Search

EP-3934527-B1 - LEADLESS ELECTROCARDIOGRAM MONITOR

EP3934527B1EP 3934527 B1EP3934527 B1EP 3934527B1EP-3934527-B1

Inventors

  • AHMAD, SAIF
  • GARG, ATUL K.

Dates

Publication Date
20260506
Application Date
20200306

Claims (8)

  1. An electrocardiogram monitor comprising: (a) a primary smart band (102) having a primary microcontroller (914), at least three electrodes, and at least one digital switch per electrode to enable or disable the electrode during data acquisition, wherein the at least three electrodes are configured to contact skin of a user and measure a first high-fidelity biopotential signal; (b) a secondary smart band (106) having a secondary microcontroller (906), at least three electrodes, and at least one digital switch per electrode to enable or disable the electrode during data acquisition, wherein the at least three electrodes are configured to contact the skin of the user and measure a second high-fidelity biopotential signal; (c) wherein the primary and secondary microcontrollers (914, 906) control the digital switches to repeatedly loop through all possible configurations of the digital switches and acquire first and second high-fidelity biopotential signals for each of the configurations; (d) wherein, for each of the configurations of the digital switches, the secondary microcontroller (906) digitizes the second high-fidelity biopotential signal to produce a second digitized signal and transmits the second digitized signal wirelessly to the primary smart band (102); (e) wherein, for each of the configurations of the digital switches, the primary microcontroller (914) wirelessly receives the second digitized signal from the secondary smart band (106), and digitizes the first high-fidelity biopotential signal to produce a first digitized signal; (f) wherein the primary microcontroller (914) aggregates the first and second digitized signals for all of the switch configurations and employs DSP techniques on the aggregated first and second digitized signals to produce a first high-fidelity ECG waveform signal; (g) wherein the primary smart band further comprises a D/A converter (1102) to convert the second digitized signal to an analog signal; and a differential amplifier (1104) which, for each of the configurations of the digital switches, receives as inputs the analog signal from the D/A converter (1102) and the first high-fidelity biopotential signal and outputs a high-fidelity differential signal via analog signal conditioning and amplification; (h) wherein the primary microcontroller (914) digitizes and aggregates the high-fidelity differential signal for all of the switch configurations to produce a second high-fidelity ECG waveform signal; and (i) wherein the primary microcontroller (906) employs data fusion techniques to combine the first and second high-fidelity ECG waveform signals to produce a higher quality and fidelity ECG waveform signal.
  2. The electrocardiogram monitor of claim 1 wherein at least one of the three electrodes of the primary and secondary smart bands include a reference electrode and the digital switches for the reference electrodes are changeover switches that allow these reference electrodes to be used either as RLD or ground electrodes during data acquisition to further improve ECG waveform signal quality and fidelity.
  3. The electrocardiogram monitor of claim 1 or 2 wherein the primary and secondary smart bands each further comprise: an enclosure (202) having a backplate (228, 318); and straps (206, 208, 306, 308) connected to the enclosure (202), wherein the at least three electrodes of the primary and secondary smart bands further comprise: at least three rigid strip electrodes (216, 218, 220, 312, 314, 316) provided on each of the backplates of the primary and secondary smart bands; and at least three flexible strip electrodes (222, 224, 226, 320, 322, 324) provided on each of the straps; wherein the at least three rigid strip electrodes are electrically connected to respective electrodes of the at least three flexible strip electrodes to maximize electrode contact area and eliminate dependency on electrode position around a limb of the user to enhance ECG waveform signal quality.
  4. The electrocardiogram monitor of any one of claims 1 to 3 further comprising data storage for storing the first and second ECG signals and related information, and wherein the primary smart band and secondary smart band optionally comprise separate power sources.
  5. The electrocardiogram monitor of any one of claims 1 to 4 further comprising a radio transceiver (910, 916) and antenna (912, 918) in the primary smart band or the secondary smart band for transmitting the higher quality and fidelity ECG waveform signal and related information to a separate computing device selected from the group consisting of a mobile device, smartphone, tablet, laptop, and computer.
  6. The electrocardiogram monitor of any one of claims 1 to 5 further comprising a display 204 configured to display information to the user, wherein the information is selected from one or more of the group consisting of time, date, battery strength, wireless connectivity strength, Bluetooth status, HR, HRV, ECG waveform and alarm status, and wherein the display is optionally a touchscreen display that is configured to receive inputs from the user; and/or further comprising an alarm, wherein the first microcontroller computes HR and HRV data and triggers and displays the alarm if the HR and/or HRV data are beyond pre-determined thresholds.
  7. The electrocardiogram monitor of any one of claims 1 to 6 further comprising a twin wireless charger (802) for charging the primary smart band and secondary smart band.
  8. The electrocardiogram monitor of any one of claims 1 to 7 wherein the primary and secondary smart bands are configured to be attached at various locations along limbs of the user.

