Electrical components of physiological monitoring devices

Abstract

The present disclosure relates to a device configured to contact a surface of a mammal to record physiological signals, and further to related systems / methods. The device may include a housing that accommodates a circuit board and flexible wings extending from the housing. The device may include electrodes coupled to the flexible wings and electrical traces for transmitting electrical signals between the electrodes and the circuit board. The electrical traces may have an insulating material with a conductive material and a resistor printed on the surface of the insulating material. The trace layer may include conductive vias for transmitting signals from the bottom of the trace layer to the top of the trace layer. The housing may include a battery with a battery terminal connector configured to provide electrical access to both terminals on one side of the battery. The housing may include a floating trigger button.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 062,314, filed August 6, 2020, which is incorporated herein by reference in its entirety. [Background technology]

[0002] For purposes of this disclosure, certain aspects, advantages, and novel attributes of various embodiments are described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, various embodiments may be implemented to achieve one or more advantages taught herein, but may not necessarily achieve other advantages that may be taught or suggested herein. [Technical Field]

[0003] Disclosed herein are materials, devices, methods, and systems for monitoring physiological signals. For example, such physiological signals may include cardiac signals, such as electrocardiogram signals.

[0004] Abnormal heart rhythms, or arrhythmias, can cause a variety of symptoms, including loss of consciousness, palpitations, dizziness, and even death. Arrhythmias that cause these symptoms are often indicators of serious underlying heart disease. Identifying these symptoms as being due to abnormal heart rhythms is important because treatments such as pacemaker implantation and percutaneous catheter ablation can correct these problems and prevent serious illness or death. For example, monitors such as Holter monitors are currently used to monitor heart rhythms. Summary of the Invention

[0005] The embodiments described herein are directed to physiological monitoring devices that can be worn continuously and comfortably by a human or animal subject for at least one week or longer, and more typically for two to three weeks or longer. In one embodiment, the device is specifically designed to sense and record cardiac rhythm (e.g., electrocardiogram, ECG) data, although in various alternative embodiments, one or more additional physiological parameters may be sensed and recorded. Such physiological monitoring devices may include many features to facilitate and / or enhance the patient experience and to provide more accurate and timely diagnosis of cardiac arrhythmias.

[0006] In some embodiments, the electronic device for monitoring physiological signals in a mammal comprises: at least two flexible wings extending laterally from the housing, the flexible wings comprising a first set of materials that allow the wings to conform to a surface of a mammal, and the housing comprising a second set of materials; a printed circuit board assembly contained within a housing, the housing configured to prevent deformation of the printed circuit board in response to movement of the mammal; at least two electrodes embedded within the flexible wings, the electrodes configured to provide conformal contact with a surface of the mammal and to detect physiological signals of the mammal; at least two electrode traces embedded within the wings and mechanically decoupled from the housing, the electrode traces configured to provide conformal contact with a surface of the mammal and to transmit electrical signals from the electrodes to the printed circuit board assembly; and at least one hinge portion connecting the wing to the housing, the hinge portion configured to bend freely in an area where the hinge portion is joined to the housing.

[0007] In certain embodiments, each wing may include an adhesive. In embodiments, the electrodes may be in the same plane as the adhesive. In certain embodiments, each wing includes at least one rim, the rim being thinner than adjacent portions of each wing. The housing may further include a dimple or groove configured to allow airflow between the housing and the surface of the mammal. In certain embodiments, the rim is configured to prevent release of a portion of the wing from the surface of the mammal. In some embodiments, the electronic device for monitoring a physiological system may include a measuring instrument configured to detect motion signals in at least one axis. The measuring instrument may be an accelerometer that may be configured to detect motion signals in three axes.

[0008] In embodiments, the motion signal may be collected simultaneously with the physiological signal. In certain embodiments, a match between the physiological signal and the motion signal identifies motion artifacts. Further embodiments may relate to an event trigger coupled to the printed circuit board assembly. In some embodiments, the event trigger input may be supported by a housing or suspended on a cushioning material, such as a spring or foam, to prevent mechanical stress on the printed circuit board when the trigger is activated, thereby reducing the source of artifacts in the recorded signal.

[0009] In some embodiments, the event trigger may be concave or convex and larger than a human finger to allow for easy location of the event trigger. In another embodiment, the event trigger may be convex within a concave region. In certain embodiments, the electrode traces are configured to minimize signal distortion during mammalian movement. In certain embodiments, a gasket may be used as a means for sealably attaching to the housing.

[0010] In certain embodiments, a method of monitoring physiological signals in a mammal may include attaching an electronic device to the mammal, the device comprising at least two electrodes configured to detect physiological signals from the mammal, at least one meter configured to detect a secondary signal, and at least two electrode traces connected to the electrodes and the housing, and the method may also include comparing the physiological signals to the secondary signals to identify artifacts.

[0011] In certain embodiments, identifying artifacts includes a comparison between a frequency spectrum of the physiological signal and a frequency spectrum of a secondary signal. In embodiments, the secondary signal includes a motion signal that can be used to derive activity and position of the mammal. In certain embodiments, the secondary signal is collected in three axes. In some embodiments, a tertiary signal may also be collected. In certain embodiments, the secondary signal includes information about a connection between the electronic device and the mammal. In some embodiments, the secondary signal may be used to detect when the mammal is asleep.

[0012] In some embodiments, a method of removing and replacing a portion of a modular physiological monitoring device may include applying the device to a mammal for a period of more than seven days to collect physiological data; using the device to detect a first set of physiological signals; removing the device from the mammal's surface; removing the first component from the device; and incorporating the first component into a second physiological monitoring device, the second physiological monitoring device configured to detect the second set of physiological signals.

[0013] In some embodiments, the first component is electrically connected to other device components without the use of a permanent connection. In some embodiments, the device may further include a spring connection. In certain embodiments, the first component may be preserved for a second use by a housing to prevent damage. In certain embodiments, the first component is secured within the device by a mechanism capable of re-securing the second component when the first component is removed.

[0014] Certain embodiments may relate to a system for inferring heart rate information from time series data of heart beat intervals, such as those obtained from either consumer wearable products or medical device products. Further aspects relate to improvements to the system that allow for inferring heart rate information in a more robust and / or timely manner by using additional data sources. This additional data may include summary statistics or specific signal features obtained from an ECG, user activity time series data obtained from an accelerometer, information related to user state, or information related to the date / time of recording.

[0015] In certain embodiments, a system for selectively transmitting electrocardiogram signal data from a wearable medical sensor may include the following, where QRS refers to the three fiducial points in an ECG recording during ventricular depolarization:

[0016] A wearable medical sensor incorporating a QRS detector that produces a real-time estimate of each R-peak location in the ECG.

[0017] The transmission of a time series of RR intervals along with onset timestamps from the sensor to a smartphone or internet-connected gateway device according to a pre-defined schedule.

[0018] The smartphone or internet-connected gateway device sends the RR interval time series and onset timestamps to the server.

[0019] The most likely rhythm and its onset / offset times are inferred from the RR interval time series data using a server-side algorithm.

[0020] Filtering the list of inferred cardiac rhythms according to specific filter criteria, such that only inferred rhythms that match the given criteria are retained after filtering.

[0021] The onset / offset times of each rhythm remaining after filtering are sent from the server to a smartphone or a gateway device connected to the Internet.

[0022] The onset / offset times of each rhythm remaining after filtering are transmitted from a smartphone or a gateway device connected to the Internet to a wearable sensor.

[0023] Transmitting the section of the recorded ECG corresponding to each onset-offset time pair from the sensor to a smartphone or internet-connected gateway device.

[0024] Sending the recorded ECG section corresponding to each onset-offset time pair from the smartphone or internet-connected gateway device to the server.

[0025] The rhythm filter criteria may be specified by a physician or other medical professional prior to the patient's use of the wearable sensor. In other embodiments, the rhythm filter criteria are dynamic and can be updated during use of the system according to predefined rules. In some embodiments, these predefined rules may describe adjustment of the filter criteria based on previous findings during use of the system. In some embodiments, the onset and offset times of each inferred rhythm may be adjusted so that the resulting duration of each rhythm is shorter than a predetermined maximum allowable duration. The calculated confidence measure may be an input to the rhythm filter criteria. In some embodiments, the system includes inferring heart rate information from the RR interval time series data. In certain embodiments, the heart rate inference system is implemented as a cloud service accessible via an API.

[0026] In certain embodiments, the heart rate inference system is provided through a software library that can be incorporated into a stand-alone application. The RR interval value may be estimated from the photoplethysmography signal.

[0027] In a particular embodiment of the method for inferring heartbeat information, the heartbeat inference system calculates a confidence score for each type of heartbeat, and the method includes the following steps.

[0028] Calculating the frequency and duration of each heartbeat type inferred from the collection of RR interval time series data for a given user.

[0029] Estimating a confidence statistic for each rhythm type based on the inferred frequency and duration of the rhythm across the collection of time series of RR intervals for the given user.

[0030] Evaluating whether the confidence statistic for each inferred rhythm exceeds a predetermined threshold.

[0031] Returning cadence information to the call software only for those inferred cadences whose confidence statistics exceed a threshold.

[0032] In certain embodiments, the heartbeat inference system accepts additional data sources, including one or more of the following:

[0033] User activity time series data measured by an accelerometer.

[0034] Information about the specific day and time of the time series recording for each RR interval.

[0035] Information about the user's age, gender, clinical indication for monitoring, medical conditions, medication information, and medical history.

[0036] ECG signal characteristics and summary statistics such as the mean, median, standard deviation, or sum of ECG signal sample values ​​over a given period of time.

[0037] For example, a confidence rating provided by a measurement device to indicate the quality of the heart beat for each beat or subsequent time period.

[0038] Intrabeat interval measurement.

[0039] In an embodiment, a system for monitoring cardiac signal data includes:

[0040] A wearable medical sensor configured to detect an electrocardiographic signal from a mammal and estimate an R-peak location within the electrocardiographic signal.

[0041] Here, the wearable medical sensor is configured to transmit the time series of RR intervals and timestamps to an intermediary device, and the intermediary device is further configured to transmit the time series of RR intervals and timestamps to a server.

[0042] Here, the server is configured to infer the most probable rhythms and their onset / offset times from the time series of RR intervals and timestamps, and the server is configured to filter the most probable rhythms according to a first criterion and send them to a filtered dataset.

[0043] wherein the server is configured to send the filtered data set back to the wearable sensor via the intermediary device; and

[0044] Here, the sensor transmits full-resolution cardiac signals for the time period surrounding each filtered event to the server.

[0045] In certain embodiments, a system for monitoring cardiac signal data comprises:

[0046] a server configured to communicate with the wearable sensor; The wearable sensor is configured to detect a cardiac signal from the mammal and estimate an R-peak location within the cardiac signal;

[0047] The wearable sensor is configured to transmit a time series of the RR intervals and a timestamp to a server;

[0048] The server is configured to infer the most probable rhythm and its onset / offset times from the RR interval time series and timestamps. The server is configured to filter the most probable rhythms according to a first criterion and send them to a filtering dataset;

[0049] The server is configured to transmit a summary of the filtering data.

[0050] In certain embodiments, a server for monitoring cardiac signal data includes:

[0051] a portal configured to communicate with the wearable sensor; The wearable sensor is configured to detect a cardiac signal from the mammal and estimate an R-peak location within the cardiac signal; The wearable sensor is configured to transmit the time series of RR intervals and timestamps to an intermediary device, the intermediary device further configured to transmit the time series of RR intervals and timestamps to a server;

[0052] The server also a processor configured to infer a most probable rhythm and its onset / offset times from the time series of R-R intervals and timestamps; The processor is configured to filter the most probable rhythms according to the first criterion into a filtering data set;

[0053] The server is configured to transmit a summary of the filtered data set.

[0054] In an embodiment, a non-transitory storage medium having computer-executable instructions stored therein, comprising: The computer-executable instructions are readable by a computing system including one or more computing devices; The computer-executable instructions are executable on a computing system to cause the computing system to perform an operation; The computing system receiving, by the computing system via a communications link, physiological sensor data generated by the patient monitoring device; The physiological sensor data relates to a first patient; The computing system also analyzing, by a computing system, the physiological sensor data to determine whether there are one or more points in the physiological data that are likely to be indicative of one or more predetermined sets of conditions; generating, by the computing system, an electronic data package for transmission to the patient monitoring device after determining that at least one of the one or more points in the physiological data is likely to indicate at least one of the one or more predetermined conditions; The electronic data package includes location data regarding which at least one of the one or more points in the physiological sensor data is likely to indicate at least one of one or more predetermined conditions.

[0055] In certain embodiments, the physiological sensor data may include a sampling of interval data measured from the recorded signal data, where the sampling of interval data is smaller in data size than the recorded signal data.

[0056] In certain embodiments, a system for monitoring physiological signals in a mammal may include a wearable adhesive monitor configured to detect and record cardiac data from the mammal, comprising: The wearable adhesive monitor is configured to extract features from the heart rate data, the wearable adhesive monitor is configured to transmit the features to a processing unit, and the processing unit is configured to analyze the features, identify locations of interest, and transmit the locations of interest back to the wearable adhesive monitor.

[0057] In certain embodiments, a system for evaluating physiological sensor data from a patient monitoring device includes: a computer processor; and a non-transitory computer readable medium in combination with the computer processor configured to provide a program including an instruction set stored on the first server; The set of instructions is executable by a computer processor and is further configured to execute a sensor data inference module of the program; The sensor data inference module of the program stores instructions to: receiving physiological sensor data generated by a patient monitoring device, the physiological sensor data relating to a first patient; analyzing the physiological sensor data to determine whether there are one or more points in the physiological data that are likely to be indicative of one or more predetermined sets of conditions; generating an electronic data package for transmission to the patient monitoring device after determining that at least one of the one or more points in the physiological data is likely to indicate at least one of the one or more predetermined conditions; The electronic data package includes location data regarding at least one of the one or more points in the physiological sensor data that may indicate at least one of the one or more predetermined conditions.

[0058] In certain embodiments, the computerized method comprises: accessing computer-executable instructions from at least one computer-readable storage medium; executing computer-executable instructions, Thereby, computer hardware including at least one computer processor is provided with: receiving, by a server computer via a communications link, physiological sensor data generated by the patient monitoring device; analyzing, by the server computer, the physiological sensor data to determine whether there are one or more points in the physiological data that are likely to be indicative of one or more predetermined conditions; generating, by the server computer, an electronic data package for transmission to the patient monitoring device after determining that at least one of the one or more points of physiological data is likely to indicate at least one of the one or more predetermined conditions; The electronic data package includes location data for at least one of the one or more points in the physiological sensor data that indicate a high probability that at least one of the one or more predetermined conditions is indicated.

[0059] These and other aspects and embodiments of the present invention are described in more detail below with reference to the drawing figures. [Brief explanation of the drawings]

