A sound spectrogram analysis of children's crying after painful stimuli during the first year of life

In a prospective study we tested the hypothesis that a cry from an infant can be used as part of an instrument to measure pain. Ten healthy newly born infants were subjected to painful stimuli on four occasions during their first year of life. The sound of the crying was analysed with regard to duration. With the help of a sound spectrogram, the fundamental frequencies of the first five crying sounds were analysed. The number of crying sounds decreased with age. There was a considerable difference between the 10 children, and also between the different pricking occasions for the respective children. We conclude that if crying is to be used as part of an instrument for measuring pain, the child's age has to be taken into account

Comparison of sprinkler activation times under flat and corrugated metal deck ceiling

The distance of sprinklers below ceiling is of fundamental importance since it has a great influence on activation time. Accepted distances are specified in different sprinkler standards such as NFPA 13, FM 2-0 and EN 12845 for different configurations. This distance is unambiguously defined for flat smooth ceilings, but for corrugated ceilings, such as corrugated metal deck ceilings found in many warehouses, the distance can be measured from either the top or the bottom of the deck. NFPA 13 states that it should be measured from the bottom if the thickness of the deck is below 75 mm and from the top if it is higher. The requirement in NFPA 13 has been adopted from the FM datasheets, but the authors have been unable to identify any background to this requirement. In this paper, the activation time of sprinkler heads at different distances below a corrugated ceiling with thickness of 125 mm was simulated using FDS 6.6.0 and compared to distances below a flat smooth ceiling. The case was based on a warehouse with 6-tier storage of Uncartoned Expanded Plastics (UEP) with a ceiling height of 11.2 m and clearance to storage of 2.6 meters. Only the activation of the first sprinkler was simulated since it was expected that the drag from droplets of previously activated sprinkler heads would thicken the ceiling jet, making the activation time of additional sprinkler less sensitive to the distance from ceiling. The results show that the corrugated ceiling has a large influence on the ceiling jet allowing sprinklers further from the ceiling to activate. In the case studied, the activation time of sprinklers below the corrugated ceiling more closely resembled those under a flat smooth ceiling when the distance below the corrugated ceiling was measured from the bottom of the deck. More simulations and experiments are however needed before any guidance on changes in sprinkler standards can be given

Newborn pain cry analysis based on pitch frequency tracking.

The aim of the newborn pain cry analysis is to test the hypothesis that cry can be used as a tool to detect signs of nocioceptive pain. Previous studies applying signal processing techniques to analyze the sound of these cries have been done. The subject of this paper is to adapt and improve the original method with the help of new signal processing methods. The pitch frequency is extracted from the waveform of the recorded babies' cries using time domain methods. The fluctuations of this parameter are analyzed in terms of jitter. In particular, a sliding buffer approach is presented, as well as an improvement of the Average Mean Difference Function (AMDF). Comparison between original and news results has been done

Newborn infants' cry after heel-prick: analysis with sound spectrogram

The aim of the study was to test the hypothesis that a newborn infant's cry can be used in conjunction with an instrument to measure pain. Crying due to pain was analysed after a heel-prick stimulus. In a prospective, descriptive study, 50 healthy newborn infants were subjected to a heel-prick for phenylketonuria screening. Their cries of pain were recorded and analysed. Duration of the crying sound was analysed and, using a sound spectrogram, the fundamental frequency and the cry melody of the first five cry sounds were analysed. The analysis showed that the crying sound after the painful stimulus of the heel-prick had a significantly higher fundamental frequency and lasted longer at the first than at the fifth cry. The first cry had a more varied crying melody than the fifth. There were large differences between individual cries from a single infant, as well as in the duration of each cry, total crying time, and fundamental frequencies between infants. While the first cry was more like a cry of pain, the fifth cry more resembled crying for reasons other than pain. The results suggest that newborn infants react to pain in a recognizable way. However, other stimuli may cause a similar reaction. Crying can therefore be used to measure pain in newborn infants only when the cause of crying is known