Department’s Foetal Heart-Rate Recorder

Press, Volume C, Issue 29587, 9 August 1961, Page 20

Department’s Foetal Heart-Rate Recorder

Successful efforts have been made at the Auckland industrial development laboratories of the Department of Scientific and Industrial Research to construct a foetal heart-rate recorder, says the annual report of the department. The report says the foetal pulse rate is one important indication of a baby's condition before and during labour, a period when the foetus may be subjected to many stresses, and when there is a need for a reliable method of indicating any onset of foetal distress without delay. The recording of the foetal heart rate is, however, complicated by the presence of the much more powerful maternal heart pulse and the many other sources of interference that occur during labour. The heart-recorder developed at the laboratories uses a heart-sound pickup which delivers this conglomeration of sounds to a system which is specially designed to deal with a foetal pulse which may be for most of the time

even below the level of background -noise. This is accomplished by first sensing the rate of change of the pulse rate and excluding all pulses whose periods differ by more than say 10 per cent, per pulse. To do this, a voltage analogue is produced proportional to each pulse period, and the analogues of the last two consecutive pulses are stored and compared. If the voltages differ by more than the pre-set limit the last pulse period is rejected, and recording does not resume until consecutive pulses are once more within the limit. It is not inconceivable that noise impulses may occur with a periodic difference within the acceptable limits, but it is unlikely that such a coincidence would persist for more than a few consecutive pulses. A delay circuit is therefore provided which ensures that the rate is not recorded unless a certain number of consecutive pulses occur within the acceptable limit. The instrument, therefore.

Luigi Infantine, the Italia®' tenor, needs little introduction to New Zealand audiences on this, bis third vtait to the country. He will give concerts at the Theatre on August -2 and Since his last New Zealand tour, in 1957, Infantine has toured extensively in Britain. Europe. Scandinavia, Russia.. Malaya. Ceylon. South America and South Africa. - Although concert tours and, recordings occupy most oL his time. Infantino still makes appearances in star roles at La Scala and other, great opera houses in Italy. Luigi Infantino was born in Racalmuto in Sicily on April, 24, 1921. He studied in Parma and made his operatic debut there in 1943. He signed an, extended contract with the Teatro San Carlo in Naples, he came to London with this, company in 1946 and gave, several ’ performances at the. Royal Opera House, Covent Garden. Luigi Infantino made his. debut art La Scala Milah during the first opera season,’ after the war, for the opening of the theatre after i{B reconstruction. Infantino is married to the famous Italian classical actress, Sarah Ferrati, and they have one daughter, Monaca. , The photograph above shows Luigi Infantino as the Duke of Mantua in the 1958; Covent Garden production of ’’Rigoletto.”

writes the record only when it is satisfied that consecutive true pulses are being received and leaves small blank spaces in the periods when no useful information has been received. A continuous record of foetal heart rate is therefore plotted on a paper chart recorder.