This paper describes the fabrication of pressure-driven, open-channel microfluidic systems with lateral dimensions of 45–300 microns carved in omniphobic paper using a craft-cutting tool. Vapor phase silanization with a fluorinated alkyltrichlorosilane renders paper omniphobic, but preserves its high gas permeability and mechanical properties. When sealed with tape, the carved channels form con...

OBJECTIVES The present study evaluates complete supra-annular bioprostheses in patients with an aortic annulus of 18 to 23 mm in diameter. BACKGROUND Aortic valve replacement in patients with small aortic annulus using stented bioprostheses is often associated with unsatisfactory hemodynamic results and high incidence of patient-prosthesis mismatch. METHODS Between February 2000 and January...

BACKGROUND To evaluate normal regurgitant characteristics of St. Jude (SJ) and Medtronic-Hall (MH) mitral valves, four sizes (25-31 mm) of each were studied in a pulsatile flow model. METHODS AND RESULTS Regurgitant flow was measured by flowmeter at left ventricular pressures of 80, 130, and 180 mm Hg. Peak regurgitant flow rates ranged from 6.2 to 12.7 cm3/sec in SJ valves and from 7.9 to 17...

This paper describes the fabrication of pressure-driven, open-channel microfluidic systems with lateral dimensions of 45-300 microns carved in omniphobic paper using a craft-cutting tool. Vapor phase silanization with a fluorinated alkyltrichlorosilane renders paper omniphobic, but preserves its high gas permeability and mechanical properties. When sealed with tape, the carved channels form con...

This paper presents a microfluidic system for the active and precise control of microdroplet division in a micro device. Using two horizontal pneumatic valves formed at downstream of bifurcating microchannel, flow resistances of downstream channels were variably controlled. With the resistance control, volumetric ratio of downstream flows was changed and water-in-oil microdroplets were divided ...

The proposed hybrid control employs a primary expansion valve that provides most of the pressure drop, while small secondary balancing valves in the distributor lines to the evaporator circuits adjust the refrigerant flow to provide equal circuit exit superheats. This paper presents experimental results for application of hybrid control of expansion valves to a 5-ton R410A domestic heat pump. B...

Both echocardiography (specifically transesophageal echocardiography [TEE]) and multidetector row computed tomography (MDCT) have played an integral role in preprocedural planning for transcatheter aortic valve replacement, heavily influencing the moniker of “multimodality imaging.” The strengths of each modalities are complementary (Table), although there is overlap between the preprocedural a...

An easy to fabricate, thermally-actuated, self-regulated hydrogel valve for flow control in pneumatically driven, microfluidic systems is described. This microvalve takes advantage of the properties of the hydrogel, poly(N-isopropylacrylamide), as well as the aqueous fluid itself to realize flow control. The valve was designed for use in a diagnostic system fabricated with polycarbonate and aim...

Atrioventricular annuli are important in haemodynamic flexibility, competence, and support for tricuspid and mitral valves. The anatomical features of the annuli, such as circumference, organisation of connective tissue fibres, myocardium, and cellularity, may predispose to annular insufficiency and valvular incompetence. These pathologies occur more commonly in females, although the anatomic...