Details are described of a simulated body shape utilized to determine patient dosimetry within whole body ultraviolet treatment cabinets. The body shape was designed to have a shape characteristic of the patient group undergoing treatment and was utilized in several Waldmann whole body treatment cabinets and with irradiance measurements undertaken using a Bentham DM150C spectroradiometer. It was considered that the rigid defined structure of the body shape allowed satisfactory reproducibility of measurements in such cabinets and also allowed additional parameters to be identified for evaluation of performance of such units.

An advantage of a holistic model of respiration is that it can embrace a wealth of clinical data to help in validation. Once accepted as valid it can then be used predictively in clinical practice. The holistic model is itself formed from a set of models which represent current concepts of the function of different parts of the overall system, e.g. the Riley three-compartment model of the lung, the concept of tissue storage compartments for gases, the idealization of fully stirred pools of blood. Mathematical representations of physiological concepts are linked together, within limits of clinical accuracy; this allows the model to be used by students of physiology and other preclinical disciplines. It also becomes possible to pose searching questions of clinical relevance which go beyond what can be taught in textbook form. With a holistic model the interaction between bodily processes may be shown. The student may experiment, observe and analyse data far more powerfully than mental manipulation of concepts alone would permit. With a holistic model there is also the potential for obtaining a better representation of each subsystem since the setting of rather arbitrary boundary conditions can be avoided.The model of human respiration 'MacPuP (Dickinson, 1977,

Intense pulsed light systems are currently in widespread use in clinical applications. Verification of spectral content and associated pulse waveforms is, however, not featured in product support and calibration. A measurement system was developed to determine the spectral output of such sources within a series of discrete wavelength intervals. Such a system utilised a series of 11 broadband optical filters with centre wavelengths within the range 450-950 nm in circuit with silicon photodiodes as optical detectors. Signals were captured using a low cost 8-channel 16-bit universal serial bus data capture module interfaced to a laptop computer. This allowed the pulse profile of selected filter components to be separately captured and analysed. Calibration of individual filter channels was undertaken using a Bentham dmc150 spectroradiometer and reference tungsten light source. Initial measurements undertaken of the intense pulsed light output of a Lumenis One system using the system are described.

A routine review of light exposure within a neonatal intensive care unit is described following the introduction of a new model of neonatal phototherapy lamp. Spectral measurements were undertaken using a Bentham Dmc150 spectroradiometer system. Safety assessments were undertaken based on likely exposure of parents at the cot side, neonates in adjacent cots and the effectiveness of eye protection for neonates with direct phototherapy. An aphakic eye response was used for assessment of neonatal risk and the blue-light response for estimation of adult exposure using current ICNIRP guidelines. Such estimations indicated exposure levels of parents at the cot side and neonates in adjacent cots were within current established safe limits. The level of light blocking provided by the available neonatal eye protection was estimated to be entirely adequate and presented no hazard to the infant when correctly positioned over the neonate. It is likely, however, that an increased safety factor is potentially present for the neonate due to the fact that the neonate's eyes will typically be shut for over 50% of the time. It is identified, however, that the aphakic response is essentially associated with mature adult retinal cells, and that the maturing cells of the neonate may exhibit additional light sensitivity, especially in the case of premature infants. Changes in neonatal physiology associated with neonatal phototherapy are discussed, which may influence mechanisms of light-induced retinal damage.