance level of each feature was examined. Finally, tremor signals were categorized by SVM, weighted KNN and NN classifiers. The performance of methods was compared with an ROC graph. RESULTS: The results have demonstrated that dominant frequency, maximum amplitude and energy of the first IMF, deviation of the direct path, sample entropy and fuzzy entropy have the potential to create a significant difference between the tremor signals. The classification accuracy rate of tremor signals in three groups for Weighted KNN, NN and SVM with Gaussian and Quadratic kernels resulted in 95.1%, 93.2%, 91.3% and 88.3%, respectively. CONCLUSION: Generally, nonlinear and nonstationary analyses have a high potential for a quantitative and objective measure of MS tremor. Weighted KNN has shown the best performance of classification with the accuracy of more than 95%. It has been indicated that DBS has a positive influence on reducing the MS tremor. Therefore, DBS can be used in the objective improvement of tremor in MS patients.

Reliability of Knee Flexion-Extension Lyapunov Exponent in People With and Without Anterior Cruciate Ligament Deficiency.

OBJECTIVES: The current study assessed the intrasession and intersession reliability of the knee flexion-extension Lyapunov exponent in patients with anterior cruciate ligament deficiency and healthy individuals. STUDY DESIGN: University research laboratory. METHODS: Kinematic data were collected in 14 patients with anterior cruciate ligament deficiency and 14 healthy individuals walked on a treadmill at a self-selected, low, and high speed, with and without cognitive load. The intraclass correlation coefficient, standard error of measurement, minimal metrically detectable change, and percentage of coefficient of variation were calculated to assess the reliability. RESULTS: The knee flexion-extension Lyapunov exponent had high intrasession reliability, with intraclass correlation coefficients ranging from .83 to .98. In addition, the intersession intraclass correlation coefficient values of these measurements ranged from .35 to .85 regardless of group, gait speed, and dual tasking. In general, relative and absolute reliability were higher in the patients with anterior cruciate ligament deficiency than in the healthy individuals. CONCLUSIONS: Although knee flexion-extension Lyapunov exponent demonstrates good intrasession reliability, its low intersession reliability indicates that changes of these measurements between different days should be interpreted with caution.

Gait speed is more challenging than cognitive load on the stride-to-stride variability in individuals with anterior cruciate ligament deficiency.

BACKGROUND: Several investigations have studied gait variability of individuals with anterior cruciate ligament (ACL) deficiency; however, the effect of dual-tasking on the gait variability of these individuals remained unclear. The aim of the present study was to determine the effect of gait speed and dual-tasking on knee flexion-extension variability in subjects with and without ACL deficiency. METHODS: The knee flexion-extension Lyapunov exponent (LyE) was measured in 22 ACL-deficient (Mean±SD) (25.95 ±â€¯4.69 years) and 22 healthy subjects (24.18 ±â€¯3.32 years). They walked at three levels of gait speed in isolation or concurrently with a cognitive task. RESULTS: Repeated-measure analyses of variance (ANOVAs) demonstrated that the interaction of group by gait speed was statistically significant. As the gait speed increased from low to high, the knee flexion-extension LyE significantly decreased for the subjects with ACL deficiency (effect size: 0.57, P = 0.01). The interaction of group by cognitive load was not statistically significant (P = 0.07). In addition, the ACL-deficient subjects had statistically slower reaction times than healthy subjects during the dual-task compared with the single-task condition. CONCLUSIONS: The ACL-deficient and healthy individuals had a tendency to maintain safe gait. It seems that the ACL-deficient subjects sacrificed the cognitive task more than the healthy individuals to pay more attention toward gait. Additionally, it seems that the gait speed was more challenging than cognitive load on the stride-to-stride variability in the individuals with ACL deficiency.

Reliability of kinematic measures in subjects with anterior cruciate ligament deficiency during dual-task walking.

