AU2021103840A4 - Development of a Screening tool for Sleep Apnea for experts in clinical setups - Google Patents

Abstract

TITLE OF INVENTION: Development of a Screening tool for Sleep Apnea for experts in clinical setups FIELD OF INVENTION: COMPUTER SCIENCE ABSTRACT Sleep apnea is a type of breathing disorder caused by interruptions in breathing or shallow breathing during night sleep. The disorder can occur in three different forms namely, Obstructive Sleep apnea (OSA), Central Sleep apnea (CSA) and Mixed Sleep apnea (MSA) among which OSA is the most prevalent. In all these three forms of sleep apnea, the interrupted breathing activity leads to the problem of oxygen deficiency leading to the development of chronic cardiac related ailments. Hence an earlier detection of sleep apnea can save patient from life risk. The Invention discloses a low-power, high-performance algorithm for sleep apnea detection based on ECG signal. DRAWINGS SHEET 1 OF 1 ECG Pre- QRS Feature Feature Classificat Apnea signal processing -W Detectraction -k Reduction -o ion using - or (BPF) using PT using PCA ANN Normal Proposed PT-based method of sleep apnea detection

Description

DRAWINGS SHEET 1 OF 1

ECG Pre- QRS Feature Feature Classificat Apnea signal processing -W Detectraction -k Reduction -o ion using - or (BPF) using PT using PCA ANN Normal

Proposed PT-based method of sleep apnea detection

TITLE OF INVENTION: Development of a

Screening tool for Sleep Apnea for experts in

clinicalsetups

FIELD OF INVENTION: COMPUTER SCIENCE BACKGROUND OF THE INVENTION

Polysomnography (PSG) is the gold standard test used for detection of sleep apnea disorder conducted in a sophisticated sleep lab facility under the supervision of a trained person. PSG is an overnight sleep test conducted on the patient .0 involving the monitoring of various physiological parameters tapped from the set of sensor electrodes put on patient's body. The test proves to be very cumbersome and expensive involving complex analysis.

The study is being carried out by several researchers for suggesting an alternative means of detecting sleep apnea that can

be used in a home environment with reduced number of physiological parameters tapped from the patient for analysis. Respiration function and Heart function re highly interdependent. The heart function can be captured using the Electrocardiography (ECG), a well established diagnostic modality available as a common health care facility. The respiration or the breathing information has representation in the normal ECG as its amplitude and frequency parameters in modulated form. During breathing disorder caused by sleep .5 apnea condition, ECG signal characteristics change and deviate from its normal characteristics. The medical experts observe such changes in ECG characteristics and infer about the sleep apnea conditions.

PRIOR ART OF WORK

("US8037885B2"): A pharyngeal airway having a pharyngeal

wall of a patient at least partially surrounding and defining the

airway is treated by selecting an implant dimensioned so as to

be implanted at or beneath a mucosal layer of the pharyngeal

wall and extending transverse to said wall. The implant has

mechanical characteristics for the implant, at least in

combination with a fibrotic tissue response induced by the

implant, to stiffen said pharyngeal wall to resist radial

collapse. The implant is implanted into the pharyngeal wall

transverse to a longitudinal axis of the airway

("US10206571B2"): Apparatus, systems, and methods are

provided for treating obstructive sleep apnea. A CPAP system with an integrated oximeter sensor is disclosed wherein the sensor communicates with an oximeter processor that controls the blower. A nasal air flow sensor may also be incorporated that provides more data to the processor. A unique lightweight, flexible and stretchable hose for CPAP systems is also disclosed. The hose may have a magnetic connection with the blower.

("US7322356B2"): A method for treating a patient diagnosed

with obstructive sleep apnea includes identifying a patient as

having sleep apnea susceptible to a first positive airway

treatment which is at a first operating pressure level in excess

of that which is otherwise tolerable to the patient. The patient

is treated with an airway treatment selected to alter a portion

of an airway tissue of the patient. The patient is then treated

with a second positive airway pressure treatment at a second

pressure level, which is below the pressure threshold.

