Heart rate and respiratory output device and heart rate and respiratory output program

Abstract

The present disclosure is a heartbeat / respiration output device M characterized by comprising: a heartbeat / respiration extraction unit 1 that extracts, from radar signals or ultrasound signals reflected by the body surface of a patient P, frequency components from micro vibrations of the heartbeat and / or respiration; a temporal change calculation unit 2 that calculates an amplitude temporal change or a phase temporal change of the frequency components from micro vibrations of the heartbeat and / or respiration; a sound signal modulation unit 4 that, based on the amplitude temporal change or phase temporal change of the frequency components from micro vibrations of the heartbeat and / or respiration, performs amplitude modulation or frequency modulation on sound signals having an audible band frequency; and a heartbeat / respiration output unit 5 that outputs the sound signals after amplitude modulation or frequency modulation.

Description

Technical Field

[0001] The present disclosure relates to a technique for listening to a heartbeat and / or respiration like a stethoscope while reducing the burden on doctors or nurses, reducing the risk of infection, providing remote diagnosis and treatment, enabling early disease detection, and conducting future prognosis research based on radar signals or ultrasonic signals reflected from the body surface.

Background Art

[0002] Techniques for calculating the heart rate and respiratory rate while reducing the burden on doctors or nurses, reducing the risk of infection, providing remote diagnosis and treatment, enabling early disease detection, and conducting future prognosis research based on radar signals reflected from the body surface are disclosed in Patent Document 1 and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in Patent Document 1 and the like, if the irradiation direction of the radar signal is not correctly adjusted, the heart rate and respiratory rate may be erroneously calculated. And in Patent Document 1 and the like, even if the heart rate and respiratory rate are erroneously calculated, the authenticity of the alert is not correctly determined.

[0005] Therefore, in order to solve the above problems, the present disclosure correctly adjusts the irradiation direction of the radar signal or ultrasonic signal and correctly determines the authenticity of the alert for the heart rate and / or respiratory rate while reducing the burden on doctors or nurses, reducing the risk of infection, providing remote diagnosis and treatment, enabling early disease detection, and conducting future prognosis research based on radar signals (including ultrasonic signals) reflected from the body surface.

Means for Solving the Problems

[0006] To solve the aforementioned problem, the amplitude-time change or phase-time change of frequency components due to minute vibrations of heartbeat and / or respiration is calculated from radar signals or ultrasonic signals reflected from the body surface. Then, based on the amplitude-time change or phase-time change of frequency components due to minute vibrations of heartbeat and / or respiration, an audio signal having audible frequencies is amplitude-modulated or frequency-modulated. As a result, a doctor or nurse can listen to the heartbeat and / or respiration as if using a stethoscope.

[0007] Specifically, the present disclosure is a heart rate and respiration output device characterized by comprising: a heart rate and respiration extraction unit that extracts frequency components due to minute vibrations of heartbeat and / or respiration from radar signals or ultrasonic signals reflected from the body surface and calculates the amplitude time change or phase time change of the frequency components due to minute vibrations of heartbeat and / or respiration; and a heart rate and respiration output unit that amplitude modulates or frequency modulates an audio signal having audible band frequencies based on the amplitude time change or phase time change of the frequency components due to minute vibrations of heartbeat and / or respiration and outputs the audio signal after amplitude modulation or frequency modulation.

[0008] This configuration allows (1) the direction of the radar or ultrasound signal to be correctly adjusted so that a doctor or nurse can experimentally listen to the heart rate and / or respiration; (2) the doctor or nurse can correctly determine the authenticity of heart rate and / or respiratory rate alerts by directly listening to the heart rate and / or respiration; and (3) it is applicable to reducing the burden on doctors or nurses, reducing the risk of infection, remote medical consultation and treatment, early disease detection, and future predictive research.