OBJECTIVE: To define the throughout within- and between-day reliability of gait parameters in single - and dual-task conditions in subjects with and without anterior cruciate ligament deficiency (ACLD). METHODS: Fourteen subjects with ACLD and 14 healthy subjects completed a walking task on a treadmill with three levels of velocity (self-selected, high and low), with or without performing an auditory Stroop task over two sessions each 3-5 days apart. The gait kinematic parameters, including maximum and minimum hip flexion, total hip range of motion, maximum and minimum knee flexion and total knee range of motion were recorded using a motion analysis system. The intraclass correlation coefficient (ICC), the standard error of measurement (SEM), and the coefficient of variation (CV) were used to determine inter- and intrasession reliability of kinematic and cognitive measures. RESULTS: ICCs for ACLD group in dual-task and single task conditions ranged between 0.50 to 0.93 and 0.53 to 0.93, respectively. ICC values for healthy groups in dual-task and single task conditions ranged between 0.36 to 0.90 and 0.39 to 0.87, respectively. When comparing relative reliability across kinematic variables in different velocities, ICC values were generally identical in all three levels of velocity. CONCLUSION: The findings suggest that dual-tasking could also be applied reliably for the assessment of functional activities in subjects with and without ACLD.

Local dynamic stability of the spine and its coordinated lower joints during repetitive Lifting: Effects of fatigue and chronic low back pain.

The nonlinear Lyapunov exponent (LyE) has been proven effective for evaluating the local stability of human movement and exploring the effects of load, speed and direction of individuals with and without nonspecific chronic low back pain (CLBP). The purpose of this study was to examine spinal and lower joint stability and response to fatigue of individuals with and without CLBP while performing lifting-lowering movements. Fourteen healthy individuals and 14 patients with nonspecific CLBP were recruited to perform lifting movement repeatedly while holding two equally-sized dumbbells in their hands. The participants continued lifting until they reported their highest level of fatigue. Kinematic data for the spine and its coordinated lower joints were recorded during the task (more than 40 lifting cycles on average). The first and last 20 cycles of each cyclic time series were defined as early- and late-fatigue conditions, respectively. The maximum LyE was estimated to quantify the local dynamic stability of the angular displacement time series of the spine, hip, knee and ankle on different anatomical planes in both the early- and late-fatigue conditions. The results revealed that local stability of the spine and hip was affected by fatigue. Spinal stability decreased as fatigue increased on the sagittal plane (p<0.05). The hip exhibited a similar affectation (destabilization under fatigue) on all anatomical planes. Patients with CLBP showed more stable hip movement on the frontal and transverse planes (p<0.05). These results suggested that lifting/progressive fatigue could increase the risk of injury to the spine and hip. These findings indicate that patients with CLBP applied different control strategies for the hip; thus, spinal control stability should be evaluated together with the stability of the lower joints.

The effect of orthotic devices on knee adduction moment, pain and function in medial compartment knee osteoarthritis: a literature review.

Background Knee braces and foot orthoses are commonly used to improve knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). However, no literature review has been performed to compare the effects of foot orthoses and knee braces in this group of patients. Purpose The aim of this review was to evaluate the effects of foot orthoses and knee braces on knee adduction moment, pain and function in individuals with knee OA. Study design Literature review. Method The search strategy was based on the Population Intervention Comparison Outcome method. A search was performed in PubMed, Science Direct, Google Scholar and ISI web of knowledge databases using the PRISMA method and based on selected keywords. Thirty-one related articles were selected for final evaluation. Results The results of the analysis of these studies demonstrated that orthotic devices reduce knee adduction moment and also improve pain and function in individuals with knee OA. Conclusion Foot orthoses may be more effective in improving pain and function in subjects with knee OA. Both knee braces and foot orthoses reduce the knee adduction moment in knee OA and consequently patients typically do not need to use knee braces for a long period of time. Also, foot orthoses and knee braces may be more effective for medial compartment knee OA patients due to the fact that this treatment helps improve pain and function. Implications for Rehabilitation Knee braces and foot orthoses are commonly used for improving knee adduction moment, pain and function in subjects with knee osteoarthritis (OA). Orthotic devices can reduce knee adduction moment, pain and improve function in knee OA. The combined use of a knee braces and foot orthoses can provide more improvement in knee adduction moment, reduced pain and increased function.

The effect of combined mechanism ankle support on postural control of patients with chronic ankle instability.

