Optical compensation of hologram distortion avoiding interpage crosstalk on reconstructed image in angle-multiplexed holograms.

We are studying a form of holographic data storage with phase conjugation, and we compensated for hologram distortion due to shrinkage of photopolymer materials in the holographic medium by controlling the wavefront of the reference beam. When a high NA lens and narrow angle interval of angle multiplexing are employed to obtain a high data recording density, some wavefronts cause interpage crosstalk on the reconstructed image. We tried to determine the moving range of actuators in a deformable mirror for controlling the wavefront.

Half-data-page insertion method for increasing recording density in angular multiplexing holographic memory.

We have developed a method to use a half-size data page between two full-size data pages to increase the recording density in angular multiplexing holographic memory up to 1.5× as much as the conventional angular multiplexing sequence. In our recording sequence, the full- and half-size data pages are alternately multiplexed.

Symptomatic T2 vertebral hemangioma in a pregnant woman treated by one stage combination surgery; posterior stabilization and anterior subtotal tumor resection. Case report.

A 27-year-old woman presented with vertebral hemangioma manifesting as sudden onset of paraplegia, and bladder and bowel dysfunction during pregnancy. Magnetic resonance imaging revealed a mass lesion that had infiltrated into the entire T2 vertebral body and expanded to the vertebral canal. Laminectomy from T1 to T3 and biopsy of the lesion were performed.

Acute extracranial-intracranial bypass using a radial artery graft along with trapping of a ruptured blood blister–like aneurysm of the internal carotid artery. Clinical article.

Object: Fragile aneurysm walls and poorly defined necks render the surgical treatment of blood blister–like aneurysms (BBAs) located at nonbranching sites of the supraclinoid internal carotid artery extremely challenging. Such aneurysms have a remarkable tendency to rupture during surgery, especially during the acute period. The authors describe the clinical course of patients with subarachnoid hemorrhage (SAH) caused by BBA rupture and emphasize the value of internal carotid artery trapping combined with high-flow extracranial-intracranial (trapping/EC-IC) bypass during the acute period following SAH.

Optical compensation of distorted data image caused by interference fringe distortion in holographic data storage.

Photopolymer materials shrink because of photopolymerization. This shrinkage distorts the recorded interference fringes in a medium made of such material, which in turn degrades the reconstructed image quality. Adaptive optics controlled by a genetic algorithm was developed to optimize the wavefront of the reference beam while reproducing in order to compensate for the interference fringe distortion.

Dramatic disappearance of moyamoya disease-induced chorea after indirect bypass surgery.

A 31-year-old woman with moyamoya disease presented with choreiform movements persisting for 4.5 years. Magnetic resonance imaging showed a fine vascular plexus in the base of the brain but no parenchymal brain damage.