PurposeThere have been few reports regarding same-day discharge following uncomplicated procedures such as cerebral angiography and neurointervention. We present same-day experience with cerebral angiography and neurointervention during the past three years.Materials and MethodsFour hundred and fifty-three patients underwent cerebral angiography or neurointervention at Asan Medical Center between January 2009 and December 2011. Of these patients, 249 (55%) underwent diagnostic catheter cerebral angiography and 204 patients (45%) underwent neurointerventional procedures as same-day procedures. We analyzed any complications, the modified patient-care process, the yearly trend in patient increases, disease categories, and the additional duration of admission for these procedures.ResultsThe number of overall patients increased by an average of 51% annually. The disease categories included aneurysm (51%), atherosclerosis (11%) and arteriovenous malformation (10%), etc. for which the patient underwent angiography, and aneurysm (42%), venous malformation (28%), and arteriovenous malformation (17%), etc. for which patients underwent neurointervention. Same-day care patients were admitted to the intermediary care unit in the angiosuite. Neurointervention patients were sent to the neurology intensive unit after the procedure. The same-day care patients stayed in angiosuite for six hours following the transfemoral procedure. The mean admission duration for neurointervention was 2.4 days. There were no reported complications for the same-day care procedures.ConclusionOur study revealed an increasing tendency toward same-day care for patients who require angiography and neurointervention. Further studies will be required to better define the cost-minimization effects of outpatient practice as well as the patient perception of this fast-tracking method. We propose that outpatient angiography and neurointervention will undoubtedly continue to increase over the next decade.

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This paper proposes the modeling and design of a controller for an inductive power transfer (IPT) system with a semi-bridgeless active rectifier (S-BAR). This system consists of a double-sided Inductor-Capacitor-Capacitor (LCC) compensation network and an S-BAR, and maintains a constant output voltage under load variation through the operation of the rectifier switches. Accurate modeling is essential to design a controller with good performance. However, most of the researches on S-BAR have focused on the control scheme for the rectifier switches and steady-state analysis. Therefore, modeling based on the extended describing function is proposed for an accurate dynamic analysis of an IPT system with an S-BAR. Detailed mathematical analyses of the large-signal model, steady-state operating solution, and small-signal model are provided. Nonlinear large-signal equivalent circuit and linearized small-signal equivalent circuit are presented for intuitive understanding. In addition, worst case condition is selected under various load conditions and a controller design process is provided. To demonstrate the effectiveness of the proposed modeling, experimental results using a 100 W prototype are presented.