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Biomedical subjects

D A Gough

Publications and source records attributed to D A Gough.

16 recordsLinked to original sources
PubMed1991

Design and validation of the transparent oxygen sensor array.

A new oxygen monitoring system has been developed that consists of an array of transparent, independently-connected oxygen sensors mounted on a glass plate. This system is intended for continuous monitoring of oxygen at multiple locations on the surface of exteriorized tissues, while simultaneously visualizing microvascular activity. The sensor array is fabricated by techniques similar to those employed for semiconductors, which facilitate customization of sensor size and pattern to best monitor oxygen in a given physiologic preparation. Methods are described for characterizing the performance of the sensor array in vitro, including studies on the oxygen sensitivity, stability of the signal, and detection of oxygen gradients. An example of in vivo application of the sensor array is also presented.

Animals↗
PubMed1990

Application of chronic intravascular blood glucose sensor in dogs.

An intravenous glucose sensor was implanted in six dogs for 1-15 wk. The glucose sensor is a flexible cylinder, approximately 0.2 cm diam and 30 cm long, with a tip containing immobilized glucose oxidase and catalase coupled to a potentiostatic O2 sensor. The sensor and a similar O2 reference sensor were implanted in the superior vena cava near the entrance of the right atrium. The sensor response was conveyed externally either by a telemetry system implanted nearby, surgically accessed leads, or chronically maintained percutaneous leads. Summing over the six implants, there was a total implantation period of 333 days during which glucose sensors were functional on demand. The sensor response showed agreement with conventionally assayed blood samples after accounting for a response lag. Sensor response to glucose showed little change over the implant period. Biocompatibility, enzyme lifetime, O2 availability, O2 sensor stability, and biochemical interference were not limitations. Results demonstrated that this sensor can function effectively as an implant in dogs for a period of months and has the potential for long-term operation.

Animals↗
PubMed1989

Physiological preparation for studying the response of subcutaneously implanted glucose and oxygen sensors.

A physiological preparation has been developed for studying the response of glucose end oxygen sensors chronically implanted in subcutaneous tissues. The preparation employs a chamber permanently mounted on the back of a rat that supports the growth of vascularized subcutaneous tissue around the sensors and is used in conjunction with chronic intravascular catheters for blood sampling and fluid infusion. A total of 26 glucose and oxygen sensors were implanted in nine chambers. At 10 days, the tissue surrounding the sensors was cellular, well vascularized and permeable. Glucose sensors responded to glucose infusions with a 10-15 minute lag.

Animals↗
PubMed1986

A transparent oxygen sensor array.

The development of a transparent array of independently connected oxygen sensors is described. With an appropriate sensor pattern, this device may be useful to monitor the distribution of oxygen on the surface of tissues, while permitting simultaneous tissue visualization. The electrochemical characteristics of individual oxygen sensors are examined and models are proposed for the distribution of oxygen in the vicinity of individual sensors.

Biomedical Engineering↗
PubMed1976

Rubella 1974 and its aftermath, congenital rubella syndrome.

An epidemic of rubella reached its peak in the Atlantic provinces in 1974, subsiding in early 1975. With the exception of Quebec the remainder of Canada showed a reverse trend, with a large increase in the numbers of cases reported in the first 41/2 months of 1975. The Halifax virus laboratory reported 106 serologically proven cases of rubella in 1974, 44 of them in pregnant women. In the aftermath of the epidemic many infants were born with the congenital rubella syndrome (CRS). A study carried out from Sept. 1, 1974 through Apr. 30, 1975 showed an 80% correlation between clinical diagnosis and the presence of rubella-specific IgM antibodies in 35 of these infants. Of the 23 infants in whom the diagnosis of CRS was made by laboratory or clinical findings or both, laboratory criteria were met in 20 (87.0%), clinical criteria in 19 (82.6%) and both laboratory and clinical criteria in 16 (69.6%).

Antibodies, Viral↗
PubMed1973

Enzyme electrodes.

From the discussion of electrodes and enzymes herein, and from the accounts of enzyme electrodes that have appeared in the literature, clinical determinations of certain metabolites and soluble enzymes by means of enzyme electrodes seem quite feasible. Such devices may be made highly specific by the use of appropriate enzymes and a high degree of accuracy can be obtained. Instantaneous and continuous determinations can be made from physiological fluids, and undesirable physiologic responses can theoretically be minimized, thus making long-term clinical monitoring a possibility. Enzyme electrodes may also have a useful lifetime and meet other practical requirements.

Catalase↗