[0060] [Figure 1A] FIG. 1A is a perspective view of a physiological monitoring device according to one embodiment. [Figure 1B] FIG. 1B is a diagram of a degradation profile of a physiological monitoring device according to one embodiment. [Figure 2A] FIG. 2A is a top perspective view of a printed circuit board assembly of a physiological monitoring device according to one embodiment. [Figure 2B] FIG. 2B is a bottom perspective view of a printed circuit board assembly of a physiological monitoring device according to one embodiment. [Figure 3A] FIG. 3A is a perspective view of a flexible body and gasket of a physiological monitoring device according to one embodiment. [Figure 3B] FIG. 3B is an exploded view of a flexible body and gasket of a physiological monitoring device according to one embodiment. [Figure 3C] FIG. 3C is an illustration of a flexible body and gasket of a physiological monitoring device according to one embodiment. [Figure 3D] FIG. 3D is an illustration of a flexible body and gasket of a physiological monitoring device according to one embodiment. [Figure 3E] FIG. 3E is a perspective view of a flexible body and gasket of a physiological monitoring device according to one embodiment. [Figure 4] FIG. 4 is an exploded view of a housing of a physiological monitoring device according to one embodiment. [Figure 5A]FIG. 5A is a perspective view of a battery holder of a physiological monitoring device according to one embodiment. [Figure 5B] FIG. 5B is a perspective view of a battery holder of a physiological monitoring device according to one embodiment. [Figure 6A] FIG. 6A is a cross-sectional view of a physiological monitoring device according to one embodiment. [Figure 6B] FIG. 6B is a cross-sectional view of a physiological monitoring device according to one embodiment. [Figure 7] FIG. 7 is an exploded view of one embodiment of a physiological monitoring device that includes many optional items. [Figure 8A] FIG. 8A is a perspective view of a person wearing one embodiment of a physiological monitoring device, illustrating how the device flexes in response to body motion and posture. [Figure 8B] FIG. 8B is a perspective view of a person wearing an embodiment of a physiological monitoring device, illustrating how the device flexes in response to body motion and posture. [Figure 9A] FIG. 9A illustrates various steps in applying a physiological monitoring device to a patient's body according to one embodiment. [Figure 9B] FIG. 9B illustrates various steps in applying a physiological monitoring device to a patient's body according to one embodiment. [Figure 9C] FIG. 9C illustrates various steps in applying a physiological monitoring device to a patient's body according to one embodiment. [Figure 9D] FIG. 9D illustrates various steps in applying a physiological monitoring device to a patient's body according to one embodiment. [Figure 9E] FIG. 9E illustrates various steps in applying a physiological monitoring device to a patient's body according to one embodiment. [Figure 9F] FIG. 9F illustrates various steps in applying a physiological monitoring device to a patient's body according to one embodiment. [Figure 10A] FIG. 10A shows a schematic representation of a first alternative example of a trace layer. [Figure 10B]FIG. 10B is a close-up view of insert A of the first alternative trace layer of FIG. 10A. [Figure 10C] FIG. 10C shows a schematic diagram of another alternative trace layer. [Figure 11A] FIG. 11A is a schematic diagram illustrating the inner surface of an example battery terminal connector configured to contact a battery terminal. [Figure 11B] FIG. 11B is a schematic diagram showing the outer surface of the battery terminal connector opposite the surface shown in FIG. 11A. [Figure 11C] FIG. 11C illustrates a schematic of the inner surface of another example battery terminal connector configured to contact a battery terminal. [Figure 11D] FIG. 11D is a schematic diagram showing the outer surface of the battery terminal connector opposite the surface shown in FIG. 11C. [Figure 11E] FIG. 11E shows a side view of the battery with the battery terminal connectors connected. [Figure 11F] FIG. 11F shows the inner surface of another example of a battery terminal connector configured to contact a battery terminal. [Figure 11G] FIG. 11G shows the inner surface of another example of a battery terminal connector configured to contact a battery terminal. [Figure 11H] FIG. 11H is a schematic diagram showing the outer surface of the battery terminal connector opposite the surface shown in FIG. 11C. [Figure 11I] FIG. 11I shows a schematic diagram of the outer surface of the battery terminal connector opposite the surface shown in FIG. 11C. [Figure 12A] FIG. 12A is a partially exploded view of another example of an upper housing. [Figure 12B] FIG. 12B is a perspective view of a flexible upper frame of another example of the upper housing. [Figure 12C] FIG. 12C is a side view of a flexible upper frame of another example of an upper housing. [Figure 12D] FIG. 12D is a top view of a flexible upper frame of another example of an upper housing. [Figure 12E] FIG. 12E is a perspective view of the inner surface of another example of the upper housing. [Figure 12F] FIG. 12F is a side view of the upper and lower housings of another example of the upper housing. [Figure 12G] FIG. 12G is a side view of a ridge configured to seal the upper and lower housings. [Figure 13A] FIG. 13A is a perspective view of another example of the lower housing. [Figure 13B] FIG. 13B is a side view of another example of the lower housing. [Figure 14A] FIG. 14A is an orthogonal side view of an example wave spring. [Figure 14B] FIG. 14B is an orthogonal side view of an example wave spring. [Figure 15A] FIG. 15A is a perspective view of another example of a physiological monitoring device. [Figure 15B] FIG. 15B is an exploded view of another example of a physiological monitoring device. [Figure 15C] FIG. 15C is a side view of the housing of the physiological monitoring device with the upper housing removed. [Figure 15D] FIG. 15D is a side view of the housing of the physiological monitoring device shown in FIG. 15C. [Figure 15E] FIG. 15E is a side view of the housing of the physiological monitoring device shown in FIG. 15D, with the lower housing also omitted. [Figure 15F] FIG. 15F is a side view of the housing of the physiological monitoring device shown in FIG. 15E, further omitting the battery and spring. [Figure 15G] FIG. 15G is a cross-sectional view of the housing of the physiological monitoring device shown in FIG. 15F, taken between circuit board 120 and spring contact spacer 632. [Figure 15H] FIG. 15H is a cross-sectional view of the housing of the physiological monitoring device shown in FIG. 15G, further omitting the spring contact spacers. [Figure 15I]FIG. 15I is a side view of the housing of the physiological monitoring device shown in FIG. 15H, which additionally includes a circuit board. [Figure 16A] FIG. 16A is a top perspective view of a physiological monitoring device. [Figure 16B] FIG. 16B is a bottom view of the physiological monitoring device. [Figure 16C] FIG. 16C is a top perspective view of a physiological monitoring device, including a liner. [Figure 16D] FIG. 16D is a bottom view of the physiological monitoring device, including the liner. [Figure 17A] FIG. 17A is a cross-sectional view of an abrader including a compressible spring. [Figure 17B] FIG. 17B is a cross-sectional view of an abrader containing compressible foam. [Figure 18] FIG. 18 is a schematic diagram of one embodiment of the heartbeat inference service. [Figure 19] FIG. 19 is a schematic diagram of one embodiment of a system for extracting and transmitting data features from a physiological monitor. DETAILED DESCRIPTION OF THE INVENTION

[0061] The following description is directed to a number of different embodiments. However, the described embodiments can be implemented and / or varied in many different ways. For example, the described embodiments can be implemented in any suitable device, apparatus, or system for monitoring any of a number of physiological parameters. For example, the following discussion focuses primarily on long-term patch-based heart rate monitoring devices. In one alternative embodiment, the physiological monitoring device can be used, for example, for pulse oximetry and obstructive sleep apnea diagnosis. The manner in which the physiological monitoring device is used can also vary. In some cases, the device may be worn for one week or less, while in other cases, the device may be worn for at least seven days and / or for more than seven days, for example, 14 to 21 days or more.

[0062] Many other alternative embodiments and applications of the described techniques are possible. Accordingly, the following description is provided for illustrative purposes only. Throughout this specification, reference may be made to the term "conformal." Those skilled in the art will understand that the term "conformal," as used herein, refers to a relationship between surfaces or structures in which a first surface or structure conforms to the contours of a second surface or structure.

[0063] Because abnormal heart rhythms, or arrhythmias, often have other, less serious causes, determining whether these symptoms are due to arrhythmias presents a significant challenge. Furthermore, arrhythmias are rare and often paroxysmal, making rapid and reliable diagnosis difficult. As mentioned above, currently, heart rate monitoring is primarily achieved through the use of devices such as Holter monitors, which use short-term (less than one day) electrodes attached to the chest. The electrodes are connected by wires to a recording device, typically worn on a belt. The electrodes must be replaced daily, and the wiring is cumbersome. Furthermore, the recording device has limited memory and recording time. Wearing the device often restricts patient movement and prevents certain activities during monitoring, such as bathing.

[0064] Furthermore, Holter monitors are capital equipment and have limited availability, often leading to supply constraints and associated testing delays. These limitations significantly hinder the diagnostic utility of the device, patient compliance with the device, and the potential to capture all important information. Lack of compliance and device shortcomings often lead to the need for additional equipment, follow-on monitoring, or other testing to make a correct diagnosis.

[0065] Current methods of correlating symptoms with the occurrence of arrhythmias using heart rate monitoring devices such as Holter monitors and electrocardiographs are often insufficient to make an accurate diagnosis. In fact, Holter monitors have been shown to be non-diagnostic up to 90% of the time (DE Ward et al., "Evaluation of the Diagnostic Value of 24-Hour Ambulatory Electrocardiographic Monitoring," Biotelemetry Patient Monitoring, Vol. 7, 1980).

[0066] Furthermore, the actual medical procedure of obtaining and initiating heart rate monitoring is typically highly complex. Numerous steps are typically required to order, track, monitor, retrieve, and analyze data from such devices. Heart monitoring devices used today are almost always ordered by cardiologists or cardiac electrophysiologists (EPs) rather than the patient's primary care physician (PCP). This is important because the PCP is often the first to see the patient and the first to determine that the patient's symptoms may be due to arrhythmia. After the patient sees the PCP, the PCP schedules an appointment with the cardiologist or EP. This appointment is usually scheduled several weeks after the initial consultation, potentially delaying diagnosis and increasing the likelihood of an arrhythmia episode going undiagnosed. Once the patient finally sees the cardiologist or EP, a heart rate monitoring device is typically ordered. The monitoring period is 24–48 hours (Holter monitor) or up to one month (cardiac event monitor or mobile telemetry device). Once monitoring is complete, patients typically must return the device to the clinic, which can be inconvenient in itself. The data is processed by the monitoring company or by technicians at the hospital or office, and a report is ultimately sent to a cardiologist or EP for analysis. This complex process means that fewer patients receive heart rate monitoring than would otherwise be possible.

[0067] To address some of these issues related to cardiac monitoring, the assignee of the present application has developed various embodiments of a compact, long-term wearable physiological monitoring device. One embodiment of this device is the Zio® Patch. Various embodiments are described, for example, in U.S. Patent Nos. 8,150,502, 8,160,682, 8,244,335, 8,560,046, and 8,538,503, the entire disclosures of which are incorporated herein by reference in their entireties. Generally, the physiological patch-based monitors described in these documents are designed to fit comfortably around the patient's chest and be worn for at least one week, typically two to three weeks. The monitor continuously detects and records heart rate signal data while the device is worn, and this heart rate data is then available for processing and analysis.

[0068] Such small, long-term patch-type physiological monitoring devices offer many advantages over prior art devices. At the same time, further improvements are desirable. One of the most significant improvements would be more timely notification of critical arrhythmias to the managing clinician. A characteristic of these early implementations was that, for performance, compliance, and cost reasons, the device recorded information only during the extended wear period, with analysis and reporting occurring after recording was completed. Adding the ability to analyze collected rhythm information in real time or in a timely manner would be a desirable improvement. While diagnostic monitors currently exist that provide such timely reporting capabilities, they require periodic recharging or replacement of one or more electrical components of the system. This practice reduces patient compliance and ultimately reduces diagnostic yield. Therefore, a key improvement is the development of a physiological monitor that can provide both long-term recording and timely reporting without the need for battery charging or replacement.

[0069] Patient compliance and device adhesion performance are two factors that affect the duration of ECG recording and, therefore, the diagnostic yield results. Compliance can be improved by improving patient comfort and is influenced by factors such as fit, device appearance, and the degree to which the device interferes with normal daily activities. Longer ECG recordings are more diagnostically useful and valuable, so improving device adhesion and patient compliance is desirable.

[0070] Signal quality is important throughout the entire wear period, but may become even more important when marking the recording where the patient exhibits clinically significant symptoms. Marking the recording is most easily accomplished by a trigger on the exterior of the device. However, because the trigger may be part of a skin-contact platform that incorporates electrodes, significant motion artifact may occur when the patient feels the trigger. A desirable device improvement would be a symptom trigger that can be activated with minimal motion artifact.

[0071] Furthermore, it is desirable for the device to be simple and cost-effective to manufacture, allowing for scalability in manufacturing and improved quality through process repeatability. Simplicity in manufacturing also allows for easy disassembly, allowing for efficient recovery of printed circuit boards for reuse in other quality-controlled devices. Efficient reuse of this expensive component is important for reducing the cost of diagnostic monitors.

[0072] However, there are clinical scenarios in which a longer-term, lower-cost solution would be a valuable addition to the cardiac ambulatory monitoring portfolio. Hints at a potential solution to this need can be found in the continuous heart rate detection features increasingly being implemented in various consumer health and fitness products, such as smartwatches and wearable fitness bands. While continuous heart rate data can be used to provide information about a user's general fitness level, using this data to provide meaningful information related to the user's health and wellness is more challenging and valuable. For example, if potential arrhythmias could be detected from continuous heart rate data, consumer devices equipped with heart rate sensing could potentially serve as screening tools for the early detection of cardiac abnormalities. Such an approach could be clinically valuable in providing a long-term, cost-effective screening method for at-risk populations, such as heart failure patients at risk for atrial fibrillation. This monitoring approach could also be useful for adjusting therapeutic drug dosage over time while minimizing side effects in the treatment of paroxysmal atrial fibrillation. In addition to arrhythmia detection, appropriate analysis of heart rate information could potentially be applied to sleep and stress monitoring.

[0073] Long-term ambulatory monitoring using physiological devices such as adhesive patches has many clinical applications, especially if it can provide timely information on the occurrence and duration of arrhythmias observed during the monitoring period. Efficient detection of atrial fibrillation is a critical monitoring need, especially given its prevalence with an aging population. This need extends beyond symptomatic patients, and considering the increased risk of stroke associated with this arrhythmia, it is necessary to monitor asymptomatic atrial fibrillation on a broad population-based basis in individuals at risk due to factors such as advanced age, the presence of chronic conditions such as heart disease, or prior surgical procedures. In the latter case, perioperative and postoperative monitoring can be clinically valuable not only during arrhythmia prevention procedures (e.g., MAZE ablation and hybrid endomyocardial-epicardial therapy, both of which treat atrial fibrillation) but also during general surgery involving anesthesia. The purpose of ambulatory monitoring of atrial fibrillation can sometimes be reduced to a simple binary yes or no question: whether atrial fibrillation occurred during a given period. For example, monitoring patients after ablation procedures typically seeks to confirm success, defined as the complete absence of atrial fibrillation. Similarly, monitoring of patients after stroke is primarily concerned with assessing the presence of atrial fibrillation.

[0074] However, even in such scenarios, if atrial fibrillation occurs, it may be clinically meaningful to assess the daily burden (percentage of time spent in atrial fibrillation per day) and episode duration (e.g., expressed as a histogram of episode duration or as the percentage of episodes exceeding a certain limit, such as 6 minutes) to better characterize its occurrence, either in absolute terms or in comparison with a previous benchmark (e.g., using a baseline pre-procedure monitoring result). Indeed, measuring the daily burden of atrial fibrillation, assessing atrial fibrillation episode duration, considering the occurrence of atrial fibrillation during sleep and waking, and assessing the presence of atrial fibrillation in response to the patient's degree of physical exertion are important in various clinical scenarios, including evaluating the effectiveness of drug-based treatments for this arrhythmia.

[0075] Having this information available in a timely manner during the monitoring period would allow the managing physician to iteratively titrate therapy until management is optimized, for example, by adjusting the dose or frequency of a novel oral anticoagulant (NOAC).A further example of this management paradigm is when patients are notified of asymptomatic AF—either directly from the device via an audible or vibration-based alert, from an application connected to the device, or by communication from the managing clinician via phone, email, or text message—enabling timely application of a “medicine in the pocket” approach for AF management.

[0076] Certainly, the theme of timely management and / or intervention is evident in situations where clinically significant arrhythmias, such as asymptomatic second-degree or complete heart block, prolonged pauses, high-rate supraventricular tachycardia, prolonged ventricular tachycardia, or ventricular fibrillation, are observed. For example, the clinical scenario in which prolonged pauses or complete heart block precipitate syncope is a particularly important case, where the availability of timely and reliable monitoring methods could reduce or eliminate the need for in-hospital monitoring in at-risk patients. This theme also extends to more subtle morphological changes, such as drug-induced QT prolongation, which has been shown to have significant cardiac safety implications. Timely recognition of such prolongation could, for example, lead to early termination of clinical trials evaluating the safety and efficacy of a drug or to adjustments in dosage or frequency as a means of eliminating the observed prolongation.

[0077] Physiological Monitoring Devices 1A and 1B, perspective and exploded profile views of one embodiment of a physiological monitoring device 100 are provided. As seen in FIG. 1A, the physiological monitoring device 100 may include a flexible body 110 coupled to a watertight, rigid housing 115. As will be understood by those skilled in the art, the housing as described herein and throughout this specification may be constructed from a rigid or flexible material, thereby making the housing stiff to resist deformation or soft to flex and / or deform under force. The flexible body 110 (sometimes referred to as a "flexible substrate" or "flexible construction") typically includes two wings 130, 131 extending laterally from the housing 115 and two flexible electrode traces 311, 312, each embedded in one of the wings 130, 131. Each electrode trace 311, 312 is coupled to a flexible electrode (not visible in FIG. 1A ) on the bottom surface of flexible body 110. The electrodes are configured to sense cardiac rhythm signals from a patient to which monitoring device 100 is attached. Electrode traces 311, 312 then transmit those signals to electronics (not visible in FIG. 1A ) contained in housing 115. Rigid housing 115 also typically contains a power source, such as one or more batteries.

[0078] The combination of a highly flexible body 110 and housing 115, including flexible electrodes and electrode traces 311, 312, can provide many advantages. A key advantage is high-fidelity signal capture. The highly conformal flexible wings 130, 131, electrodes, and traces 311, 312 limit the transfer of external energy to the electrode-skin interface. For example, if the housing 115 is subjected to motion, the system of conformal adhesion to the skin limits the extent to which that motion affects the monitored signal. The flexible electrode traces 311, 312 generally help provide conformal contact with the subject's skin and help prevent the electrode 350 (not visible in FIG. 1 but visible in FIG. 6A, described below) from peeling or lifting off the skin, potentially resulting in strong motion artifact rejection and better signal quality by minimizing the transfer of stress to the electrode 350. Additionally, flexible body 110 includes configurations and various features that facilitate comfortable wearing of device 100 by the patient for 14 days or more without removal. Housing 115, which typically does not adhere to the patient in the embodiments described herein, includes features that contribute to the comfort of device 100. Hinge portions 132 are relatively thin and highly flexible portions of flexible body 110. They allow flexible body 110 to flex freely in the area where it is joined to housing 115. This flexibility enhances comfort because, as the patient moves, housing 115 can freely lift off the patient's skin. Electrode traces 311, 312 are also very thin and flexible to allow for patient movement without signal distortion.