[0009] Furthermore, this disclosure provides a heart rate and respiration output device characterized in that the heart rate and respiration output unit applies one of amplitude modulation and frequency modulation to the audio signal based on the amplitude time change or the phase time change of the frequency component due to minute vibrations of the heartbeat, and applies the other of amplitude modulation and frequency modulation to the audio signal based on the amplitude time change or the phase time change of the frequency component due to minute vibrations of respiration.

[0010] With this configuration, heart rate and respiration can be heard as the magnitude and pitch of an audio signal, respectively, or as the pitch and magnitude of an audio signal, respectively, and as a result, heart rate and respiration can be heard simultaneously and separately.

[0011] Furthermore, this disclosure relates to a heart rate and respiration output device characterized in that the heart rate and respiration extraction unit extracts the positive and negative frequency components due to minute vibrations of the heartbeat and then multiplies them by complex to calculate the phase time change of the frequency components due to minute vibrations of respiration, thereby removing the phase time change of the frequency components due to minute vibrations of the heartbeat.

[0012] With this configuration, when listening to respiration, frequency components due to minute vibrations of respiration (DC components including extremely low frequency components) are not extracted, and frequency components due to minute vibrations of the heartbeat (±10 or 10 2 By extracting frequencies (on the order of Hz), robustness can be improved and the influence of disturbances can be reduced. This allows for considering only the reflected signal from the chest, without considering the reflected signal from the abdomen. However, disturbances such as air conditioner louvers, curtains swaying in the wind, and the movements of nurses are mainly included in the DC component and are close in frequency to the minute vibrations of respiration, making it difficult to improve robustness and reduce the influence of disturbances. Furthermore, when the reflected signals from the abdomen and chest are combined, there is a risk of misinterpreting the respiratory rate as twice the normal rate depending on the conditions of the combination.

[0013] Furthermore, this disclosure provides a heart rate and respiration output device characterized in that the heart rate and respiration extraction unit upscales the amplitude time change or the phase time change having a sampling frequency lower than the audible frequency range of the audio signal with an uprate frequency higher than the audible frequency range of the audio signal.

[0014] With this configuration, even when the amplitude-time changes or phase-time changes of frequency components due to minute vibrations of heartbeat and / or respiration are sampled at a "low sampling frequency," the amplitude-time changes or phase-time changes of frequency components due to minute vibrations of heartbeat and / or respiration can be up-rated at a "high up-rate frequency," thereby allowing the audio signal having audible frequencies to be amplitude-modulated or frequency-modulated using the up-rated modulated information.

[0015] Furthermore, this disclosure provides a heart rate and respiration output device characterized in that, when the heart rate and respiration extraction unit uprates the amplitude-time change or the phase-time change, it performs one of the following: a low-pass filter process after zero-padding processing on the amplitude-time change or the phase-time change; a copy interpolation process on the amplitude-time change or the phase-time change; or a spline interpolation process on the amplitude-time change or the phase-time change.

[0016] With this configuration, (1) by using a low-pass filter after zero-padding processing, the computational load during up-rate processing increases, but the accuracy during up-rate processing can be improved; (2) by using copy interpolation processing, discontinuous noise during up-rate processing remains, but the computational load during up-rate processing can be reduced; and (3) by using spline interpolation processing, the computational load during up-rate processing can be reduced, and the accuracy during up-rate processing can be improved.

[0017] Furthermore, this disclosure is a heart rate and respiration output program that causes a computer to execute each processing step corresponding to each processing unit of the heart rate and respiration output device described above.

[0018] This configuration makes it possible to provide a program that has the aforementioned effects. [Effects of the Invention]

[0019] Thus, this disclosure enables the correct adjustment of the direction of radar or ultrasound signals and the correct determination of the authenticity of heart rate and / or respiratory rate alerts when calculating heart rate and / or respiratory rate based on radar signals (including ultrasound signals) reflected from the body surface, while reducing the burden on physicians or nurses, lowering the risk of infection, enabling remote medical care and treatment, early disease detection, and future predictive research. [Brief explanation of the drawing]

