Biomedical subjects

Y O Chia

Publications and source records attributed to Y O Chia.

3 recordsLinked to original sources

PubMed1979

Development of a closed-loop artificial pancreas.

A closed-loop glucose controlled insulin infusion system was developed, consisting of elements for continuous blood glucose analysis, a computer control system, and infusion systems. Improvements include decreased size, cost reduction and better performance. The algorithm used was a piecewise linear representation of the sigmoidal curve commonly employed. The apparatus has been applied to simulation of the healthy beta cell and glucose clamp studies.

Artificial Organs↗

PubMed1977

Control of blood glucose in diabetics using an artificial pancreas.

Studies have been performed using an on-line computer system programmed for blood gucose control of insulin and dextrose infusion (artificial pancreas). The aim of these studies was to test performance of the artificial pancreas and to suggest directions for future optimisation. Blood glucose stabilisation studies of diabetic volunteers were extended throughout the day and included three main meals and light exercise periods. Monitoring of blood glucose profiles of the same diabetics after depot insulin were performed on a separate occasion for comparison. The presence of insulin antibodies did not impair operation of the artificial pancreas. Most of the insulin infused by the artificial pancreas was to initially correct hyperglycaemia with relatively little required to subsequently maintian euglycaemia. The afternoon intra-meal average infusion rate was 0-9 U/hr. It is suggested that correction of fasting hyperglycaemia and maintenance of euglycaemia in diabetics be treated as separate control problems for the artificial pancreas. The overall ability of the artificial pancreas to control blood glucose to a degree not attainable by conventional insulin therapy is confirmed, in this case under conditions which include patient activity.

Adult↗

PubMed1975

Carrier solutions for low-level intravenous insulin infusion.

In the use of low-level intravenous insulin infusion for treating diabetic hyperglycaemia and ketoacidosis adsorption of insulin to containers or plastic infusion apparatus results in significant losses of 60-80% of insulin in dilute physiological saline solution (40 U/l). It is therefore necessary to add protein to the carrier solution to minimize losses and maintain a constant delivery rate. Recovery studies showed that 3.5% w/v polygeline solution (polymer of degraded gelatin) was a suitable medium for this purpose, offering some advantages over human serum albumin. A minimum concentration of 0.5% polygeline was required to ensure adequate delivery of insulin to the patient.

Biological Availability↗