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Biomedical subjects

A E Bunn

Publications and source records attributed to A E Bunn.

5 recordsLinked to original sources

Assessing malnutrition in gastric carcinoma: bioelectrical impedance or clinical impression?

The value of bioelectrical impedance (BI) as an index of body composition was assessed in 32 patients with gastric carcinoma, 20 with advanced disease. Bioelectrical impedance was compared with standard nutritional parameters: weight, body mass index (BMI), albumin, transferrin and triceps skinfold thickness. There was no correlation between BI and these parameters with the exception of weight and BMI in the male patients. Clinical assessment of nutrition on the other hand correlated well with the standard parameters. Although BI may be a useful adjunct to the routine assessment of nutritional status in normal subjects, its use in clinical patients should be treated with caution, particularly in those with advanced gastrointestinal malignancy.

Adult

The estimation of tube wall compliance using acoustic input impedance.

An acoustic-electric analog and transmission line theory have been used to examine acoustic wave propagation in a tube with a compliant wall. The input impedance (i.e., input pressure-flow) has been simulated using a distributed element model. A relative minimum and maximum, denoted by fr and f2, respectively, that are independent of tube length have been identified theoretically and confirmed experimentally from input impedance measurements on a compliant tube. A method has been devised which uses measured values of fr and f2 to deduce the tube wall properties from the theoretical model. This method has been validated on a tube with known wall properties determined using standard methods. In practice, the input impedance is measured through a short section of rigid connecting pipe. In this case fr remains constant while f2 is reduced. This reduction can be accounted for by the volume compliance of the gas within the lumen of the rigid pipe. The theory could have useful applications such as estimating the wall properties of the airways from noninvasive measurements made through the mouth.

Acoustics

A comprehensive on-line computerised lung function screening test.

An on-line computerised lung function screening test is described which prints out 22 lung function parameters and a functional diagnosis. The complete test with print-out data takes less than 8 min per patient which implies that more than 60 out-patients can be 'screened' per day. Furthermore, for patients about to undergo major surgery a lung function operative risk grading is also available. The developed computer system is comparatively inexpensive, simple to operate and can be immediately on-lined to most apparatus without special interfacing. The total screening system can be operated by a single technologist and the required respiratory manoeuvres can be performed by almost all patients irrespective of the degree of lung function impairment. Although comprehensive in itself the screening test has been invaluable in deciding upon which patients require more intensive and time-consuming lung function investigations.

Computers

A new lung function index: the area under the maximum expiratory flow-volume curve.

A new lung function index, the area under the maximum expiratory flow-volume curve (AFVx) is described. A predicted AFVx based on age, sex and height is determined, and the measured to predicted AFVx ratio is assessed by comparison with other established lung function parameters. This ratio appears to be a very sensitive indicator of the degree of lung function impariment.

Age Factors