NECK-WORN PHYSIOLOGICAL MONITOR

摘要

The invention provides a neck-worn sensor that is a single, body-worn system that measures the following parameters from an ambulatory patient: heart rate, pulse rate, pulse oximetry, respiratory rate, temperature, thoracic fluid levels, stroke volume, cardiac output, and a parameter sensitive to blood pressure called pulse transit time. From stroke volume, a first algorithm employing a linear model can estimate the patient's pulse pressure. And from pulse pressure and pulse transit time, a second algorithm, also employing a linear algorithm, can estimate systolic blood pressure and diastolic blood pressure. Thus, the sensor can measure all five vital signs along with hemodynamic parameters. It also includes a motion-detecting accelerometer, from which it can determine motion-related parameters such as posture, degree of motion, activity level, respiratory-induced heaving of the chest, and falls.

主权项

1. A sensor for simultaneously measuring from a patient systolic blood pressure (SYS), stroke volume (SV), and an index correlating to fluid content in the thoracic cavity (TFI), the sensor comprising:
a sensing portion having a flexible housing; an elongated securement member extending from the sensing portion, the elongated securement member being configured to pass at least substantially around the patient's neck with sufficient length to support the sensing portion generally against the sternal portion of the patient's chest when the sensor is in use and operating; at least one pair of electrode contact points disposed within the housing, with each pair of electrode contact points comprising a current-injecting electrode contact point and a voltage-sensing electrode contact point; an analog ECG circuit disposed within the housing and in electrical contact with said at least one pair of electrode contact points, the ECG circuit configured to generate an analog ECG waveform based on sensed voltage; an analog impedance circuit disposed within the housing and in electrical contact with said at least one pair of electrode contact points, the impedance circuit being configured to generate an analog impedance waveform based on sensed voltage; a digital processing system disposed within the housing and comprising a microprocessor and an analog-to-digital converter, the digital processing system being configured to: 1) digitize the analog ECG waveform to generate a digital ECG waveform, and 2) digitize the analog impedance waveform to generate a digital impedance waveform; a blood pressure-monitoring system disposed within the housing and configured to operate a first algorithm, which first algorithm collectively processes the digital impedance and digital ECG waveforms to determine a value of SYS; a SV-monitoring system disposed within the housing and configured to operate a second algorithm, which second algorithm processes the digital impedance waveform to determine a value of SV; and a thoracic fluid-measuring system disposed within the housing and configured to operate a third algorithm, which third algorithm processes the digital impedance waveform to determine a value of TFI.