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Biomedical subjects

J D Gaylor

Publications and source records attributed to J D Gaylor.

50 records · Page 3Linked to original sources
PubMed1976

Banked blood microfiltration. I. Microfilter composed of five polyurethane foam layers with graded pore size.

Aggregates of amorphous material which develop with storage of banked blood may be a source of pulmonary microembolism in patients having massive transfusions. In order to remove such debris, blood microfilters have been developed and are in routine clinical use. This paper describes the evaluation of one such filter, the Bentley PF 127 model B, which is composed of five layers of polyurethane foam. The time of filtration as a function of the pressure applied, the number of particles removed, the observed changes in blood cells, and the results of scanning electron microscopy of the filter after filtration of human banked blood, are reported.

Blood Banks↗
PubMedDate not supplied

Development of a blood urea monitoring system for the closed loop control of dialysis.

Optimal hemodialysis prescription through real-time blood urea (BU) monitoring and closed loop control of urea removal would be of significant clinical value. Progress toward a bedside BU analyzer and a control system is described here. An Amicon Minifilter inserted into the arterial bloodline provides a 1 ml/min stream of protein free ultrafiltrate for analysis. In vitro tests with bovine blood have shown excellent correlation between plasma (CP) and ultrafiltrate (CU) urea levels: CP = 0.961CU + 0.071, (n = 34, r = 0.998). In clinical hemodialysis studies, CU accurately represented the decay in CP. The BU analyzer uses a standard UV endpoint assay with a proportioning roller pump. The absorbance of the reacted mixture is read in a spectrophotometer after a 5 min incubation. For future control system design, the transfer function (TF) of the BU analyzer was measured using multifrequency binary testing. The data indicated that the analyzer may be modeled by a second order TF with a pure time delay. The same form of TF was also found to describe the Minifilter. Control of the removal rate of NaCl (substituted for urea) through automatic dialysate flow adjustment has been achieved with a simulated dialyzer-patient circuit (using a conductivity probe in place of the BU analyzer). A modified BU analyzer using computer controlled precision syringes for improved sample processing time and accuracy is also reported.

Animals↗