[0020] [Figure 1] This figure shows the configuration of the heart rate respiration output device of the present disclosure. [Figure 2] This figure shows the procedure for processing heart rate and respiratory output according to the present disclosure. [Figure 3] This figure shows a specific example of the heart rate extraction process described in this disclosure. [Figure 4] This figure shows a specific example of the respiratory extraction process described herein. [Figure 5] This figure shows a specific example of the heart rate and respiration extraction process described herein. [Figure 6] This figure shows a specific example of the audio signal modulation processing described herein. [Figure 7] This figure shows a specific example of the frequency uprate processing described herein. [Figure 8] This figure shows a specific example of the frequency uprate processing described herein. [Figure 9] This figure shows a specific example of the frequency uprate processing described herein. [Figure 10] This figure shows a specific example of the heart rate and respiration output processing described herein. [Figure 11] This figure shows a specific example of the heart rate and respiration output processing described herein. [Modes for carrying out the invention]

[0021] Embodiments of the present disclosure will be described with reference to the attached drawings. The embodiments described below are examples of the implementation of the present disclosure, and the present disclosure is not limited to these embodiments.

[0022] (Configuration of the heart rate and respiratory output device in this disclosure) Figure 1 shows the configuration of the heart rate and respiration output device of this disclosure. Figure 2 shows the procedure for processing heart rate and respiration output of this disclosure. The heart rate and respiration output device M comprises a heart rate and respiration extraction unit 1, a time variation calculation unit 2, a frequency amplification unit 3, an audio signal modulation unit 4, and a heart rate and respiration output unit 5, and can be implemented by installing the heart rate and respiration output program shown in Figure 2 onto a computer.

[0023] The radar transceiver R or ultrasound transceiver R transmits a radar signal or ultrasound signal (carrier band) to irradiate the surface of the patient P's body, receives the radar signal or ultrasound signal (carrier band) reflected from the surface of the patient P's body, and converts the received radar signal or ultrasound signal to the baseband band for output. The radar or ultrasound system may be CW, FMCW, standing wave, or any other system. The radar signal or ultrasound signal (carrier band) has a wavelength on the order of 1 to 10 mm, which is equal to the order of the minute vibration amplitude on the surface of the patient P's body.

[0024] The heart rate and respiration output device M calculates the amplitude-time change or phase-time change of frequency components due to minute vibrations of the heartbeat and / or respiration from the radar signal or ultrasound signal (baseband) reflected from the patient P's body surface. Then, based on the amplitude-time change or phase-time change of frequency components due to minute vibrations of the heartbeat and / or respiration, it amplitude-modulates or frequency-modulates an audio signal having audible frequencies (on the order of 10Hz to 10kHz, especially on the order of 100Hz). As a result, a doctor or nurse can listen to the heartbeat and / or respiration as if using a stethoscope.

[0025] Therefore, the direction of the radar or ultrasound signal can be correctly adjusted so that a physician or nurse can experimentally listen to the heart rate and / or respiration. Furthermore, by directly listening to the heart rate and / or respiration, the physician or nurse can correctly determine the authenticity of the heart rate and / or respiratory rate alerts. In addition, it is applicable to reducing the burden on physicians and nurses, lowering the risk of infection, remote medical consultation and treatment, early disease detection, and future predictive research. The following describes specific examples of each process of the heart rate and respiratory output device M.

[0026] (Specific example of the heart rate and respiration extraction process described herein) Specific examples of the heart rate and respiration extraction process of this disclosure are shown in Figures 3 and 4. The heart rate and respiration extraction unit 1 extracts frequency components (±10 or 10) due to minute vibrations of the heart rate and / or respiration from the radar signal or ultrasound signal (I / Q complex signal converted to the baseband band) reflected from the body surface of the patient P. 2 Step S1 extracts DC components (on the order of Hz and / or including extremely low frequency components). Alternatively, the heart rate and respiration extraction unit 1 extracts frequency components (+10 or 10) due to minute vibrations of heartbeat and / or respiration from the radar signal or ultrasound signal (real signal converted to the baseband band) reflected from the body surface of the patient P. 2 Extract the DC component (including Hz-order and / or extremely low-frequency components) (Step S1).

