Wearable wireless device applicable to the hand or foot, wireless system including the device and method for reducing the risk of different critical situations of hypoxia and/or bradycardia

A method of reducing false alarms in a wearable pulse-oximeter-based device applicable to a hand or a foot of a user, said device comprising (i) a pulse-oximeter sensor designed to measure and output blood oxygen saturation and heart rate values, intended to reduce critical situations of hypoxia and/or bradycardia that may happen in SIDS episodes, and designed to deliver electrical stimulus to the user with a timing pattern and an intensity pattern in order to cause a reaction of the user when a) said device stops measuring heart rate values or blood oxygen saturation values, b) heart rate measurement generates values below a first corresponding predefined limit level, or c) blood oxygen saturation measurement generates values below a second predefined limit level, (ii) a block section for housing elements forming the pulse-oximeter sensor comprising a blood oxygen saturation sensor and a heart rate meter, (iii) a measurement and display driver circuit, and (iv) a display;

• the device further comprising (v) a pair of electrodes designed for delivering current stimulus to the user, wherein the current stimulus is generated by an electrical stimulus generator, (vi) a control and alarm-generating circuit storing an algorithm, and (vii) a power supply, said method comprising:
• receiving said blood oxygen saturation by said blood oxygen saturation sensor and said heart rate values by said heart rate meter in said block section,
• carrying out checking routines in said control and alarm-generating circuit, based on user predefined parameters and said algorithm, to verify correct placement of the device on the body of the user and a normal operation of the device and setting delays in the current stimulus delivered to the user when measuring low heart rate or blood oxygen saturation values to avoid false alarming,
• measuring a first lapsed time (t1), by way of a first timer, from a moment said heart rate measurements fall below a first user-settable limit, said first lapsed time (t1) having a first predefined time limit (T1), wherein the first timer stops measuring when t1=T1,
• measuring a second lapsed time (t2), by way of a second timer, from a moment said pulse-oximeter sensor is still operational but does not pick up any heart rate values and the measured heart rate is zero, said second lapsed time (t2) having a second predefined time limit (T2), wherein the second timer stops measuring when t2=T2,
• measuring a third lapsed time (t3), by way of a third timer, from a moment said blood oxygen saturation measurements fall below a second user-settable limit, said third lapsed time (t3) having a third predefined time limit (T3), wherein the third timer stops measuring when t3=T3,
• measuring a fourth lapsed time (t4) by ways of a fourth timer, from a moment said pulse-oximeter sensor is still operational but does not pick up any blood oxygen saturation values at all and the oxygen saturation is zero, said fourth lapsed time (t4) having a fourth predefined time limit (T4), wherein the fourth timer stops measuring when t4=T4,
• determining that the pulse-oximeter sensor is still operational but does not pick up any heart rate values, and
• determining that the pulse-oximeter sensor is still operational but does not pick up any blood oxygen saturation values at all.