WO2024103275A1

WO2024103275A1 - Ambulatory monitoring wearable non-invasive device for ischemic heart disease (ihd) detection

Info

Publication number: WO2024103275A1
Application number: PCT/CN2022/132165
Authority: WO
Inventors: Saeed Khoshfetrat Pakazad; Marcin Meyer; Yue Pan
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2022-11-16
Filing date: 2022-11-16
Publication date: 2024-05-23

Abstract

A non-invasive, wearable ambulatory monitoring device for Ischemic Heart Disease (IHD) detection and methods of detection and monitoring. An ambulatory electrocardiography apparatus comprises: a wearable element (10) comprising a right arm component (23), a left arm component (24), and a chest component (22). The right arm component (23) comprises a right arm electrode (13), the left arm component (24) comprises a left arm electrode (14) and the chest component (22) comprises anterior, lateral and posterior electrodes (11, 12). Each electrode is a dry textile electrode. The apparatus further comprises a data acquisition and processing module to receive input signals from the electrodes. The methods include obtaining ambulatory electrocardiography data and ambulatory detecting, monitoring or assessing of Ischemic Heart Disease.

Description

AMBULATORY MONITORING WEARABLE NON-INVASIVE DEVICE FOR ISCHEMIC HEART DISEASE (IHD) DETECTION

Technical Field

The present invention relates to monitoring devices for Ischemic Heart Disease (IHD) detection. In particular, the present invention relates to a non-invasive, wearable ambulatory monitoring device for Ischemic Heart Disease (IHD) detection.

Background

Ischemia is a result of restricted blood flow to the cardiac tissue due to build-up of atherosclerotic plaques in the cardiac arteries. Chest pain (angina) is a symptom of ischemia which can occur at rest or during exercise when the cardiac load, and therefore oxygen demand, is increased.

Ischemic Heart Disease (IHD) , which is synonymous with Coronary Artery Disease (CAD) , is the most common cardiovascular disease and the primary cause of death, accounting for 1 in every 4 deaths. Heart disease is estimated to cost the United States of America about $363 billion each year from 2016 to 2017, in respect of the cost of health care services, medicines, and lost productivity due to death.

When ischemia occurs without any symptoms such as chest pain (angina) , it is called silent ischemia. The prevalence of silent ischemia falls in two groups of population:

1. An asymptomatic population, consisting of individuals who have IHD but are not aware of it -about 2.5%of the population under age 60 and more than 10%above age 70 [Cohn PF, Fox KM, Daly C. Silent myocardial ischemia. Circulation. 2003 Sep 9; 108 (10) : 1263-77. doi: 10.1161/01. CIR. 0000088001.59265. EE. PMID: 12963683] . In a study with 3, 664 asymptomatic patients, 6 percent of patients had evidence of high-risk silent ischemia [Zellweger, Michael J., Rory Hachamovitch, Xingping Kang, Sean W. Hayes, John D. Friedman, Guido Germano, and Daniel S. Berman. “Threshold, Incidence, and Predictors of Prognostically High-Risk Silent Ischemia in Asymptomatic Patients without Prior Diagnosis of Coronary Artery Disease. ” Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology 16, no. 2 (April 2009) : 193–200] .

2. Patients with known CAD: In patients who have had Myocardial infarction (heart attack) , the reported frequency of silent ischemia varies from 30%to 43%. Additionally, approximately 50%of patients who have stable or unstable angina show silent ischemia on Holter monitoring [Cohn et al above] .

Ambulatory ECG monitoring during daily activities and sleep can reveal early episodic signs of silent ischemia in asymptomatic population. If these early signs are detected by the wearable device, the user can be notified, an IHD diagnosis made and, if needed, preventive interventions can be started, to slow, inhibit or reverse the atherosclerotic process. The wearable for ambulatory monitoring can also benefit patients with known CAD to better manage and monitor their condition.

An effective and efficient ambulatory monitoring device for IHD screening requires high sensitivity and specificity, but the wearable device should also be comfortable to be worn continuously during diverse daily life conditions and during sleep. Current ambulatory monitoring devices are limited in their comfort and effectiveness. Holter monitors are typically limited to several days of recording due to the use of wet electrodes combined with skin adhesives, which can result in skin irritation and detachment due to sweating. Wires interconnecting the electrodes also interfere with daily activities.

Adhesive ECG patches avoid the use of wires, but present the same issues as wet electrodes described above. Additionally, they usually have limited number of electrodes (leads) compared with Holter monitors and the consequential limited spatial distribution of the electrodes reduces the accuracy of detection.