[0027] In Figure 3, the heart rate and respiration extraction unit 1 calculates a spectrogram S showing the time evolution of each frequency component from the radar signal or ultrasound signal (I / Q complex signal converted to the baseband band) reflected from the body surface of the patient P. Then, from the spectrogram S, the frequency components due to minute vibrations of the heartbeat (±10 or 10 2 The unit extracts frequencies (on the order of Hz). Alternatively, the heart rate and respiration extraction unit 1 calculates the bandpass filter result B of the frequency components due to minute vibrations of the heartbeat from the radar signal or ultrasound signal (real signal converted to the baseband band) reflected from the surface of the patient P's body. In either case, small amplitude peaks due to minute vibrations of the heartbeat are extracted approximately once or twice every two seconds, and similar amplitude peaks of the first and second heart sounds in a single heartbeat are extracted.

[0028] Here, the heart rate and respiration extraction unit 1 extracts (ri[n], rq[n]) (where r is the positive frequency, i and q are the i and q components, and n is time) as the positive frequency component due to minute heartbeat vibrations from the radar signal or ultrasound signal (I / Q complex signal converted to the baseband band) reflected from the surface of the patient P's body, and (li[n], lq[n]) (where l is the negative frequency, i and q are the i and q components, and n is time) as the negative frequency component due to minute heartbeat vibrations. Alternatively, the heart rate and respiration extraction unit 1 extracts b as the frequency component due to minute heartbeat vibrations from the radar signal or ultrasound signal (real signal converted to the baseband band) reflected from the surface of the patient P's body, p Extract [n] (where b is the passband frequency range of the bandpass filter result B, p is the heart rate, and n is time).

[0029] In Figure 4, the heart rate and respiration extraction unit 1 calculates a spectrogram S showing the time evolution of each frequency component from the radar signal or ultrasound signal (I / Q complex signal converted to the baseband band) reflected from the body surface of patient P. Then, it extracts the frequency components due to minute vibrations of respiration (DC components including extremely low frequency components) from the spectrogram S. Alternatively, the heart rate and respiration extraction unit 1 calculates the bandpass filter result B for the frequency components due to minute vibrations of respiration from the radar signal or ultrasound signal (real signal converted to the baseband band) reflected from the body surface of patient P. In either case, amplitude peaks due to minute vibrations of respiration are extracted approximately once or twice every 10 seconds, and amplitude peaks due to minute vibrations of the heart rate are extracted approximately three times between the respiratory amplitude peaks.

[0030] Here, the heart rate and respiration extraction unit 1 extracts (ci[n], cq[n]) (where c is the center frequency, i and q are the i and q components, and n is time) as frequency components due to minute vibrations of respiration from the radar signal or ultrasound signal (I / Q complex signal converted to the baseband band) reflected from the surface of the patient P's body. Alternatively, the heart rate and respiration extraction unit 1 extracts b as frequency components due to minute vibrations of respiration from the radar signal or ultrasound signal (real signal converted to the baseband band) reflected from the surface of the patient P's body. r Extract [n] (where b is the passband frequency range of the bandpass filter result B, r is respiration, and n is time).

[0031] A specific example of the heartbeat and respiration extraction process of the present disclosure is also shown in FIG. 5. The heartbeat and respiration extraction unit 1 extracts positive and negative frequency components (±10 or on the order of 10 2 Hz) due to the minute vibration of the heartbeat from the radar signal or ultrasonic signal (I / Q complex signal converted to the baseband band) reflected on the body surface of the patient P (step S1). Then, the heartbeat and respiration extraction unit 1 performs complex multiplication and division on the positive and negative frequency components (±10 or on the order of 10 2 Hz) due to the minute vibration of the heartbeat (step S1).

