PubMed HealthSearch

Biomedical subjects

M Armstrong-James

Publications and source records attributed to M Armstrong-James.

4 recordsLinked to original sources

Carbon fibre microelectrodes.

A technique for making recording microelectrodes containing an ultrafine carbon fibre is described. This technique can be used for single- and multi-barrel microelectrodes. These microelectrodes not only have a very low signal-to-noise ratio comparable with that found in tungsten microelectrodes but are simpler to make. When used in a multi-barrel array for iontophoretic application of drugs the carbon fibre microelectrode has many advantages over a fluid electrolyte-filled recording barrel, including very high signal-to-noise ratio and relative immunity to spike distortion during application of iontophoretic current.

Animals

Automated high-speed analysis of gastrointestinal myoelectric activity.

The value of myoelectric recording in the gastrointestinal tract has been limited by the difficulty of analyzing the prolonged recordings which are required to demonstrate integrated physiological activity. This problem has been solved by the use of a tape recording system with accelerated replay, originally developed for cardiac monitoring. Rapid replay not only reduces the time required for data retrieval but also increases the frequency of the recorded signals to allow electronic separation of fast and slow wave activity for on-line conversion into digital pulses suitable for computer analysis. The technique is illustrated by the analysis of an imperfect prolonged multichannel recording of cannine gastrointestinal myoelectric activity, demonstrating some of the possibilities for data analysis and error detection inherent in the system.

Animals