Body-worn pulse oximeter

Abstract

The invention provides a body-worn system that continuously measures pulse oximetry and blood pressure, along with motion, posture, and activity level, from an ambulatory patient. The system features an oximetry probe that comfortably clips to the base of the patient's thumb, thereby freeing up their fingers for conventional activities in a hospital, such as reading and eating. The probe secures to the thumb and measures time-dependent signals corresponding to LEDs operating near 660 and 905 nm. Analog versions of these signals pass through a low-profile cable to a wrist-worn transceiver that encloses a processing unit. Also within the wrist-worn transceiver is an accelerometer, a wireless system that sends information through a network to a remote receiver, e.g. a computer located in a central nursing station.

Description

CROSS REFERENCES TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 218,055, filed Jun. 17, 2009, and to U.S. Provisional Application No. 61 / 218,057, filed Jun. 17, 2009, and to U.S. Provisional Application No. 61 / 218,059, filed Jun. 17, 2009, and to U.S. Provisional Application No. 61 / 218,060, filed Jun. 17, 2009, and to U.S. Provisional Application No. 61 / 218,061, filed Jun. 17, 2009, and to U.S. Provisional Application No. 61 / 218,062, filed Jun. 17, 2009, all of which are incorporated herein by reference in their entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not ApplicableBACKGROUND OF THE INVENTION[0003]1. Field of the Invention[0004]The present invention relates to medical devices for monitoring vital signs, e.g., saturation of peripheral oxygen, or SpO2.[0005]2. Description of the Related Art[0006]SpO2, sometimes referred to as the ‘fifth vital sign’, represents a patient's blood oxygen satura...

AI Technical Summary

Benefits of technology

The invention is a body-worn monitor that continuously measures pulse oximetry and other vital signs from a patient's thumb. It features a comfortable clip that can be easily adjusted for different patients and activities. The monitor uses motion sensors to determine the patient's posture and activity level, which helps improve the accuracy of alarms and alerts generated by the monitor. The system is designed to provide accurate readings even when the patient is moving or at rest. It also includes a wrist-worn transceiver that sends the monitored data to a central nursing station or computer for further analysis and interpretation. The invention helps to continuously monitor patients in a hospital environment and transition them to the home.

Problems solved by technology

For example, the sensor worn on the lower arm (which may be within the wrist-worn transceiver) monitors movement of the patient's hand and fingers; such motion typically disrupts the RED / IR(PPG) waveforms.

For example, a walking patient typically yields noisy PPG waveforms, but also has a low probability of being hypoxic due to their activity state.

Similarly, a patient that is convulsing or falling typically yields noisy RED / IR(PPG) waveforms from which it is difficult to extract an SpO2 value.

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