[0032] In the left column of FIG. 5, the principle of the complex multiplication and division process of the heartbeat and respiration extraction unit 1 is explained. The radar signal or ultrasonic signal (carrier band) reflected on the body surface of the patient P is subjected to heartbeat phase modulation due to the minute vibration of the heartbeat and also to respiration phase modulation due to the minute vibration of respiration. Here, the radar signal or ultrasonic signal (carrier band) reflected on the body surface of the patient P is also subjected to heartbeat amplitude modulation, but since it is more uncertain compared to the heartbeat phase modulation, it is disadvantageous for high-precision heartbeat extraction, and it is also subjected to respiration amplitude modulation, but since it is more uncertain compared to the respiration phase modulation, it is disadvantageous for high-precision respiration extraction.

[0033] In the right column of FIG. 5, the heartbeat and respiration extraction unit 1 extracts, as the positive frequency component due to the minute vibration of the heartbeat, Ae j{θr+(θp+φ)} (A is the amplitude, θ r is the respiration phase change, θ p is the heartbeat phase change, φ is the initial phase of the heartbeat phase change), and extracts, as the negative frequency component due to the minute vibration of the heartbeat, Ae j{θr-(θp+φ)-π} (π is the phase difference between the upper and lower sidebands of the phase modulation).

[0034] Then, the heartbeat and respiration extraction unit 1 calculates, as the complex-multiplied positive and negative frequency components, Ae j{θr+(θp+φ)} *Ae j{θr-(θp+φ)-π} =|A| 2 e j(2θr-π) . Therefore, the complex-multiplied positive and negative frequency components |A| 2 e j(2θr-π)Therefore, the heart rate phase change θ due to minute oscillating heartbeats. p +φ removed, respiratory phase change θ due to minute vibrations of respiration r It is possible to extract it.

[0035] Thus, when listening to respiration, the frequency components due to minute vibrations of respiration (DC components including extremely low frequency components) are not extracted, and the frequency components due to minute vibrations of the heartbeat (±10 or 10) are not extracted. 2 By extracting frequencies (on the order of Hz), robustness can be improved and the influence of disturbances can be reduced. This allows for considering only the reflected signal from the chest, without considering the reflected signal from the abdomen. However, disturbances such as air conditioner louvers, curtains swaying in the wind, and the movements of nurses are mainly included in the DC component and are close in frequency to the minute vibrations of respiration, making it difficult to improve robustness and reduce the influence of disturbances. Furthermore, when the reflected signals from the abdomen and chest are combined, there is a risk of misinterpreting the respiratory rate as twice the normal rate depending on the conditions of the combination.

[0036] On the other hand, the heart rate and respiration extraction unit 1 uses the positive and negative frequency components obtained by complex division, and Ae j{θr+(θp+φ)} / Ae j{θr-(θp+φ)-π} =e j{2(θp+φ)+π} The positive and negative frequency components e obtained by complex division are calculated. j{2(θp+φ)+π} Therefore, the respiratory phase change θ due to minute vibrations of respiration. r The heart rate phase change θ due to minute heart rate oscillating has been removed. p +φ can be extracted.

[0037] Thus, when listening to the heartbeat, the frequency components (±10 or 10) due to minute vibrations of the heartbeat are important. 2 Extracting frequencies (on the order of Hz) can improve robustness and reduce the impact of external disturbances, but it is important to note that whether the first and second heart sounds in a single heartbeat are in phase, out of phase, or in other states varies depending on the individual or animal species.

[0038] (Specific examples of audio signal modulation processing in this disclosure) Prior to the audio signal modulation processing of this disclosure, the time variation calculation unit 2 calculates the frequency components (±10 or 10) due to minute vibrations of heartbeat and / or respiration. 2 Calculate the amplitude-time variation or phase-time variation of the DC component (including DC components on the order of Hz and / or extremely low frequency components) (Step S2).

