The Alarm Burden of Excess Continuous Pulse Oximetry Monitoring Among Patients With Bronchiolitis

Guidelines discourage continuous pulse oximetry monitoring of hospitalized infants with bronchiolitis who are not receiving supplemental oxygen. Excess monitoring is theorized to contribute to increased alarm burden, but this burden has not been quantified. We evaluated admissions of 201 children (aged 0-24 months) with bronchiolitis. We categorized time ≥60 minutes following discontinuation of supplemental oxygen as “continuously monitored (guideline-discordant),” “intermittently measured (guideline-concordant),” or “unable to classify.” Across 4402 classifiable hours, 77% (11,101) of alarms occurred during periods of guideline-discordant monitoring. Patients experienced a median of 35 alarms (interquartile range [IQR], 10-81) during guideline-discordant, continuously monitored time, representing a rate of 6.7 alarms per hour (IQR, 2.1-12.3). In comparison, the median hourly alarm rate during periods of guideline-concordant intermittent measurement was 0.5 alarms per hour (IQR, 0.1-0.8). Reducing guideline-discordant monitoring in bronchiolitis patients would reduce nurse alarm burden.

Valve-Actuator-Integrated Reference Electrode for an Ultra-Long-Life Rumen pH Sensor

We demonstrated a newly developed Ag/AgCl reference electrode- with a valve-actuator for two years or longer rumen pH monitoring. Previous studies on pH sensors reported that the short lifetime of Ag/AgCl reference electrodes is caused by an outflow of internal electrolyte. We introduced a valve-actuator into a liquid junction to reduce the outflow by intermittent measurement. The results indicated that the potential change when switching the liquid junction was less than 0.5 mV and its response time was less than 0.083 s. In the 24-h potential measurement with the valve-actuator-integrated reference electrode (VAIRE), the valve was actuated once every hour, and the standard deviation of the potential was 0.29 mV. The lifetime of the VAIRE was estimated at 2.0 years calculating from an electrolyte outflow, which is significantly longer than that of conventional reference electrodes. A pH sensor using the VAIRE was estimated to operate for 2.0 years with the pH error ≤0.1, which meets the requirement of cows’ rumen pH monitoring.

Multi-Mobile Sensing With Temporal-Spatial Coupling via Compressed Sensing

In this paper, the problem of using a limited number of mobile sensors to sense/measure a time-varying distribution of a field over a multi dimensional space is considered. As the number of sensors, in general, is not adequate for capturing the dynamic distribution with the needed spatial resolution, the sensors are required to be transited between the sampled locations, resulting in intermittent measurement at each sampled location. Therefore, it becomes challenging to use the measured data to recover/restore not only the dynamic process at each sampled/measured location, but also the dynamic distribution over the entire measured space, with high temporal and spatial resolutions. Such a multi-mobile sensing problem, however, cannot be addressed by using existing methods directly. In this work, we propose to tackle this problem through the compressed sensing framework. The randomness requirement of the compressed sensing, however, results in the temporal-spatial coupling, and the constraints in selecting the sampled locations due to the limit of the sensor speed. We propose a spatial-temporal pairing method to avoid the temporal-spatial coupling, and a checking-and-removal process to remove the sensor speed constraint. Simulation results of a video recovery example is presented and discussed to illustrate the proposed method.