# US 2019/0167207 A1 · Sleep signal conditioning device and method

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2019/0167207 A1
- Document ID: US20190167207A1
- Status: Published application
- Kind: A1
- Application number: 16/092,578
- Filed: 2017-04-06
- Published: 2019-06-06
- Earliest claimed: 2016-04-15
- Assignees: Koninklijke Philips N.V.
- Applicants: Koninklijke Philips N.V.
- Inventors: ERIK GOSUINUS PETRUS SCHUIJERS
- Web page: https://patentgrep.com/patent/US20190167207A1

## CPC

- A61B 5/7278: {Artificial waveform generation or derivation, e.g. synthesizing signals from measured signals}
- A61B 5/0205: Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
- A61B 5/024: Measuring pulse rate or heart rate
- A61B 5/0816: {Measuring devices for examining respiratory frequency (measuring frequency of electric signals G01R23/00)}
- A61B 5/11: Measuring movement of the entire body or parts thereof, e.g. head or hand tremor or mobility of a limb {(A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721)}
- A61B 5/1102: {Ballistocardiography}
- A61B 5/1118: {Determining activity level}
- A61B 5/4809: {Sleep detection, i.e. determining whether a subject is asleep or not}
- A61B 5/6892: {Mats}
- A61B 5/7221: {Determining signal validity, reliability or quality (preventing, reducing or removing noise induced by motion artefacts A61B5/7207; noise originating from a therapeutic or surgical apparatus A61B5/7217)}
- A61B 2562/0247: Pressure sensors
- A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D)

## Abstract

A method and device are provided for conditioning a sleep signal from a sleep sensor for a sleep monitor. A sleep sensor is configured to sense a physiological signal, such as a cardiac or respiratory signal from a sleeping mammal, such as a human, e.g. an infant or a baby. If the mammal exhibits also (gross) body movement during his sleep, the sensor signal may be clipped. The method and device provide a conditioning of the sleep signal by providing an estimation of the sleep signal instead of the conditioned sleep signal itself when the sensor signal is clipping.

## Claims

### Claim 1

Sleep signal conditioning device for a sleep monitor, the device comprising:
a first processing unit for providing a first parameter indicative of the magnitude of a first sensor signal from a first sleep sensor sensing a physiological signal from a sleeping mammal;
a second processing unit for providing a second parameter indicative of the magnitude of a second sensor signal from a second sleep sensor sensing a physiological signal from the sleeping mammal, wherein the first sensor signal is different from the second sensor signal;
a clipping detector for detecting when the first sensor signal is clipping;
a divider for calculating a ratio based on dividing the first parameter by the second parameter when the first sensor signal is not clipping;
a multiplier for generating an estimated first sensor signal based on multiplying a second output signal based on the second sensor signal by the ratio; and
a switch for providing a first output sleep signal based on the estimated first sensor signal when detecting that the first sensor signal is clipping and a first output signal based on the first sensor signal when detecting that the first sensor signal is not clipping.

### Claim 2 (depends on 1)

Device according to claim 1, wherein the first and second processing unit are arranged to provide an amplitude or an energy as the parameter indicative of the magnitude of the signal.

### Claim 3 (depends on 1)

Device according to claim 1, wherein the first and second processing unit comprise an IIR filter and/or FIR filter.

### Claim 4 (depends on 1)

Device according to claim 1, wherein at least one of the processing units is arranged to determine the parameter indicative of the magnitude of the signal based also on a signal portion after a preceding signal portion where the first sensor signal was clipping, while the divider is arranged to use the determined parameter in the calculation of the ratio used during said preceding signal portion.

### Claim 5 (depends on 1)

Device according to claim 1, wherein an ability to extract respiratory and cardiac features from a current signal portion is determined and the divider is arranged in dependence thereon to control whether or not to include the current signal portion in the calculation of the ratio.

### Claim 6 (depends on 1)

Device according to claim 1, wherein the device comprises a first conditioning unit for conditioning the first sensor signal to the first output signal and a second conditioning unit for conditioning the second sensor signal to the second output signal, or
the first parameter as provided by the first processing circuit constitutes the first output signal and the second parameter as provided by the second processing circuit constitutes the second output signal.

### Claim 7 (depends on 1)

Device according to claim 1, wherein the device comprises a second clipping detector for detecting when the second sensor signal is clipping; and the divider is arranged for calculating the ratio when the second sensor signal is not clipping.

### Claim 8 (depends on 1)

Device according to claim 1, comprising:
a plurality of processing units for processing a plurality of sensor signals from a respective plurality of sleep sensors;
a plurality of clipping detectors for detecting when a respective one of the sensor signals is clipping;
at least one divider for calculating a ratio matrix, wherein each element of the ratio matrix is a ratio based on dividing, when the respective sensor signals are not clipping, respective parameters indicative of the amplitude of respective sensor signals;
at least one multiplier for generating at least one respective estimated signal based on multiplying a selected output signal based on a selected other one of the sensor signals by the respective element of the ratio matrix; and
a plurality of switches for providing per switch a respective sleep output signal based on the respective estimated signal when detecting that the respective signal is clipping and based on a respective output signal based on the respective signal when detecting that the respective signal is not clipping.

### Claim 9 (depends on 1)

Sleep monitoring system comprising:
a first sleep sensor for sensing a physiological signal from a sleeping mammal;
a second sleep sensor for sensing a physiological signal from the sleeping mammal;
a sleep signal conditioning device according to claim 1, wherein the first sleep sensor is for providing the first sensor signal to the device and the second sleep sensor is for providing the second sensor signal to the device; and
a sleep monitor for monitoring the sleep output signal received from the sleep signal conditioning device.

### Claim 10 (depends on 1)

System according to claim 1, comprising a mattress, wherein the first and second sleep sensor are positioned in, adjacent of or in proximity of the mattress for measuring the mammal asleep on the mattress.

### Claim 11 (depends on 9)

System according to claim 9, wherein the first and second sensors have a different dynamic range and/or accuracy.

### Claim 12 (depends on 9)

System according to claim 9, wherein the first and second sensors are piezoelectric sensors.

### Claim 13 (depends on 9)

System according to claim 9, wherein the first and second sensor are pressure sensors for sensing the physiological signal, such as a hearth beat and/or a breathing, and/or a movement of the mammal.

### Claim 14

Sleep signal conditioning method for a sleep monitor, comprising the steps of:
processing a first sensor signal for providing a first parameter indicative of the magnitude of the first sensor signal from a first sleep sensor sensing a physiological signal from a sleeping mammal;
processing a second sensor signal for providing a second parameter indicative of the magnitude of the second sensor signal from a second sleep sensor sensing a physiological signal from the sleeping mammal, wherein the first sensor signal is different from the second sensor signal;
detecting when the first sensor signal is clipping;
calculating a ratio based on dividing the first parameter by the second parameter when the first sensor signal is not clipping;
generating an estimated first sensor signal based on multiplying a second output signal based on the second sensor signal by the ratio; and
a switch for providing a first output sleep signal based on the estimated first sensor signal when detecting that the first sensor signal is clipping and a first output signal based on the first sensor signal when detecting that the first sensor signal is not clipping; and
providing a first output sleep signal based on the estimated first sensor signal when detecting that the first sensor signal is clipping and a first output signal based on the first sensor signal when detecting that the first sensor signal is not clipping.

### Claim 15 (depends on 14)

A computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor, the computer or processor is caused to perform the method of claim 14.