Higher energy-efficiency, readily transportable incubators

Transport incubators are devices used to house and protect premature or small babies individually during journeys between home and hospital or between hospitals, often in circumstances where the maintenance of comfortable environmental conditions within the incubators is essential for the survival of the infants. During use, the transport incubator has to frequently rely for its energy supply solely upon the storage capacity of a [`]built-in' electric battery, which is the principal inhibiting factor limiting the available performance and duration of operation. During the present study of the environmental and engineering factors which affect the performances of such transport incubators, carried out for Air-Shields Vickers plc, consideration has been given to the use of two technologies to seek to improve both the quality of the artificially created internal environment in the incubator and the duration of operation independent of external electricity supplies. In particular, consideration has focused upon two possibilities:1. 1. The use of a thermoelectric heat-pump (a) as a substitute for the conventional resistance heater within the incubator, so that the utilisation of the existing electric-battery charge would thereby be enhanced; and (b) to provide active refrigeration within the incubator without incurring the problems of noise and vibration normally associated with the presence of a compressor refrigerator.2. 2. The potential for stored thermal energy to augment the energy-storage capacity of the electric battery. It has been shown that the use of a thermoelectric heat-pump can approximately triple the duration of use per electric-battery charge, as well as provide refrigeration cooling without incurring a significant weight penalty. The cost of the thermoelectric heat-pump is less than the additional expense incurred for the larger battery, which would otherwise be necessary to achieve the required operational duration. Also weight penalties would be involved in the use of a larger battery. Employing a supplementary thermal-store has been shown to be feasible and desirable, so that any heat lost during the permitted short-period, intermittent access to the incubator under adverse weather conditions can be [`]made good' rapidly. This requires a very high but transient supply of heat.