T-shirts having textile-integrated electrodes have been provided and provide a tight fit to keep the electrodes in contact with the skin. However, this can be uncomfortable for long-term wearing. Moreover, upper thorax/chest deformations during different types of activities and movements including sleeping on the side can cause electrode detachment from the body and motion artifacts.

The limited number of electrodes with such arrangements typically results in sparse sampling of what is a complicated, spatially varied distribution of electric potential on the body surface. The most informative regions of this distribution, such as areas of local maxima or minima, or high gradients might be missed with sparse sampling.

Diagnosis based on heuristic pattern recognition in the ECG, for example ST-segment deviations, for IHD detection have been assessed but show low specificity and sensitivity, especially in women.

Accordingly, the present invention seeks to address these problems with prior art ambulatory monitoring devices.

Summary of the invention

A first aspect of the present disclosure provides an ambulatory electrocardiography apparatus comprising: a wearable element comprising: a right arm component, a left arm component, and a chest component; wherein the right arm component comprises a right arm electrode, the left arm component comprises a left arm electrode and the chest component comprises anterior, lateral and posterior electrodes; wherein each electrode is a dry textile electrode and wherein the apparatus further comprises a data acquisition and processing module to receive input signals from the electrodes.

In an example, the right arm component and the left arm component each comprises a band providing a mount for the respective electrodes.

In an example, the chest component comprises a chest strap or belt providing a mount for the anterior, lateral and posterior electrodes.

In certain examples, the wearable element comprises a tee shirt.

In certain examples, the chest component comprises an array of electrodes.

In certain examples, the apparatus comprises 10 to 30 electrodes or 10 to 20 electrodes.

In certain examples, each electrode is demountable to its respective component by means of a snap fastener arrangement.

In some examples, each of the left arm component, right arm components and chest component is formed of a material having an elasticity in a longitudinal direction sufficient to maintain contact between the electrodes and skin of a person wearing the apparatus; and wherein each electrode is substantially mechanically isolated from the material in the longitudinal direction. Optionally, mechanical isolation of the electrodes from the material is provided by an opening or gap between each electrode and adjacent material such that the electrode is supported within the material by a lateral web of material.

In some examples, each electrode includes an encapsulated amplification and filtering circuit. In some examples, the data acquisition and processing module applies a high frequency QRS analysis to data acquired by the module from the electrodes.

In some examples, the data acquisition and processing module is configured to monitor all electrodes continuously or is configured to monitor continuously a subset of all electrodes and switch to monitoring all electrodes in response to acquiring an adverse input signal from one or more electrodes of the subset.

In some examples, the apparatus further comprises at least one of an accelerometer and at least one gyroscopic sensor outputting activity data to the data acquisition and processing module.

Optionally, the data acquisition and processing module is configured to correlate activity data with electrode input signals to generate a risk assessment for a patient.

In some examples, the data acquisition and processing module includes a network communication processor to transmit acquired data to a data processing system remote from the apparatus. Optionally, the network communication processor comprises a short-range wireless device, a local area network device or a mobile communications device.

A second aspect of the present disclosure provides a method of obtaining ambulatory electrocardiography data, the method comprising: applying an ambulatory electrocardiography apparatus comprising a wearable element to a patient from whom electrocardiography data is required; wherein the wearable element comprises a right arm component, a left arm component and a chest component; wherein the right arm component comprises a right arm electrode, the left arm component comprises a left arm electrode and the chest component comprises anterior, lateral and posterior electrodes; wherein each electrode is a dry textile electrode and wherein the wearable element further comprises a data acquisition and processing module to receive input signals from the electrodes.

A third aspect of the present disclosure provides a method of ambulatory detection, monitoring or assessment of ischemic heart disease, the method comprising: applying an ambulatory electrocardiography apparatus comprising a wearable element to a patient having or at risk of ischemic heart disease; wherein the wearable element comprises a right arm component, a left arm component and a chest component; wherein the right arm component comprises a right arm electrode, the left arm component comprises a left arm electrode and the chest component comprises anterior, lateral and posterior electrodes; wherein each electrode is a dry textile electrode and wherein the wearable element further comprises a data acquisition and processing module to receive input signals from the electrodes; processing the input signals from the electrodes; and determining, from the processed input signals, the presence or absence of signals indicative of ischemic heart disease.

