Homecare monitoring blood pressures and heartbeats are commercially available using dedicated devices, for example, wrist watch, pulse oximetry. With the advent of Smartphone and compressive sensing technology, we wish to monitor precisely the electrical waveforms of heartbeats called the electrocardiography (ECG) for an aging global villager biomedical wellness homecare system. Our design separates into 3 innovative modules within the size-weight and power-cost bandwidth (Swap-CB) limitation. We develop each separately but in concert with one another: (i) Smart Electrode (adopting a low-power-mixed signal embedded with modern compressive sensing firmware and applying the nanotechnology to improve the electrodes’ contact impedance as well as novel transduction mechanism, between ECG and electronics, e.g., a pressure mattress coupling, or fiber-optics coupling); (ii) Learnable Database (utilizing adaptive wavelets transforms for systolic and diastolic P-QRS-T-U features extraction Aided Target Recognition and adopting Sequential Query Language for a relational database allowing distant monitoring and retrievable); (iii) Smartphone (inheriting a large touch screen interface display with powerful computation capability and assisting caretaker reporting system with GPS and ID and two-way interaction with patient panic button for programmable emergence reporting procedure). While (i) is novel, (ii) and (iii) are mature. Together, they can eventually provide a supplementary home screening system for the post- or the prediagnosis care at home with a built-in database searchable with the time, the place, and the degree of urgency happened, using in situ screening.
Home-alone senior tends to suffer and worry about midnight and early morning crisis, heart attack, or stroke. While their bodies secrete hormones regulating hearts and blood pressures ready for the wake-up actions, their limbs are still stiff suffering bad circulations over the sleep. For caretakers, we design an affordable, and comfortable biomedical wellness (BMW) monitoring device of detail electrocardiogram (ECG) waves for early warning monitoring at homes. Thus, we review heart monitoring ECG as a common sense baseline, before we present compressing sensing technology (reader may skip over the following and go directly to Compressive Sensing).
A healthy heart is controlled by a sequence of electrical signals fired in order, following the proper timing with an oxygen-rich red blood taking from our lungs to the
The basic principle underlying the genesis of the ECG waveforms and their polarity—positive, negative, or isoelectric—is as follows. Electrical activity moving toward the positive terminal of a lead generates a positive wave. Electrical activity moving away from the positive terminal of a lead generates a negative wave. Electrical activity moving at 90 degrees to a lead will generate a biphasic wave (equal positive and negative components, or isoelectric).
The first three leads devised by Einthoven constitute the Einthoven triangle. These leads are numbered I, II, and III—these are bipolar leads because they contain both a positive and a negative poles shown in Figure
The first three leads of ECG devised by Einthoven constitute the Einthoven triangle [
By joining the wires from the right arm, left arm, and left foot with 5000 Ohm resistors Frank Wilson defines an “indifferent electrode” later called the “Wilson Central Terminal.” The combined lead acts as an earth and is attached to the negative terminal of the ECG. An electrode attached to the positive terminal then becomes “unipolar” and can be placed anywhere on the body. Wilson defines the unipolar limb leads VR, VL, and VF where “V” stands for voltage (the voltage seen at the site of the unipolar electrode).
A typical ECG tracing of the cardiac cycle (heartbeat) consists of a P wave, a QRS complex, a T wave, and a U wave which is normally visible in 50 to 75% of ECGs. The baseline voltage of the electrocardiogram is known as the isoelectric line, typically measured as the portion of the tracing following the T wave and preceding the next P wave. The waves and the intervals to interpret the electrical activity of the hearts are listed in Table
The waves and the intervals to interpret the electrical activity of the hearts.
