10 research outputs found
A Virtual-Based Haptic Endoscopic Sinus Surgery (ESS) Training System: from Development to Validation
Simulated training platforms offer a suitable avenue for surgical students
and professionals to build and improve upon their skills, without the hassle of
traditional training methods. To enhance the degree of realistic interaction
paradigms of training simulators, great work has been done to both model
simulated anatomy in more realistic fashion, as well as providing appropriate
haptic feedback to the trainee. As such, this chapter seeks to discuss the
ongoing research being conducted on haptic feedback-incorporated simulators
specifically for Endoscopic Sinus Surgery (ESS). This chapter offers a brief
comparative analysis of some EES simulators, in addition to a deeper
quantitative and qualitative look into our approach to designing and
prototyping a complete virtual-based haptic EES training platform
An Improved Approach for Output Feedback Model Predictive Control of Hybrid Systems
In this paper, a modified robust model predictive control scheme is proposed
for linear parametric variable (LPV) and hybrid systems based on a
quasi-min-max algorithm. Using a new cost function resulted in reduced unwanted
disturbances during switching. In addition, the effects of uncertainties are
reduced in the prediction dynamics, and robust stability of piecewise switching
LPV systems subjected to linear matrix inequality (LMI) input constraints are
guaranteed. Simulation results demonstrate the performance of the proposed
controller compared to prior research
The job creation potential of the Information and Communication Technology sector: The case of Iran
Abstract. This article examines the Information and Communication Technology (ICT) job creation in Iran's economy. The results show that this sector has low job creation coefficient among 23 economic sectors. Therefore, considering the importance of ICT, policymakers should make appropriate decisions to increase linkages between ICT and other economic sectors to improve its performance in the economy
A Data-Driven Model with Hysteresis Compensation for I2RIS Robot
Retinal microsurgery is a high-precision surgery performed on an exceedingly
delicate tissue. It now requires extensively trained and highly skilled
surgeons. Given the restricted range of instrument motion in the confined
intraocular space, and also potentially restricting instrument contact with the
sclera, snake-like robots may prove to be a promising technology to provide
surgeons with greater flexibility, dexterity, space access, and positioning
accuracy during retinal procedures requiring high precision and advantageous
tooltip approach angles, such as retinal vein cannulation and epiretinal
membrane peeling. Kinematics modeling of these robots is an essential step
toward accurate position control, however, as opposed to conventional
manipulators, modeling of these robots does not follow a straightforward method
due to their complex mechanical structure and actuation mechanisms. Especially,
in wire-driven snake-like robots, the hysteresis problem due to the wire
tension condition can have a significant impact on the positioning accuracy of
these robots. In this paper, we proposed an experimental kinematics model with
a hysteresis compensation algorithm using the probabilistic Gaussian mixture
models (GMM) Gaussian mixture regression (GMR) approach. Experimental results
on the two-degree-of-freedom (DOF) integrated robotic intraocular snake (I2RIS)
show that the proposed model provides 0.4 deg accuracy, which is an overall 60%
and 70% of improvement for yaw and pitch degrees of freedom, respectively,
compared to a previous model of this robot
Comparative analysis of agricultural water pricing between Azarbaijan Provinces in Iran and the state of California in the US: a hydro-economic approach
Iranian water authority has recently announced that one of the effective ways to avoid unprecedented high water consumption in Iran’s agriculture sector is to increase water price. This paper analyzes the feasibility of this policy by using a hydro-economic approach with the aim to consider the role of water pricing in agricultural water management. Such an analysis was conducted through comparing price of water consumed for producing selected agricultural crops (i.e. wheat, sugar beets, onion, tomato, barley, potato, corn, alfalfa hay and watermelon) in a case study on two provinces (East Azarbaijan and West Azarbaijan) in Iran to that in the state of California (CA) in the USA. According to the paper, the method uses the Purchasing Power Parity (PPP) Index for the first time to analyze the water prices of agricultural crops in the case study due to the specific regional circumstances in the Case Study (i.e. severe fluctuations and continuously changing currency) that prevent using the norm of Nominal Exchange Rate Index (NERI). The results show there is no significant difference between the water price for producing the selected crops in West Azarbaijan (W.AZ) and East Azarbaijan (E.AZ) provinces and that in the state of California if PPP Index is applied. Water price for producing each kilogram of some crops such as wheat, sugar beet, onion and watermelon (except potato and barley) is estimated to be between 60–80 percent of that in the state of California. However, this ratio is ironically equal to 116% for alfalfa hay and 105% for corn. As a result, considering the obtained results, one may realize that the whole problem can be hardly attributed to the low price of agricultural water in our case study and raising agricultural water price would never be effective for reducing water consumption in the studied area unless price adjustment accompanies developing necessary infrastructures. Unlike the views that advocate raising water prices, there are two distinct views: The first declares that agricultural water should be free of charge to the farmers because it returns to the hydrological cycle. The second view stipulates that instead of raising water prices in agriculture sector, the cost of water supply for agriculture should be reduced by new technologies. It is advised that before adjusting agricultural water price, institutional reforms are required based on the experiences of other countries and establishing local water distribution cooperatives
A Multi-Purpose Continuum Robot for Minimally Invasive Surgery
This thesis is about ''A Multi-Purpose Continuum Robot for Minimally Invasive surgery'' which consists of five chapters. It starts with an Introduction and Literature Review that studies some of the most famous surgical robotic systems and analyses their pros and cons. Chapter two has to do with the problem statement and challenges that need to be addressed while designing our specific surgical tool, and a CAD design of a flexible continuum robot will be done for our brain surgery application. In chapter three, the kinematic modeling of the proposed robot is analyzed by a new model based on the Euler spirals and the results are compared with conventional constant curvature models. In chapter four, a model predictive control algorithm is proposed that considers the input saturation constraints on robot actuators. Finally, a discussion and conclusion will be provided in chapter five
The Immediate Effect of Lateral Wedge Insoles, With and Without a Subtalar Strap, on the Lateral Trunk Lean Motion in Patients With Knee Osteoarthritis
Background: Orthotic interventions for knee osteoarthritis (OA) aim to reduce mechanical loading on the medial compartment of the knee and may lessen the lateral trunk lean as the most important compensatory gait strategy. The lateral wedge insole is a known orthotic intervention for knee OA. However, the question whether the addition of a subtalar strap to the wedge improves its effect has not been addressed in the literature. Objective: To compare the effects of lateral wedge insoles, with and without a subtalar strap, on the lateral trunk lean in patients with knee OA. Methods: Twenty-three patients aged over 40 years, with grade I or II OA of the medial compartment of one knee, based on the American College of Rheumatology criteria, were included in this study. The patients were diagnosed with OA based on a clinical examination, and the diagnosis was confirmed with radiographs. A 3-dimensional motion measurement system was used to collect the gait data for 3 different conditions: (1) with no insole, (2) with a lateral wedge insole, and (3) with a lateral wedge insole and a subtalar strap. The immediate effect of the 3 test conditions on the lateral trunk lean was compared during a gait cycle a stance phase and at the point of midstance. Results: Based on the laboratory coordinate system, the 3 conditions had no significant effect on the lateral trunk lean during a gait cycle and a stance phase and at the point of midstance in patients with knee OA. Conclusion: The results of this study demonstrated that the lateral wedge insoles, with and without a subtalar strap, had no immediate effect on the lateral trunk lean in patients with knee OA. However, the long-term effect of lateral wedge insoles on the lateral trunk lean in these patients requires further investigation