Search PubMed⌕ Search

Biomedical subjects

C V Nelson

Publications and source records attributed to C V Nelson.

30 records · Page 2Linked to original sources
PubMed1975

Determination of the locus of the heart vector from body surface measurements: model experiments.

Based on the Gabor-Nelson equations a technique is described for measuring the location of the resultant heart dipole (locus-cardiogram). The technique uses three rows of eight electrodes, a head and a foot lead. Experiments with a male and a female human torso model showed good agreement between actual andmeasured dipole locations. The presence of intrathoracic electricla inhomogeneities shifts theapparetn locus of the dipole toward the highly conductive mass. The conductivity of the volume conductor and the dipole monent value do not introduce any error into the computed locus of the dipole. It is concluded that the technique is accurate and simple enough to be used for experimental and clinical observation.

Body Surface Area↗
PubMed1975

Sum of two vectors having an included angle greater than ninety degrees.

If the angle between two vectors is acute an increase in either vector will increase the resultant. If the angle is obtuse, however, an increase in one vector may either decrease or increase the resultant. A mathematical derivation and a simple geometric construction are presented. The theory is applied to vectors in the horizontal plane in right ventricular hypertrophy. It is shown that as the right ventricular vector is increased from a small value, the resultant vector may first decrease and then increase again with a continuous clockwise rotation.

Cardiomegaly↗
PubMedDate not supplied

Micrografts. II: Evaluation of 25:1, 50:1, and 100:1 expansion skin grafts in the porcine model.

This study was undertaken to evaluate 25:1, 50:1, and 100:1 expansions of micronized skin grafts in a porcine model. Two full-thickness skin excisions (graft and control) were performed on each of 30 immature pigs (20 pounds). The pigs were divided into three groups of 10 animals each: group A, 25 cm2; group B, 50 cm2; and group C, 100 cm2. One square centimeter of the excised skin was thinned to produce a thick split-thickness skin graft. Four 90-degree passes were made through a skin mesher with the smooth side of the plastic mesh carrier to produce uniform pieces of skin. These pieces were applied to one area on each pig. Both the graft and control sites were covered with film. The film was removed on postoperative day 7, and excision sites were photographed on postoperative days 7, 10, 14, and 21. Healing was evaluated with a 12 x 12 inch digitizing pad to estimate the percent area healed. Healing was compared via analysis of variance, with percent area healed used as the dependent variable and treatment (control or graft) and postoperative day and expansion size used as the independent variables. No difference was found on postoperative day 7. On postoperative day 10, 25:1 grafts healed better than the 50:1 grafts, which were healed more than the 100:1 grafts. No difference was seen between 25:1 and 50:1 grafts on postoperative day 14; however, they were healed better than the 100:1 expansion grafts. No difference was seen between the graft sites on postoperative day 21.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