Description

TECHNICAL FIELD In general, this invention relates to electrocardiogram (ECG) monitoring in humans with wearable technology, and in particular to continuous and unobtrusive ECG monitoring utilizing a pair of ergonomically designed wireless smart bands that the user wears around the left and right wrists. BACKGROUND A regular ECG test is an essential diagnostic tool that characterizes the heart's activity at a given point in time. Abnormal heart rhythms and cardiac symptoms may however sporadically appear, disappear, and reappear over time. Consequently, point-in-time ECG tests may miss critical cardiac anomalies, thereby leading to an increased risk of morbidity and mortality. It is therefore important to monitor ECG continuously in at-risk patients as they go about their normal activities. Quite often, serious heart conditions like atrial fibrillation (AF), cardiomyopathy, and coronary heart disease are diagnosed with continuous ECG monitoring. This allows for timely clinical interventions like medication and cardiac surgery that reduce adverse outcomes like stroke and heart attack, thereby saving lives. In clinical practice, it is common to undertake continuous ECG monitoring using a Holter system that can generally record 24-48 hours of cardiac data. The Holter is a small wearable biopotential measurement device comprising several ECG leads. These ECG leads are snapped on to sticky gel electrodes that are attached at various locations on the patient's chest. A Holter monitoring system is inconvenient and obtrusive due to the sticky gel chest electrodes that often cause discomfort and the unwieldy leads that hang between the electrodes and the Holter unit. Recently, Medtronic has developed and marketed a leadless Holter system (SEEQ™) in the form of an adhesive chest strip (~ 4.5" long, ~ 2.0" wide, and ~ 0.6" thick) for continuous ECG monitoring. Though leadless, this monitor is awkward and uncomfortable because it uses sticky chest electrodes and it is too bulky to be attached to the chest. Various kinds of belts that can be worn around the chest for continuous ECG monitoring are available in the market today. Many of these ECG chest belt systems are leadless and employ dry reusable electrodes. Still, these ECG belts need to be worn under clothing and are often quite tight around the chest, causing difficulty and uneasiness to the wearer. Currently, continuous ECG monitoring technology comes with a number of problems and encumbrances. These include discomfort, uneasiness, sleep disruptions, difficulty in carrying out day-to-day activities, and inability to undertake long-term monitoring (for example, monitoring for days, months, and years). With the advent of newer generation wearables like smartwatches, attempts have been made to integrate ECG monitoring into a smartwatch. For example, Apple has provided dry ECG electrodes on the backplate of a smartwatch (left-side electrodes) and a second set of electrodes on the smartwatch rim (right-side electrodes). A user has to wear the smartwatch on one wrist so that the electrodes underneath touch the wrist. Additionally, the user has to touch the second set of electrodes on the smartwatch rim with his/her other hand so that the heart lies in-between the left-side (backplate) and right-side (rim) electrodes that are electrically connected to signal amplification/conditioning circuitry inside the smartwatch. The quality of ECG signal acquired in this manner is generally satisfactory. However, the main limitation is that the user has to touch and hold a second set of electrodes on the smartwatch with his/her other hand for monitoring ECG waveform data. As a result, this system only provides an on demand 30 seconds of ECG monitoring, and not continuous and/or long-term ECG monitoring. To avoid touching a second set of electrodes with the other hand and to accomplish leadless continuous ECG monitoring, attempts have been made to develop wearable single upper limb ECG systems. Prior art has proposed the use of single arm wearable devices for leadless ECG monitoring. These systems comprise an upper arm band with more than one electrode on the underside that come in contact with the arm when the band is worn. The electrodes are interfaced with an amplification and control unit that may be affixed to the outer surface of the band. Single arm ECG systems have produced mixed results for a diverse population. The ECG signal acquired by these systems is often noisy, unreliable, and unusable, more so for women and older people. Based on the principles of single arm ECG systems, other prior art has also proposed leadless ECG monitoring employing wearable single wrist systems. The quality and fidelity of data acquired by single wrist ECG systems has not been properly tested and/or verified. Intuitively, a single wrist ECG system will produce noisier and weaker signals as compared to a single arm ECG system. This is because the wrist is physically farther away from the heart