[0039] In Figure 3, the time variation calculation unit 2 calculates the frequency components (±10 or 10) due to minute vibrations of the heartbeat. 2 As an amplitude-time change of the order of Hz, √(ri[n] 2 +rq[n] 2 ),√(li[n] 2 +lq[n] 2 ), or a p [n](=b p The amplitude of [n] is calculated. Alternatively, the time variation calculation unit 2 calculates the frequency components (±10 or 10) due to minute vibrations of the heartbeat. 2 As a phase-time change of the order of Hz, tan -1 (rq[n] / ri[n]), tan -1 (lq[n] / li[n]), or θ p [n](=b p Calculate the phase of [n].

[0040] In Figure 4, the time-varying calculation unit 2 calculates the amplitude-time change of the frequency component (DC component including extremely low-frequency components) due to minute vibrations of respiration as √(ci[n] 2 +cq[n] 2 ), or a r [n](=b r The amplitude of [n] is calculated. Alternatively, the time variation calculation unit 2 calculates the tan as the phase time change of the frequency components (DC components including extremely low frequency components) due to minute vibrations of respiration. -1 (cq[n] / ci[n]), or θ r [n](=b r Calculate the phase of [n].

[0041] In Figure 5, the time variation calculation unit 2 calculates 2θ as the phase-time change of the frequency components (DC components including extremely low-frequency components) due to minute vibrations of respiration. r-π (extracting the argument of e) is calculated. Alternatively, the time variation calculation unit 2 calculates the frequency components due to minute vibrations of the heartbeat (±10 or 10 2 As a phase-time change of the order of Hz, 2(θ p Calculate (+φ) + π (extract the argument of e).

[0042] A specific example of the audio signal modulation processing of this disclosure is shown in Figure 6. The audio signal modulation unit 4 amplitude modulates or frequency modulates an audio signal having audible frequency band based on the amplitude time change or phase time change of frequency components due to minute vibrations of heartbeat and / or respiration (step S4). The heartbeat and respiration output unit 5 outputs the audio signal after amplitude modulation or frequency modulation (step S5).

[0043] In the upper panel of Figure 6, the modulated information in the heart rate output is the amplitude-time change (√(ri[n] 2 +rq[n] 2 ),√(li[n] 2 +lq[n] 2 ), a p [n]), or phase time change (tan -1 (rq[n] / ri[n]), tan -1 (lq[n] / li[n]), θ p [n], 2(θ p [n] + φ) + π), and the modulation method is either amplitude modulation or frequency modulation.

[0044] In the lower panel of Figure 6, the modulated information in the respiratory output is the amplitude-time change (√(ci[n] 2 +cq[n] 2 ), a r [n]), or phase time change (tan -1 (cq[n] / ci[n]), θ r [n], 2θ r [n]-π) and the modulation method is amplitude modulation or frequency modulation.

[0045] The audio signal modulation unit 4 may apply one of the modulations, amplitude modulation and frequency modulation, to the audio signal based on the amplitude-time change or phase-time change of the frequency components due to minute vibrations of the heartbeat, and may also apply the other modulation, amplitude modulation and frequency modulation, to the audio signal based on the amplitude-time change or phase-time change of the frequency components due to minute vibrations of the breath (step S4).

[0046] For example, in heart rate output, modulated information is √(ri[n] 2 +rq[n] 2 ) and in respiratory output, modulated information is 2θ r Let [n]-π. Then, when amplitude modulation is applied to the heart rate output and frequency modulation is applied to the respiratory output, the modulated audio signal is expressed by the first equation of Equation 1. Furthermore, when frequency modulation is applied to the heart rate output and amplitude modulation is applied to the respiratory output, the modulated audio signal is expressed by the second equation of Equation 1. Here, S[n] is the modulated audio signal, f is the audible frequency band, and β is the modulation index.

number

[0047] In this way, heart rate and respiration can be heard as the magnitude and pitch of audio signals, respectively, or as the pitch and magnitude of audio signals, respectively, and as a result, heart rate and respiration can be heard simultaneously and separately.

