Instrumentation for the detection and interruption of apnea episodes for premature newborn

Abstract

Apnea of prematurity is very frequent in premature newborns (PNB). If the apnea episode is not interrupted in time, it can cause several damages to the newborn's central nervous system. In this paper, we introduce a novel technology for detecting apnea of prematurity episodes, based on cardiac pulse frequency (PF) and arterial oxygen saturation (SpO2) simultaneously, and using vibrotactile stimulation to interrupt such episodes. The thresholds of the newborns' PF and SpO2 had been established to identify the apnea episode automatically through the proposed system: for babies ≤ 35 weeks gestation, PF is ≤ 100 bpm and SpO2 ≤ 80%; for babies > 35 weeks gestation, PF is ≤ 80 bpm and SpO2 ≤ 80%. The system used vibrotactile stimuli at 250 Hz for 4 s. To manage the system that activates the vibratory device automatically and registers those parameters, a program had been developed. It registers apnea occurrence, period of manual stimulation and vibratory stimulation duration. This technique was tested on 4 PNB. It was observed 10 apnea episodes and the device was successful in the detection of all of them. The vibrotactile stimulation was capable of promoting the return of respiratory movements in 9 of the 10 detected events of apnea and seemed to be a promising means of handling them.

Treatment options for apnoea of prematurity

“…A limited study of four newborns with AOP used vibrotactile stimulation in response to abnormalities of heart rate and O 2 saturation to shorten apnoeic events 36. It had previously been observed that shorter episodes of apnoea are associated with behavioural arousal, raising the possibility that providing exogenous arousal could help shorten or even prevent apnoeic episodes.…”

Effect of Tactile Stimulation on Termination and Prevention of Apnea of Prematurity: A Systematic Review

“…The sample size ranged from one to four infants with a median of four infants. The mean GA varied between studies from 28 to 31.25 weeks and the mean birth weight varied from 1,280 to 1,495.5 g. Two studies only reported inclusion criteria instead of mean values for GA and birth weight ( 19 , 22 ). In one study, aminophylline was administered during the study, which started 7 days after birth ( 23 ).…”

“…The included studies described different study designs: two observational ( 22 , 24 ) and two randomized crossover studies ( 19 , 23 ). In the observational studies the amount of successfully terminated apneas were compared with the total amount of apneas.…”

“…There was a considerable variation between the studies in the detection of apneas and stimulation systems used. Camargo et al ( 22 ) used heart rate (HR) and oxygen saturation measurements to identify apnea. A decrease in oxygen saturation or HR below the set threshold of 80% and 80 or 100 bpm automatically actuated a vibrating disk attached to the infants’ thorax, which exerts a vibration of 250 Hz for 4 s. Frank et al ( 24 ) also used a closed-loop system.…”

“…However, the response time was not significantly reduced as the nurse had to actuate the mechanical stimulation. In contrast to this, Frank et al ( 24 ) and Camargo et al ( 22 ) used a closed-loop system to study the effect of stimulation on the termination of apnea. The devices were able to terminate 90% of all apneas, but these results were not compared with manual stimulation.…”