Automated Diagnosis-Assisting Medical Devices Utilizing Pattern Localization Of Quasi-Periodic Signals

• US 20140275809A1
• Filed: 03/13/2014
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Abandoned Application

• Current Assignee: CSD Labs GmbH
• Original Assignee: CSD Labs GmbH
• Inventors: Schriefl, Andreas J., Reinisch, Andreas J.
• Application Number:
  US14/210,026
• Publication Number:
  US 20140275809A1
• Time in Patent Office: Days
• US Class Current: 600/300
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7235 Details of waveform analysis A61B5/349 takes precedence
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 7/003 Detecting lung or respiration noise
• CPC Class Codes: A61B 7/04 Electric stethoscopes microphones, acoustic transducers therefor H04R
• CPC Class Codes: G06F 2218/10 by analysing the shape of a waveform, e.g. extracting parameters relating to peaks

Abstract

A method for localizing a pattern in a quasi-periodic signal includes estimating, using a controller, a rate or a frequency of a quasi-periodic signal, and defining a search window based on the estimated rate or frequency of the quasi-periodic signal. A starting position is defined in the received quasi-periodic signal, the starting position corresponding to a first maximum. A portion of the quasi-periodic signal in the search window is cross-correlated with a template signal pattern to be matched to produce a second maximum. The second maximum is defined by the controller as a new starting position. The new starting position is stored.

Claims

1. A method for localizing a pattern in a quasi-periodic signal, the method comprising:

estimating, using a controller, a rate or a frequency of a quasi-periodic signal;

defining, using the controller, a search window based on the estimated rate or frequency of the quasi-periodic signal;

defining, using the controller, a starting position in the received quasi-periodic signal, the starting position corresponding to a first maximum;

cross-correlating, using the controller, a portion of the quasi-periodic signal in the search window with a template signal pattern to be matched to produce a second maximum that is defined by the controller as a new starting position; and

storing, using the controller, the new starting position.

2. The method of claim 1, further comprising:

determining, using the controller, a localized pattern of the template signal pattern;

extracting, using the controller, a signal segment from the localized pattern;

analyzing, using the controller, the signal segment simultaneously in time and frequency domains to produce parallel outputs;

combining, using the controller, the parallel outputs via a statistical or mathematical function to produce a result; and

automatically indicating, using the controller, a diagnosis based on the result.

3. The method of claim 2, further comprising indicating the diagnosis directly on a device selected from a group consisting of the electronic stethoscope, a second device attached to the electronic stethoscope, and a third device in wireless communication with the electronic stethoscope.

4. The method of claim 2, further comprising indicating the diagnosis via one or more of a display and audio output of a portable device.

5. The method of claim 1, further comprising:

receiving, using the controller, a representation of the quasi-periodic signal;

removing, using the controller, a DC component from the received signal to produce a purely time-varying signal;

filtering, using the controller, the time-varying signal to produce a pre-processed signal;

auto-correlating, using the controller, at least a portion of a representation of the pre-processed signal with itself and storing in a memory device a corresponding auto-correlation output for the at least portion of the representation of the pre-processed signal;

applying, using the controller, a biphasic tapering function to the auto-correlation output, the tapering function including a time constant parameter that is a function of the quasi-periodic signal and producing the first maximum; and

storing in the memory device a representation, based on the first maximum, as an indication of a rate or a frequency of the quasi-periodic signal.

6. The method of claim 1, further comprising:

saving, using the controller, the representation in a file of a predetermined file format;

sending, using a data communication, the file in an e-mail;

printing, using a printer, the file; and

storing the file on a portable device.

7. The method of claim 1, further comprising:

receiving, from an auscultation device, the quasi-periodic signal as an auscultation signal;

recording, using the controller, raw auscultation data associated with the auscultation signal;

sending, using a data connection, the raw data auscultation data to a hospital information system;

analyzing, using computation services of the hospital information system, the raw auscultation data; and

storing, on a memory device of the hospital information system, analysis results for later review by a medical professional.

8. The method of claim 1, further comprising:

retrieving, using the controller, a patient list from a hospital information system;

selecting, using a selection input, a patient from the patient list;

obtaining, using the controller, patient specific parameters; and

transferring to the hospital information system, via a data connection, one or more of patient data, raw auscultation data, the patient specific parameters, and a diagnosis suggestion.

