Noninvasive RIP device may accurately measure breathing patterns in children
A novel noninvasive respiratory inductance plethysmography (RIP) monitor may provide instantaneous measures of breathing indices on a tablet computer, providing the data required for diagnosis and evaluation of the severity of a certain respiratory disorder and subsequent initiation of respective treatments, according to a study.
RIP, in addition to pneumotachography, allows analysis of pulmonary function (PF) and tidal breathing in patients who may have minimal cooperation because of their age or disease severity. PF is particularly essential in the diagnosis and management of paediatric respiratory diseases.
Named pneuRIP, the novel wireless PF analyser consists of a palm-sized hardware module and a software application that can be installed on any tablet computer. The system uses RIP bands to generate measurements of respiratory rate in breaths per minute (BPM), phase angle between abdomen and rib cage, and laboured breathing index (LBI).
The resulting data are wirelessly transmitted to the connected tablet and displayed on the screen in real time.
“This instant display of [values and graphics of breathing indices] is crucial for determining the severity of the pulmonary diseases and [identifying] treatment options,” the study authors said. “Th[e] system is a significant improvement from the current RIP system, [respitrace,] which provides data that are neither instantaneous nor direct and needs further analysis to derive the work of breathing [WOB] indices.”
Results from the benchtop experiment showed that the pneuRIP-derived values were similar to that derived from respitrace and in agreement with normal breathing frequencies and phase angles.
“At low and high phase angles, and low and high breathing frequencies, pneuRIP displayed a much lower variance for the phase angle. Since mechanically there was negligible variation, pneuRIP is more accurate and consistent at higher and lower phase angles,” the authors noted. “Large phase angles are often found in children exhibiting respiratory distress, the symptoms pneuRIP is designed to measure.”
To determine whether the new system accurately differentiated between breathing under load and normal breathing conditions, testing was conducted in 10 children aged 10 to 17 years.
The children were asked to breathe normally for 10 minutes with comfortably seated in a chair and with the RIP bands placed around them. Breathing under load was simulated by placing an external bidirectional laminar resistive load (20 cm H2O litres per second) in the children’s mouths. Both conditions were also measured using the basic respitrace system.
Measurements for LBI, phase angle, BPM and percentage rib cage (RC%) differed between the two systems. The respective percentage differences were 2.9, 31.8, 26.7 and 4.8 percent under normal breathing, and 1.6, 4.1, 52.7 and 8.5 percent under loaded breathing conditions. [J Med Devices 2017;11:doi:10.1115/1.4035546]
“For LBI, phase angle and RC%, the two systems were in general agreement. For BPM the pneuRIP is shown to be more accurate than the respitrace when compared to manually counting the breaths: 36.4 vs 13.2 percent accuracy for normal breathing and 60.7 vs 16.9 percent accuracy for breathing under load,” the authors pointed out.
The novel RIP device is said to provide useful diagnostic information that is comparable to other PF approaches, but without the invasive and demanding requirements of PF diagnostic measurements (ie, oesophageal balloon or catheter placement, endotracheal tube placement, pneumotachography and pressure transducer calibration).
The device is equipped with a stable sensor that is said to be safe from measurement drifts and require no calibration. Another feature is the potential to securely email reports and graphics to other locations such as electronic medical records.
PneuRIP has not yet been tested with patients, but the authors believe that it may have applications in multiple settings, such as intensive care units, outpatient clinics, emergency departments, postoperative follow-up and home care.