[0079] 1B, a partially exploded view of the physiological monitoring device 100 shows in more detail the components that make up and are housed within the rigid housing 115. In this embodiment, the housing 115 includes an upper housing member 140 that detachably couples with a lower housing member 145. Sandwiched between the upper and lower housing members 140 and 145 are an upper gasket 370 and a lower gasket 360 (not visible in FIG. 1B, but directly below the upper gasket 370). The gaskets 370, 360 help make the housing members and / or the body 115 watertight when assembled. Numerous components of the monitoring device 100 may be housed between the upper and lower housing members 140 and 145. For example, in one embodiment, the housing 115 may house a portion of the flexible body 110, a printed circuit board assembly (PCBA) 120, a battery holder 150, and two batteries 160. Printed circuit board assembly 120 is disposed within housing 115 so as to contact electrode traces 311, 312 and battery 160. In various embodiments, one or more additional components may be included within or attached to rigid housing 115. Some of these optional components are further described below with reference to additional drawing figures.

[0080] According to various alternative embodiments, the battery holder 150 can hold two batteries (as in the illustrated embodiment), one battery, or more than two batteries. In other alternative embodiments, other power sources may be used. In the illustrated embodiment, the battery holder 150 includes a plurality of retention tabs and / or protrusions 153 for retaining the battery 160 within the holder 150. Additionally, the battery holder 150 includes a plurality of feet and / or protrusions 152 for establishing the correct spacing of the battery 160 from the surface of the PCBA 120 and ensuring proper contact with the spring fingers and / or contacts 235 and 236. The spring fingers 235 and 236 are used in this embodiment instead of soldering the battery 160 to the PCBA 120. While soldering could be used in alternative embodiments, one advantage of the spring fingers 235 and 236 is that the battery 160 can be removed from the PCBA 120 and the holder 150 without damaging either of those components, thus allowing multiple reuse of both. Eliminating solder connections also simplifies and speeds assembly and disassembly of the monitoring device 100.

[0081] In some embodiments, the upper housing member 140 can function as a patient event trigger. When a patient is wearing the physiological monitoring device 100 for heart rate monitoring, it is typically advantageous for the patient to be able to register any cardiac events they perceive with the device 100 (e.g., log them into the device's memory). For example, if the patient feels what they believe to be an episode of cardiac arrhythmia, the patient can trigger the device 100 in some way, resulting in a recording of the perceived event. In some embodiments, the patient's triggering of a perceived event can initiate the transmission of data related to the triggered event. In some embodiments, the triggering of a perceived event can simply mark a continuous recording with the location of the triggered event. In some embodiments, both the transmission of the associated data and the marking of the continuous recording may occur. At some later point, the patient's recorded symptoms during the perceived event can be compared to the patient's actual heart rhythm as recorded by the device 100, which may help determine whether the patient's perceived event correlates with an actual cardiac event. However, one problem with patient event triggers in currently available wearable heart rate monitoring devices is that the small trigger can be difficult to find and / or activate, especially because the monitoring devices are typically worn under clothing. Furthermore, pressing the trigger button can affect the electronics and / or electrodes on the device, such that the heart rate signal recorded at that moment is altered by the patient's triggering action. For example, pressing the trigger can transmit vibrations to one or both electrodes, causing the heart rate signal recorded at that moment to appear arrhythmia-like (even when no actual arrhythmia event has occurred). Furthermore, the trigger can be activated inadvertently, for example, while sleeping or lying on the device.

[0082] However, in the embodiment shown in FIGS. 1A and 1B, the housing 115 is sufficiently rigid and the flexible body 110 is sufficiently flexible so that movement applied to the housing 115 by the patient may result in little or no abnormal signals being sensed by the electrodes. In this embodiment, the central portion of the upper housing member 140 is slightly recessed, which, when pressed by a patient wearing the device 100, causes a trigger input on the PCBA 120. Because the entire top surface of the housing 115 functions as the patient event trigger, combined with the fact that it is slightly recessed, it will generally be very easy for a patient to find and depress the trigger, even under clothing. Furthermore, the recessed nature of the button allows it to be lowered to protect it from inadvertent activation. Thus, this embodiment can alleviate some of the problems encountered with patient event triggers in currently available cardiac rhythm monitors. These and other aspects of the features shown in FIGS. 1A and 1B are described in further detail below.

[0083] 2A and 2B , printed circuit board assembly 120 (or PCBA) can include top surface 220, bottom surface 230, patient trigger input 210, and spring contacts 235, 236, and 237. Printed circuit board assembly 120 may be used to mechanically support and electrically connect electronic components using conductive paths, tracks, or electrode traces 311 and 312. Furthermore, due to the sensitive nature of PCBA 120 and its requirement to mechanically interface with rigid body 115, it is beneficial for PCBA 120 to be substantially rigid enough to prevent unwanted deflections that could introduce noise or artifacts into the ECG signal. This is particularly true during patient trigger activation, where forces are transmitted through rigid body 115 to PCBA 120. One way to ensure PCBA rigidity, in some embodiments, is to ensure that the PCBA's thickness is relatively above a certain value. For example, a thickness of at least about 0.08 cm is desirable, and more preferably, a thickness of at least about 0.17 cm is desirable. In this application, PCBA 120 may also be referred to as or referred to as a printed circuit board (PCB), printed wiring board (PWB), etched wiring board, or printed circuit assembly (PCA). In some embodiments, wire-wrap or point-to-point structures may be used in addition to or instead of PCBA 120. PCBA 120 may include analog and digital circuits.

[0084] The patient trigger input 210 may be configured to communicate a signal from a patient trigger, such as the upper housing member 140 described above, to the PCBA 120. For example, the patient trigger input 210 may be a PCB switch or button that responds to pressure from the patient trigger (e.g., the top surface of the upper housing member 140). In various embodiments, the patient trigger input 210 may be a surface-mounted switch, a tactile switch, a FED-illuminated tactile switch, or the like. In some embodiments, the patient trigger input 210 may also activate an indicator such as an LED. Certain embodiments may include a trigger that is located remotely, such as on a separate device or as a smartphone app.

[0085] One significant challenge in collecting cardiac signals from human or animal subjects using a compact, two-electrode physiological monitoring device, such as the device 100 described herein, is that having only two electrodes sometimes provides a limited perspective when trying to distinguish between artifacts and clinically significant signals. For example, if a left-handed patient brushes their teeth while wearing a compact, two-electrode physiological monitoring device on the left side of their chest, the toothbrushing can often produce motion artifacts in the recorded signal that can look very similar to ventricular tachycardia, a serious cardiac arrhythmia. To alleviate this concern, the traditional approach is to add leads (i.e., vectors), which are typically done by adding wires to various locations on the patient's chest, as in a Holter monitor. This approach is not consistent with compact, wearable, long-term monitors such as the physiological monitoring device 100.

[0086] An alternative approach to the above problem is to provide one or more additional data channels to assist in signal discrimination. In some embodiments, for example, device 100 can include a data channel for detecting patch motion. In certain embodiments, an accelerometer or other suitable device can provide patch motion by simply analyzing single-axis measurements, or alternatively, the combined magnitude of all three axes. The accelerometer can record device motion at a sufficient sampling rate so that its frequency spectrum can be algorithmically compared to that of the recorded ECG signal. If the motion and recorded signal match, it is clear that the device recorded during that time period is not from a clinical source (e.g., due to a cardiac abnormality), and therefore that portion of the signal can be confidently marked as an artifact. This technique is particularly useful in the tooth-brushing example mentioned above, where the rapid frequency and high-amplitude artifact of the motion are similar to the heart rate and morphology, respectively, of potentially life-threatening arrhythmias such as ventricular tachycardia. Other suitable devices described in this section and elsewhere in this specification can also be utilized to provide motion information.

[0087] In some embodiments, using magnitudes on all three axes for such analysis can obscure sudden changes in values ​​due to shifts in position rather than changes in activity. In other embodiments, it may be advantageous to use a specific measurement axis, such as along the longitudinal axis of the body, to focus on specific types of artifacts introduced by vertical motion associated with walking or running. Similarly, using a gyroscope in combination with an accelerometer may provide additional resolution as to the nature of the motion experienced. While an accelerometer alone may be sufficient to analyze whole-body motion, certain motions, such as rotational motion due to arm movement, may be sufficiently complex to be discerned using an accelerometer alone.

[0088] In addition to detecting motion artifacts, an accelerometer tuned to the dynamic range of human physical activity can also provide information on the patient's activity level during recording, improving the accuracy of algorithms' detection of true arrhythmias. Given the single-lead limitations of the device 100, arrhythmias such as supraventricular tachycardia, which require the observation of less noticeable waves (e.g., P waves) in addition to rate changes, are difficult to distinguish not only by computerized algorithms but also by trained human eyes. This particular arrhythmia is also characterized by its sudden onset, and if a sudden increase in the patient's activity level is detected simultaneously with an increase in heart rate, it may be more reliably distinguished from non-pathological sinus tachycardia. Broadly speaking, providing activity information in clinical settings may enable the differentiation of exercise-induced arrhythmias from non-exercise-induced arrhythmias. Similar to motion artifact detection, measurements from a single-axis accelerometer optimized for a specific direction may help more specifically determine activity types, such as walking or running. This additional information may help more specifically identify symptoms and thereby positively influence subsequent treatment strategies.

[0089] In certain embodiments, an accelerometer with three axes can provide advantages beyond what motion magnitude can provide. When the subject is not moving rapidly, three-dimensional accelerometer measurements can approximate the tilt of the PCBA 120 and, therefore, the body's orientation relative to its original orientation. The original body orientation can be assumed to be either upright or supine, which is required for proper positioning and application of the device to the body. This information may be useful in ruling out certain cardiac disorders that manifest as beat-to-beat morphological changes, such as cardiac alternans, a condition commonly observed in cases of heart failure, where periodic amplitude changes are observed. Similar beat-to-beat morphological changes are observable in healthy subjects upon shifts in body position due to shifts in heart position relative to the electrode vector, for example, from an upright to a squatting position. By design, the single-channel device 100 does not have an alternative ECG channel to easily rule out potential pathological shifts in morphology, but correlation with body positional shifts may help explain these normal changes and avoid unnecessary treatment due to misdiagnosis.

[0090] In other embodiments, the accelerometer can also be used as a sleep indicator based on body orientation and movement. When presenting clinical events (e.g., resting), it is diagnostically beneficial to be able to present information in a way that clearly separates events occurring during sleep from those occurring during wakefulness. Indeed, certain algorithms, such as ECG-derived respiration rate, only make sense to run when the patient is relatively motionless, allowing for the observation of subtle signal modulations caused by chest movement due to breathing. Respiration rate information is useful as one channel of information needed to detect sleep apnea in certain patient populations.

[0091] In certain embodiments, the accelerometer may also be used to detect free fall, such as syncope. The accelerometer may enable device 100 to mark syncope and other free fall events without relying on a patient trigger. In some embodiments, triggering such a free fall event can initiate transmission of relevant data. To enable timely detection of such important events, and at the same time, considering the battery and memory limitations of small wearable devices such as device 100, accelerometer readings may be taken in bursts, with only interesting information, such as potential free fall, being written to memory at a high sampling rate. An extension of this event trigger concept is to use specific tapping actions on device 100 as patient triggers, instead of or in combination with the buttons described above. The use and detection of multiple types of tapping sequences can provide better resolution and accuracy as to what exactly the patient was feeling, instead of relying on the patient manually recording symptoms and duration in a trigger log after the fact. An example of such added resolution is indicating symptom severity via the number of consecutive taps.

[0092] Alternatively, in other embodiments, optical sensors may be used to distinguish between device movement and patient body movement. Furthermore, in additional embodiments, the device may not require a button or trigger. In many more embodiments, suitable devices described in this section or elsewhere herein may also be used.

[0093] Another optional data channel that may be added to the physiological monitoring device 100 is a channel for detecting flexion and / or bending of the device 100. In various embodiments, for example, the device 100 may include a strain gauge, piezoelectric sensor, or optical sensor to detect motion artifacts within the device 100 itself, thus helping to distinguish motion artifacts from heart rate data. Yet another optional data channel for the device 100 may be a channel for detecting heart rate. For example, a pulse oximeter, microphone, or stethoscope can provide heart rate information. Overlapping heart rate data can facilitate distinguishing ECG signals from artifacts. This is particularly useful when arrhythmias such as supraventricular tachycardia are interrupted by artifacts and it must be determined whether the episode was actually multiple short episodes or a single sustained episode. Another data channel may be included to detect ambient electrical noise. For example, the device 100 may include an antenna for picking up electromagnetic interference. Detecting electromagnetic interference can facilitate distinguishing electrical noise from actual ECG signals. Any of the above data channels can be stored to support future noise discrimination or applied in real time for immediate determination of clinical relevance.

[0094] 3A and 3B, flexible body 110 is shown in more detail. As shown in FIG. 3A, flexible body 110 may include wings 130, 131, a thin border 133 (or "rim" or "edge") around at least a portion of each wing 130, 131, electrode traces 311, 312, and a hinge portion 132 (or "shoulder") at or near the junction of each wing 130, 131 with housing 115. Also shown in FIG. 3A is top gasket 370, which is not considered part of flexible body 110 for purposes of this description, but which facilitates attachment of flexible body 110 to housing 115.

[0095] The hinge portions 132 are relatively thin, more flexible portions of the flexible body 110. They allow the flexible body 110 to flex freely in the area where it is joined to the housing 115. This flexibility enhances comfort because the housing 115 can lift freely from the patient's skin as the patient moves. The electrode traces 311, 312 are also very thin and flexible to allow for patient movement without signal distortion. The border 133 is a portion of the flexible body 110 that is thinner than its immediately adjacent portions, providing a smooth transition from the flexible body 110 to the patient's skin and thus preventing edge lift and the ingress of dirt and debris under the flexible body 110.

[0096] As shown in more detail in FIG. 3B , the flexible body 110 can include multiple layers. As previously mentioned, in some embodiments, the top gasket 370 and the bottom gasket 360 are not considered part of the flexible body 110 for purposes of this description, but are shown for completeness of the description. However, this distinction is for ease of explanation only and should not be construed to limit the scope of the described embodiments. The flexible body 110 can include a top substrate layer 300, a bottom substrate layer 330, an adhesive layer 340, and a flexible electrode 350. The top and bottom substrate layers 300, 330 can be made of any suitable flexible material, such as one or more flexible polymers. Suitable flexible polymers can include, but are not limited to, polyurethane, polyethylene, polyester, polypropylene, nylon, Teflon, and carbon-impregnated vinyl. The material of the substrate layers 300, 330 can be selected based on desired properties. For example, the materials for the substrate layers 300, 330 may be selected based on flexibility, resilience, durability, breathability, moisture wicking, adhesiveness, and / or the like. In one embodiment, for example, the top substrate layer 300 may be made of polyurethane, and the bottom substrate layer 330 may be made of polyethylene or alternatively polyester. In other embodiments, the substrate layers 300, 330 may be made of the same material. In yet another embodiment, the substrate layer 330 may include multiple perforations in the area above the adhesive layer 340 to provide even more breathability and moisture wicking. In various embodiments, the physiological monitoring device 100 may be worn continuously by a patient for as long as 14 to 21 days or more without removal during wear, with the device 100 being worn during showering, exercise, etc. Therefore, the materials used and the thickness and configuration of the substrate layers 300, 330 affect the functionality of the physiological monitoring device 100. In some embodiments, the material of the substrate layers 300, 330 acts as an electrostatic discharge (ESD) barrier to prevent arcing.

[0097] Typically, the upper and lower substrate layers 300, 330 are attached to one another via an adhesive placed on one or both layers 300, 330. For example, the adhesive or bonding material between the substrate layers 300, 330 can be an acrylic-based, rubber-based, or silicone-based adhesive. In other alternative embodiments, the flexible body 110 can include two or more layers of flexible material.

[0098] In addition to the selection of materials, the dimensions of the substrate layers 300, 330, i.e., thickness, length, and width, can be selected based on the desired characteristics of the flexible body 110. For example, in various embodiments, the thickness of the substrate layers 300, 330 may be selected to provide the flexible body 110 with an overall thickness of between about 0.1 mm and about 1.0 mm. According to various embodiments, the flexible body 110 can also have a length of between about 7 cm and about 15 cm and a width of between about 3 cm and about 6 cm. Generally, the flexible body 110 will have a length sufficient to provide the necessary amount of separation between the electrodes 350. For example, in one embodiment, the distance from the center of one electrode 350 to the center of the other electrode 350 should be at least about 6.0 cm, more preferably at least about 8.5 cm. This separation distance can vary depending on the application. In some embodiments, the substrate layers 300, 330 may all have the same thickness. Alternatively, the two substrate layers 300, 330 may have different thicknesses.

[0099] As discussed above, the hinge portion 132 allows the rigid body 115 to lift away from the patient while the flexible body 110 remains adhered to the skin. The functionality of the hinge portion 132 is important in allowing the device to remain attached to the patient through various activities that may stretch the skin. Additionally, the hinge portion 132 allows for significantly improved comfort while wearing the device. Generally, the hinge portion 132 will have a width sufficient to provide sufficient lift of the rigid body 115 without creating excessive peel forces on the flexible body 110. For example, in various embodiments, the width of the hinge portion 132 should be at least about 0.25 cm, and more preferably at least about 0.75 cm.

