Body-worn pulse oximeter

Patent metadata

Field	Value
Publication number	US-11638533-B2
Application number	US-202017080725-A
Country	US
Kind code	B2
Filing date	Oct 26, 2020
Priority date	Jun 17, 2009
Publication date	May 2, 2023
Grant date	May 2, 2023

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.

First claim

What is claimed is:

1. A method for performing a continuous noninvasive blood pressure measurement (cNIBP) value from a patient, comprising:
(i) measuring an electrical signal indicative of a pulse pressure wave launched by the patient's heart recursively using an electrical sensor worn noninvasively on the patient's body;
(ii) measuring an optical signal indicative of the pulse pressure wave at an extremity of the patient using a photoplethysmogram sensor worn noninvasively on the patient's body;
(iii) calculating a time-dependent pulse transit time value from the measured electrical signal and the measured optical signal;
(iv) iterating steps (i)-(iii) for a pre-determined period to calculate an average pulse transit time value from a series of the time-dependent pulse transit time values determined during the pre-determined period, wherein time-dependent pulse transit time values from the series that differ from the average pulse transit time value by more than one standard deviation are discarded and the average pulse transit time value is recalculated without the discarded time-dependent pulse transit time values;
(v) calculating a blood pressure value from the average pulse transit time value calculated in step (iv); and
(vi) recursively performing steps (i)-(v) such that the average pulse transit time value is a rolling average updated at each pulse pressure wave.

Assignees

• Sotera Wireless Inc

Inventors

• Moon Jim
• Mccombie Devin
• Dhillon Marshal
• Banet Matthew

Classifications

• A61B5/02125

  of pulse wave propagation time · CPC title

• A61B5/021

  Measuring pressure in heart or blood vessels · CPC title

• A61B5/1118 Primary

  Determining activity level · CPC title

• A61B5/02225

  using the oscillometric method · CPC title

• A61B5/0245 Primary

  by using sensing means generating electric signals, {i.e. ECG signals} · CPC title