Feature | Description | Duration |
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RR interval | The interval between an R waveand the next R wave. Normal resting heart rate is between 60 and 100 bpm | 0.6 to 1.2 s |
P wave | During normal atrial depolarization, the main electrical vector is directed from the SA node towards the AV node and spreads from the rightatriumto the left atrium. This turns into the P wave on the ECG | 80 ms |
PR interval | The PR interval is measured from the beginning of the P wave to the beginning of the QRS complex. The PR interval reflects the time the electrical impulse takes to travel from the sinus node through the AV node and entering the ventricles. The PR interval is therefore a good estimate of AV node function | 120 to 200 ms |
PR segment | The PR segment connects the P wave and the QRS complex. The impulse vector is from the AV node to the bundle of His to the bundle branches and then to the Purkinje Fibers. This electrical activity does not produce a contraction directly and is merely traveling down towards the ventricles and this shows up flat on the ECG. The PR interval is more clinically relevant | 50 to 120 ms |
QRS complex | The QRS complex reflects the |
80 to 120 ms |
J-point | The point at which the QRS complex finishes and the ST segment begins. Used to measure the degree of ST elevation or depression present | N/A |
ST segment | The ST segment connects the QRS complex and the T wave. The ST segment represents the period when the ventricles are depolarized. It is isoelectric | 80 to 120 ms |
T wave | The T wave represents the |
160 ms |
ST interval | The ST interval is measured from the J point to the end of the T wave | 320 ms |
QT interval | TheQT intervalis measured from the beginning of the QRS complex to the end of the T wave (<0.4 sec = 400 ms). A prolonged QT interval is a risk factor for ventricular tachyarrhythmias and sudden death. It varies with heart rate and for clinical relevance requires a correction for this, giving the QTc | 300 to 430 ms |
U wave | The U wave is hypothesized to be caused by the repolarization of the interventricular septum. They normally have a low amplitude, and even more often completely absent. They always follow the T wave and also follow the same direction in amplitude. If they are too prominent we suspect hypokalemia, hypercalcemia, or hyperthyroidism usually | |
J wave | The J wave, elevated J-Point or Osborn Wave, appears as a late delta wave following the QRS or as a small secondary R wave. It is considered pathognomonicof hypothermiaorhypocalcemia |
Shows the structure diagram of the normal human heart from an anterior view. In theheart, aventricleis one of two large chambers that collect and expelbloodreceived from anatrium towards the peripheral beds within the body and lungs. The atrium (an adjacent/upper heart chamber that is smaller than a ventricle) primes the pump.
(a) Shows the healthy ECG waveform, (b) abnormal heart beats are exemplified, (c) affordable air mattress ECG home monitoring system.
From the practical and experimental studies and research, the abnormal ECG heart beats are categorized as follows: Ventricle Depolarization (reducing Peak R-Trough S) to T for Ventricle Repolarization time width; heart attacks; Atrial Fibrillation (AF) (arrhythmia, or abnormal heartbeat): Sino-Atrial (SA) node at right atrium triggers the atria pushing blood into the ventricles. Atrio-Ventricular (AV) node contracts the ventricles, pumping blood to the lungs and body; abnormalities of the left heart; abnormalities of the right heart; abnormalities of the atria; abnormally fast rates (tachycardias); abnormally slow rates (bradycardias and conduction blocks).
A number of featured ECG devices can be found in the commercial market. These ECG analyses provide the information on the heart beat rate, rhythm, and the ECG waveform. Selected products are shown in Table
Selected featured ECG commercial devices.
