Electro-optical system, apparatus, and method for ambulatory monitoring

Patent metadata

Field	Value
Publication number	US-9504394-B2
Application number	US-99535206-A
Country	US
Kind code	B2
Filing date	Jul 12, 2006
Priority date	Jul 28, 2005
Publication date	Nov 29, 2016
Grant date	Nov 29, 2016

Abstract

An electro-optical system, apparatus, and method allow long-term, ambulatory measurements to be made on a patient using light transmitted into the patient and resulting light received from the patient.

First claim

What is claimed is:

1. An electro-optical monitoring system comprising:
a light transceiver comprising:
a first light source configured to generate light having a first wavelength, the first light source coupled to receive a first periodic electrical signal having a first frequency, the first periodic electrical signal amplitude modulating the first light source to generate first amplitude modulated light, the first light source to transmit the first amplitude modulated light into biological tissue of a person at a transmission rate of at least 0.1 light transmissions per second;
a second light source configured to generate light having a second different wavelength, the second light source coupled to receive a second periodic electrical signal having a second different frequency, the second periodic electrical signal amplitude modulating the second light source to generate second amplitude modulated light, the second light source to transmit the second amplitude modulated light into the biological tissue of the person at a rate of at least 0.1 light transmissions per second; and
a light receiver configured to receive light from the biological tissue, the received light indicative of a combination of the first amplitude modulated light and the second amplitude modulated light having passed into and out of the biological tissue, the light receiver adapted to provide an electronic transceiver output signal indicative of at least one characteristic of the received light; and

a processing/storage circuit, comprising:
a first electronic signal source to generate the first periodic electrical signal;
a second electronic signal source to generate the second periodic electrical signal;
an amplitude demodulator configured to amplitude demodulate the transceiver output signal to provide a first demodulated signal representative of a first characteristic of the received light and to provide a second demodulated signal representative of a second different characteristic of the received light;
a signal processor coupled to said amplitude demodulator and adapted to process the first demodulated signal and the second demodulated signal to generate a processed signal, wherein the processed signal includes signal samples having a sample rate of at least 0.1 samples per second;

and
a storage device coupled to said signal processor and adapted to store at least four hours of the processed signal as a stored-processed signal, wherein the stored-processed signal has a stored signal duration sufficient to detect an intermittent medical condition of the person having an occurrence period of at least four hours.

2. The electro-optical monitoring system of claim 1 , wherein said light transceiver includes at least four light sources for providing at least two different light wavelengths and at least two light receivers.

3. The electro-optical monitoring system of claim 1 , wherein said signal processor includes at least two of:
a physiology measurement processor adapted to measure at least one of a heart rate, a respiration rate, a Mayer wave, a heart beat interval, a respiration interval, or a Mayer wave period of the person in response to the transceiver output signal;
a concentration measurement processor adapted to measure a concentration of at least one of oxyhemoglobin, deoxyhemoglobin, water, cytochrome, lipid, or a fluorescent molecule of the person in response to the transceiver output signal;
an oxygenation measurement processor adapted to measure a tissue oxygenation of the person in response to the transceiver output signal;
a blood volume measurement processor adapted to measure a blood volume of the person in response to the transceiver output signal;
a scattering measurement processor adapted to measure a scattering characteristic of the person in response to the transceiver output signal;
a molecule property measurement processor adapted to measure the change in at least one of a concentration, a lifetime, or a quantum yield of a fluorochrome molecule;
a drug processor adapted to measure at least one of a pharmacodynamic characteristic or a pharmacokinetic characteristic of a drug;
a sudden infant death syndrome detection processor adapted to detect a drop in oxygenation level of the person in response to the transceiver output signal;
a seizure detection processor adapted to detect a seizure of the person in response to the transceiver output signal;
a vasomotor symptom detection processor adapted to detect a vasomotor symptom of the person in response to the transceiver output signal;
a dizzy spell detection processor adapted to detect a dizzy spell of the person in response to the transceiver output signal;
an ischemia detection processor adapted to detect ischemia of the person in response to the transceiver output signal;
a stroke recovery detection processor adapted to characterize a stroke recovery of the person in response to the transceiver output signal;
a hemorrhage detection processor adapted to detect a hemorrhage of the person in response to the transceiver output signal;
a heart condition detection processor adapted to detect a heart condition of the person in response to the transceiver output signal;
a hallucination episode detection processor adapted to detect characteristic brain activity associated with a hallucination of the person in response to the transceiver output signal; or
a density change processor adapted to detect a density change in the biological tissue in response to the transceiver output signal.

4. The electro-optical monitoring system of claim 1 , wherein said storage device comprises a data transfer/marking software module adapted to store at least one of a time tag or a detection tag with the stored processed data, wherein the time tag is stored in response to at least one of an event detection by said signal processor or a manual indication by the person, and the detection tag is stored in response to the detection by said signal processor.

5. The electro-optical monitoring system of claim 1 , wherein said storage device comprises a data compression software module adapted to compress the processed signal.

6. The electro-optical monitoring system of claim 1 , wherein said storage device comprises:
a recirculating buffer memory coupled to said signal processor; and
a capture memory coupled to the recirculating buffer memory, wherein the contents of the recirculating buffer memory are transferred to the capture memory in response to at least one of an event detection by said signal processor or a manual indication.

7. The electro-optical monitoring system of claim 1 , wherein the processing/storage circuit further comprises an event input device coupled to said storage device and adapted to receive a manual indication from the person that a symptom associated with a medical condition is occurring, wherein a time tag is stored to the stored data in response to the manual indication.

8. The electro-optical monitoring system of claim 1 , wherein further comprising a reference sensor adapted to sense a characteristic of at least one of the person or said light transceiver and to provide a reference signal indicative of the characteristic, and wherein the signal processor is adapted to process the transceiver output signal and the reference signal to provide the processed signal.

9. The electro-optical monitoring system of claim 8 , wherein the reference sensor comprises a motion sensor, the characteristic comprises a motion, and the reference signal comprises a motion signal.

10. The electro-optical monitoring system of claim 1 , wherein said light transceiver has an adhesive surface such that said light transceiver can be directly adhesively coupled to the pe

Assignees

• Zhang Quan
• Strangman Gary
• Massachusetts Gen Hospital

Inventors

• Zhang Quan
• Strangman Gary

Classifications

• A61B5/7232

  involving compression of the physiological signal, e.g. to extend the signal recording period · CPC title

• A61B5/4509

  Bone density determination · CPC title

• A61B5/1455

  using optical sensors, e.g. spectral photometrical oximeters · CPC title

• A61B5/0059

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title

• A61B5/0002

  Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network (endoradiosondes A61B5/07) · CPC title