Chris Ray

Publications (2)0 Total impact

• Source

  Available from: Esteve Farres

  Article: A dry electrophysiology electrode using CNT arrays

  Giulio Ruffini, Stephen Dunne, Esteve Farres, Josep Marco-Pallares, Chris Ray, Ernest Mendoza, Ravi Silva, Carles Grau
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  ABSTRACT: We describe the concept of a dry electrode sensor for biopotential measurement applications (ENOBIO) designed to eliminate the noise and inconvenience associated to the use of electrolytic gel. ENOBIO uses nanotechnology to remove gel-related noise, as well as maintaining a good contact impedance to minimise interference noise. The contact surface of the electrode will be covered with an array/forest of carbon nanotubes and will also be tested with an Ag/AgCl coating to provide ionic-electronic transduction. The nanotubes are to penetrate the outer layers of the skin, the Stratum Corneum, improving electrical contact. We discuss requirements, skin properties, nanotube penetration and transduction, noise sources, prototype design logic and biocompatibility. A future paper will report test results.
  11/2005;
• Source

  Available from: Giulio Ruffini

  Article: Stationary Phase in Coherent State Path Integrals

  Chris Ray, Giulio Ruffini
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  ABSTRACT: In applying the stationary phase approximation to coherent state path integrals a difficulty occurs; there are no classical paths that satisfy the boundary conditions of the path integral. Others have gotten around this problem by reevaluating the action. In this work it is shown that it is not necessary to reevaluate the action because the stationary phase approximation is applicable so long as the path, about which the expansion is performed, satisfies the associated Lagrange's equations of motion. It is not necessary for this path to satisfy the boundary conditions in order to apply the stationary phase approximation.
  02/2001;