("CN107205693A"): Invention is related to a kind of

detection, the device for the generation assessed and terminate snoring, sleep apnea event and hypopnea event, it will be disorderly to reduce or eliminate anoxic, hypercapnia and heart and lung hemodynamics, and the mode in every morning to their crucial dormant datas of the user report of described device.

("CN107635615B"): Devices, systems, and methods for

treating obstructive sleep apnea are provided. A single valve

assembly removably located within the outer contour of the

nasal pillow mask uses positive airway pressure from a low

flow hose to automatically create a therapeutic-on-demand air

splint in the pharynx. During inhalation, the valve system of

the mask allows room air to be inhaled. During exhalation, the

other valve controls a therapeutic back pressure equal to the

prescribed pressure setting of the CPAP blower. The mask

may be worn with the CPAP blower off and provides a system

F5 to activate the CPAP blower only when needed.

("US10272226B2"): A device for treating a patient suffering

from obstructive sleep apnea or snoring can include an expiratory valve connected to a manifold. The expiratory valve can include a body portion including a feedback port configured to be connected to an air flow generator. The expiratory valve can include a plunger at least partially disposed in the body portion. The expiratory valve can include a pressurizing chamber positioned between an end of the plunger and an end of the expiratory valve. The pressurizing

|5 chamber can be configured to receive air from the air flow

generator through the feedback port.

("US5535739A"): In the treatment of

obstructive sleep apnea a method and apparatus are disclosed

for optimizing the controlled positive pressure to minimize the

flow of air from a flow generator while still ensuring that flow

limitation in the patient's airway does not occur. In particular,

the invention relates to a breathing device and method of use

to adjust a controlled positive pressure to the airway of a

patient by detecting flow limitation from analysis of an

inspiratory flow waveform. Once the presence of flow

limitation has been analyzed, the system determines an action to take for adjustment of the controlled positive pressure. The pressure setting is raised, lowered or maintained depending on whether flow limitation has been detected and on the previous actions taken by the system. The preferred breathing apparatus consists of a flow generator, a flow sensor, an analog to digital converter, a microprocessor, and a pressure controller, a patient supply hose, a nasal fitting, and, optionally, a pressure transducer. Using the method of the present invention, the microprocessor adjusts the air pressure in the patient supply hose when flow limitation is detected in the airway of the patient.

("US5803066A"): In the treatment of obstructive sleep apnea,

a method and apparatus are disclosed for detecting

obstructive apnea and optimizing the controlled positive

pressure to minimize the flow of air from a flow generator

while still ensuring that flow limitation in the patient's airway

does not occur. In particular, the invention relates to a

breathing device and method of use to adjust a controlled

1i nositive nressreto the airwav ofanatient hv detertino flow limitation from analysis of an inspiratory flow waveform.

Once the presence of flow limitation has been analyzed, the

system determines an action to take for adjustment of the

controlled positive pressure. The pressure setting is raised,

lowered or maintained depending on whether flow limitation

has been detected and on the previous actions taken by the

system. The preferred breathing apparatus consists of a flow

generator, a flow sensor, an analog to digital converter, a

microprocessor, and a pressure controller, a patient supply

hose, a nasal fitting, and, optionally, a pressure transducer.

Using the method of the present invention, the microprocessor

adjusts the air pressure in the patient supply hose when flow

limitation is detected in the airway of the patient

("US20160354603Al"): An upper airway stimulator for

treating obstructive sleep apnea is described. In some

embodiments, the upper airway stimulator monitors the phase

difference between ribcage expansion and abdomen

expansion to detect apneic events and stimulates to alleviate

those events. In some embodiments, the upper airway stimulator applies primary stimulation when an apneic event is not detected and secondary stimulation when an apneic event is detected. In some embodiments, the upper airway stimulator applies primary stimulation when the patient is not in an apneic position and secondary stimulation when the patient is in an apneic position.

