Improved method for spectral reflectance estimation and application to mobile phone cameras.

We propose an improved method for estimating surface-spectral reflectance from the image data acquired by an RGB digital camera. We suppose a multispectral image acquisition system in the visible range, where a camera captures multiple images for the scene of an object under multiple light sources. First, the observed image data are described using the camera spectral sensitivities, the surface-spectral reflectance, the illuminant spectral power distributions, an additive noise term, and a gain parameter.

Measurement and Estimation of Spectral Sensitivity Functions for Mobile Phone Cameras.

Mobile phone cameras are often significantly more useful than professional digital single-lens reflex (DSLR) cameras. Knowledge of the camera spectral sensitivity function is important in many fields that make use of images. In this study, methods for measuring and estimating spectral sensitivity functions for mobile phone cameras are developed.

Occlusion of canine aneurysms using microporous self-expanding stent grafts: long-term follow-up.

Purpose: The treatment of large or giant cerebral aneurysms by surgical and/or endovascular techniques is difficult and poses relatively high risks. Therefore, a microporous self-expanding (hybrid) stent graft composed of a thin, expandable, segmented polyurethane (SPU) membrane with micropores and a drug-delivery system was developed.

Materials And Methods: A commercially available, self-expanding carotid stent was covered with a thin microporous SPU membrane fabricated by the dip-coating method and the excimer laser ablation technique, with an intraluminal coating of argatroban.

Treatment of rabbit carotid aneurysms by hybrid stents (microporous thin polyurethane-covered stents): preservation of side-branches.

Objective: We sought to determine the patency of normal arterial branches from the covered segments of an artery after stenting.

Background: Most intracranial aneurysms occur at arterial branching points (bifurcations, side-branches, or perforators). The post-stenting patency of normal arterial branches from the covered segments of the artery is important.

Development of microporous self-expanding stent grafts for treating cerebral aneurysms: designing micropores to control intimal hyperplasia.

Treatment of large (diameter 12-25 mm) or giant (diameter >25 mm) cerebral aneurysms with a broad neck in the cranio-cervical area is difficult and carries relatively high risks, even with surgical and/or endovascular methods. To this end, we have been developing a high-performance, self-expanding stent graft which consists of a commercially available NiTi stent (diameter 5 mm, length 20 mm) initially covered with a thin microporous segmented polyurethane membrane fabricated by the dip-coating method. Micropores are then created by the excimer laser ablation technique, and the outer surface is coated with argatroban.

Development of novel covered stents using salmon collagen.

In this study, we newly developed self-expandable or balloon-expandable covered stents with a biodegradable salmon collagen (SC) film. The SC-covered stents were fabricated by placing a bare stent in a mixture of acidic SC solution and a fibrillogenesis-inducing buffer (pH 6.8) including a cross-linking agent (water-soluble carbodiimide), and subsequent incubation at 4 degrees C for 24 h and lyophilization.

High-performance self-expanding stent graft: development and application to experimental aneurysms.

Large or giant aneurysms in the craniocervical area with broad necks are of concern and are treated surgically, endovascularly, or in both ways. Surgically, their treatment is difficult, with relatively high risks. For their embolization, we have been developing a high-performance stent graft that has three characteristics: a thin and expandable segmented polyurethane (SPU) membrane, micropores formed by the excimer laser ablation technique, and a drug delivery system at the membrane.

Stent-supported coil embolization for carotid artery pseudoaneurysm as a complication of endovascular surgery--case report.

A 57-year-old male presented with right amaurosis fugax and left transient ischemic attack caused by stenosis of the intracranial segment of the right internal carotid artery (ICA). Percutaneous transluminal angioplasty with stenting was successfully performed to dilate the stenosis. However, serial angiography revealed the development of a large pseudoaneurysm in the cervical ICA, probably as a result of carotid wall injury caused by the guiding catheter during the procedures.

A "mouse in a trap" method for cerebral protection during carotid stenting: Technical note.

Carotid artery angioplasty and stenting (CAS) is now used as an alternative to surgical endarterectomy. The introduction of cerebral protection systems during stenting has improved carotid artery stenosis treatment, with less periprocedural complications. A "mouse in a trap" method was conceived and used in three patients.

Occlusion of experimental aneurysms with heparin-loaded, microporous stent grafts.

Objective: An embolization technique using a stent graft has been developed to replace the conventional type of direct surgery or neurointervention with platinum coils and/or bare stents. The utility of a commercially available metal stent wrapped with a microporous elastomeric film coated with a thin, heparin-loaded, photocured gelatinous layer for the treatment of experimental carotid artery sidewall aneurysms in dogs was evaluated.

Methods: The stent graft was used for embolization of experimental carotid artery aneurysms in dogs.

Fabrication of drug-eluting covered stents with micropores and differential coating of heparin and FK506.

To reduce in-stent restenosis rates, we developed a novel drug-eluting covered stent with a microporous elastometric covered film, in which its luminal surface was flat and immobilized with heparin for anticoagulation and its outer surface immobilized with FK506 to prevent neointimal hyperplasia. One month after implantation into the bilateral common carotid arteries, all stented arteries were patent and the luminal surfaces were fully covered with a confluent of endothelial cells irrespective of the drug immobilization. In the control group, which consisted of covered stents without drug immobilization, intensive inflammatory cells adjacent to the stents and neointimal hyperplasia, indicating vascular injury, were observed.

Embolization of experimental aneurysms using a heparin-loaded stent graft with micropores.

Purpose: For percutaneous transluminal angioplasty (PTA), a heparin-loaded stent graft, composed of a commercially available metallic stent with a microporous and surface-modified thin film, has been developed. Early controlled endothelialization is promoted by a regular array of micropores produced by an excimer laser ablation technique. Early thrombus is prevented by a drug delivery system established by impregnation of photoreactive gelatin with heparin.

A recurrent intradural cervical neurenteric cyst operated on using an anterior approach: a case report.

The neurenteric cyst is an uncommon congenital lesion. In most reported cases, it has been operated on via a posterior approach using a laminectomy, despite the fact that the cyst is usually located ventral to the spinal cord. Reports have shown that early postoperative results have been good with the posterior approach, but very few studies of the long-term postoperative recurrence of neurenteric cysts have been conducted.

Fabrication of micropored elastomeric film-covered stents and acute-phase performances.

To prevent thrombus formation in the acute phase and restenosis in the subacute to chronic phase after stenting of atherosclerotic arteries, we developed a covered stent with a micropored elastomeric film, the blood-contacting surface of which was coated with a photocured gelatin layer immobilized with heparin. Segmented polyurethane (SPU) film (30 microm in wall thickness) as a cover material was multiply micropored by excimer laser-directed microprocessing (pore diameter, 30 microm; interpore distance, 125 microm). An aqueous mixed solution of benzophenone-derivatized gelatin and heparin was coated on the micropored SPU film.

Operative findings in cases of trigeminal neuralgia without vascular compression: proposal of a different mechanism.

Trigeminal neuralgia is known to be caused by vascular compression at the trigeminal root entry zone (REZ) and microvascular decompression provides good outcome in most of cases. However, in some cases, no vascular compression was observed at the REZ. Over the last 2(1/2) years, the first author operated on 53 cases of trigeminal neuralgia with microvascular decompression and encountered nine cases where no offending vessels were noted at or near the REZ.