9. The method of claim 1, further comprising:

receiving, from an auscultation device, the quasi-periodic signal as an auscultation signal;

recording, using the controller, auscultation data associated with the auscultation signal;

providing, using inputs of the auscultation device, user setting options for modifying settings of the auscultation device;

communicating, using an audio output of the auscultation device, between a medical professional and an user of the auscultation device;

alerting, using the controller, the medical professional when the auscultation data is uploaded and available for access;

allowing, using the controller, the medical professional to access the auscultation data.

10. The method of claim 1, further comprising:

sending, via a data connection, raw data of the rate or the frequency of the quasi-periodic signal to a hospital information system;

analyzing, using another controller of the hospital information system, the raw data; and

storing, on a memory device of the hospital information system, results of the analysis for later review by a medical professional.

11. A system for localizing a pattern in a quasi-periodic signal, the system comprising:

a processor; and

a memory device with stored instructions that, when executed by the processor, cause the system to;

estimate a rate or a frequency of a quasi-periodic signal;

define a search window based on the estimated rate or frequency of the quasi-periodic signal;

define a starting position in the received quasi-periodic signal, the starting position corresponding to a first maximum;

cross-correlate a portion of the quasi-periodic signal in the search window with a template signal pattern to be matched to produce a second maximum that is defined by the controller as a new starting position; and

store the new starting position.

12. The system of claim 11, wherein the memory device further causes the system to:

determine a localized pattern of the template signal pattern;

extract a signal segment from the localized pattern;

analyze the signal segment simultaneously in time and frequency domains to produce parallel outputs;

combine the parallel outputs via a statistical or mathematical function to produce a result; and

automatically indicate a diagnosis based on the result.

13. The system of claim 11, wherein the memory device further causes the system to indicate the diagnosis directly on a device selected from a group consisting of the electronic stethoscope, a second device attached to the electronic stethoscope, and a third device in wireless communication with the electronic stethoscope.

14. The system of claim 13, wherein the memory device further causes the system to indicate the diagnosis via one or more of a display and audio output of a portable device.

15. The system of claim 13, wherein the memory device further causes the system to:

receive a representation of the quasi-periodic signal;

remove a DC component from the received signal to produce a purely time-varying signal;

filter the time-varying signal to produce a pre-processed signal;

auto-correlate at least a portion of a representation of the pre-processed signal with itself and storing in a memory device a corresponding auto-correlation output for the at least portion of the representation of the pre-processed signal;

apply a biphasic tapering function to the auto-correlation output, the tapering function including a time constant parameter that is a function of the quasi-periodic signal and producing the first maximum; and

store a representation, based on the first maximum, as an indication of a rate or a frequency of the quasi-periodic signal.

16. The system of claim 11, wherein the memory device further causes the system to:

save the representation in a file of a predetermined file format;

send the file in an e-mail;

print the file; and

store the file on a portable device.

17. The system of claim 16, wherein the memory device further causes the system to:

receive the quasi-periodic signal as an auscultation signal;

record raw auscultation data associated with the auscultation signal;

send the raw data auscultation data to a hospital information system;

analyze, via computation services of the hospital information system, the raw auscultation data; and

store, on a memory device of the hospital information system, analysis results for later review by a medical professional.

18. The system of claim 17, wherein the memory device further causes the system to:

retrieve a patient list from a hospital information system;

select a patient from the patient list;

obtain patient specific parameters; and

transfer to the hospital information system, via a data connection, one or more of patient data, raw auscultation data, the patient specific parameters, and a diagnosis suggestion.

19. The system of claim 17, wherein the memory device further causes the system to:

receive the quasi-periodic signal as an auscultation signal;

record auscultation data associated with the auscultation signal;

provide user setting options for modifying settings of the auscultation device;

communicate between a medical professional and an user of the auscultation device;

alert the medical professional when the auscultation data is uploaded and available for access;

allow the medical professional to access the auscultation data.

20. The system of claim 11, wherein the memory device further causes the system to:

send raw data of the rate or the frequency of the quasi-periodic signal to a hospital information system;

analyze, using another controller of the hospital information system, the raw data; and

store, on a memory device of the hospital information system, results of the analysis for later review by a medical professional.