In an example of the methods of the second and third aspects, the ambulatory electrocardiography apparatus is an ambulatory electrocardiography apparatus of the first aspect of the present disclosure.

Brief description of the figures.

The above and other aspects and embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 is a schematic representation of the front and rear views of a first embodiment of an ambulatory electrocardiography apparatus in accordance with the present invention;

Figure 2 is a schematic representation of the front and rear views of a second embodiment of an ambulatory electrocardiography apparatus in accordance with the present invention;

Figure 3 is a schematic representation, in top and cross-sectional views, of an embodiment of an electrode suitable for use in the embodiments of Figures 1 and 2;

Figure 4 is a flow diagram illustrating the steps of an embodiment of the method of the second aspect of the present invention; and

Figure 5 is a flow diagram illustrating the steps of an embodiment of the method of the third aspect of the present invention.

Detailed Description

Example embodiments are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the systems and processes herein described. It is important to understand that embodiments can be provided in many alternate forms and should not be construed as limited to the examples set forth herein.

Accordingly, while embodiments can be modified in various ways and take on various alternative forms, specific embodiments thereof are shown in the drawings and described in detail below as examples. There is no intent to limit to the particular forms disclosed. On the contrary, all modifications, equivalents, and alternatives falling within the scope of the appended claims should be included. Elements of the example embodiments are consistently denoted by the same reference numerals throughout the drawings and detailed description where appropriate.

The terminology used herein to describe embodiments is not intended to limit the scope. The articles “a, ” “an, ” and “the” are singular in that they have a single referent, however the use of the singular form in the present document should not preclude the presence of more than one referent. In other words, elements referred to in the singular can number one or more, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises, ” “comprising, ” “includes, ” and/or “including, ” when used herein, specify the presence of stated features, items, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, items, steps, operations, elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be interpreted as is customary in the art. It will be further understood that terms in common usage should also be interpreted as is customary in the relevant art and not in an idealized or overly formal sense unless expressly so defined herein.

In order to address the limitations described above, by improving wearing comfort and extend measurement duration as well as improving measurement accuracy, preferred embodiments of the systems of the present system use soft breathable dry/textile electrodes instead of wet electrodes to improve long-term wearability. Additionally, rather than a tightly-fitting T-shirt design, examples of the present invention are based on a combination of chest strap and two armbands which are able to be wrapped around body parts and which maintain the electrodes in good contact with skin during daily activities/sport and sleep, thereby minimizing motion artifacts and enabling comfortable usage.

The form factor of examples of embodiments of the present invention allows for an increase in the number of electrodes and in body surface coverage (posterior, lateral and right anterior electrodes) of the electrodes, which improves detection accuracy.

With reference to Figure 1, there is shown an embodiment of an ambulatory ECG monitoring wearable apparatus 10 in accordance with the present invention. The apparatus includes a right arm band 23 and a left arm band 24 and a chest belt or strap 22. Each arm band includes a respective electrode, RA electrode 13 mounted to right arm band 23 and LA electrode 14 mounted to left arm band 24. Chest strap 22 provides a mount for a plurality of electrodes disposed around the thorax, including anterior electrodes 11 on the chest, posterior electrodes 12 on the back and lateral electrodes around the sides. The RA and LA electrodes of the two

arms bands

23, 24 and the electrodes of the chest belt 22 are electrically connected by means of interconnect lines 15 to a control module 20 conveniently mounted, in the embodiment shown, to or integrated with the chest strap 22. The control module 20 contains the programmed electronics for measurement, digitization, processing and data storage/transfer.

Conveniently, in the embodiment shown in Figure 1, interconnect lines 15 are integrated into a wearable elements in the form of a tee shirt 21 and are attachable to electrodes in the arm bands and chest strap by suitable means, such as snap connectors as will be described in further detail below. In alternative embodiments, chest strap 22 and right and

left arm bands

23,24 are integrated or partially integrated into the wearable element, tee shirt 21.

In the embodiment shown in Figure 2, the wearable element is in the form of a strap assembly 30 having right and

left shoulder straps

30, 31 each coupled at the front and at the back to chest strap 22 and having right and left armband straps 32, 33 connecting to their

respective arm bands

23, 24. Interconnect lines are integrated into the

straps

30, 31, 32, 33 and communicate with electronics module 20 mounted to or integrated with the chest strap 22.