BACKGROUND: Chronic ankle instability is associated with neuromechanical changes and poor postural stability. Despite variety of mechanisms of foot and ankle orthoses, almost none apply comprehensive mechanisms to improve postural control in all subgroups of chronic ankle instability patients. OBJECTIVES: The purpose of this study was to investigate the effect of an ankle support implementing combined mechanisms to improve postural control in chronic ankle instability patients. STUDY DESIGN: Cross-sectional study. METHODS: An ankle support with combined mechanism was designed based on most effective action mechanisms of foot and ankle orthoses. The effect of this orthosis on postural control was evaluated in 20 participants with chronic ankle instability and 20 matched healthy participants. The single-limb stance balance test was measured in both groups with and without the new orthosis using a force platform. RESULTS: The results showed that application of combined mechanism ankle support significantly improved all postural sway parameters in chronic ankle instability patients. There were no differences in means of investigated parameters with and without the orthosis in the healthy group. No statistically significant differences were found in postural sway between chronic ankle instability patients and healthy participants after applying the combined mechanism ankle support. CONCLUSION: The combined mechanism ankle support is effective in improving static postural control of chronic ankle instability patients to close to the postural sway of healthy individual. the orthosis had no adverse effects on balance performance of healthy individuals. Clinical relevance Application of the combined mechanism ankle support for patients with chronic ankle instability is effective in improving static balance. This may be helpful in reduction of recurrence of ankle sprain although further research about dynamic conditions is needed.

The effects of a short-term memory task on postural control of stroke patients.

BACKGROUND: Many studies have been conducted on the changes in the balance capabilities of stroke patients. However, results regarding the effects of dual-task activities on postural control in these patients have been variable. OBJECTIVE: To evaluate the effects of a short-term memory task on the sway characteristics of stroke patients. METHOD: Center of pressure (COP) fluctuations were measured in three levels of postural difficulty (rigid surface with closed and open eyes and foam surface with closed eyes), as well as two levels of cognitive difficulty (easy and difficult). COP parameters included mean velocity, standard deviation of velocity in both medial-lateral (M.L) and anterior-posterior (A.P) directions, total phase plane portrait, area. Nineteen stroke patients and 19 gender, age, height, and weight matching healthy volunteers participated in this study. RESULTS: Our findings indicate that mean velocity (F = 14.21, P = 0.001), standard deviation of velocity in both M.L (F = 17.50, P = 0.000) and A.P (F = 11.03, P = 0.002) directions, total phase plane portrait (F = 44.12, P = 0.001), and area (F = 13.95, P = 0.01) of center of pressure of patients were statistically greater than normal subjects, while significant interaction of group × postural difficulty and postural × cognitive difficulty were observed for all parameters of postural sway. CONCLUSIONS: Different measures of postural sway showed complex response to postural and cognitive difficulties between stroke patients and normals. Cognitive error was not affected by the main effects of group and postural difficulty, while greatly increased at more difficult cognitive task (F = 75.73, P = 0.000).

The effects of Task-Oriented Motor Training on gait characteristics of patients with type 2 diabetes neuropathy.

BACKGROUND: It is known that general gait training improves lower extremity muscle strength and endurance in Diabetes Neuropathy (DN). But, it is still unknown whether Task-Oriented (TO) gait training would change gait biomechanics and the risk of falling in DN. TO gait training focuses on promoting timing and coordination of lower extremity movements through goal-directed practices with sufficient repetition. METHODS: A group of 14 patients with DN participated in a time-series study. All subjects participated in four sessions of assessments (Initial, Pre, Post and Follow-Up). Training was twice a week for 12 weeks. Vertical and horizontal Ground Reaction Forces (GRF), Time Get up and Go (TGUG) and Fall Efficacy Scale-International (FES-I) were evaluated. Gait training started with stepping patterns that progressively changed to complicated patterns of walking. Then, training continued combining walking patterns with upper extremity activities and then ended with treadmill-paced practice. RESULTS: DN patients significantly increased Second Vertical Peak Force and Horizontal Propulsive Force in addition decrease in Minimum Vertical Force. TGUG significantly decreased while FES-I reflected significant increase after gait training. DISCUSSION: Conclusively, training not only improved gait performance, confidence in daily activities and attenuated risk of falling, but also helped DN patients to improve feet biomechanics, muscles timing and coordination. CONCLUSIONS: Gait training with respect to principles of motor learning allowed patients to effectively improve through sessions.