[0100] Additionally, the shape or footprint of the flexible body 110 may be selected based on desired characteristics. As seen in FIG. 3A , the wings 130, 131 and the border 133 may have rounded edges, giving the flexible body 110 an overall "peanut" shape. However, the wings 130, 131 may be formed in any number of different shapes, such as rectangles, ellipses, loops, or strips. In the embodiment shown in FIGS. 3A and 3B , the footprint of the top substrate layer 300 is larger than the footprint of the bottom substrate layer 330, and an extension of the top substrate layer 300 forms the border 133. Thus, the border 133 is made of the same polyurethane material from which the top layer 300 is made. Because the border 133 includes only the top layer 300, it is thinner than the adjacent portions of each wing 130, 131. The thinner, more compliant rim and / or border 133 is believed to enhance adherence of the physiological monitoring device 100 to the patient by providing a transition from the adjacent, slightly thicker portions of the wings 130, 131 to the patient's skin, and therefore helping to prevent the edges of the device 100 from peeling up from the skin. The border 133 may also help to prevent dirt and other debris from collecting under the flexible body 110, promote adhesion to the skin, and may also help improve the aesthetics of the device 100. In an alternative embodiment, the footprints of the substrate layers 300, 330 may be the same, in which case the border 133 is eliminated.

[0101] 1A-3B includes only two wings 130, 131 extending in generally opposite directions from the housing 115 (e.g., at a 180-degree angle relative to each other), other configurations are possible in alternative embodiments. For example, in some embodiments, the wings 130, 131 may be oriented asymmetrically relative to each other and / or one or more additional wings may be included. Any suitable configuration and number of wings 130, 131 and electrode traces 311, 312 may be used, so long as sufficient electrode spacing is provided to enable physiological signal monitoring and the wings 130, 131 are configured to provide extended attachment to the skin. While the above-described embodiment has proven advantageous for adherence, patient comfort, and accuracy of collected cardiac rhythm data, alternative configurations may be possible in alternative embodiments.

[0102] Adhesive layer 340 is an adhesive applied to two portions of the bottom surface of bottom substrate layer 330, each portion corresponding to one of wings 130, 131. Thus, adhesive layer 340 does not extend along the portion of bottom substrate layer 330 to which housing 115 is attached. While adhesive layer 340 may be made of any suitable adhesive, certain adhesives have been found to be advantageous for providing long-term adhesion to a patient's skin that is relatively comfortable and free of skin irritation. For example, in one embodiment, adhesive layer 340 is a hydrocolloid adhesive. In another embodiment, adhesive layer 340 comprises a hydrocolloid adhesive that includes naturally occurring or synthetic absorbent materials that draw moisture from the skin when sweating occurs.

[0103] Referring now to FIG. 3B , each of the two portions of adhesive layer 340 includes a hole into which one of electrodes 350 fits. The electrodes 350 are made of a flexible material to further provide overall conformability for the flexible body 110. In one embodiment, for example, the flexible electrodes 350 may be made of hydrogel electrodes 350. The electrodes 350 generally provide conformal, non-irritating contact with the skin to enhance electrical connection with the skin and reduce motion artifacts. In some embodiments, the hydrogel electrodes 350 are punched into the adhesive layer 340, thus forming holes that can be filled with the hydrogel electrodes 350. In an alternative embodiment, the electrodes 350 and adhesive 340 may be replaced with an adhesive layer made of a conductive material, such that the entire adhesive layer on the underside of each wing 130, 131 functions as an electrode. Such an adhesive layer may include a hybrid adhesive / conductive substance or an adhesive substance mixed with conductive elements or particles. For example, in one embodiment, such an adhesive layer may be a hybrid of a hydrogel and hydrocolloid adhesive. The housing 115 of FIG. 1A also protects the electronics and power source contained in the housing 115, enhances the patient's ability to provide input related to perceived cardiac events, and allows for easy manufacturing and reusability of at least a portion of the contents of the housing 115. These and other features of the physiological monitoring device 100 are described in more detail below.

[0104] As mentioned above, in some embodiments, adhesive layer 340 may cover a portion of the underside of bottom substrate layer 330 such that at least a portion of the bottom surface of flexible body 110 is free of adhesive layer 340. As seen in FIG. 3A , hinge portions 132 may be formed in flexible body 110 as portions of each wing 130, 131 where adhesive layer 340 is not applied. Hinge portions 132 are generally located at or near the junction of flexible body 110 and housing 115, thus providing device 100 with flexibility to accommodate patient movement. In some embodiments, hinge portions 132 may have a width that is smaller than the width of adjacent portions of wings 130, 131, thus providing device 100 with the "peanut" shape described above. As shown in FIG. 8 , as the subject moves, device 100 flexes to accommodate the patient's movement. This bending of the device can be severe and is likely to occur multiple times during long-term monitoring. The hinge portion 132 may allow for dynamic conformance to the subject, while the rigidity of the housing 115 may allow the housing 115 to pop out of the patient's skin during flexion of the device, thus preventing the device 100 from peeling off the skin at its ends.

[0105] The flexible body 110 further includes two electrode traces 311, 312 sandwiched between the top substrate layer 300 and the bottom substrate layer 330. Each electrode trace 311, 312 can include an electrode interface portion 310 and an ECG circuit interface portion 313. As shown in the embodiment of Figures 3C and 3D, the ECG circuit interface portion 313 is in physical contact with the spring fingers 237 and in electrical communication with the PCBA 120 when the device 100 or augmented device portion 101 is assembled. The electrode interface portion 310 contacts the hydrogel electrode 350. Thus, the electrode traces 311, 312 transmit cardiac signals (and / or other physiological data in various embodiments) from the electrode 350 to the PCBA 120.

[0106] The material and thickness of the electrode traces 311, 312 are important for providing the desired combination of flexibility, durability, and signal transmission. For example, in one embodiment, the electrode traces 311, 312 may include a combination of silver (Ag) and silver chloride (AgCl). The silver and silver chloride may be arranged in layers. For example, one embodiment of the electrode traces 311, 312 may include a top layer of silver, a middle layer of carbon-impregnated vinyl, and a bottom (patient-facing) layer of silver chloride. In another embodiment, both the top and bottom layers of the electrode traces 311, 312 may be made of silver chloride. In one embodiment, the top and bottom layers may be applied to the middle layer in the form of silver ink and silver chloride ink, respectively. In an alternative embodiment, each electrode trace may include only two layers, such as a top layer of silver and a bottom layer of silver chloride. In various embodiments, the material of the bottom layer of each electrode trace 311, 312, such as AgCl, may be selected to match the chemistry of the hydrogel electrode 350 and create a half-cell with the subject's body.

[0107] The thickness of the electrode traces 311, 312 may be selected to optimize any of a number of desirable properties. For example, in some embodiments, at least one of the layers of the electrode traces 311, 312 may have a thickness sufficient to minimize or delay material wear due to the anodic / cathode effect over time. Additionally, the thickness may be selected for desired flexibility, durability, and / or signal transmission quality.

[0108] As mentioned above, in some embodiments, the top gasket 370 and the bottom gasket 360 may be attached to the top substrate 300 and the bottom substrate 330 of the flexible body 110. The gaskets 360, 370 may be made of any suitable material, such as urethane, that provides a watertight seal between the top housing member 140 and the bottom housing member 145 of the housing 115. In one embodiment, the top gasket 370 and / or the bottom gasket 360 may include an adhesive surface. FIG. 3E depicts yet another embodiment in which the top gasket 370 includes a tab 371 that protrudes away from the profile of the top housing 140 while remaining adhered to the top substrate 300. The tab 371 covers a portion of the electrode traces 311, 312 and provides strain relief for the traces at the point of highest stress where the flexible body meets the housing.

[0109] Referring now to the embodiment of FIG. 4 , the upper and lower housing members 140, 145 of the housing 115 are shown in greater detail. When coupled together with gaskets 360, 370 between them, the upper and lower housing members 140, 145 can be configured to form a watertight enclosure for containing the PCBA 120, battery holder 150, battery 160, and any other components contained within the housing 115. The housing members 140, 145 can be made of any suitable material for protecting the internal components, such as water-resistant plastic. In one embodiment, the upper housing member 140 can include rigid sidewalls and / or hooks 440, a light pipe 410 for transmitting visual information from an LED on the PCBA through the housing member, a slightly flexible top surface 420, and an inner trigger member 430 extending inward from the top surface 420. The top surface 420 is configured to be depressed by the patient when the patient perceives what appears to be an arrhythmia or other cardiac event. When pressed, top surface 420 depresses inner trigger member 430, which contacts and activates trigger input 210 of PCBA 120. Additionally, as described above, top surface 420 may have a concave shape (a recess facing the inside of housing 115) to accommodate the shape of a finger. The design of upper housing member 140 is believed to isolate activation of trigger input 210 from electrode 350, thereby minimizing artifacts in data recording.

[0110] Continuing with reference to FIG. 4 , the lower housing member 145 can be configured to removably connect to the upper housing member 140 to facilitate easy attachment and detachment of the housing members 140, 145 for reusability of at least some of the components of the monitoring device 100. In some embodiments, the bottom surface 445 (the surface facing the patient) of the lower housing member 145 can include a plurality of dimples 450 (or “bumps,” “protrusions,” etc.) that contact the patient's skin during use. The dimples 450 can allow airflow between the bottom surface 445 and the patient's skin, thereby preventing a seal from forming between the bottom surface 445 and the skin. The dimples 450 are believed to improve comfort and help prevent the patient's perception of the monitoring device 100 falling when the housing 115 lifts off the skin and breaks the seal with the skin in currently available devices. In yet another embodiment, the bottom surface 445 of the lower housing member 145 can include a plurality of divots (recesses instead of protrusions) to prevent a seal from forming.

[0111] Referring now to the embodiment of FIG. 5A, the battery holder 150 is shown in more detail. The battery holder 150 may be made of plastic or other suitable material and is configured to be attached to the PCBA 120 and then to the housing 115, and can hold two batteries 160 (FIG. 1B). In alternative embodiments, the battery holder 150 may be configured to hold one battery or two or more batteries. Multiple protrusions 152 provide a stable platform for the battery 160 to be positioned a certain distance from the surface of the PCBA 120, avoiding unwanted contact with sensitive electronic components while providing proper compression of the spring contacts 235 (FIG. 5B). The protrusions 153 lock the battery 160 in place and resist the upward force exerted by the spring contacts 235 on the battery. The battery holder 150 also properly positions the battery 160 and provides proper compression of the spring contacts 236. The use of the battery holder 150 in combination with the spring contacts 235 and 236 allows the battery 160 to be electrically connected to the PCBA 120 while having additional electronic components between the battery 160 and the PCBA 120 and maintaining a very compact assembly. The battery holder 150 may include flexible hooks 510 that engage with corresponding rigid hooks 440 on the upper housing member 140. In a normal assembled state, the flexible hooks 510 remain securely mated with the rigid hooks 440. For disassembly, the flexible hooks 510 are bent using an appropriate tool threaded through the upper housing 140 to disengage from the rigid hooks 440, after which the upper housing 140 can be removed.

[0112] Referring now to the embodiment of Figures 6A and 6B, a physiological monitoring device 100 is shown in a side cross-sectional view. As shown in Figure 6A, the physiological monitoring device 100 may include a flexible body 110 coupled to a housing 115. The flexible body 110 may include a top substrate layer 300, a bottom substrate layer 330, an adhesive layer 340, and electrodes 350. Electrode traces 311, 312 are also typically part of the flexible body 110 and are embedded between the top and bottom substrate layers 300, 330, but are not shown in Figure 6. The flexible body 110 forms two wings 130, 131 extending to opposite sides of the housing 115 and a boundary 133 surrounding at least a portion of each wing 130, 131. The housing 115 may include an upper housing member 140 coupled to a lower housing member 145 to sandwich a portion of the flexible body 110 therebetween, providing a watertight sealed compartment for the PCBA 120. The upper housing member 140 can include an inner trigger member 430, and the PCBA can include a patient trigger member 210. As discussed above, the lower housing member 145 can include a plurality of dimples 450 or divots to enhance the comfort of the monitoring device 100.

[0113] It is desirable for the PCBA 120 to be sufficiently rigid to prevent bending and introducing unwanted artifacts into the signal. In certain embodiments, an additional mechanism can be used to reduce and prevent unwanted bending of the PCBA 120. This mechanism is shown in FIG. 11B. A support post 460 is integral with the lower housing 145 and is located directly below the patient trigger input 210. During triggering of a patient symptom, the upper housing member 140 is depressed, engaging the inner trigger mechanism 430 and transmitting a force through the patient trigger input 210 to the PCBA 120. The force is further transmitted through the PCBA 120 to the support post 460 without generating a bending moment, thus avoiding unwanted artifacts.

[0114] 7 , in some embodiments, physiological monitoring device 100 can include one or more additional optional features. For example, in one embodiment, monitoring device 100 can include a removable liner 810, an upper label 820, a device identifier 830, and a lower label 840. Liner 810 may be applied to the flexible member and / or the upper surface of body 110 to aid in applying device 100 to a subject. As described in further detail below, liner 810 can help support boundary 133 of flexible body 110, as well as wings 130, 131, during removal of one or more adhesive covers (not shown) that cover adhesive surface 340 prior to use. Liner 810 can be relatively rigid and / or stiff to help support flexible body 110 during removal of the adhesive covers. In various embodiments, for example, liner 810 can be made of cardboard, thick paper, plastic, or the like. The liner 810 typically includes an adhesive on one side for adhering to the top surfaces of the wings 130 , 131 of the flexible body 110 .

[0115] Labels 820, 840 may be any suitable labels and may include a product name, manufacturer name, logo, design, and / or the like. They may be removably or permanently attached to upper housing member 140 and / or lower housing member 145, but typically will be permanently attached to prevent unregulated reuse and / or resale of the device by unauthorized users. Device identifier 830 may be a barcode sticker, a computer-readable chip, RFID, or the like. Device identifier 830 may be permanently or removably attached to PCBA 120, flexible body 110, or the like. In some embodiments, it may be beneficial for device identifier 830 to remain on PCBA 120.

[0116] 8A and 8B, the physiological monitoring device 100 generally includes a hinge portion 132 at or near the junction of each wing 130, 131 and the housing 115. Furthermore, while each wing 130, 131 is typically adhered to the patient via an adhesive layer 340, the rigid body 115 is not adhered to the patient and is therefore free to "float" (e.g., move up and down) above the patient's skin during movement and patient position changes. In other words, as the patient's chest contracts, the housing pops or floats above the skin, minimizing stress on the device 100, increasing comfort, and reducing the tendency of the wings 130, 131 to peel off from the skin. The benefits provided by the combination of the raised rigid body 115 and adhered wings 130, 131 are illustrated in FIGS. 8A and 8B. In FIG. 8A, the patient is sleeping, and in FIG. 8B, the patient is playing golf. In both instances, monitoring device 100 is squeezed together by the patient's body, causing wings 130, 131 to approach each other, causing housing 115 to float above the skin. This advantage of a floating, non-adherent portion of a physiological monitoring device is explained in further detail in U.S. Patent No. 8,560,046, previously incorporated by reference.

[0117] 9A-9F, one embodiment of a method for applying physiological monitoring device 100 to the skin of a human subject is described. In this embodiment, prior to the first step shown in FIG. 9A, the patient's skin may be prepared, typically by shaving a small area of ​​skin on the left chest where device 100 will be placed, and scrubbing and / or cleaning the shaved area. As shown in FIG. 9A, once the patient's skin has been prepared, the first step of applying device 100 may include removing one or both of two adhesive covers 600 from adhesive layer 340 on the bottom surface of device 100, thus exposing adhesive layer 340. As shown in FIG. 9B, the next step may be applying device 100 to the skin such that adhesive layer 340 adheres to the skin in a desired location. In some embodiments, one adhesive cover 600 may be removed, the uncovered adhesive layer 340 may be applied to the skin, and then the second adhesive cover 600 may be removed, and the second adhesive layer 340 may be applied to the skin. Alternatively, both adhesive covers 600 can be removed before applying device 100 to the skin. While adhesive cover 600 is removed, liner 810 serves as support for flexible body 110, providing a place for the physician or other user to grab and preventing flexible body 110 and boundary 133 of flexible body 110 from folding in on itself or forming wrinkles. As discussed above, liner 810 can be made of a relatively stiff, firm material to provide support for flexible body 110 during application of device 100 to the skin. Referring to FIG. 9C , after device 100 is applied to the skin, pressure can be applied to flexible body 110, pressing it against the chest, to help ensure that device 100 adheres to the skin.

[0118] In a next step, referring to FIG. 9D, liner 810 is removed (e.g., peeled) from the top surface of flexible body 110. Once liner 810 is removed, pressure may be applied again to help ensure flexible body 110 adheres to the skin, as shown in FIG. 9E. Finally, as shown in FIG. 9F, upper housing member 140 may be pressed to turn on physiological monitoring device 100. This described method is but one embodiment. In alternative embodiments, one or more steps may be skipped and / or one or more additional steps may be added.

[0119] In certain embodiments, upon completion of the desired monitoring period, e.g., approximately 14-21 days in some cases, the patient (or physician, nurse, etc.) may remove the physiological monitoring device 100 from the patient's skin, place the device 100 in a prepaid mailing pouch, and mail the device 100 to a data processing facility. At this facility, the device 100 may be partially or completely disassembled, the PCBA 120 removed, and stored physiological data, such as continuous cardiac rhythm information, downloaded from the device 100. The data may then be analyzed by any suitable method and then provided to the physician in the form of a report. The physician may then discuss the report with the patient. Other portions of the device 100, such as the PCBA 120 and / or the housing 115, may be reused in the manufacture of subsequent devices for the same patient or other patients. Because the device 100 is constructed as a combination of several removably coupled parts, various parts may be reused for the same or different embodiments of the device 100. For example, the PCBA 120 may be used first in an adult heart rate monitor and then used a second time to construct a sleep apnea monitor. The same PCBA 120 may additionally or alternatively be used with a different sized flexible body 110 to construct a pediatric heart monitor. In this manner, at least some of the components of the device 100 may be interchangeable and reusable.

