Publications by authors named "Amir Rezaie"

3 Publications

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A novel design and implementation of wheelchair navigation system using Leap Motion sensor.

Disabil Rehabil Assist Technol 2020 Jul 7:1-7. Epub 2020 Jul 7.

Department of Electrical Engineering, Amirkabir University of Technology, Tehran, Iran.

In this paper, a novel design for a leap motion wheelchair navigation system is proposed, and the suggested model is implemented on a prototype. The behaviour of the created prototype is closely observed during the different performance tests carried out, and the results are presented throughout this manuscript. In the prototype, a Leap Motion sensor is implemented to acquire navigation data through hand gestures of the users. This navigations system design is specifically implemented to facilitate wheelchair use for amputee users and stroke patients as it does not rely on the movement of the fingers. Through this design, wheelchair movement can be controlled through detection of finger, fist, palm or wrist (for amputees) movement by the leap motion sensor. Bluetooth connection is used as the navigation system's communication means, removing the need for constant internet connection and providing freedom of movement outside of internet-covered territory. Additionally, two Dynamixel motors are used as movement force, which yield optimal computational time and minimal delay. The performance of the designed prototype is tested by considering response time and speed resolution as evaluation metrics. Results suggest that the designed wheelchair will give movement independence to users who cannot use their fingers to control the movement of their wheelchairs, while reducing delay, being independent of internet connection, providing high resolution and minimising detection error. The promising results obtained from prototype testing suggest the possibility of real-life application of this wheelchair navigation system, which can greatly assist amputee users and rehabilitation patients.Implications for rehabilitationA novel wheelchair navigations system designed to facilitate amputee users, stroke patients and rehabilitation patients.The proposed system eliminates the reliance on finger movements, is gaze independent, and does not require voice or gesture control, creating much more freedom for users undergoing specific medical conditions or still under rehabilitation or treatment.Results demonstrate very low delay time in wheelchair command to action, allowing improved control for users and reducing the occurrence of control-related accidents.The designed wheelchair navigation system is independent of internet connection, allowing more freedom in range for wheelchair users compared to available cloud based models.
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http://dx.doi.org/10.1080/17483107.2020.1786734DOI Listing
July 2020

Improving the biological activity of fingolimod loaded PHBV nanoparticles by using hydrophobically modified alginate.

Drug Dev Ind Pharm 2020 Feb 6;46(2):318-328. Epub 2020 Feb 6.

Department of Pharmaceutics, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.

Uncontrolled distribution of nanoparticles (NPs) within the body can significantly decrease the efficiency of drug therapy and is considered among the main restrictions of NPs application. The aim of this study was to develop a depot combination delivery system (CDS) containing fingolimod loaded poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) NPs dispersed into a matrix of oleic acid-grafted-aminated alginate (OA-g-AAlg) to minimize the nonspecific biodistribution (BD) of PHBV NPs. OA-g-AAlg was synthesized in two step; First, Alg was aminated by using adipic dihydrazide (ADH). The degree of hyrazide group substitution of Alg was determined by trinitro-benzene-sulfonic acid (TNBS) assay. Second, OA was attached to AAlg through formation of an amide bond. Chemical structure of OA-g-AAlg was confirmed with FTIR and HNMR spectroscopy. Furthermore, rheological properties of OA-g-AAlg with different grafting ratios were evaluated. release studies indicated that 47% of fingolimod was released from the CDS within 28 days. Blood and tissue samples were analyzed using liquid chromatography/tandem mass spectrometry following subcutaneous (SC) injection of fingolimod-CDS into Wistar rats. The elimination phase half-life of CDS-fingolimod was significantly higher than that of fingolimod (∼32 d vs. ∼20 h). To investigate the therapeutic efficacy, lymphocyte count was assessed over a 40 day period in Wistar rats. Peripheral blood lymphocyte count decreased from baseline by 27 ± 8% in 2 days after injection. Overall, the designed CDS represented promising results in improving the pharmacokinetic properties of fingolimod. Therefore, we believe that this sustained release formulation has a great potential to be applied to delivery of various therapeutics.
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http://dx.doi.org/10.1080/03639045.2020.1721524DOI Listing
February 2020

Accuracy enhancement of 3D profilometric human face reconstruction using undecimated wavelet analysis.

Appl Opt 2012 Jun;51(16):3120-31

Automation and Intelligent Monitoring Systems Research Lab, Electrical Engineering Department, Amirkabir University of Technology, Hafez Street, Tehran, Iran.

Three-dimensional profilometric object reconstruction is a challenging topic; among the various methods available, we implement the line projection technique, which has superiorities over other methods. In order to increase the accuracy of measurement, a wavelet transform analysis is used in two stages of denoising and phase extraction. Because of the denoising capability and multiresolution characteristics of wavelet transforms, we employ an undecimated wavelet transform for noise reduction and a continuous wavelet transform in the phase extraction stage. The aim is to add a preprocessing stage of denoising based on the undecimated wavelet transform to enhance the accuracy of measurement in noisy patterns. The experimental results on the human face as a complex object demonstrate that the combination of undecimated and continuous wavelet transforms could increase measurement accuracy in noise-contaminated patterns.
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http://dx.doi.org/10.1364/AO.51.003120DOI Listing
June 2012
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