Body-worn system for continuously monitoring a patients BP, HR, SpO2, RR, temperature, and motion; also describes specific monitors for apnea, ASY, VTAC, VFIB, and ‘bed sore’ index
The invention provides a body-worn monitor that measures a patient's vital signs (e.g. blood pressure, SpO2, heart rate, respiratory rate, and temperature) while simultaneously characterizing their activity state (e.g. resting, walking, convulsing, falling). The body-worn monitor processes this information to minimize corruption of the vital signs by motion-related artifacts. A software framework generates alarms/alerts based on threshold values that are either preset or determined in real time. The framework additionally includes a series of ‘heuristic’ rules that take the patient's activity state and motion into account, and process the vital signs accordingly. These rules, for example, indicate that a walking patient is likely breathing and has a regular heart rate, even if their motion-corrupted vital signs suggest otherwise.
1. A method for continuously monitoring a patient, comprising the following steps:
detecting a first time-dependent physiological waveform indicative of one or more contractile properties of the patient's heart with a first sensor comprising a first detector configured to be worn on the patient's body;
detecting a second time-dependent physiological waveform indicative of one or more contractile properties of the patient's heart with a second sensor comprising a second detector configured to be worn on the patient's body;
detecting sets of time-dependent motion waveforms with at least two motion-detecting sensors positioned on locations selected from a forearm, upper arm, and a body location other than the forearm or upper arm of the patient, wherein each set of motion waveforms is indicative of motion of the location on the patient's body to which it is affixed;
processing the first and second time-dependent physiological waveforms and the sets of time-dependent motion waveforms with one or more microprocessors, the microprocessor(s) configured to
determine at least one vital sign from the patient using the first and second time-dependent physiological waveforms;
analyze at least a portion of the sets of time-dependent motion waveforms with a motion-determining algorithm to determine a posture and an activity state for the patient, and determine therefrom if the patient is resting, moving, sitting, standing, walking, running, falling, lying down, or convulsing; and
generate an alarm by processing the patient's motion and comparing the vital sign to a predetermined motion-dependent alarm/alert thresholds and heuristic rules corresponding to the motion.
2. A method according to claim 1 , further comprising displaying a graphical icon simultaneously indicating patient posture and activity state on a monitor positioned at a location remote from the patient.