PURPOSE To assess the histologic changes produced by platinum microcoils with an inner core of cross-linked bovine collagen in experimentally induced aneurysms in swine, and to assess the feasibility of the system for the delivery of the collagen. METHODS Bilateral pouch aneurysms were created in the side wall of the common carotid artery in seven barnyard pigs. Eight aneurysms were treated w...

This paper presents a position sensor based on novel configuration of linear variable differential transformer. Design and optimization the using finite element method are presented. The measurements also conducted to validate experimentally performance. has short air core coils long magnetic armatures. axis rectangular excitation coil two antiserially connected pick up is perpendicular motion ...

BACKGROUND AND PURPOSE Platinum coil embolization is one of the significant advances in interventional neuroradiologic techniques that has been introduced this decade. Our purpose was to evaluate the angiographic and histologic effects of collagen-coated platinum microcoil delivery in the canine artery. METHODS We embolized the bilateral internal maxillary arteries of 18 dogs; one uncoated an...

Introduction Micro Helmholtz coils are needed in medical technology for high-resolution magnetic resonance imaging (MRI) or for nuclear magnetic resonance (NMR) spectroscopy at the micro level. The coil sensitivity, and therefore the desired signal, is maximized when the size of the coil matches that of the sample [1, 2]. Small sample analysis with micro Helmholtz coils shows exceptional perfor...

Neural stimulation represents a powerful technique for neural disorder treatment. This paper deals with optimization of coil design parameters to be used during stimulation for modulation of neuronal firing to achieve pain relief. Pain mechanism is briefly introduced and a hierarchical stimulation model from coil stimulation to neuronal firing is proposed. Electromagnetic field distribution for...

Seven dural arteriovenous fistulas were successfully embolized with mechanical detachable coils. Two lesions were located in the transverse-sigmoid sinus, four in the cavernous sinus, and one in the marginal sinus. All lesions were completely occluded on postembolization angiography. No recurrent symptoms appeared during a mean follow-up period of 11 months. Owing to the length and retrievabili...

BACKGROUND AND PURPOSE Endovascular treatment of aneurysms with coils, a less invasive alternative to surgery, is too often associated with recurrences. In a canine model, recanalization after coil embolization can be inhibited by in situ beta radiation. METHODS Radioactive platinum coils were produced by immersion in a (32)P-oligodeoxynucleotide solution. In vitro and in vivo (32)P-oligodeox...

Applying shielding coils is a practical way to protect current transformers (CTs) for large-capacity generators from the intensive magnetic interference produced by adjacent bus-bars. The aim of this study is to build a simple analytical model for the shielding coils, from which the optimization of the shielding coils can be calculated effectively. Based on an existing stray flux model, a new a...

BACKGROUND AND PURPOSE The International Subarachnoid Aneurysm Trial (ISAT) showed that patients with intracranial aneurysms treated with coil embolization have better clinical outcomes than those undergoing neurosurgical clipping. However some patients treated endovascularly have recurrence of aneurysms. Low packing density is often cited as a reason for recurrence. Coiling with hydrogel cover...

BACKGROUND AND PURPOSE Endovascular coil embolization has become an accepted alternative for the treatment of intracranial aneurysms. The purpose of this study was to evaluate the clinical safety and the angiographic stability of aneurysm occlusion with a new class of biologically active platinum coils after a 6-month period. METHODS Twenty-five patients with 25 intracranial aneurysms were tr...