Design and development of a novel viscoelastic ankle-foot prosthesis based on the human ankle biomechanics.

BACKGROUND AND AIM: In the present study, a new approach was applied to design and develop a viscoelastic ankle-foot prosthesis. The aim was to replicate the intact ankle moment-angle loop in the normal walking speed. TECHNIQUE: The moment-angle loop of intact ankle was divided into four parts, and the appropriate models including two viscoelastic units of spring-damper mechanism were considered to replicate the passive ankle dynamics. The developed prototype was then tested on a healthy subject with the amputee gait simulator. The result showed that prosthetic ankle moment-angle loop was similar to that of intact ankle with the distinct four periods. DISCUSSION: The findings suggest that the prototype successfully provided the human ankle passive dynamics. Therefore, the viscoelastic units could imitate the four periods of a normal gait. CLINICAL RELEVANCE: The novel viscoelastic foot prosthesis could provide natural ankle dynamics in a gait cycle. Applying simple but biomechanical approach is suggested in conception of new designs for prosthetic ankle-foot mechanisms.

Quantitative analysis of human ankle characteristics at different gait phases and speeds for utilizing in ankle-foot prosthetic design.

BACKGROUND: Ankle characteristics vary in terms of gait phase and speed change. This study aimed to quantify the components of ankle characteristics, including quasi-stiffness and work in different gait phases and at various speeds. METHODS: The kinetic and kinematic data of 20 healthy participants were collected during normal gait at four speeds. Stance moment-angle curves were divided into three sub-phases including controlled plantarflexion, controlled dorsiflexion and powered plantarflexion. The slope of the moment-angle curves was quantified as quasi-stiffness. The area under the curves was defined as work. RESULTS: The lowest quasi-stiffness was observed in the controlled plantarflexion. The fitted line to moment-angle curves showed R2 > 0.8 at controlled dorsiflexion and powered plantarflexion. Quasi-stiffness was significantly different at different speeds (P = 0.00). In the controlled dorsiflexion, the ankle absorbed energy; by comparison, energy was generated in the powered plantarflexion. A negative work value was recorded at slower speeds and a positive value was observed at faster speeds. Ankle peak powers were increased with walking speed (P = 0.00). CONCLUSIONS: Our findings suggested that the quasi-stiffness and work of the ankle joint can be regulated at different phases and speeds. These findings may be clinically applicable in the design and development of ankle prosthetic devices that can naturally replicate human walking at various gait speeds.

Spectral characteristics of postural sway in diabetic neuropathy patients participating in balance training.

BACKGROUND: The aim of the present study is to have a detailed frequency analysis about the effect of balance training with respect to reactive movement strategies and sensory strategies in type 2 diabetic neuropathy (DN) patients. Also understand changes in the role of each postural subsystem for controlling quiet standing after balance training. METHODS: A group of 19 patients were included in the quasi experimental, time- series study. Total frequency power, 99% power frequency, centroidal frequency and frequency spectrum in the intervals between 0.01-0.1, 0.1-0.5, 0.5-1 Hz and 1-3 Hz are reported. The training protocol consisted two patterns of limits of stability trainings, three approaches in weight shifting trainings and one stable standing practice on the biodex stability system. RESULTS: Repeated measure ANOVA analysis and the LSD test indicated significant differences for the eyes open ML- frequency power and ML-FFT sway power within low-medium (0.1-0.5 HZ) frequencies. CONCLUSIONS: Decrease in postural sway at low-medium frequencies showed lower reliance on vestibular system. Also, better controlling hip muscles after balance training relieve DN patients' requirement to more exploratory sway as a compensatory strategy and showed better balance performance after balance training in DN patients. TRIAL REGISTRATION: UMIN-CTR Search Clinical Trials: UMIN000004485.

Pulsed low-intensity ultrasound enhances healing rate in the osteoperforated tibia in a rabbit model.