[0048] The audio signal modulation unit 4 may apply amplitude modulation and frequency modulation to the audio signal based on the amplitude-time change or phase-time change of frequency components due to minute vibrations of the heartbeat, or apply the same amplitude modulation and frequency modulation to the audio signal based on the amplitude-time change or phase-time change of frequency components due to minute vibrations of the breath (step S4).

[0049] For example, in heart rate output, modulated information is √(ri[n] 2 +rq[n] 2) and in respiratory output, modulated information is 2θ r Let [n]-π. Then, when frequency modulation is applied to the heart rate output and frequency modulation is applied to the respiratory output, the modulated audio signal is expressed by the first equation of Equation 2. Furthermore, when amplitude modulation is applied to the heart rate output and amplitude modulation is applied to the respiratory output, the modulated audio signal is expressed by the second equation of Equation 2. Here, S[n] is the modulated audio signal, f is the audible frequency band, and β is the modulation index.

number

[0050] In this way, both heart rate and respiration can be heard as the pitch of the audio signal, or as the magnitude of the audio signal. As a result, although inferior to the case of Equation 1, heart rate and respiration can be heard simultaneously and separately.

[0051] (Specific examples of frequency uprate processing in this disclosure) Specific examples of the frequency up-rate processing of this disclosure are shown in Figures 7 to 9. The frequency up-rate unit 3 up-rates the amplitude-time change or phase-time change calculated in step S2, which has a sampling frequency lower than the audible frequency band of the audio signal, with an up-rate frequency higher than the audible frequency band of the audio signal (step S3).

[0052] In Figure 7, the frequency up-rate unit 3 performs a low-pass filter process after zero-padding on the amplitude-time change or phase-time change when up-rating the amplitude-time change or phase-time change. Although this increases the computational load during up-rating, it improves the accuracy during up-rating (eliminating the discontinuous noise shown in Figure 8).

[0053] In Figure 8, the frequency up-rate unit 3 performs copy interpolation processing to the amplitude-time change or phase-time change when up-rates the amplitude-time change or phase-time change (zero-padding processing is not performed). As a result, although discontinuous noise remains during up-rate (there is no continuity in Figures 7 and 9), the computational load during up-rate can be reduced.

[0054] In Figure 9, the frequency up-rate unit 3 performs spline interpolation on amplitude-time changes or phase-time changes when up-rating (zero-padding is not performed). This reduces the computational load during up-rating and improves accuracy during up-rating (eliminating the discontinuous noise shown in Figure 8).

[0055] Therefore, even when the amplitude-time changes or phase-time changes of frequency components due to minute vibrations of heartbeat and / or respiration are sampled at a "low sampling frequency," by upscaling the amplitude-time changes or phase-time changes of frequency components due to minute vibrations of heartbeat and / or respiration at a "high up-rate frequency," it is possible to amplitude-modulate or frequency-modulate an audio signal having audible frequencies using the upscaled modulated information.

[0056] (Specific example of the heart rate and respiration output processing described herein) Specific examples of the heart rate and respiration output processing of this disclosure are shown in Figures 10 and 11. The audio signal modulation unit 4 amplitude modulates or frequency modulates an audio signal having an audible frequency based on the amplitude time change or phase time change frequency-upgraded in step S3 (step S4). The heart rate and respiration output unit 5 outputs the audio signal amplitude-modulated or frequency-modulated in step S4 (step S5). In Figures 10 and 11, the output target, modulated information, and modulation method are different.

[0057] The upper part of Figure 10 shows the amplitude-time change or phase-time change of the heartbeat or respiration frequency-upgraded in step S3. Although this amplitude-time change or phase-time change is outside the audible frequency range, it becomes modulated information. The middle part of Figure 10 shows the speech signal amplitude-modulated in step S4, and this speech signal is within the audible frequency range. The lower part of Figure 10 shows the speech signal frequency-modulated in step S4, and this speech signal is also within the audible frequency range.