[0120] In further embodiments, described in more detail below, the monitoring data may be transmitted via wireless or other communications media for analysis, rather than requiring physical transport of the device for analysis and reporting.

[0121] Advantageously, physiological monitoring device 100 can provide long-term adhesion to the skin. The combination of the flexible and conformable configuration of body 110, the watertight and low-profile configuration of housing 115, and the interface therebetween allows device 100 to compensate for stresses that arise as the subject's skin stretches and flexes. As a result, device 100 can be worn continuously on a patient for 14 to 21 days or even longer without removal. In some cases, device 100 can be worn for longer or shorter periods of time, but 14 to 21 days can often be a desirable amount of time for collecting cardiac rhythm data and / or other physiological signal data from a patient.

[0122] One or more of the various components of the physiological monitoring device 100 may be alternatively configured or substituted with component embodiments disclosed elsewhere herein. For example, in some embodiments, the electrodes 350 and / or the flexible body 110 may be configured to deliver one or more therapeutic agents to the patient's skin, such as via a drug-eluting adhesive or other suitable delivery system. The one or more therapeutic agents may be configured to combat skin irritation, itching, and / or bacterial growth, induce or block histamine release, and / or include anesthetic properties, any of which can improve patient compliance and / or extend the duration of wear of the physiological monitoring device 100. The therapeutic agents may also serve alternative or additional therapeutic purposes. In some embodiments, the therapeutic agent may be incorporated directly into the adhesive layer 340. For example, the therapeutic agent may be mixed into a hydrocolloid solution during manufacturing of the adhesive layer 340. The therapeutic agent may be configured to elute from the adhesive layer 340 upon contact with the patient's skin. The adhesive layer 340 may be configured to provide a controlled release of the agent. For example, adhesive layer 340 may be configured to release the agent gradually and / or at a substantially constant rate over a period of time (e.g., approximately 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, etc.). Adhesive layer 340 may include perforations and / or microporous structures configured to facilitate diffusion of one or more therapeutic agents through the thickness of adhesive layer 340. In some embodiments, therapeutic agents may be incorporated into one or more overlying support layers of flexible body 110, such as upper substrate layer 300 and / or lower substrate layer 330. The support layers of flexible body 110 may include pockets or reservoirs configured to store one or more therapeutic agents. The pockets may be in fluid communication with adhesive layer 340 through perforations formed in the substrate layers or through holes or channels formed in the substrate layers. In some embodiments, the one or more therapeutic agents can diffuse through adhesive layer 340 to reach the skin.In some embodiments, the perforations in the substrate layer may extend through the adhesive layer 340 to the surface of the patient's skin. In some embodiments, the electrode 350 or flexible body 110 may be configured to include an antimicrobial agent to inhibit microbial growth. The agent may be coated or embedded in the adhesive or electrode gel material. These antimicrobial agents may be configured to be released gradually and / or at a substantially constant rate over a period of time (e.g., approximately 1 day, 3 days, 5 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 1 month, 3 months, 5 months, 1 year, 3 years, 5 years, etc.). The adhesive layer 340 may include a perforated and / or microporous structure configured to facilitate diffusion of one or more therapeutic agents through the thickness of the adhesive layer 340. Alternatively, the antimicrobial properties may be inherent in the structure of the adhesive, gel, or any substrate or support layer. In other embodiments, the electrode 350 or flexible body 110 may be configured to release deodorant or perfume ingredients to limit odors resulting from extended wear. Similar to the therapeutic and antimicrobial agents described above, the ingredients may be configured to be released over time and / or to diffuse through the thickness of the adhesive or gel layer.

[0123] 10A-10C schematically illustrate alternative examples of the trace layer 609. The trace layer 609 may include electrical traces 611, 612 for each electrode 350 (as shown in FIG. 3B ) of the physiological monitoring device 100. The electrical traces 611, 612 may be disposed on (e.g., printed on) a non-conductive insulating layer 613. In some embodiments, the insulating layer 613 may include a polyester and / or another non-conductive polymer, such as polyethylene terephthalate (PET). One or more of the electrical traces 611, 612 may be disposed on the same insulating layer 613. The insulating layer 613 may be configured to maintain separation between the electrical traces 611, 612 that are coupled to separate electrodes 350. The electrical traces 611, 612 may extend from the electrodes 350 into the housing 115 and make electrical contact with the PCBA 120. In some embodiments, such as those in which the physiological monitoring device 100 includes two opposing wings 130, 131 arranged generally parallel to one another, the electrical traces 611, 612 may extend generally parallel along a direction defining a longitudinal axis of the device. A transverse axis may be defined substantially perpendicular to the longitudinal axis. The longitudinal axis and / or the transverse axis may substantially bisect the housing 115 of the physiological monitoring device 100.

[0124] Each trace 611, 612 may extend from an electrode contact region configured to contact an electrode 350 along a connecting portion of the trace layer 609 to a housing region configured to be received within the housing 115 (e.g., between the upper housing 140 and the lower housing 145, as shown above in FIG. 7 and below in FIGS. 12-13B). The housing region of the trace layer 609 may have an area configured to generally match the perimeter of the upper and lower housings 140, 145 where the housings meet (or, such as 640 and 645, as described below in connection with the embodiment of FIGS. 12A-15I). For example, the trace layer 609 may comprise a generally circular housing region. The trace layer 609 may have a plurality of holes 616 extending between the upper and lower surfaces of the trace layer 609. The holes 616 may allow for the passage of mechanical elements (e.g., posts, as described elsewhere herein), such as mechanical elements that couple or mate the upper and lower housings 140, 145. The holes 616 may be generally disposed along the perimeter of the housing region of the trace layer 609. The holes 616 may extend only through the insulating layer 613 and not through the electrical traces 611, 612. At least some of the holes 616 may be configured with dimensions that substantially match the size of one or more mechanical interlocking elements (e.g., posts), such that passage of the one or more mechanical interlocking elements through the holes 616 can help stabilize the orientation of the trace layer 609 and / or help secure the trace layer 609 to the housing 115. The housing region of the trace layer 609 may include a large central hole (or holes such as holes 640 and 645, as described below in connection with the embodiments of FIGS. 12A-15I) through which components in the upper housing 140 can directly contact components in the lower housing 145. The housing region of the electrical traces 611, 612 may be disposed on opposite sides of the insulating layer 613 within the housing region of the trace layer 609. The trace layer 609 may extend generally along the longitudinal axis between the electrode contact areas.The connection portion of the trace layer 609 between the electrode contact area and the housing area may include a width along the lateral direction that is less than the width of the electrode contact area and / or the housing area of ​​the trace layer 609 .

[0125] The electrical traces 611, 612 may be disposed (e.g., printed and / or painted in any suitable manner) on one or both sides (top and bottom) of the insulating layer 613. The electrical traces 611, 612 may include any of the conductive materials discussed elsewhere herein. For example, in some embodiments, the electrical traces 611, 612 may include a layer of silver (Ag) printed on the insulating layer 613. In embodiments, the electrode interface portions 310 of the electrical traces 611, 612 may include a layer of silver chloride (AgCl) in addition to, or instead of, the layer of silver or other conductive material typically used for the traces 611, 612, as described elsewhere herein. In some embodiments, a layer of silver chloride or other electrode-interfacing material may be printed on the layer of silver or other conductive material of the electrical traces 611, 612. Silver provides more isotropic conductance than silver chloride, resulting in better lateral conductance in the x and y directions, but potentially worse longitudinal conductance along the z direction (transverse to the longitudinal and lateral axes). In some embodiments, the electrical traces 611, 612 may be located primarily on one side (e.g., the bottom or patient-facing side) of the insulating layer 613. For example, the electrode interface portion 310 and portions of the traces 611, 612 along with the connection portion of the trace layer 609 may be located on only one side, while the ECG circuit interface portion 313 of the traces 611, 612 may be located on the opposite side of the trace layer 609. Locating the electrode interface portion 310 and the ECG circuit interface portion 313 on opposite sides of the trace layer 609 allows for an easy interface between the electrical traces 611, 612 and the PCBA 120 and may be located on opposite sides of the trace layer 609 from the patient's skin to minimize the amount of space occupied by the housing 115 between the patient and the trace layer 609. In certain embodiments, the trace layer 609 may include one or more vias 619 formed in through holes in the trace layer 609 that extend through the insulation 613.Through holes may be formed through the conductive material electrical traces 611, 612 and filled with the same and / or different conductive material to form vias 619 that conduct electrical signals from one side of the trace layer 609 to the other. The vias 619 can simplify the design and construction of the trace layer 609 by avoiding the use of bent metal parts. In some embodiments, conductive rivets may be used in addition to or instead of the conductive vias 619. The ECG circuit interface portions 313 of the traces 611, 612 may include a relatively larger surface area than the traces 611, 612 along the connecting portion of the trace layer 609 to provide sufficient contact area for electrical contacts to electrically couple the traces 611, 612 to the PCBA 120.

[0126] 10B , in some embodiments, one or more resistors 614 may be disposed within the electrical traces 611, 612. The resistors 614 may comprise a conductive material that has a higher resistance than the conductive material(s) (e.g., silver and / or silver chloride) typically used to conduct electricity between the electrodes 350 and the PCBA 120. For example, the resistors 614 may comprise carbon and / or an increased amount of carbon compared to the electrical traces 611, 612. In some embodiments, the resistors can have a resistance of at least about 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 kiloohms (kΩ). The material of the resistors 614 may be selected to reduce or minimize “popcorn” noise or 1 / f noise. As shown in FIGS. 10A-10C , resistor 614 may intersect the conductive paths of electrical traces 611, 612 between electrode interface portion 310 and ECG interface portion 313 and be positioned in-line with the conductive material of electrical traces 611, 612. Resistor 614 may be positioned on the housing portion of trace layer 609 so as to be housed within housing 115. Resistor 614 may be positioned (e.g., printed) on substrate layer 613 in the same manner as the conductive material of electrical traces 611, 612 or in a different manner. Resistor 614 can replace resistors that would otherwise be placed on PCBA 120, thereby potentially providing space-saving benefits. In some embodiments, resistor 614 may be used to reduce the current traveling along the electrical circuit formed by body and interface electrode 350. Resistor 614 may act as a safety net to ensure that physiological monitoring device 100 is suitable for use with a patient.

[0127] Returning to FIG. 10A , in some embodiments, the electrode interface portion 310 may include a central aperture 617. The central aperture 617 may be generally circular or any suitable shape, such as oval, square, triangular, rectangular, or any suitable polygonal shape. The central aperture 617 can provide improved moisture management. For example, moisture trapped between the electrode 350 and the patient's skin may be able to evaporate through the electrode (e.g., a hydrogel electrode), through the central aperture 617, and / or through a breathable substrate layer disposed on the central layer. Improved moisture management can reduce delamination and enable longer use, increasing the wear time of the physiological monitoring device. In some embodiments, the trace layer 609 can include multiple central apertures 617 disposed on the top surface of the electrode 350. The cumulative surface area of ​​the one or more central openings and / or vias 619 may be balanced relative to the surface area of ​​the electrode 350 to prevent drying of the hydrogel electrode 350 and / or to attenuate fluctuations in conductivity that may occur as the electrode peels off from the skin because metal is more conductive than hydrogel. In some embodiments, no substrate layer is disposed over the trace layer 609, or any overlying substrate layer may include a corresponding opening disposed over the central opening 617 such that at least a portion of the top surface of the electrode 350 is exposed to the ambient environment. In some embodiments, the diameter of the central opening 617 may be somewhat smaller than the outer diameter of the electrode 350 such that the trace layer 609 rests on the top surface of the electrode 350. An electrical connection may be made between the top surface of the electrode and the bottom surface of the trace layer 609 via the electrode interface portions 310 of the electrical traces 611, 612. In some embodiments, the diameter of the central opening 617 substantially matches the outer diameter of the electrode 350 such that the electrode 350 can be received within the central opening 617. Electrical connections may be formed between the lateral edges of the conductive traces 611, 612 and the lateral sides of the electrode 350 in addition to, or instead of, interactions between other portions and surfaces.In some embodiments, the electrode 350 (e.g., a hydrogel electrode or any suitable electrode) may be formed in situ within the central opening and / or may be expanded within the central opening 617. The electrode 350 may be expanded to have a diameter slightly larger than the diameter of the central opening 617 so that a compressive force induces sufficient contact between the trace layer 609 and the electrode 350.

[0128] FIG. 10A illustrates an example of the trace layer 609. FIG. 10B depicts an enlarged view of insert A of FIG. 10A . As shown in FIG. 10A , the connecting portion of the trace layer 609 may substantially bisect the hydrogel electrode 350 and / or the electrode interface portion 310 of the traces 611, 612. The electrical traces 611, 612 may be substantially straight along the connecting portion of the trace layer 609, as shown in FIG. 10A . In some embodiments, one or more of the electrical traces 611, 612 may include multiple bends. The multiple bends can form a zigzag or accordion-like configuration that allows one or more of the electrical traces 611, 612 to better absorb tensile and / or compressive strain along the longitudinal axis. FIG. 10C illustrates another example of the trace layer 609. The trace layer 609 may not be symmetrical about the transverse and / or longitudinal axes, as shown in FIG. 10C . In some embodiments, the electrode interface portion 310 of one trace 611 may be configured to be positioned higher on the patient's body than the electrode interface portion 310 of the other trace 612. The electrode interface portion 310 can extend laterally away from the portion of the trace 611, 612 along the connecting portion of the trace layer 609, parallel to the horizontal axis. The electrode interface portion 310 may extend away from the connecting portion in the opposite direction. In some embodiments, the entire trace 611 may be configured to be positioned higher on the patient's body than the opposing trace 612, as shown in FIG. 10C. The connecting portions of the trace layer 609 may be substantially parallel, or may be offset along the horizontal axis such that the connecting portions are not parallel. In some embodiments, both connecting portions may be offset, and the electrode interface portions 310 of different traces 611, 612 may extend in opposite directions, as shown in FIG. 10C. The lateral offset of the electrodes 350 along the horizontal axis can be configured to properly position the electrodes as shown in FIGS. 9A-9F while allowing the horizontal axis to remain parallel to the patient's height.

[0129] In some embodiments, the electrode interface portion 310 of one or more of the traces 611, 612 may be configured as a closed loop of trace layer 609 that extends 360 degrees around the central opening 617. The trace layer 609 along the loop may include a substantially uniform width, which may be the same width as the trace layer 609 along the connecting portion. In certain embodiments, the width may be non-uniform. The electrical traces 611, 612 may extend along the entire circumference of the loop or may extend only partially along the loop such that the electrical traces 611, 612 do not form a closed loop with themselves.

[0130] In some embodiments, the physiological monitoring device 100 can include a battery terminal connector 650 configured to physically connect two opposing terminals of a battery. FIGS. 11A-11E schematically depict two examples of battery terminal connectors 650. FIG. 11B depicts an inner surface of the battery terminal connector 650 configured to contact the battery terminals, and FIG. 11A depicts an outer surface of the battery terminal connector 650 opposite the surface depicted in FIG. 11B. FIG. 11D depicts an inner surface of another example of the battery terminal connector 650 configured to contact the battery terminals, and FIG. 11C depicts an outer surface of the battery terminal connector 650 opposite the surface depicted in FIG. 11D. FIG. 11E shows a side view of a battery 160 to which the battery terminal connector 650 is coupled (e.g., glued). The battery terminal connector 650 electrically connects to each terminal of the battery 160 and may be configured to functionally rearrange electrical access to the battery terminals. The battery terminal connector 650 may be configured to connect the terminals of a coin-cell battery or a battery including opposing top and bottom sides, with one terminal located on the top side and the opposite terminal located on the bottom side. In particular embodiments, the battery terminal connector 650 may be configured to position electrical access to both battery terminals on a single side (e.g., the top) of the battery to simplify electrical coupling of each terminal to the PCBA 120. Thus, the battery terminal connector 650 may include a first portion 655 (e.g., the bottom), an upper portion 657 (e.g., the top), and a connecting portion 656 joining the first portion 655 and the second portion 657. At least the connecting portion 656 of the battery terminal connector 650 may be sufficiently flexible to allow the connecting portion 656 to bend, fold, or wrap around the side of the battery 160 between the top and bottom sides of the battery 160.

[0131] The battery terminal connector 650 may include an insulating layer 651 and two conductive battery traces 652, 653. Each of the battery traces 652, 653 may be configured to contact one of two battery terminals. The insulating layer 651 may be configured to maintain separation between the two battery traces 652, 653, thereby insulating the battery traces 652, 653 from each other. The insulating layer 651 may be configured to prevent at least one of the battery traces 652, 653 from contacting a battery terminal electrically coupled to the other battery trace. The insulating layer 651 may be formed of a non-conductive material. For example, the insulating layer 651 may include polyethylene, such as polyethylene terephthalate (PET), or other suitable non-conductive polymer. The battery traces 652, 653 may be formed of a highly conductive material configured to electronically connect the battery terminals to the circuitry of the physiological monitoring device 100. For example, the battery traces 652, 653 may include silver or copper (e.g., tin-plated copper foil). At least a portion of the inner surface of the battery terminal connector 650 may be adhered to the battery terminals using a conductive adhesive (e.g., a conductive acrylic adhesive) configured to electrically couple each of the battery terminals to one of the battery traces 652, 653.

