This description provides a system and a method to identify and monitor the patient's life-threatening conditions due to pathological electrolyte fluctuation in blood serum and arrhythmias. The system comprise a device worn by the patient with integrated biosignal sensors； real-time signal processing modules are integrated into the wearable device； an instant death risk assessment module is used on a server, PC or a smart device. Life-threatening arrhythmias are identified by real-time analysis by continuously recorded photopletismogram signal, while electrolyte fluctuations are observed by analyzing a short-term electrocardiogram signal recorded by integrated biopotential sensors. The system user has the ability to enter, by smart device, other information related to his/her state of health, visible on the doctor's smart device. The doctor in his smart device sees detailed information about the patient's state of health, the risk of life-threatening conditions. The system is intended for the monitoring of the health status of patients with chronic kidney disease which are using hemodialysis but can also be adapted to monitor other patients at home after severe illness. The test tool is non-invasive, can be used continuously and repeatedly, does not limit the patient's movements, is wireless, test results and the feedback are transmitted over the internet.Šiuo aprašymu pateikiami sistema ir būdas, skirti atpažinti ir stebėti paciento gyvybei pavojingas būsenas dėl patologinių elektrolitų fliuktuacijų kraujo serume ir aritmijų epizodų. Sistemą sudaro paciento dėvimas įtaisas su integruotais biosignalų jutikliais； į dėvimą įtaisą integruoti realaus laiko signalų apdorojimo moduliai； serveryje, asmeniniame kompiuteryje ar išmaniajame įtaise naudojamas staigios mirties rizikos vertinimo modulis. Gyvybei pavojingos aritmijos atpažįstamos realiu laiku analizuojant nuolatos registruojamą fotopletizmogramos signalą, o elektrolitų fliuktuacijos stebimos analizuojant trumpala