The combination of two arms bands and associated electrodes (LA, RA) and one chest strap (containing a plurality of anterior, lateral and posterior electrodes) which are electrically connected through embedded electrical interconnect lines in a tee shirt or strap assembly provides movement flexibility and comfortably maintains the electrodes in proper contact with the skin during sleep and daily activities while at the same time enabling monitoring of the electrical activity of the heart, which improves sensitivity and specificity of IHD detection.

The number of electrodes and their coverage over the body can be higher than is conventionally the case, e.g., with 12 lead ECG, giving rise to improved detection accuracy through improved sensitivity and specificity, in particular by the inclusion of posterior and lateral electrodes.

Advantageously, the electrodes incorporated into the apparatus are soft, conformal, breathable dry textile electrodes as these have the capacity to reduce motion artifacts and improve contact impedance, thereby enabling long-term ambulatory ECG monitoring without discomfort for the wearer.

Active electrodes may be used to reduce the effects of higher skin contact impedance shown by dry electrodes, which may further reduce the effects of motion artifacts and triboelectric noise.

A particularly advantageous form of electrode construction is illustrated in Figure 3, which shows in both plan and cross-sectional views an embodiment of an electrode adapted for incorporation into a strap or band 45 of an the apparatus of the present invention. The electrode 40 includes a conductive textile electrode body 41 having a soft foam core 42 to improve conformity and contact impedance with the surface of the skin.

Advantageously, the electrode is an active electrode and includes an encapsulated electronic amplification and filtering component. In the embodiment shown, conveniently, the encapsulated electronic amplification and filtering component is in the form of a button 44 physically and electrically attachable to the conductive textile electrode body 41 by means of a snap connector 43 as will be familiar to the skilled person, allowing rapid replacement of electrodes should the need arise, such as through deterioration of the electrodes or damage. A dry electrode, in contrast to a wet electrode, has a high interface impedance and triboelectric noise, which is reduced by the incorporation of in situ filtering and amplification. Amplification and filtering component 44 is electrically connected to the control module 20 by means of interconnect lines 15, typically woven into the fabric.

Typically, a fabric from which the wearable element is formed will be stretchable one direction, typically the elongate direction, as viewed in the context of a strap or band (see arrow in Figure 3) . In the preferred embodiments of the invention, the electrode is mounted to the wearable element in a way which provides mechanical isolation between the electrode and the fabric in the direction of stretching of the fabric. As shown in Figure 3, this can be achieved by coupling the electrode to a lateral bridge or web 51 formed across an aperture 50 formed in the fabric of the strap or band 45. By this means, motion artifacts, signals produced by movement of an electrode with respect to the skin rather than by sensing heart activity, can be significantly reduced. Motion artifacts are particularly problematic in ambulatory analyses and the present invention has been particularly successful in reducing motion artifacts, thereby enhancing sensitivity and specificity.

For the detection of IHD, detection based on High Frequency QRS (HFQRS) is advantageously used, either in addition to ST-segment deviations, or instead of it. HFQRS has been shown to have higher accuracy in detection of IHD in several multi-centre studies when compared to conventional diagnosis based on ST-segment deviations [see: Amit, Guy, et al. “Quantifying QRS Changes during Myocardial Ischemia: Insights from High Frequency Electrocardiography. ” Journal of Electrocardiology, Churchill Livingstone, 29 Mar. 2014; and Leinveber, Pavel, Josef Halamek, and Pavel Jurak. “Ambulatory Monitoring of Myocardial Ischemia in the 21st Century-an Opportunity for High Frequency QRS Analysis. ” Journal of Electrocardiology 49, no. 6 (November 1, 2016) : 902–6. ] . HFQRS is measured in the 150-250Hz frequency band thereby avoiding the common ECG artifacts, such as motion artifacts, mostly occurring below 150Hz.

Control module 20 includes an electronic circuit to acquire data from the plurality of electrodes. In some embodiments, IHD detection is achieved by means of a programmed processor integrated into the control module 20. In alternative embodiments, the control module 20 transfers acquired data can be transferred to the Cloud for processing. The data transfer can be done through a wireless connection (such as Bluetooth) to a gateway (such as the wearer’s mobile phone or e-sim equipped smart watch) or directly from the wearable device to the cloud. The wearable system can also include accelerometer and gyroscope sensors in the armbands and/or the chest strap to measure the intensity of physical activity and distinguish between different types of physical activity and sleep. This information can be used by the algorithm for risk assessment, as IHD happening at low intensity physical activity is associated with higher risk. Also, the algorithm can use this information to distinguish IHD happening during sleep or certain types of activity. The movement information can also be used for motion artifact removal in different movement scenarios.

