Sharif Digital Repository

In many modern medical procedures, needle insertion is an inevitable part of the diagnosis or treatment protocols. The accuracy of the needle insertion is adversely affected by a number of factors. A needle, frequently assumed to be flexible, is inserted into a soft tissue and induces complex mechanical interactions that may result in considerable uncertainties. Tissue intrinsic characteristics as well as its deformation and rotation may cause dramatic complexities. This work considers the needle movement inside the tissue from the dynamics and control point of view. The proposed approach can be regarded as an initial step towards automation of needle insertion procedures; it can also be... 

Validation of dosimetry accuracy in the context of advanced methods for radiotherapy, including proton therapy for ensure the accuracy of treatment plan is nessecory. One of the reasons for using MC code is the modeling of PT systems and the support of more accurate computation of dose distribution in clinical tarin. The purpose of this project is to validate the modeling of a spot scanning proton therapy system using a GATE MC code. In this study, the dose distribution calculated in the calibration process of the device and syno TPS is used as a criterion and the dose distribution obtained from the GATE MC code is calculated and validated with it. For this purpose, a water phantom was used... 

Convenient medical diagnostics and treatments can replace conventional healthcare procedures because of their fast and profitable applications with reduced infection risk. Meanwhile, early diagnosis of cancer is leading research subject due to the high fatality rate of the disease and being a vital precursor in the treatment effectiveness. Electrochemical-based micro-biosensors are the best candidates for measuring biomarker concentrations in body fluids. To address this need, we used a simple fabrication approach to develop an effective immunosensor for the early detection of cancer, in particular prostate cancer. The carbon fibers, obtained from the electrospinning technique, decorate the... 

Subcutaneous needle insertion is one of the key methods of limited invasive surgery in medical diagnosis and treatment. However, errors in needle targeting can reduce the effectiveness of such efforts. One of the main factors of errors is due to the human guidance of the needle, which many researches have approached in recent years, and among the suggested solutions is the use of automatic or semi-automatic assist systems. Considering the treatment of prostate cancer by brachytherapy method, this research has developed a semi-automatic physician assistance system using navigation based on the potential field method and ultrasound images of the needle location, and sliding mode fuzzy...