("US7469697B2"): Methods and systems involve monitoring

one or more patient conditions using a monitoring device that

is fully or partially implantable. Feedback information is

developed based on the monitored conditions and is provided

to a device delivering therapy to treat sleep disordered

breathing. Components of the monitoring device are disposed

within an implantable housing that is separate from the

housing of the therapy device. The therapy device may

comprise a housing that is implantable or patient-external. The

feedback information may be used to adjust

the sleep disordered breathing therapy.

DETAILED DESCRIPTION

The plan of implementation of the detection of Sleep Apnea

can be realized using the various well established methods as

presented in Fig. 2. ECG being a noninvasive technique has a

large number of hidden parameters that help in detection of

the respiratory behavior, in turn the presence and absence of

Sleep Apnea. The first and the foremost step is to get the ECG

signal either using data acquisition hardware like analog front

end from the electrodes attached to human being or download

bio-signal recordings from healthy subjects as well those with

ailments. Next step is the preprocessing of ECG signal to

eliminate the undesired noise from it, so that the pure ECG

signal can be easily analyzed further for the accurate detection

of sleep apnea. Preprocessing involves cascaded stages of

filtering process involving a low pass filter (LPF) with cut off

150 Hz used to remove baseline wander noise, a high pass

filter with cutoff 0.05 Hz to remove motion artifacts and

finally a notch filter with cutoff 50 Hz to remove power line interference as shown. Based on the strategies that can be employed for ECG signal analysis, the important are the QRS complex detection, ECG feature Extraction, Heart

Rate Variability and ECG Derived Respiration (EDR) Signal

extraction. For each of the strategies followed, the important

signal processing methods used are the Pan Tompkins

algorithm, under time domain approach and

Fourier Transform, Wavelet Transform and Hilbert Transform

based techniques under frequency domain approach. The first

step common to all the methods is the QRS complex and

ventricular beat detection followed by morphological and

rhythm analysis. The parameters analyzed under each method

differ from each other.

7WI.nal for (Malmwbr krp pu '.'.deltion7

-- + 'i i t r p aw -' - , e $i ~uA .n,.

Trwkrs Ti 4If-enf

AIO hfl 1 Ldh $r JL i *"1&id 9A pit t *3

Surwy.f E basd OSAk dte~fcinhoed

ECG "d* Instrumentation L ow Pass Filterto

H High Pass Filter to Amplifier _moe_ base.line remove motion artifacts

& wader noise power line interference

Stepwise processes involved in data acquisition of`ECG signal

and also the range of RR intervals. Mean heart rate provides the information to distin guish the normal case with that of apnea condition. But if there are repeated episodes of bradycardia and tachycardia condition, then it is the presence of sleep apnea. Based on the number of episodes of apnea it can be decided as mild OSA, moderate OSA, severe OSA or simplynormalifthe heart rate is well withinthe ideal range ofheart beat between 60 to 70 bpm. The implementation of QRS complex detection, which can be imple mented either using Pan-Tompkins algorithm as shown or using wavelet trans formation technique as shown Amplitude and location of QRS complex is important to detect other parameters of ECG helpful in enhancing the accuracy of QRS detection. The collection of a set of parameters required to gather characteristics of ECG signal with respect to its respiration behavior.

Moving ECG SandPass Squaring window Sign al Filterfunction Integrator 4 Detected

Pan Tompkins algorithm for QRS complex detection

InputECG Signal Discrete Spline Moving Peak Detector it wavelet Interpolation Averaging Transform 4

|Threshold Stepwise process of discrete wavelet transform method

The above discussed procedures are implemented using LabVIEW2014 from TI providing the robust environment for data flow programming providing user friendly built-in functions

1 1 (i) 300 200 00A

10D 200 300 400 500 600

(ii) (iv)

. 200 30 .40 0 100 200 300 400 500 00

(iii) (v) O1S 03 - -. f - _

100 200 400 500 600 100 200 300 400 500 600

Stages of Pan-Tompkins algorithm: (i) a raw ECG signal X05, (ii) BPF output, (iii) differentiator output, (iv) squared output, and (v) output of MWI

Page 12 of 13

Claims (1)

1. • The Invention discloses a low-power, high-performance algorithm for sleep apnea detection based on

   ECG signal.