[0132] The battery terminal connector 650 may include any suitable arrangement of battery traces 652, 653 and an insulating layer 651. In various embodiments, one of the battery traces 652 may extend from a first side (e.g., a bottom side) of the battery to a second side (e.g., a top side) of the battery. The first battery trace 652 may be exposed to an inner surface of the battery terminal connector 650 on the first side of the battery 160 and exposed only to an outer surface of the battery terminal connector 650 on the second side of the battery 160. The second battery trace 653 may be disposed only on the second side of the battery 160. The second battery trace 653 may be exposed to both the inner and outer surfaces of the battery terminal connector 650 on the second side of the battery 160. The PCBA 120 may be configured to make electrical contact with both battery traces 652, 653 on the outer surface of the battery terminal connector 650, as described elsewhere herein. An insulating layer 651 may be disposed on at least the second side of the battery 160 to separate the battery traces 652, 653 on the second side and to insulate the first battery trace 652 from the battery terminal on the second side of the battery 160. In an embodiment, the insulating layer 651 may be disposed on an inner surface of the battery terminal connector 650 along the connecting portion 656 and / or along at least a portion of the first side (e.g., bottom) of the battery 160. The insulating layer 651 can be disposed on an outer surface of the battery terminal connector 650 along the connecting portion 656 and / or along the first side (e.g., bottom) of the battery 160.

[0133] 11A-11B , in some embodiments, the second battery trace 653 may be disposed (e.g., via printing or other suitable means) on the outer surface of the battery terminal connector 650, but may include an extension 654 that extends beyond the edge of the insulating layer 651 so that a battery terminal on the second side of the battery 160 can electrically contact the extension 654 of the second battery trace 653 and transfer current through the extension 654 to the outer surface of the battery terminal connector 650. In some embodiments, as shown in FIGS. 11C-11D , the second battery trace 653 may be disposed (e.g., printed) on the inner and outer surfaces of the battery terminal connector 650. The second battery trace 653 may sandwich a portion of the insulating layer 651. The battery terminal connector 650 may include through-holes filled with conductive material to form vias electrically connecting the second battery trace 653 on the inner surface and the outer surface of the battery terminal connector so that current can be transferred from the second side of the battery through the battery terminal connector 650 to the outer surface of the battery terminal connector 650. In some embodiments, vias can also electrically connect the first battery trace 652 between the inner and outer surfaces of the battery terminal connector 650. Conductive rivets may be used in addition to or in place of the conductive vias disclosed herein. FIGS. 11F-11I depict one example of a battery terminal connector 650 configured to contact a battery terminal. FIG. 11F depicts the outer surface of the battery terminal connector 650 prior to application of a non-conductive coverlay and / or layer 658 (as shown in FIG. 11H), and FIG. 11G depicts the inner surface of the battery terminal connector 650 prior to addition of adhesive 660 (as shown in FIG. 11I). In some embodiments, a second non-conductive layer 658 can cover the first battery trace 652 and the connecting portion 656 on the outer surface of the battery terminal connector 650. In certain embodiments, the battery terminal connector 650 can have at least one protruding tab 659 for positionally securing the battery terminal connector and battery assembly within the device housing. There may be one, two, three, four or more protruding tabs.Those skilled in the art will appreciate that the protruding tabs may be formed in any suitable manner, such as curved or angular.

[0134] 12A-12G show multiple perspective views of another embodiment of upper housing 640. FIG. 12A shows a partially exploded view of upper housing 640. In some embodiments, upper housing 640 can have a circular, oval, obround, rectangular, square, or any other suitable profile shape in the horizontal plane. Upper housing 640 can include a flexible upper frame 642 and a rigid shell 643. FIG. 12B shows a perspective view of flexible upper frame 642. FIG. 12C shows a side view of flexible upper frame 642. FIG. 12D shows a top view of flexible upper frame 642. Rigid shell 643 can be more rigid than flexible upper frame 642. For example, rigid shell 643 can be formed from a hard plastic (e.g., polycarbonate such as Makrolon®) and flexible upper frame 642 can be formed from a softer rubber (e.g., Santoprene®). The upper housing 640 may include a button 644 that forms at least a portion of the upper surface of the upper housing 640 and surrounds the internal components of the housing 615 from above. The button 644 may be a separate piece that is assembled with the flexible upper frame 642 and the rigid shell 643 to form the upper housing 640, as shown in FIG. 12A . The button 644 may be rigid relative to the flexible upper frame 642. In some embodiments, the button 644 may be formed from the same material as the rigid shell 643. The button 644 may be securely attached to the flexible upper frame 642 by any suitable means (e.g., using adhesive, detents, snap fits, etc.) such that the button 644 is configured as a “floating” button above the interior space of the upper housing 640. In some embodiments, the flexible upper frame 642 may be overmolded over at least a portion of the upper and lower surfaces of the button 644. The overmolding may be used to secure the button 644 to the rigid shell 643. In some embodiments, the button 644 may be completely encased within the flexible upper frame 642 .

[0135] The rigid shell 643 may form the lateral surfaces (e.g., the periphery) of the upper housing 640, as shown in FIG. 12A . The rigid shell 643 may form an outer annular portion or periphery of the top surface of the upper housing 640, as shown in FIG. 12A . The flexible top frame 642 may be overmolded to the rigid shell 643. The flexible top frame 642 may bond the rigid shell 643 to the button 644, as described elsewhere herein. The flexible top frame 642 may fill an annular gap in the top surface of the upper housing 640 between the periphery formed by the rigid shell 643 and the button 644, forming a flexible border for the button 644. The flexible top frame 642 may be configured to be biased such that the button 644 can be depressed downwardly against the rigid shell 643 to actuate the trigger 210. In some embodiments, the underside of the button 644 may be formed with a convex surface or other protrusion configured to actuate the trigger input 210. In some embodiments, a protrusion (e.g., an inverted dome, a pillar, or any suitable shape) may be attached to the underside of the button 644. The protrusion may accentuate trigger actuation so that less strain is required to actuate the trigger input 210. The protrusion may be made of metal and / or plastic.

[0136] In some embodiments, the button 644 may be configured as a cantilever button rather than a floating button, in which case a cantilever arm connects the button 644 to a lateral side (e.g., inner diameter) of the rigid shell 643. The cantilever arm may be hidden by the flexible upper frame 642 so that the button 644 still appears as a floating button. In some embodiments, the button 644 may not be a floating button, but may be integral with or directly bonded to the rigid shell 643. The button 644 may be semi-rigid but include sufficient flexibility to allow the button 644 to elastically deform. The button 644 may have a raised and / or convex configuration (e.g., a dome-shaped configuration) when unbiased. The button 644 may be configured such that the shape of the button 644 can elastically deform to activate the trigger input 210. For example, the dome may be at least partially inverted at or near its apex so that the center of the dome-shaped button 644 extends downward within the space enclosed by the upper housing 640 to actuate the trigger input 210. In some embodiments, when a threshold strain is reached, the dome may snap or buckle into an inverted configuration in which less pressure is required to continue to depress the dome. The buckling or snapping effect may be configured to provide a useful tactile indication of the actuation of the trigger 210. In some embodiments, upon release of pressure, the dome may snap back to its unbiased configuration. In some embodiments, the dome-shaped button 644 may include a conductive material or be coated with a conductive surface, and the dome-shaped body may directly contact an electrical terminal on the PCBA 120 to actuate the trigger input without requiring an additional trigger input button 210 on the PCBA. In certain embodiments, the button 644 may be rigid and attached to an elastically deformable snap dome that makes direct contact with an electrical terminal on the PCBA 120, providing tactile feedback to the user.In some embodiments, the semi-rigid button 644 may be snapped onto the rigid shell 643, such as via a lip seal (the button 644 may be mounted on an O-ring). In some embodiments, the button 644 may be ultrasonically welded or sealed onto the rigid shell 643. In some embodiments, the button 644 may be formed as a thinned portion of the top surface of the rigid shell 643. In some embodiments, the button 644 may be formed from a soft material, such as a thermoplastic elastomer, configured to fold, flex, and / or rebound. The button 644 may include a hard outer piece attached to a soft material for a user to press and / or a hard inner piece attached to a soft material for contacting the trigger input 210. In some embodiments, the softer material for contacting the trigger input may include a soft conductive piece (such as a conductive foam pill) that enables the trigger input by shorting pads or traces on the PCBA without requiring an explicit button component on the PCBA. In some embodiments, the button 644 may be configured like a computer keyboard button. For example, button 644 may be configured to sit on one or more support members surrounding trigger input 210 and hold button 644 in a biased, non-contact position above trigger input 210. In some embodiments, an electrical signal indicative of a button press may be passed through a printed circuit board, through a flex circuit attached to the button, or through electrical traces applied to rigid shell 643. These electrical traces may be applied via laser direct structuring, plating onto a plateable substrate applied in a secondary molding process, or printing by aerosol jet, inkjet, or screen printing of a conductive material.

[0137] The flexible upper frame 642 may include an upper rim 642a configured to interface with an upper surface of the rigid shell 643, as described elsewhere herein, and a lower rim 642b. The lower rim 642b may include a larger diameter than the upper rim 642a. The upper rim 642a and / or the lower rim 642b may include an annular (e.g., ring-like) configuration. The lower rim 642b may be configured to interface with an underside of a lateral sidewall of the rigid shell 643 (e.g., via an overmolding or a snap fit). The inner diameter of the lower rim 642b may be configured to interface with an outer diameter of the PCBA 120 (e.g., via a snap fit). The lower rim 642b may operably couple the PCBA 120 to the rigid shell 643. In some embodiments, the lower rim 642b may be approximately the same stiffness as the upper rim 642a. In some embodiments, the lower rim 642b may be stiffer than the upper rim 642a. The upper rim 642a may be joined to the lower rim 642b by one or more vertical ribs 642c. The multiple ribs 642c may be spaced (e.g., substantially uniformly) around the periphery of the upper housing 640. The ribs 642c may help retain the PCBA 120 within the upper housing. In some embodiments, the PCBA 120 may be configured with grooves around the periphery of the PCBA 120 to at least partially accommodate one or more of the ribs 642c. The ribs 642c may at least partially conform to the shape of the PCBA 120. The ribs 642c may help absorb shocks that would otherwise be transmitted to the PCBA 120, potentially causing operational artifacts, for example. Some of the ribs 642c may not join the upper rim 642a and the lower rim 642b. Some of the ribs 642c may extend upward from the lower rim 642b but are not attached to the upper rim 642a, as shown in Figures 12B-12D. Some of the ribs 642c may extend downward from the upper rim 642a but are not attached to the lower rim 642b.In some embodiments, only a single rib 642c connects the upper rim 642a and the lower rim 642b, as shown in Figures 12B-12D. In some embodiments, the upper rim does not connect to the lower rim, or one of the two rings may be omitted entirely.

[0138] In some embodiments, one or more connecting ribs 642c may be circumferentially disposed substantially opposite the trigger input 210. The one or more connecting ribs and / or frame 642 may function as a fulcrum or pivot point against which the upper rim 642a and button 644 are depressed. A fulcrum-like configuration may allow the button 644 to be depressed deeper on the side of the PCBA 120 that constitutes the trigger input 210. In some embodiments, one or more fulcrum posts may extend vertically upward (e.g., from the PCBA 120) below the button 644. The fulcrum posts may be circumferentially spaced below the underside of the button 644. The fulcrum posts may have a height that is less than the height of the trigger input 210. The fulcrum posts function as a fulcrum, and when the underside of the button 644 contacts the fulcrum post, they can facilitate biasing the underside of the button 644 toward the trigger input 210 as the button 644 is pressed. The fulcrum post may be particularly useful when the trigger input is located off-center of the button 644 (e.g., on the periphery of the PCBA 120). In some embodiments, the upper rim 642a of the flexible top frame 642 may be filled to form a continuous area such that the top frame 642 forms a flush top surface with the top surface of the rigid shell 643 and covers a central portion of the top surface of the upper housing 640. In some embodiments, the button 644 may be formed as an integral part of the flexible top frame 642 and may have approximately the same, or even less, rigidity as the rest of the flexible top frame 642. In some embodiments, the button 644 (which may be flexible or rigid) may be coupled to the top surface (e.g., below the top surface) of the flexible top frame 644. The button 644 may be attached to the top surface (which may be flexible or rigid) of the top frame 642 via a snap fit, a barb fit, adhesive, suction, or the like. In some embodiments, to minimize the possibility of the PCBA flexing during application of force to the input trigger by the button, the upper housing 640 can include a stop structure that limits the travel of the button 644 to minimize stress on the board.Such stop structures may also be implemented as components on the PCBA, for example as inactive molded components that are press-fit into the PCBA, or as active components such as antennas that are soldered to the board but have intentional extensions to allow for limiting button movement.

[0139] FIG. 12E depicts a perspective view of the inner surface of the upper housing 640. In some embodiments, the upper housing 640 may include downwardly extending columns 641 configured to secure or aid in securing the upper housing 640 to the lower housing 645. The columns 641 may be spaced (e.g., substantially uniformly) around the periphery of the upper housing 640. The columns 641 may have channels configured to receive and retain (e.g., via a press fit or interference fit) posts 646 extending from the lower housing 645, as described elsewhere herein. The columns 641 may be formed as part of the rigid shell 643. The columns 641 may be integrally formed with the rigid shell 643. The columns 641 may be disposed inside the flexible upper frame and / or the lower rim 642b of the housing 640. As shown in FIG. 12E, one or more of the columns 641 may merge with the inner diameter of the rigid shell 643. One or more of the posts 641 may be spaced inward from the inner diameter of the rigid shell 643. The posts 641 may extend to a height greater than, approximately equal to, or less than the height of the inner diameter of the upper housing 640, as shown in FIG. 12E. The flexible upper frame 642 may extend to a height greater than, approximately equal to, or less than the height of the inner diameter of the rigid shell 643, as shown in FIG. 12E. In certain embodiments, and as described above, the button 644 may be flexible as an integral part of the housing and / or shell 643. In such embodiments, the upper rim 642a is no longer necessary. A window may be added to the button 644, covered with a thin layer of translucent material, to allow light transmission from the underlying LED.

[0140] As shown in FIG. 12F, upper 714 and lower 716 housing portions may be positioned above and below the flexible body 718. In embodiments, as shown in FIG. 6D2, a gasket 719 may be disposed between the upper 714 and lower 716 housings, co-molded to one or more of the housings. The gasket may compress an adhesive assembly and a raised interface (shown below in FIG. 12G) or another gasket on the opposite housing to provide watertightness for the internal electronic hardware. As depicted in FIG. 12G, a ridge 721 may be disposed on the upper edge of the lower housing 716, configured to press into the adhesive layer and / or gasket 719. One skilled in the art will appreciate that the ridge 721 may be any suitable shape, such as, for example, a rimmed ridge as depicted in FIG. 721. In some examples, the ridge may be rounded, square, and / or polygonal. In particular examples, the height of the ridges can be about 0.15 mm, such as about 0.01 mm to 0.5 mm, about 0.05 mm to 0.4 mm, about 0.1 mm to 0.3 mm, about 0.1 mm to 0.2 mm, or about 0.13 mm.

[0141] 13A-13B show multiple perspective views of another example of a lower housing 645. The lower housing 645 can be configured to mate with the upper housing 640. FIG. 13A depicts a perspective view of the lower housing 645, and FIG. 13B depicts a side view of the lower housing 645. In some embodiments, the lower housing 645 can include a plurality of posts 646 extending upward from the body of the lower housing 645 beyond an upper periphery configured to mate with the lower periphery of the upper housing 640. The posts 646 can be configured to extend into an interior space enclosed by the upper housing 640. In other embodiments, the posts 646 may not extend beyond the upper peripheral edge of the lower housing 645. In some embodiments, the posts 646 can be configured to pass through holes 616 in the trace layer 609 and can help secure the trace layer 609 to the lower housing 645, as described elsewhere herein. The plurality of posts 646 may be configured to be received within and mate with an equal number of posts 641 disposed opposite the posts 646 in the upper housing 640. For example, the plurality of posts 646 may be configured to form a press fit or interference fit with the plurality of posts 641 such that the posts 646 and posts 641 are configured to secure or lock the upper housing 640 and the lower housing 645. The engagement between the posts 646 and posts 641 may resist a separation force between the upper housing 640 and the lower housing 645. The separation force may be induced by a spring 665 described elsewhere herein, a reaction force due to compression of a gasket between the upper and lower housings 640, 645 to form a watertight seal, a transfer of force from the upper housing 640 to the lower housing 645 during actuation of the trigger 210, etc. In some embodiments, some or all of the posts 646 may be disposed on the upper housing 640 and some or all of the posts 641 may be disposed on the lower housing 645. In some embodiments, the lower housing 645 may include one or more buckle posts configured to contact the bottom surface of the PCBA 120 (or a spring contact spacer as described elsewhere herein).The buckle posts may be configured to capture and securely contact the PCBA 120 against the upper housing 640, accommodate thickness tolerances of the PCBA 120, and / or provide additional rigidity to elicit a solid tactile response to the pressure of the button 644. In embodiments, the lower housing 645 is joined with the upper housing 645 through an alternative process, such as ultrasonic welding, potentially eliminating the need for press-fit posts.