OBJECTIVES: The effect of pulsed low-intensity ultrasound (PLIUS) on healing rate in osteoperforated rabbit tibia during the healing period was investigated. METHODS: Using dental drills, 2-mm through holes were drilled at the midshaft of the right tibia in 36 mature New Zealand white rabbits. Animals were then randomly divided into normal, placebo control, and PLIUS treatment (20 minutes/day, five times/week) groups, and were euthanized at Weeks 2, 4, and 6 postoperatively (n=4 for each group and time point). Normalized radiographic density of the medial, central, and lateral sides of the holes was measured immediately after surgery and then every 2 weeks up to 6 weeks. Animals were euthanized after specified time points, both right and left tibias were removed, and using a standard three-point bending tester, maximum force to break and stiffness of the bones were measured. RESULTS: It was revealed that, in control and treatment groups, radiographic and mechanical measures increased as the time point increased. Outcome measures were found to be significantly greater in the PLIUS treatment group compared with that of the control group at 4- and 6-week time points. CONCLUSIONS: It is concluded that PLIUS can enhance healing rates in osteoperforations.

Extraction of skin lesion texture features based on independent component analysis.

BACKGROUND/PURPOSE: During the recent years, many diagnostic methods have been proposed aiming at early detection of malignant melanoma. The texture of skin lesions is an important feature to differentiate melanoma from other types of lesions, and different techniques have been designed to quantify this feature. In this paper, we discuss a new approach based on independent component analysis (ICA) for extraction of texture features of skin lesions in clinical images. METHODS: After preprocessing and segmentation of the images, features that describe the texture of lesions and show high discriminative characteristics are extracted using ICA, and then these features, along with the color features of the lesions, are used to construct a classification module based on support vector machines for the recognition of malignant melanoma vs. benign nevus. RESULTS: Experimental results showed that combining melanoma and nevus color features with proposed ICA-based texture features led to a classification accuracy of 88.7%. CONCLUSION: ICA can be used as an effective tool for quantifying the texture of lesions.

Augmentation of bone healing by specific frequency and amplitude compressive strains.

A considerable proportion of bone fractures show signs of delayed or impaired healing. A novel device that applies interfragmentary compressive forces to the fracture site was developed and evaluated for its effect on fracture healing. The midshafts of the right tibias of 16 rabbits were osteotomized, leaving a 2-mm gap. A 4-pin, double-bar external fixator was fixed to the tibias. Interfragmental compressive displacement of 0.5 mm with a frequency of 1 Hz was applied 15 minutes per day. Mechanical stimulation began 1 week postoperatively and continued for 2 and 3 weeks. Control animals received no stimulation. Callus quality and area were assessed by radiographs. Maximum force and total energy absorbed up to failure of the healed bones were determined using a standard 3-point bending test. Postmortem radiographic examinations showed that mean radiographic measures in both anteroposterior and mediolateral views was significantly larger in experimental groups than controls (P=.029). Mechanical measures of the healed bones demonstrated that mean values of maximum force and absorbed energy were significantly higher in the experimental groups than in the control groups (P=.029). Both radiographic and mechanical measures were significantly higher after 3 weeks compared to 2 weeks of receiving stimulation (P<.05).

Quantification of rigidity in Parkinson's disease.

In this paper, a new method for quantification of rigidity in elbow joint of Parkinsonian patients is introduced. One of the most known syndromes in Parkinson's disease (PD) is increased passive stiffness in muscles, which leads to rigidity in joints. Clinical evaluation of stiffness in wrist and/or elbow, commonly used by clinicians, is based on Unified Parkinson's Disease Rating System (UPDRS). Subjective nature of this method may influence the accuracy and precision of evaluations. Hence, introducing an objective standard method based on quantitative measurements may be helpful. A test rig was designed and fabricated to measure range of motion and viscous and elastic components of passive stiffness in elbow joint. Measurements were done for 41 patients and 11 controls. Measures were extracted using Matlab-R14 software and statistic analyses were done by Spss-13. Relation between each computed measure and the level of illness were analyzed. Results showed a better correlation between viscous component of stiffness and UPDRS score compared to the elastic component. Results of this research may help to introduce a standard objective method for evaluation of PD.