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US 9,168,020 B2Granted
Frequency domain analysis transform of renal blood flow doppler signal to determine stress levels
AssigneeFujitsu Limited
InventorsJawahar Jain, David L. Marvit, Madan Bahadur, Shreyans Gandhi
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Abstract
A method of determining stress based on renal blood flow. The method includes receiving data indicating renal blood flow of a subject. The method also includes calculating a power spectrum of a signal derived from the data. The power spectrum indicates a stress level of the subject.
Claims19
A method of determining stress based on renal blood flow, the method comprising:
- receiving first data indicating a first velocity waveform of renal blood flow of a subject, wherein the first data is collected when the subject is in a non-stressed state and the first data indicating the first velocity waveform of renal blood flow is generated by:
- an ultrasound machine emitting sound waves into the subject that encounter blood that flows through a renal artery of the subject;
- the ultrasound machine receiving echoes of the emitted sound waves that result from at least partial reflection of the sound waves that encounter the blood that flows through the renal artery of the subject;
- the ultrasound machine determining a Doppler shift of each of the echoes;
- and
- based at least on the Doppler shift determined for each of the echoes, the ultrasound machine generating a spectrogram of renal blood flow velocity versus time that includes the first velocity waveform of renal blood flow;
- calculating a first power spectrum of first maximum blood flow velocity of the first velocity waveform of renal blood flow, the first power spectrum indicating a baseline stress level of the subject;
- assessing a current stress level of the subject by:
- receiving second data indicating a second velocity waveform of renal blood flow of the subject at a current time;
- calculating a second power spectrum of second maximum blood flow velocity of the second velocity waveform of renal blood flow, the second power spectrum indicating the current stress level of the subject;
- and
- comparing the second power spectrum to the first power spectrum to determine a relative stress level of the subject corresponding to a difference between the current stress level and the baseline stress level;
- and
- in response to the relative stress level exceeding a predetermined threshold, recommending a stress-reduction treatment for the subject to reduce the relative stress level.
11 more elements
A system of determining stress based on renal blood flow, the system comprising:
- an ultrasound machine configured to generate data indicating a velocity waveform of renal blood flow of a subject by:
- emitting sound waves into the subject that encounter blood that flows through a renal artery of the subject;
- receiving echoes of the emitted sound waves that result from at least partial reflection of the sound waves that encounter the blood that flows through the renal artery of the subject;
- determining a Doppler shift of each of the echoes;
- and
- based at least on the Doppler shift determined for each of the echoes, generating a spectrogram of renal blood flow velocity versus time that includes the velocity waveform of renal blood flow;
- a processing device communicatively coupled to the ultrasound machine, the processing device configured to:
- receive the data from the ultrasound machine;
- and
- calculate a power spectrum of maximum blood flow velocity of the velocity waveform of renal blood flow, the power spectrum indicating a stress level of the subject;
- and
- a display device coupled to the processing device and configured to display the stress level derived from the power spectrum to a healthcare worker.
9 more elements
A processor configured to execute computer instructions to cause a computing system to perform operations for determining stress based on renal blood flow, the operations comprising:
- receiving first data indicating a first velocity waveform of renal blood flow of a subject, wherein the first data is collected during an absence of stress events and the first data indicating the first velocity waveform of renal blood flow is generated by:
- an ultrasound machine emitting sound waves into the subject that encounter blood that flows through a renal artery of the subject;
- the ultrasound machine receiving echoes of the emitted sound waves that result from at least partial reflection of the sound waves that encounter the blood that flows through the renal artery of the subject;
- the ultrasound machine determining a Doppler shift of each of the echoes;
- and
- based at least on the Doppler shift determined for each of the echoes, the ultrasound machine generating a spectrogram of renal blood flow velocity versus time that includes the first velocity waveform of renal blood flow;
- calculating a first power spectrum of first maximum blood flow velocity of the first velocity waveform of renal blood flow, the first power spectrum indicating a baseline stress level of the subject;
- assessing a current stress level of the subject by:
- receiving second data indicating a second velocity waveform of renal blood flow of the subject at a current time;
- calculating a second power spectrum of second maximum blood flow velocity of the second velocity waveform of renal blood flow, the second power spectrum indicating the current stress level of the subject;
- and
- comparing the second power spectrum to the first power spectrum to determine a relative stress level of the subject corresponding to a difference between the current stress level and the baseline stress level;
- and
- in response to the relative stress level exceeding a predetermined threshold, recommending a stress-reduction treatment for the subject to reduce the relative stress level.
11 more elements
An ultrasound machine comprising:
- a sonography head configured to:
- emit sound waves into a subject that encounter blood that flows through a renal artery of the subject;
- and
- receive echoes of the emitted sound waves that result from at least partial reflection of the sound waves that encounter the blood that flows through the renal artery of the subject;
- a base unit coupled to the sonography head, the base unit configured to:
- determine a Doppler shift of each of the echoes;
- based at least on the Doppler shift determined for each of the echoes, generate a spectrogram of renal blood flow velocity versus time that includes a velocity waveform of renal blood flow of the subject;
- and
- calculate a power spectrum of maximum blood flow velocity of the velocity waveform of renal blood flow, the power spectrum indicating a stress level of the subject;
- and
- a display device coupled to the base unit, the display device configured to:
- display images corresponding to the velocity waveform of renal blood flow of the subject;
- and
- display stress information of the subject, wherein the displayed stress information includes or is based on the power spectrum.
11 more elements
Dependencies are inferred from the claim text.