[0142] In some embodiments, the housing 115 may include a spring 665 configured to provide a consistent force biasing the internal components enclosed by the housing 115 into contact with one another. The spring 665 may generally bias the components toward the top and / or bottom of the housing 115. The spring 665 may accommodate tolerance stacking of the internal components and maintain a substantially consistent bias and vertical position or spacing between the components despite small variations in the size or fit of the various internal components relative to one another. The spring 665 may bias the PCBA 120 into contact with a hard stop formed in the upper housing 640 so that the PCBA can provide a counterforce to resist button depression forces and enable actuation of the input trigger 210. In some embodiments, the spring 665 may be a wave spring, although other configurations of springs (e.g., coil springs) may be used. In some embodiments, the spring 665 may be replaced by an elastomeric foam, which may provide damping properties in addition to the properties described above. Figures 14A-14B show orthogonal side views of an example wave spring 665. The wave spring 665 may be configured to seat substantially along the inner diameter of the housing 115. In some embodiments, the spring 665 may be configured to seat on the bottom of the lower housing 145 and bias the internal components upward toward the upper housing 140, as described elsewhere herein.

[0143] 15A-15I show multiple views of another embodiment of a physiological monitoring device 600. The physiological monitoring device 600 may include one or more of the components described elsewhere herein. The physiological monitoring device 600 may include a housing 615 including an upper housing 640 and a lower housing 645 configured to fit together, sandwiching a flexible body 610 therebetween. The flexible body 610 may include a trace layer 609 and one or more substrate layers that form wings of the physiological monitoring device 600. The wings may include an adhesive layer 340 and electrodes 350, as described elsewhere herein. The rigid body and / or housing 615 may enclose the PCBA 120, the flexible upper frame 642, the battery 160, the battery terminal connector 650, a portion of the trace layer 609, the spring contact spacer 632, and the spring 665.

[0144] FIG. 15A depicts a perspective view of one embodiment of a physiological monitoring device 600. FIG. 15B depicts an exploded view of the physiological monitoring device 600. FIG. 15C depicts a side view of the housing 615 with the rigid shell 643 and button 644 of the upper housing 640 omitted. FIG. 15D depicts a side view of the housing 615 as shown in FIG. 15C with the flexible upper frame 642 additionally omitted. FIG. 15E depicts a side view of the housing 615 as shown in FIG. 15D with the lower housing 645 additionally omitted. FIG. 15F depicts a side view of the housing 615 as shown in FIG. 15E with the battery 160 and spring 665 additionally omitted. FIG. 15G depicts a cross-sectional view of the housing as shown in the view with the cross-section taken between the circuit board 120 and the spring contact spacer 632. Figure 15H depicts a cross-sectional view of the housing as shown in Figure 15G, additionally omitting spring contact spacer 632. Figure 15I depicts a side view of housing 615 as shown in Figure 15H, additionally including PCBA 120.

[0145] The upper housing 640 and the lower housing 645 can sandwich the flexible body 610, as described elsewhere herein. In some embodiments, the flexible body 610 may include one or more apertures 332 extending through one or more of the substrate layers to provide breathability and moisture management and / or facilitate drug delivery to the surface skin, as described elsewhere herein. An upper gasket layer 360 and / or a lower gasket layer 370 (not shown) may be provided on opposite sides of the flexible body 610 (not shown). The gasket layers 360, 370 may be adhesive for attachment to the flexible body 610. A compressible seal may be formed above and / or below the flexible body 610. In some embodiments, the compressible seal may be formed with the flexible upper frame 642. The battery 160 may be positioned below the flexible body 610, including the trace layer 609. The PCBA 120 may be positioned above a flexible body 610 that comprises the trace layer 609. The battery terminal connector 650 may be glued or otherwise coupled to the battery 160 such that the first and second battery traces 652, 653 are exposed on the outer surface of the battery terminal connector 650 on the top side of the battery 160. The first and second battery traces 652, 653 may be exposed to the interior volume of the upper housing 640 through a large central opening in the housing region of the trace layer 609, as shown in FIG. 15H.

[0146] Electrical contact between the PCBA 120 and the first and second battery traces 652, 653, and / or between the PCBA 120 and the ECG interface portions 313 of the electrical traces 611, 612, may be established by spring contacts 637, as depicted in FIGS. 15G-15I. The spring contacts 637 may be coupled to the bottom surface of the PCBA 120, as seen in FIG. 15I. The housing 615 may include a spring contact spacer 632 disposed below the PCBA 120 (not shown in FIG. 15I). In some embodiments, the spring contact spacer 632 may be rigidly affixed (e.g., glued) to the bottom of the PCBA 120. In embodiments, the spring contact spacer may be attached to or integrated with the flexible body 610. In some embodiments, the spring contact spacer may be integrated into the battery terminal connector. The spring contact spacer 632 may include a flat body and multiple legs 633 extending downward. The legs 633 may be configured to seat against the top and / or sides of the battery 160, as shown in FIG. 15E, so that the spring contact spacer 632 maintains a minimum separation distance between the battery 160 and the PCBA 120 and provides sufficient space for the spring contacts 637. The spring contact spacer 632 may include one or more holes 634 through which the spring contacts 637 can extend downward from the bottom surface of the PCBA 120, as depicted in FIG. 15G. The lower housing 645 may include a spring 665, as described elsewhere herein, positioned below the battery 160, as shown in FIG. 15E. The spring 665 may bias the battery 160 upward, biasing the first and second battery traces 652, 653 into physical and electrical contact with the corresponding spring contacts 637. The electrocardiogram interface portions 313 of the traces 611, 612 may rest on top of the battery 160 such that upward biasing of the battery 160 biases the electrocardiogram interface portions 313 of the traces 611, 612 into physical and electrical contact with the corresponding spring contacts 637.The substantially consistent spacing between the traces and PCBA 120 provided by the springs 665 and spring contact spacers 632 may reduce, minimize, or eliminate noise in the electrical signal caused by variations in the degree of electrical contact between the spring contact portions 637 and the traces. The assembly may include at least one spring contact 637 for each of the first battery trace 652, the second battery trace 653, the first electrical trace 611, and the second electrical trace 612. The assembly may also include multiple spring contacts 637 for some or all of the traces. The spring contacts 637 are configured under compression induced by the arrangement of various components, including the springs 665, and can establish an electrical path between each of the traces and PCBA 120. The compressive contact between the spring contacts 637 and the traces may be maintained even under small changes in the separation distance between the traces and PCBA 120 (e.g., caused by movement) because the spring contacts 637 may extend further downward as the separation distance increases and the bias response decreases. In some embodiments, the first and second battery traces 652, 653 can be configured to be located on opposite sides of the housing 615 from the first and second electrical traces 611, 612, as shown in FIG. 15H. In other embodiments, spring contacts can be configured to conduct electrical signals from the battery or electrocardiogram signals by contacting electrical traces applied to the upper housing 640 or the lower housing 645. These electrical traces can be applied to the housing through the use of laser direct structuring, plating on a plateable substrate applied in a secondary molding process, or printing by aerosol jet, inkjet, or screen printing of conductive materials. In other embodiments, an RF antenna for wireless communication (such as Bluetooth) can be configured through the use of such electrical traces on the upper housing 640 or the lower housing 645.

[0147] 16A-16D depict multiple views of an embodiment of a physiological monitoring device 800 similar to the physiological monitoring device depicted in FIGS. 10A-15I, such as FIG. 15A. Here, the physiological monitoring device includes a central housing 802 including an upper housing 802 and a lower housing 806 sandwiched on a flexible substrate 810. Those skilled in the art will appreciate that the housing may comprise any suitable material disclosed herein, such as a rigid polymer or a soft, flexible polymer. In some embodiments, the housing may include an indicator 808, which may be any suitable shape, such as oval, round, square, or rectangular. The indicator may include an LED light source (not shown) or any suitable light source and may be overlaid by a transparent or translucent viewing layer disposed against the inner surface of the upper housing. The viewing layer may comprise thermoplastic polyurethane or any suitable material. Indicators may be used to indicate the status of the physiological monitoring device, such as the battery life of the physiological monitoring device. In some embodiments, the indicators may indicate whether the physiological monitoring device is collecting data, transmitting data, pausing, experiencing an error, or analyzing data. The indicator may display any suitable color, such as, for example, red, amber, or green.

[0148] Extending outwardly from the housing are a plurality of wings 812. One skilled in the art will appreciate that while two wings are depicted here, other embodiments of the physiological monitoring device 800 may include more than two wings. As described elsewhere herein, the wings may be shaped to improve adhesion to and retention of the physiological monitoring device against the skin. In embodiments, the wings may be asymmetric, with a majority of one wing (the upper lobe) 814 lying above the longitudinal line and a majority of another wing (the lower lobe) 816 lying below the longitudinal line, allowing the physiological monitoring device to be positioned at an angle above the heart with the lower lobe positioned lower than the heart when the patient is standing.

[0149] Extending outward from the housing and contained on or within the wings are electrode traces 818, similar to those described elsewhere herein, such as with respect to FIGS. 10A-10C and 15A. As described elsewhere herein, the electrode traces may be printed directly onto a flexible substrate that may be part of a multilayer flexible assembly 820. Additional printed lines 822 may surround the electrode traces 818 for visual improvement of the physiological monitoring device, but the printed lines 822 may be printed on a different layer of the flexible substrate than the one on which the electrode traces are printed. The printed lines may be printed to match the shape of the electrode traces. As described elsewhere herein, the electrode traces may surround a series of ventilation holes 824 that allow the passage of air to the underlying hydrogel. In embodiments, there may be one, two, three, four, or more ventilation holes. As described elsewhere herein, openings 826 can extend through one or more layers of the physiological monitoring device to provide breathability and moisture management. In embodiments, an adhesive boundary layer 828 may extend outward from the wings, allowing for improved adhesion. FIG. 16B depicts the underside of the physiological monitoring device 800 depicted in FIG. 16A. Here, the lower housing 806 is clearly visible, as are the electrode traces 818 and printed lines 822 extending outward from the housing. FIGS. 16C and 16D depict the physiological monitoring device 800 of FIGS. 16A-16B, now including an exterior-facing top liner 826 and a skin-facing patient release liner 828 that cover the wings and enclose the housing 802. Such a release liner helps protect the physiological monitoring device 800 during storage, particularly the adhesive side of the physiological monitoring device. In embodiments, the liner can be shaped so that two sides meet to form an opening for the housing to extend vertically beyond the liner.

[0150] In some embodiments, an abrader may be used to abrade a patient's skin before adhering a physiological monitoring device 100, 600, 800 (as described elsewhere herein) to the patient. The abrader may be used to remove the top layer of skin from the patient to improve long-term adhesion of the physiological monitoring device 100, 600 and / or signal quality forming the physiological monitoring device 100, 600. FIGS. 17A and 17B schematically show cross-sectional views of two example abraders 700. The abrader 700 may include a housing 702. The housing 702 may function as a handle by which the patient or another person can hold and manipulate the abrader 700. In some embodiments, additional elements, such as an elongated handle, may extend from or otherwise be coupled to the housing 702. The abrader 700 may include a substantially flat abrading surface 704 for abrading the skin. The abrading surface 704 may generally include a large surface area. The abrading surface 704 may include a roughened surface and / or protrusions for abrading the skin. In some embodiments, the housing 702 can completely or substantially circumferentially surround the abrading surface 704, as depicted in FIGS. 17A and 17B. The housing 702 can substantially surround the abrading surface 704 during the abrading procedure. The abrading surface 704 may be coupled to the housing 702 via a compressible member or biasing element 706. In some embodiments, the compressible member 706 may be a spring, as shown in FIG. 17A. In some embodiments, the compressible member 706 may be a compressible foam, as depicted in FIG. 17B. The abrading surface 704 may be configured to protrude beyond the bottom surface of the housing 702 in an unbiased configuration.

[0151] The amount of abrasion may depend on the amount of pressure applied to the abrader 700. Higher pressure increases friction between the abrader 700 and the patient's skin, potentially resulting in more severe abrasions. Too much pressure may cause the patient to experience discomfort or pain during and / or after the abrasion procedure. Too little pressure may result in insufficient abrasion. The compressible element 706 may help the user adjust the amount of pressure applied to the abrader 700. The abrader 700 may be configured to bias the compressible element 706 sufficiently that, when pressure above a required pressure threshold is applied, the abrading surface is retracted into the housing 702 and can no longer contact the skin. In some embodiments, the abrader 700 may be finely tuned to deform the skin enclosed by the housing 702 sufficiently that the abrading surface 704 can still contact the skin when the bottom of the housing 702 is pressed against the skin. The compressible element 706 can provide a tailored amount of force at this level of compression to achieve the desired degree of abrasion. In some implementations, the desired degree of abrasion can be achieved when the abrading surface 704 fully protrudes from the housing 702 so that the housing does not substantially contact the skin. In some embodiments, an indicator can be used to indicate to the user that the desired (e.g., sufficient) amount of pressure has been achieved. For example, the foam compressible member 706 may be formed from an open-cell foam having an interior color and an exterior color that is different from the interior color. The foam may be configured to be visible to the user. For example, the housing may include an annular configuration surrounding the foam compressible member 706 so that the foam compressible member 706 is visible from above during the abrasion procedure, as depicted in FIG. 17B . The interior color of the foam may be visible when the compressible member 706 is in an unbiased configuration. The compressible member 706 may be configured such that upon achieving a threshold degree of compression, the open cells are sufficiently compressed or closed that the interior color is no longer visible to the user. The color change in the foam can act as a visual indicator to the user that sufficient pressure has been achieved, and the visibility of the internal color can indicate to the user that more pressure should be applied.

[0152] In various alternative embodiments, the shape of a particular physiological monitoring device may vary. The shape, footprint, perimeter, or boundary of the device may be, for example, circular, elliptical, triangular, compound curve, etc. In some embodiments, the compound curve may include one or more concave curves and one or more convex curves. The convex shapes may be separated by concave portions. The concave portions may be between convex portions on the housing and convex portions on the electrodes. In some embodiments, the concave portions may at least partially correspond to hinges, hinge regions, or regions of reduced thickness between the body and wings.

[0153] Although described in the context of a cardiac monitor, the device improvements described herein are not so limited. The improvements described herein may be applied to any of a wide variety of physiological data monitoring, recording, and / or transmission devices. Additionally, the improved adhesive design features may be applied to devices useful for electronically controlled dosing and / or chronic, gradual dosing of pharmacological agents or blood tests, such as glucose monitors and other blood testing devices. As such, the component descriptions, characteristics, and functions described herein may be modified as needed to include specific components for a particular application, such as electronics, antennas, power or charging connections, data ports or connections for downloading or offloading information from the device, adding or offloading fluids from the device, monitoring or sensing elements such as electrodes, probes, or sensors, or other components or parts required for the device's unique functionality. Additionally or alternatively, the devices described herein may be used to detect, record, or transmit signals or information related to signals generated by the body, including, but not limited to, one or more of ECG, EEG, and / or EMG. In certain embodiments, additional data channels may be included to collect additional data such as, for example, device motion, device flexion or bed, heart rate and / or ambient electrical or acoustic noise.

[0154] The physiological monitors described above and elsewhere herein may be further combined with data processing and transmission methods and systems that improve data collection from the monitor. Additionally, the methods and systems described below can improve monitor performance by enabling timely transmission of clinical information while maintaining the high patient compatibility and ease of use of the monitors described above. For example, the data processing and transmission methods and systems described in this section or elsewhere herein may help extend the monitor's battery life, improve the monitor's accuracy, and / or provide other improvements and advantages described in this section or elsewhere herein.

[0155] Device monitoring and clinical analysis platform The systems and methods described in detail below can selectively extract, transmit, and analyze electrocardiogram signal data and other physiological data from wearable physiological monitors such as those described above. The systems and methods described below can improve the performance of wearable physiological monitors that simultaneously record and transmit data through multiple means. For example, selective transmission of extracted data can reduce power consumption because the wearable patch does not need to transmit all recorded data. By transmitting extracted data, much of the analysis can be performed remotely from the wearable device without requiring full on-board rhythm analysis, which can also be power-intensive and shorten battery life. Furthermore, remote analysis without the power constraints inherent in wearable devices can enable greater sensitivity and accuracy in analyzing data. Reduced power consumption can help improve patient compliance by lengthening or eliminating the need for device replacement, battery replacement, or battery charging during a monitoring cycle. Reducing battery consumption can enable longer monitoring times without device replacement, such as at least one week, at least two weeks, at least three weeks, or more than three weeks.

[0156] FIG. 18 illustrates a general overview of one embodiment of a system 900 for inferring heartbeat information from an RR interval time series 902, such as might be generated by a continuous heart rate monitor 904. The RR interval time series 902 input to the system may include a series of measurements of timing intervals between successive heartbeats. Typically, each interval represents the time period between two successive R peaks as identified from an ECG signal. The R peak is part of the QRS complex, a combination of three graphical deflections typically seen on an ECG, representing depolarization of the left and right ventricles of a mammalian heart. The R peak is generally the highest and most visible upward deflection on an ECG and therefore serves as a suitable reference point. However, in further embodiments, any characteristic ECG fiducial point (such as the onset or offset of the QRS complex) can be used in place of the R peak to provide an estimate of the RR interval time series. The physical characteristics of the monitoring device, as described in connection with Figures 1-9 and throughout the specification, are configured to improve signal fidelity, which in turn provides a high level of confidence in accurately extracting RR peak data.