For power efficiency the control module can be programmed to monitor a subset of all of the electrodes on a constant basis and, in the event that indications of IHD are detected in those electrodes, the control module causes switching to monitoring through all electrodes, typically using a statistical approach, thereby improving apparatus efficiency and improving detection accuracy through enhanced sensitivity and specificity.

The apparatus of the present invention may, in certain embodiments, also include accelerometer and gyroscope sensors in the armbands and/or the chest strap to measure intensity of physical activity. This allows the apparatus to distinguish between different types of physical activity and sleep. This data allows the apparatus to perform an assessment of IHD risk. For example, IHD-indicating data generated during a low intensity physical activity is associated with higher risk of IHD than data generated during higher intensity physical activity. Additionally, the processor of the control module or cloud-processor can use this information to distinguish IHD occurring during sleep or other types of activity.

The programming of the control module and/or interaction with Cloud processing functionality is well within the capabilities of the skilled person and will not be described in further detail here.

Examples in the present disclosure can be provided as methods, systems or machine-readable instructions, such as any combination of software, hardware, firmware or the like. Such machine-readable instructions may be included on a computer readable storage medium (including but not limited to disc storage, CD-ROM, optical storage, etc. ) having computer readable program codes therein or thereon.

The present disclosure is described with reference to flow charts and/or block diagrams of the method, devices and systems according to examples of the present disclosure. Although the flow diagrams described above show a specific order of execution, the order of execution may differ from that which is depicted. Blocks described in relation to one flow chart may be combined with those of another flow chart. In some examples, some blocks of the flow diagrams may not be necessary and/or additional blocks may be added. It shall be understood that each flow and/or block in the flow charts and/or block diagrams, as well as combinations of the flows and/or diagrams in the flow charts and/or block diagrams can be realized by machine readable instructions.

The machine-readable instructions may, for example, be executed by a machine such as a general-purpose computer, a platform comprising user equipment such as a smart device, e.g., a smart phone, a special purpose computer, an embedded processor or processors of other programmable data processing devices to realize the functions described in the description and diagrams.

A processor or processing apparatus may execute the machine-readable instructions. Thus, modules of apparatus (for example, an encoder or decoder as described above) may be implemented by a processor executing machine readable instructions stored in a memory, or a processor operating in accordance with instructions embedded in logic circuitry. The term 'processor' is to be interpreted broadly to include a CPU, processing unit, ASIC, logic unit, programmable gate set, or event signal processor etc. The methods and modules may all be performed by a single processor or divided amongst several processors.

Such machine-readable instructions may also be stored in a computer readable storage that can guide the computer or other programmable data processing devices to operate in a specific mode. For example, the instructions may be provided on a non-transitory computer readable storage medium encoded with instructions, executable by a processor.

Figure 4 illustrates the steps in the method of the second aspect of the present invention, providing a method of acquiring and processing electrocardiography data using an apparatus of the present invention. The method comprises the steps of applying (100) an ambulatory electrocardiography apparatus in accordance with the present invention to a patient; acquiring (110) electrocardiography data from the electrodes; and processing (120) the acquired data.

Figure 5 illustrates the steps in the method of the third aspect of the present invention, providing a method of indicating ischemic heart disease using an apparatus of the present invention. The method comprises the steps of applying (200) an ambulatory electrocardiography apparatus in accordance with the present invention to a patient; acquiring (210) electrocardiography data from the electrodes; processing (220) the acquired data and determining, from the processed electrode input signals, the presence or absence of signals indicative of ischemic heart disease.

As indicated above, in some examples, some methods can be performed in a cloud-computing or network-based environment. Cloud-computing environments may provide various services and applications via the Internet. These cloud-based services (e.g., software as a service, platform as a service, infrastructure as a service, etc. ) may be accessible through a web browser or other remote interface of the user equipment for example. Various functions described herein may be provided through a remote desktop environment or any other cloud-based computing environment.

While various embodiments have been described and/or illustrated herein in the context of fully functional computing systems, one or more of these exemplary embodiments may be distributed as a program product in a variety of forms, regardless of the particular type of computer-readable-storage media used to actually carry out the distribution. The embodiments disclosed herein may also be implemented using software modules that perform certain tasks. These software modules may include script, batch, or other executable files that may be stored on a computer-readable storage medium or in a computing system. In some embodiments, these software modules may configure a computing system to perform one or more of the exemplary embodiments disclosed herein. In addition, one or more of the modules described herein may transform data, physical devices, and/or representations of physical devices from one form to another.