[0058] The upper panel of Figure 11 shows the amplitude-time change of the heartbeat, which has been frequency-upgraded in step S3. Although this amplitude-time change is outside the audible frequency range, it is modulated information. The middle panel of Figure 11 shows the phase-time change of the respiration, which has been frequency-upgraded in step S3. Although this phase-time change is outside the audible frequency range, it is modulated information. The lower panel of Figure 11 shows the audio signal, which has been amplitude-modulated by the amplitude-time change of the heartbeat and frequency-modulated by the phase-time change of the respiration in step S4. This audio signal is within the audible frequency range. [Industrial applicability]

[0059] The heart rate and / or respiratory rate output device and program of this disclosure, based on radar signals (including ultrasound signals) reflected from the body surface, can correctly adjust the direction of irradiation of radar signals or ultrasound signals and correctly determine the authenticity of heart rate and / or respiratory rate alerts, while enabling reduced burden on physicians or nurses, reduced risk of infection, remote medical care and treatment, early disease detection, and future predictive research. [Explanation of Symbols]

[0060] P:Patient R: Radar transceiver, ultrasonic transceiver M: Cardiac and respiratory output device S: Spectrogram B: Bandpass filter result 1: Heart rate and respiration extraction unit 2: Time change calculation unit 3: Frequency Upgrade Section 4: Audio signal modulation section 5: Heart rate and respiratory output unit

Claims

1. A heart rate and respiration extraction unit extracts frequency components due to minute vibrations of heartbeat and respiration from radar signals or ultrasonic signals reflected from the body surface, and calculates the amplitude time change or phase time change of the said frequency components due to minute vibrations of heartbeat and respiration. The system includes a heart rate and respiration output unit that amplitude modulates or frequency modulates an audio signal having audible frequencies based on the amplitude-time change or phase-time change of the frequency components due to minute vibrations of heartbeat and respiration, and outputs the audio signal after amplitude modulation or frequency modulation, The heart rate and respiration output unit applies amplitude modulation and frequency modulation to the audio signal based on the amplitude-time change or phase-time change of the frequency component due to minute vibrations of the heartbeat, and applies the other modulation of amplitude modulation and frequency modulation to the audio signal based on the amplitude-time change or phase-time change of the frequency component due to minute vibrations of respiration. A heart rate and respiratory output device characterized by the following features.

2. A heart rate and respiration extraction unit extracts frequency components due to minute vibrations of heartbeat and respiration from radar signals or ultrasonic signals reflected from the body surface, and calculates the amplitude time change or phase time change of the said frequency components due to minute vibrations of heartbeat and respiration. The system includes a heart rate and respiration output unit that amplitude modulates or frequency modulates an audio signal having audible frequencies based on the amplitude-time change or phase-time change of the frequency components due to minute vibrations of heartbeat and respiration, and outputs the audio signal after amplitude modulation or frequency modulation, The heart rate and respiration extraction unit extracts the positive and negative frequency components due to minute vibrations of the heartbeat and then performs complex multiplication to calculate the phase time change of the frequency components due to minute vibrations of respiration, with the phase time change of the frequency components due to minute vibrations of the heartbeat removed. A heart rate and respiratory output device characterized by the following features.

3. The heart rate and respiration extraction unit upscales the amplitude-time change or phase-time change, which has a sampling frequency lower than the audible frequency range of the audio signal, using an uprate frequency higher than the audible frequency range of the audio signal. A heart rate and respiratory output device according to claim 1 or 2, characterized in that...

4. The heart rate and respiration extraction unit, in upgrading the amplitude-time change or the phase-time change, performs one of the following: a low-pass filter process after zero-padding processing of the amplitude-time change or the phase-time change; a copy interpolation process for the amplitude-time change or the phase-time change; or a spline interpolation process for the amplitude-time change or the phase-time change. The heart rate and respiration output device according to claim 3, characterized in that

5. A heart rate and respiration output program for causing a computer to execute each processing step corresponding to each processing unit of the heart rate and respiration output device according to any one of claims 1 to 4.

Images