Patch sensor for measuring blood pressure without a cuff

Abstract

A monitoring device, method and system for monitoring vital signs of a patient over a wireless network are disclosed herein. The monitoring device includes an adhesive patch sensor, typically mounted on a patient's head, and a processing component. The adhesive patch sensor typically includes an optical system that generates an optical waveform, and an electrode that generates an electrical waveform. The processing component processes the optical and electrical waveforms, along with a calibration table, to determine the patient's vital signs.

Description

[0001] This application is a continuation-in-part application of U.S. patent application Ser. No. 10 / 709,014, filed on Apr. 7, 2004.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] Not Applicable BACKGROUND OF THE INVENTION [0003] 1. Field of the Invention [0004] The present invention relates to a device, method and system for measuring vital signs, particularly blood pressure. [0005] 2. Description of Related Art [0006] Pulse oximeters are medical devices featuring an optical module, typically worn on a patient's finger or ear lobe, and a processing module that analyzes data generated by the optical module. The optical module typically includes first and second light sources (e.g., light-emitting diodes, or LEDs) that transmit optical radiation at, respectively, red (X 630-670 nm) and infrared (λ˜800-1200 nm) wavelengths. The optical module also features a photodetector that detects radiation transmitted or reflected by an underlying artery. Typically the red ...

AI Technical Summary

Benefits of technology

[0017] The present invention provides a cuffless, blood-pressure monitor, featuring an adhesive patch. The patch is disposable and is typically used for 24-72 hours. The blood pressure monitor makes a transdermal, optical measurement of the time-dependent dynamics of blood flowing in an underlying artery. A processor analyzes this information, typically with a calibration table, to determine blood pressure. Once determined, the processor sends it to a hand-held wireless component (e.g., a cellular phone or wireless PDA). The processing component preferably features an embedded, short-range wireless transceiver and a software platform that displays, analyzes, and then transmits the information through a wireless network to an Internet-based system. With this system a medical professional can continuously monitor a patient's blood pressure during their day-to-day activities. Monitoring patients in this manner minimizes erroneous measurements due to ‘white coat syndrome’ and increases the accuracy of a blood-pressure measurement.

[0018] The invention has many advantages. In particular, one aspect of the invention provides a system that continuously monitors a patient's blood pressure using a cuffless blood pressure monitor and an off-the-shelf mobile communication device. Information describing the blood pressure can be viewed using an Internet-based website, using a personal computer, or simply by viewing a display on the mobile device. Blood-pressure information measured continuously throughout the day provides a relatively comprehensive data set compared to that measured during isolated medical appointments. This approach identifies trends in a patient's blood pressure, such as a gradual increase or decrease, which may indicate a medical condition that requires treatment. The invention also minimizes effects of ‘white coat syndrome’ since the monitor automatically and continuously makes measurements away from a medical office with basically no discomfort to the patient. Real-time, automatic blood pressure measurements, followed by wireless transmission of the data, are only practical with a non-invasive, cuffless monitor like that of the present invention. Measurements can be made completely unobtrusive to the patient.

[0020] The monitor is small, easily worn by the patient during periods of exercise or day-to-day activities, and makes a non-invasive blood-pressure measurement in a matter of seconds. The resulting information has many uses for patients, medical professional, insurance companies, pharmaceutical agencies conducting clinical trials, and organizations for home-health monitoring.

Problems solved by technology

This generates ‘noise’ in the plethysmograph, which in turn can lead to motion-related artifacts in data describing pulse oximetry and heart rate.

Ultimately this reduces the accuracy of the measurement.

Cuff-based blood-pressure measurements such as these typically only determine the systolic and diastolic blood pressures; they do not measure dynamic, time-dependent blood pressure.

Unfortunately, in some cases, patients experience ‘white coat syndrome’ where anxiety during the appointment affects the blood pressure that is measured.

For example, white coat syndrome can elevate a patient's heart rate and blood pressure; this, in turn, can lead to an inaccurate diagnoses.

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