APPARATUS FOR MEASURING BLOOD PRESSURE OF LABORATORY ANIMALS

摘要

An apparatus for measuring blood pressure of laboratory animals e.g. rats, comprising respective cages (10) for accomodating the animals that have a bottom (11) which is preheated between 33 and 35` C to intensify circulation of the animals. Respective cuffs are arranged around the tails of the animals pressurized by a common pressure actuator (23). The cuffs comprise optical pulse sensors coupled to respective measuring channels of a measuring and filter unit (30) with steep low-pass characteristics having cut-off frequencies under 10 Hz to eliminate disturbing noise effects. The operation is controlled by an evaluating unit (40). In the method for measuring the blood pressure, the pressure is established and changed simultaneously for each animal located in preheated cages, and in each channel the pressure corresponding to the occurrence of the first sensed beat pulse is stored and regarded as a blood pressure value if an undisturbed pulsation is going on with predetermined conditions after the first beat. The measurements are carried out in a sequence of measuring periods and the corresponding results are evaluated by mathematical statistical technique for each animal. If the results cannot be evaluated, new measuring sequences are started.