. Author manuscript; available in PMC: 2017 Oct 4.

Published in final edited form as: J Med Eng Technol. 2016 Oct 4;40(7-8):356–371. doi: 10.1080/03091902.2016.1223196

TABLE III.

The logic implemented to alert clinicians if maternal and fetal heart rate, maternal oxygen saturation and maternal blood pressure readings are abnormal. Readings that require urgent attention trigger an automated call at the end of the encounter, all other measurements are included in the encounter summary SMS to inform medical staff. Blood pressure readings are currently transmitted as photo and are therefore addressed when reviewed by medical staff after data upload; optical character recognition is being implemented for the next iteration to convert the image into numeric values automatically triggering the appropriate alert. There are currently no Bluetooth enabled blood pressure monitors approved for use in pregnancy (for the detection of pre-eclampsia).

Measurement	Logic	Detection trigger	Indication
Heart rate [bpm]	Maternal HR ≤ 60	SMS alert	Maternal bradycardia
	Maternal HR ≥ 100	SMS alert	Maternal tachycardia
	Fetal HR ≤ 120	Call	Fetal bradycardia [27]
	Fetal HR ≥ 160	Call	Fetal tachycardia [27]

Oxygen saturation [%]	Oxygen ≤ 90	Call	Maternal hypoxemia [28]

Blood pressure [mmHg]	Systolic ≤ 70	Current: Addressed at data review	Low blood pressure
	Systolic ≤ 70	Future: Call	Low blood pressure
	Systolic ≥ 140, diastolic ≥ 90	Current: Addressed at data review	Mild hypertension [29]
	Systolic ≥ 140, diastolic ≥ 90	Future: SMS alert	Mild hypertension [29]
	Systolic ≥ 155, diastolic ≥ 105	Current: Addressed at data review	Severe hypertension [29]
	Systolic ≥ 155, diastolic ≥ 105	Future: Call	Severe hypertension [29]