The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments disclosed herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. The embodiments disclosed herein should be considered in all respects illustrative and not restrictive. Reference should be made to the appended claims and their equivalents in determining the scope of the instant disclosure.

Claims

An ambulatory electrocardiography apparatus comprising:

a wearable element comprising:

a right arm component,

a left arm component, and

a chest component;

wherein the right arm component comprises a right arm electrode, the left arm component comprises a left arm electrode and the chest component comprises anterior, lateral and posterior electrodes;

wherein each electrode is a dry textile electrode and

wherein the apparatus further comprises a data acquisition and processing module to receive input signals from the electrodes.
An apparatus as claimed in claim 1 wherein the right arm component and the left arm component each comprises a band providing a mount for the respective electrodes.
An apparatus as claimed in claim 1 or claim 2 wherein the chest component comprises a chest strap or belt providing a mount for the anterior, lateral and posterior electrodes.
An apparatus as claimed in any one of claims 1 to 3 wherein the wearable element comprises a tee shirt.
An apparatus as claimed in any preceding claim wherein the chest component comprises an array of electrodes.
An apparatus as claimed in any preceding claim comprising 10 to 30 electrodes or 10 to 20 electrodes.
An apparatus as claimed in any preceding claim wherein each electrode is demountable to its respective component by means of a snap fastener arrangement.
An apparatus as claimed in any preceding claim wherein each of the left arm component, right arm components and chest component is formed of a material having an elasticity in a longitudinal direction sufficient to maintain contact between the electrodes and skin of a person wearing the apparatus; and wherein each electrode is substantially mechanically isolated from the material in the longitudinal direction.
An apparatus as claimed in claim 8 wherein mechanical isolation of the electrodes from the material is provided by an opening or gap between each electrode and adjacent material such that the electrode is supported within the material by a lateral web of material.
An apparatus as claimed in any preceding claim wherein each electrode includes an encapsulated amplification and filtering circuit.
An apparatus as claimed in any preceding claim wherein the data acquisition and processing module applies a high frequency QRS analysis to data acquired by the module from the electrodes.
An apparatus as claimed in any preceding claim wherein the data acquisition and processing module is configured to monitor all electrodes continuously or is configured to monitor continuously a subset of all electrodes and switch to monitoring all electrodes in response to acquiring an adverse input signal from one or more electrodes of the subset.
An apparatus as claimed in any preceding claim further comprising at least one of an accelerometer and at least one gyroscopic sensor outputting activity data to the data acquisition and processing module.
An apparatus as claimed in claim 13 wherein the data acquisition and processing module is configured to correlate activity data with electrode input signals to generate a risk assessment for a patient.
An apparatus as claimed in any preceding claim, wherein the data acquisition and processing module includes a network communication processor to transmit acquired data to a data processing system remote from the apparatus.
An apparatus as claimed in claim 15 wherein the network communication processor comprises a short-range wireless device, a local area network device or a mobile communications device.
A method of obtaining ambulatory electrocardiography data, the method comprising:

applying an ambulatory electrocardiography apparatus comprising a wearable element to a patient from whom electrocardiography data is required; wherein the wearable element comprises a right arm component, a left arm component and a chest component; wherein the right arm component comprises a right arm electrode, the left arm component comprises a left arm electrode and the chest component comprises anterior, lateral and posterior electrodes; wherein each electrode is a dry textile electrode and wherein the wearable element further comprises a data acquisition and processing module to receive input signals from the electrodes.
A method of ambulatory detection, monitoring or assessment of ischemic heart disease, the method comprising:

applying an ambulatory electrocardiography apparatus comprising a wearable element to a patient having or at risk of ischemic heart disease; wherein the wearable element comprises a right arm component, a left arm component and a chest component; wherein the right arm component comprises a right arm electrode, the left arm component comprises a left arm electrode and the chest component comprises anterior, lateral and posterior electrodes; wherein each electrode is a dry textile electrode and wherein the wearable element further comprises a data acquisition and processing module to receive input signals from the electrodes;

processing the input signals from the electrodes; and

determining, from the processed input signals, the presence or absence of signals indicative of ischemic heart disease.
A method as claimed in claim 17 or claim 18 wherein the ambulatory electrocardiography apparatus is an ambulatory electrocardiography apparatus as claimed in any one of claims 1 to 16.