The Ultrasonic Directional Tidal Breathing Pattern Sensor: Equitable Design Realization Based on Phase Information

Abstract

Pulmonary ailments are conventionally diagnosed by spirometry. The complex forceful breathing maneuver as well as the extreme cost of spirometry renders it unsuitable in many situations. This work is aimed to facilitate an emerging direction of tidal breathing-based pulmonary evaluation by designing a novel, equitable, precise and portable device for acquisition and analysis of directional tidal breathing patterns, in real time. The proposed system primarily uses an in-house designed blow pipe, 40-kHz air-coupled ultrasound transreceivers, and a radio frequency (RF) phase-gain integrated circuit (IC). Moreover, in order to achieve high sensitivity in a cost-effective design philosophy, we have exploited the phase measurement technique, instead of selecting the contemporary time-of-flight (TOF) measurement; since application of the TOF principle in tidal breathing assessments requires sub-micro to nanosecond time resolution. This approach, which depends on accurate phase measurement, contributed to enhanced sensitivity using a simple electronics design. The developed system has been calibrated using a standard 3-L calibration syringe. The parameters of this system are validated against a standard spirometer, with maximum percentage error below 16%. Further, the extracted respiratory parameters related to tidal breathing have been found to be comparable with relevant prior works. The error in detecting respiration rate only is 3.9% compared to manual evaluation. These encouraging insights reveal the definite potential of our tidal breathing pattern (TBP) prototype for measuring tidal breathing parameters in order to extend the reach of affordable healthcare in rural regions and developing areas.

A Novel Approach to the Identification of Compromised Pulmonary Systems in Smokers by Exploiting Tidal Breathing Patterns

“…In our previous works [ 5 , 6 ], we exhibited the complete mechanism of the ultrasonic phase-measurement-based sensor platform, TBPR, suitable for the acquisition of tidal breathing patterns from non-sedated adults. The system was calibrated against a medically graded 3 L syringe.…”

“…Recently, a plethora of research was conducted incorporating adult TBA to find pathological signatures of pulmonary ailments. In our previous work [ 5 , 6 ], we demonstrated a tidal breathing pattern recorder (TBPR), a novel phase-sensing-based equitable ultrasound sensor platform capable of recording and computing adult tidal breathing parameters.…”

A System for Monitoring Breathing Activity Using an Ultrasonic Radar Detection with Low Power Consumption

“…The gold standard instrument for assessment of breathing activity and abnormality is polysomnography (PSG) and transthoracic impedance (TTI) [7][8][9]. The main problems with these techniques are the constraint and annoyance suffered by the subject because the sensors are adhered in direct contact to the skin, as well as being uncomfortable to use [9][10][11]. As such, the direct contact techniques are inappropriate for specific and significant groups of patients, such as children and patients with burns [12].…”

“…There have been several attempts to devise direct and indirect techniques to monitor breathing activity while minimizing discomfort. These techniques include direct contact such as magnetic induction [14][15][16][17], microphone [18,19], and capacitive [20][21][22][23], and indirect contact (contactless) such as electromagnetic radar detection [24][25][26][27][28][29], laser radar detection [30][31][32][33], ultrasonic radar detection [10,[34][35][36][37], thermographic imaging [38][39][40][41][42][43], and video camera imaging [44][45][46][47][48][49][50]. Each of these techniques, however, requires different process monitoring and has benefits and drawbacks that may make it more or less appealing to use under different circumstances as discussed in reference [51].…”

“…The sensor head was placed at a distance of 0.15-0.5 m above the subject (infant) and was focused on the sound signal from the thoracic region. The sensitivity of the sensor used in this study would reduce at distances larger than 0.5 m. A recent study by Sinharay et al [10] designed an affordable, accurate, and portable device for extracting and analyzing breathing activity and breathing patterns. Their proposed system used a 40 kHz air-coupled ultrasonic sensor and a radio frequency (RF) transceiver to continuously monitor directional tidal breathing airflow.…”