Nasiff CardioResting PC-Based Bluetooth ECG System: | Nicolet Elite 100 Non-Display Doppler |
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Nasiff Associates, Inc. continues to take the lead in PC-Based Resting ECG systems. Performing fast testing and managing them easily with you at the point-of-care | The Elite from Nicolet Vascular offers everything that you need in a Doppler system. The Elite is a configurable, ultrasound Doppler used to detect the fetal heartbeat and to assist in monitoring peripheral arterial and venous blood flow |
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Tuttnauer 9′′ Fully Automatic Autoclave | OMRON Inc. |
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With the simplicity of one-touch design all your sterilization and drying needs are fulfilled. The Tuttnauer EZ9 fully automatic autoclave will fill, sterilize, exhaust, and dry at the touch of a button | With the OMRON Portable ECG Monitor HCG-801, a recording of about 30 seconds can be made when symptoms occur whether at home or away. These recordings can then be shown to the doctor, who can examine and use the information to assist in correct diagnosis of symptoms |
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CardioCare 2000 Interpretive EKG (PC Connecting Software Included) | Easy ECG Handheld Monitor FP180 |
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The CardioCare 2000 is an economically priced 12-channel resting ECG that does not compromise on performance. Suitable for use in private practice, ER, or hospital use, the CardioCare 2000 is designed for maximum ease of use and convenience. Software upgradeable and networkable, the CardioCare 2000 is an excellent choice for your diagnostic needs | FP180 (PC-80) Easy ECG monitor is a personal single-lead electrocardiographic monitor that records user’s cardiac functions and displays the data in a clear and precise waveform for daily health check. This device is intended for self-testing by adult users who might experience transient symptoms that may suggest cardiac conduction abnormity or by adult users whenever they want to have routine checks |
In 2006, several mathematicians including Candes of CalTech, Romberg of Georgia Institute of Technology, Fields Prize winner Terrence Tao of UCLA, and David Donoho of Stanford developed a sparse acquisition of image algorithm. Their motivation was to decrease the total acquisition time for MRI imaging by reducing the number of images taken necessarily, yet preserving the original image quality. When the information degree of freedom of number
Compressive sensing X-ray tomography: the Logan-Shepp phantom and its least squares reconstruction after Tomography Central Lice Theorem composing 1-D Fourier-sampling projection along 22 radial lines (here
A comfortable halter covers V1 to V6 with nano-grid dry electrodes.
Their mathematical sampling trick is based on an unstructured, sparse rectangular filtering matrix
Compressive Sensing: Applying Orthogonal Multiple Input Multiple Output (MIMO) Principle, we monitor ECG's Fourier frequency responses in the following ((i)–(iv)). term used to describe the breadth of the electrical spectrum viewed by the ECG monitor; diagnostic quality is usually 0.05 Hz to 150 Hz; monitor quality is usually 0.5 Hz to 20–50 Hz; usually printed on the ECG recording strip.
We take Block Sparse Compressive Sensing Code published by Rice University Baranuik et al. 2008 IEEE/IT. The following parameters are used: number of processed samples: 8192; signal sparsity: 16; number of measurements: 1024 FT domain; number of iterations: 20. ECG data resource (
Comparison between the original data and the CS recovering. Figure
Comparison between the original data and the CS recovering. Figure
Comparison between the original data and the CS recovering. Figure
Comparison between the original data and the CS recovering. Figure
Lead type 5 comparison using CS.
ECG is a relatively noninvasive method to monitoring the heart beats condition, except the tethered wires cable which is somewhat inconvenient during a treadmill stress test, and the cost affordability may be improved for household usages. Here we introduce several innovative components towards that popular goal.
The details of other three modules are (i) Learnable Database with management, (ii) Smartphone with computational power for wavelet feature extraction and AiTR, and (iii) Smart Electrodes with mixed signal electronics, which are available in the industrial and the academia community. We will not attempt to summarize them in this limited collaboration. We mentioned in bypassing a smartness material component, related to (iii), in terms of low-power, low impedance, one-directional pull-off nanogrip dry conducting surface (cf. Figure
(a) Good electrical contact of ECG electrode made of Ag/AgCl sensor; (b) carbon contact interface; (c) commercial pressure sensitive adhesive; (d) a gecko feet.
We can further design new electrode leads which will not suffer of ambient Electromagnetic interference (EMI). Recently, intelligent material has adopted wide-band electric field sensors based on a photonic electric field sensor, as a Macher-Zehnder interferometer, with fibrooptic buried inside a PSA pad. Then, all optics sensors will not suffer of ambient EMI. When the size-weight and power-cost constraints are satisfied, the technology of an electrode less, all optical could be useful for dry electrode design. Meanwhile, NIST at Gaithersburg has demonstrated a miniaturized sugar cube size for optical semiconductor chip magnetometer, which can detect the exceedingly weak magnetic field modulation associated with brain waves and heart beats [