This paper proposed a new design on multi-layer flexible microelectrode arrays (MEA) of epiretinal prosthesis, as well as a set of automatic testing system to evaluate and analyze the MEA. Experiment results showed that the MEA was satisfying on both flexibility and impedance and the multi-layer design didn't introduce significant differences.
Microarray Analysis ; Microelectrodes ; Prostheses and Implants ; Prosthesis Design ; Prosthesis Implantation ; instrumentation ; Retina

Cochlear Implantation ; instrumentation ; Cochlear Implants ; Electrodes ; Female ; Humans ; Infant ; Prosthesis Failure

Adult ; Aged ; Aortic Aneurysm, Abdominal ; surgery ; Blood Vessel Prosthesis Implantation ; instrumentation ; Female ; Humans ; Male ; Middle Aged

Cardiac Catheterization ; Heart Septal Defects, Ventricular ; therapy ; Humans ; Prosthesis Implantation ; instrumentation ; Septal Occluder Device

Arteries ; surgery ; Arteriosclerosis Obliterans ; surgery ; Bioprosthesis ; Blood Vessel Prosthesis ; Blood Vessel Prosthesis Implantation ; instrumentation ; Humans ; Lower Extremity ; blood supply ; surgery

The aim of this study was to investigate the pulsatile-flow performance in vitro of a new heart valve prostheses implanted with minimally invasive techniques (HVPMIT). Three HVPMITs were tested valves and another three original biological heart valve prostheses acted as reference valves. The pulsatile-flow parameters (including mean pressure drop, regurgitant percentage of stroke volume, and effective orifice area) were tested in a pulse duplicator according to the methods listed in ISO5840-2005 and GB 12279-2008. The results demonstrated that the regurgitant percentage of stroke volume of tested valves was up to 13%. It was significantly higher than that of the reference valves. This result suggested that paravalvular leakage had occurred in the tested valves. It was found in the further analysis that because HVPMIT was not sewn into the heart tissue when the HVPMIT was implanted in vivo and there was not a sewing ring in the HVPMIT, when tested valves were fixed in the pulse duplicator, some gaps might exist between the stent of HVPMIT and the fix gasket, and the paravalvular leakage could therefore take place through these gaps. This study demonstrated that there are significant differences in the shape, structure, fixation in vivo and clinical operational methods between HVPMIT and original biological heart valve prostheses. It is necessary to establish new test methods which adapt for HVPMIT to evaluate its pulsatile-flow performance according to its own features.
Animals ; Cardiac Catheterization ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; adverse effects ; instrumentation ; methods ; Minimally Invasive Surgical Procedures ; methods ; Prosthesis Design ; Pulsatile Flow

OBJECTIVETo evaluate the technical feasibility of juxtarenal abdominal aortic aneurysm (AAA) repair with fenestrated endovascular stent-graft

METHODSA 64-year-old male was diagnosed with juxtarenal AAA with severe coronary artery stenosis, fenestrations was customized according to precise helical CT data to accommodate visceral and renal arteries. Under general anesthesia and dynamic supervision of digital subtraction angiography (DSA), juxtarenal AAA was excluded with the customized fenestrated stent-graft and balloon expandable mini stent-grafts were deployed into bilateral renal arteries respectively.

RESULTSAfter operation, DSA showed the patency of the super mesenteric artery, bilateral renal arteries and left hypogastric artery, no endoleak was found. The serum creatinine decreased slightly after operation. CT angiography revealed favorable morphology of the stent-graft without tortuosity, migration, disjoint and endoleak 10 days after the operation and patency of super mesenteric artery, bilateral renal arteries and left hypogastric artery.

CONCLUSIONSThe placement of customized fenestrated endovascular stent-graft is a feasible option for juxtarenal AAA.

Aortic Aneurysm, Abdominal ; surgery ; Blood Vessel Prosthesis Implantation ; instrumentation ; methods ; Feasibility Studies ; Humans ; Male ; Middle Aged ; Stents

OBJECTIVETo explore long-term effect of the treatment of refractory benign esophageal strictures with a novel retrievable fully covered stent made of nitinol alloy.

METHODSFrom November 2009 to May 2011, the stents were placed in 8 patients with refractory benign esophageal strictures in the Department of Thoracic Surgery at the Cancer Center of Sun Yat-sen University. Esophago-gastro-duodenoscopy and barium swallow examinations were performed respectively on the 1st, 7th, 30th, 60th day after implantations of the stents and 1,2,3,6 months or even longer after removal of the stents in order to assess the long-term effect on the improvement of dysphagia and the development of complications.

RESULTSThe stents were successful deployed in all the patients. The dysphagia scores were improved instantly and significantly as compared to the preoperative scores(P<0.05). Seven patients had long-term improvement of dysphagia. The dwelling time of all the stents ranged from 4 to 60 weeks, with a median of 16.8 weeks. Six patients had their stent removed after a dwelling time of 4 to 18 weeks(median 9.7 weeks). The follow-up period was 1.5-9 months (median 6.1 months). The improvement of dysphagia was also significant during follow-up after removal of the stents(P<0.05). At the most recent follow up, two patients still had the stent in place. The first one has already been followed up for 15 months and was still on regular diet. The other one experienced improvement of dysphagia score up to two months after placement, but downgraded to 3 by the third month. Relapse of stenosis occurred in 1 patient, migration in 2 patients, and tissue hyperplasia in 3 patients, of whom 2 developed inward growth of granulation tissue due to the rupture of the covering membrane.

CONCLUSIONSThe new retrievable fully covered stent made of nitinol alloy significantly improves the swallowing function of patients with intractable benign esophageal strictures after implantation and after removal of the stents, with low incidence of long-term restenosis. However, the high rate of migrations and the poor quality of the covering membrane further implies that the design of the new stent still needs to be improved.

Adult ; Aged ; Alloys ; Esophageal Stenosis ; surgery ; Female ; Humans ; Male ; Middle Aged ; Prosthesis Implantation ; instrumentation ; methods ; Stents ; Treatment Outcome

The latest development and the merit of using flexible neural microelectrodes are mainly reported in the paper, in which the properties of based-material, the micro-structure of neural microelectrodes and the method about how to test the microelectrodes are also included.
Blindness ; physiopathology ; rehabilitation ; Electric Stimulation Therapy ; instrumentation ; Electrodes, Implanted ; Evoked Potentials, Visual ; physiology ; Humans ; Microelectrodes ; Prosthesis Implantation ; Retina ; physiopathology

Blood Vessel Prosthesis Implantation ; instrumentation ; methods ; Femoral Artery ; surgery ; Humans ; Limb Salvage ; Peripheral Vascular Diseases ; surgery ; Stents