[0157] The RR interval time series 902 data may be extracted or received from a dedicated heart rate monitor, such as a heart rate chest strap or a heart rate watch, or a wearable health or fitness device 906, 908 that incorporates heart rate sensing functionality. Alternatively, the RR interval time series 902 may be obtained from a wearable patch 904 designed to measure an ECG signal (e.g., by using a QRS detection algorithm to find the R peaks in the ECG). Additionally, the RR interval time series 902 can be estimated from alternative physiological signals, such as those obtained from photoplethysmography (PPG). In this scenario, the peak-to-peak interval time series determined from the PPG signal may be used as an accurate estimate of the RR interval time series.

[0158] In one aspect, the heart rate inference system 910 is implemented as a cloud service or server-based system that exposes an application programming interface (API) that allows RR interval time series data or other signal data to be sent to the system (e.g., via HTTP) and the resulting heart rate information returned to the calling software. The RR interval time series data 902 or other signal data can be sent to the cloud service directly from the heart rate monitor itself or indirectly via a smartphone 912, tablet, or other internet-enabled communication device 914 that can receive data from the heart rate monitor either wirelessly or via a wired connection. Additionally, the RR interval time series data 902 or other signal data can be sent from a server 916 that stores data for multiple users.

[0159] In some embodiments, the heart rate inference system 910 is provided through a software library that can be incorporated into a standalone application for installation and use on a smartphone, tablet, or personal computer. The library can provide functionality identical to that of the inference service, but the RR interval time series data 902 or other signal data is transmitted directly through functional calls rather than through a web service API.

[0160] In certain embodiments, the heartbeat inference system may accept multiple RR interval time series measured from a given user's 918 device in addition to an individual RR interval time series 902. In this scenario, the system calculates the frequency and duration of each heartbeat type inferred from the collection of time series data. These results may then be used to estimate a confidence statistic for each type of heartbeat rhythm based on the frequency and duration of that rhythm's occurrence across various time series. Furthermore, the rhythm confidence statistic may be sequentially updated for each separate invocation of the inference service. Furthermore, in some embodiments, heartbeat information inferred by the system may be fed back to the invoking software only if the confidence score for a given rhythm type exceeds a predetermined threshold.

[0161] In particular embodiments, the heartbeat inference system 910 can accept additional data sources, commonly described as alternative sensor channels, in addition to the R-R interval time series data to enhance the accuracy and / or value of the inference results. One additional data source includes user activity time series data, such as that measured by a triaxial accelerometer simultaneously with the R-R interval time series measurements. Additionally, the system can accept other relevant metadata useful for improving the accuracy of rhythm analysis, such as the user's age, gender, monitoring instructions, medical conditions, medication information, and medical history, as well as information about the specific day and time range of each time series submitted to the system. Furthermore, the measurement device may provide some measure of confidence in beat detection, for example, for each R-peak or for consecutive time periods. This confidence measure would, in a typical embodiment, be based on an analysis of a recorded signal that would not otherwise be recorded due to storage space and battery energy requirements. Finally, if the R-R interval time series data is derived from an ECG signal, the system can accept additional signal features calculated from the ECG. These features may include a time series of intrabeat interval measurements (such as QT or PR intervals, or QRS duration), or a time series of signal statistics such as the mean, median, standard deviation, or sum of ECG signal sample values ​​within a given period.

[0162] The various aspects described above can be used individually or in combination to provide applications that provide insight into an individual's health, stress, sleep, fitness and / or other qualities.

[0163] Some embodiments relate to a system for selectively transmitting electrocardiogram (ECG) signal data from a wearable medical sensor. Current wearable sensors, such as the iRhythm ZioPatch® 904 and described above in connection with FIGS. 1-9 , can record single-lead electrocardiogram (ECG) signals for up to two weeks on a single battery charge. However, in many situations, it is desirable for the sensor to transmit certain clinically relevant portions of the recorded ECG signal in real time or near real time to a computing device, such as a smartphone 912 or an internet-connected gateway device 914, for subsequent processing and analysis. In this way, potentially valuable diagnostic ECG information can be provided to the patient or their physician for the duration the patient wears the sensor.

[0164] As noted above, a key challenge with this approach is managing the battery life of the wearable sensor without requiring replacement or recharging, both of which reduce user compliance. Each transmission of the ECG from the sensor to a smartphone or local gateway device (e.g., using low-impact Bluetooth) results in a subsequent decrease in the total charge stored in the sensor battery. Some embodiments of the present disclosure, particularly those relating to FIGS. 17-24, address this issue through the use of novel hardware and software combinations that enable selective transmission of clinically relevant sections of the ECG from the wearable sensor.

[0165] In certain embodiments, the wearable sensor incorporates either a software, hardware, or hybrid QRS detector that generates real-time estimates of each R-peak location in the ECG. The R-peak location data is then used to calculate an R-R interval time series, which is then transmitted to a smartphone or gateway device according to a predefined schedule (e.g., once per hour). The R-R interval time series also includes a timestamp that records the onset time relative to the start time of the electrocardiogram recording. The R-R interval time series for a section of the ECG is significantly smaller (in terms of occupying bytes) than the ECG signal itself, and therefore can be transmitted with significantly less impact on battery life.

[0166] In some embodiments of the second stage of the system, the RR interval time series along with the onset timestamps are then transmitted by the smartphone or gateway device to a server. At the server, the RR interval time series, along with their onset and offset times, are used to infer a list of most likely cardiac rhythms during the period represented by the time series data. The list of inferred cardiac rhythms is filtered according to certain criteria so that only rhythms matching the predetermined criteria are retained after filtering. A confidence measure can also be used to assist in filtering events in a way that improves the positive predictivity of detection.

[0167] In a specific embodiment of the third stage of the system, for each rhythm in the filtered rhythm set, the server sends the onset and offset times for that particular rhythm to the smartphone or gateway device. If the inferred rhythm duration exceeds a predefined maximum duration, the onset and offset times can be adjusted so that the resulting duration is less than the maximum allowable duration. The onset and offset times received by the gateway are then sent to the wearable sensor, which transmits back to the gateway the section of the recorded ECG signal between the onset and offset times. This ECG signal is transmitted to the server, analyzed, and used to provide diagnostic information to the patient or physician.

[0168] In some embodiments, the system essentially enables a worn device to communicate timely asymptomatic arrhythmia events for up to approximately 14, 21, or 30 days or more without battery recharging or replacement (both of which reduce patient compatibility and therefore diagnostic value). This advancement is motivated by overcoming technological constraints: the desire to limit the complexity of on-board analysis to enable highly accurate, continuous arrhythmia analysis in a wearable device that is small and does not require battery replacement or charging. Similarly, streaming all recorded ECG data to an off-board analysis algorithm may be impractical without imposing greater power requirements. This has motivated the discovery of more creative “triage” approaches, in which selected features of the recorded ECG signal, including but not limited to RR intervals, are transmitted beat-by-beat, and a customized algorithm can identify the number of 90-second events (e.g., 10) required from the device at full resolution to support comprehensive analysis, e.g., a resolution capable of supporting clinical diagnosis.

[0169] In other embodiments, the system would provide the ability to detect silent arrhythmias in a timely manner in a wearable adhesive patch device that does not require frequent charging or replacement. This would be used to enhance the value of some current clinical offerings that provide clinical insight only after recordings are completed and returned for analysis.

[0170] In certain embodiments, the system could derive actionable clinical insights from data collected by low-cost, easy-to-use consumer wearable devices focused solely on fitness and wellness. For example, the technology could be used to create highly effective, low-cost screening tools that can detect the presence of atrial fibrillation in large numbers of people. Such a tool could not only more easily identify patients in need of treatment, but also deliver treatment earlier, more cost-effectively, and with better outcomes. Thus, earlier detection of atrial fibrillation could reduce the risk of stroke.

[0171] In certain embodiments, the system can provide services through a downloadable application that, after receiving customer consent and payment authorization for data access, accesses and analyzes heartbeat data stored locally on the mobile device or from the wearable device stored in an online repository. This data acquisition and analysis occurs through an algorithmic API, resulting in a clinical finding sent back to the application and provided to the user. If the data is sufficient to support a "screening-oriented" finding, e.g., "probable presence of irregular rhythm detected," the application can direct the user to a cardiologist who can provide more diagnostically focused services, such as ZIO® services, to support clinical diagnosis and treatment. In further embodiments, the system can activate an alarm if certain measurements and / or analyses indicate an alarm is needed, as described elsewhere herein.

[0172] Further examples of additional scenarios with clinical value include combining ambulatory arrhythmia monitoring with blood alcohol monitoring to study the interaction between atrial fibrillation and lifestyle factors. For example, ambulatory arrhythmia monitoring can be combined with blood glucose monitoring to examine the impact of hypoglycemia on arrhythmias. Alternatively, ambulatory arrhythmia monitoring can be combined with respiratory rate and / or volume monitoring to examine the interaction between sleep apnea and respiratory disorders. Furthermore, it is possible to evaluate the high incidence of supraventricular ectopic beats (e.g., 720 SVEs in 24 hours), which may be a precursor to atrial fibrillation.

[0173] Extraction, Communication, and Processing Systems FIG. 19 is a schematic diagram of one embodiment of a system and method 1000 for a wearable medical sensor 1002 with transmission capabilities, similar to the system and / or method described above in connection with FIG. 19 . In some embodiments, the sensor 1002, which may be any type of sensor or monitor described in this section or elsewhere herein, continuously senses an ECG or equivalent biosignal 1004 and continuously records the ECG or equivalent biosignal 1004. In certain embodiments, the sensing and / or recording steps may be performed intermittently. The collected signal 1004 may then be continuously extracted into one or more features 1006, representing exemplary features A, B, and C. The features are not intended to be samplings of different temporal sections of the signal; instead, (as described in more detail below) different features may correspond to different types or portions of data, such as R-peak location or R-peak amplitude. The features of the ECG or equivalent biosignal are extracted to facilitate remote analysis of the signal 1004. In certain embodiments, features are extracted on a window basis, with window sizes varying from, for example, one or more hours to several seconds. In certain embodiments, the window may be up to about 0.1 seconds, about 1 second, about 2 seconds, about 3 seconds, about 5 seconds, about 10 seconds, about 30 seconds, about 1 minute, about 5 minutes, about 30 minutes, about 1 hour, about 2 hours, about 4 hours, or more than 4 hours. Extraction windows, when repeated, may be separated by various amounts of time. For example, extraction windows may be separated by at least about 30 seconds, about 1 minute, about 5 minutes, about 30 minutes, about 1 hour, about 3 hours, about 6 hours, about 12 hours, about 24 hours, about 48 hours, or 3 days or more. In certain embodiments, the window size may vary depending on the features extracted. Feature extraction may be limited to one type or various types of features, and the features selected for extraction may vary depending on the nature of the observed signal.

[0174] A wide variety of different types of ECG or equivalent biosignal features can be extracted. For example, R-peak locations may be extracted. In certain embodiments, R-peak locations are extracted via a variety of methods, including the Pan-Tompkins algorithm (Pan and Tompkins, 1985), which provides a real-time QRS complex detection algorithm employing a series of digital filtering steps and adaptive thresholds, or an analog R-peak detection circuit that includes an R-peak detector consisting of a bandpass filter, a comparator circuit, and dynamic gain adjustment to locate the R-peak. The R-R interval can also be calculated from the peak locations and used as a key feature for rhythm discrimination. In embodiments, an R-peak overflow flag may be extracted. If more than a certain number of R-peaks are detected during a predetermined time window that prevents all data from being transmitted, the firmware may raise a flag. Such extraction can be used to exclude noisy segments from analysis on the basis that extremely short R-R intervals are physiologically impossible. Similarly motivated, an R-peak underflow flag can be extracted to indicate unrealistically long intervals between successive R-peaks, provided that appropriate consideration is given to resting states in this evaluation. In another implementation with the same objective, the absence of an R peak in a long interval can be associated with a confidence index that indicates the likelihood that the interval is clinical or artifactual.

[0175] In general, as used herein, the term “module” refers to logic embodied in hardware or firmware, or a collection of software instructions, possibly with entry and exit points, written in a programming language such as, for example, Python, Java, Lua, C, and / or C++. Software modules may be compiled and linked into an executable program, installed in a dynamic link library, or written in an interpreted programming language such as, for example, BASIC, Perl, or Python. It will be understood that software modules may be callable from other modules or from themselves and / or in response to detected events or interrupts. Software modules configured for execution on a computing device may be provided on a computer-readable medium, such as a compact disc, digital video disc, flash drive, or any other tangible medium. Such software code may be stored, partially or completely, on a memory device of an executing computing device, such as computing system 13000, for execution by the computing device. Software instructions may also be embedded in firmware, such as an EPROM. It will be further understood that a hardware module may be composed of connected logic units such as gates and flip-flops, and / or may be composed of programmable units such as programmable gate arrays or processors. The block diagrams disclosed herein may be implemented as modules. The modules described herein may be implemented as software modules, but may also be represented in hardware or firmware. Generally, the modules described herein refer to logical modules that can be combined with other modules or divided into sub-modules, regardless of physical organization or storage.

[0176] Each of the processes, methods, and algorithms described in the previous sections may be embodied in code modules executed by one or more computer systems or computer processors, including computer hardware, and may be fully or partially automated. The code modules may be stored on any type of non-transitory computer-readable medium or computer storage device, such as a hard drive, solid-state memory, optical disk, and / or the like. Additionally, the systems and modules may be transmitted as a generated data signal (e.g., as part of a carrier wave or other analog or digital propagated signal), over various computer-readable transmission media, including wireless-based and wired / cable-based media, and in various forms (e.g., as part of a single or multiplexed analog signal, or as multiple individual digital packets or frames). The processes and algorithms may be implemented partially or entirely in application-specific circuitry. The results of the disclosed processes and process steps may be stored, persistently or otherwise, in any type of non-transitory computer storage, such as, for example, volatile or non-volatile storage.

[0177] The various features and processes described above may be used independently of one another or may be combined in various ways. All possible combinations and subcombinations are intended to fall within the scope of the present disclosure. Furthermore, certain method or process blocks may be omitted in some embodiments. The methods and steps described herein are also not limited to any particular order, and the blocks or states associated therewith may be executed in other orders as appropriate. For example, described blocks or states may be executed in orders other than those specifically disclosed, or multiple blocks or states may be combined into a single block or state. Illustrated blocks or states may be executed serially, in parallel, or in other ways. Blocks or states may be added or deleted from the disclosed exemplary embodiments. The exemplary systems and components described herein may be configured differently from those described. For example, elements may be added, deleted, or rearranged compared to the disclosed exemplary embodiments.

[0178] In particular, conditional language such as "can," "could," "might," or "could," unless otherwise specified or understood within the context in which it is used, is generally intended to convey that certain embodiments include certain features, elements, and / or steps that other embodiments do not include. Thus, such conditional language is generally not intended to imply that the features, elements, and / or steps are somehow required for one or more embodiments, or that one or more embodiments necessarily include logic that, in conjunction with user input or activation, determines whether those features, elements, and / or steps are included in or performed in any particular embodiment. The term "comprises" means "including but not limited to." The term "or" means "and / or."

[0179] It should be understood that any process description, element, or block in the flow or block diagrams described herein and depicted in the accompanying figures may represent a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or step in the process. Alternative implementations are within the scope of the embodiments described herein in which elements or functions may be omitted or performed in a different order than shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as will be understood by those skilled in the art.

[0180] All of the methods and processes described above may be at least partially embodied in software code modules executed by one or more computers and may be partially or fully automated. For example, the methods described herein may be executed by a computing system and / or any other suitable computing device. The methods may be executed on a computing device in response to the execution of software instructions or other executable code read from a tangible computer-readable medium. A tangible computer-readable medium is a data storage device capable of storing data readable by a computer system. Examples of computer-readable media include read-only memory, random-access memory, other volatile or non-volatile memory devices, CD-ROMs, magnetic tape, flash drives, and optical data storage devices.

[0181] It should be emphasized that many variations and modifications can be made to the above-described embodiments, and that elements thereof are understood to be among other acceptable examples. All such modifications and variations are intended to be included herein within the scope of this disclosure. The foregoing description details particular embodiments. However, no matter how detailed the foregoing may be, it will be understood that the systems and methods can be implemented in many ways. For example, features of one embodiment can be used with features of a different embodiment. Also, as noted above, it should be noted that the use of a particular term when describing a particular feature or aspect of the systems and methods should not be construed as meaning that the term is redefined herein to be limited to include any particular feature of the feature or aspect of the systems and methods with which the term is associated.

[0182] Various embodiments of physiological monitoring devices, methods, and systems are disclosed herein. These various embodiments may be used alone or in combination, and various changes to individual features of the embodiments may be made without departing from the scope of the present invention. For example, the order of various method steps may be changed in some cases, and / or one or more optional features may be added to or deleted from the described devices. Accordingly, the description of the embodiments provided above should not be construed as unnecessarily limiting the scope of the present invention, which is defined in the claims.

[0183] Various modifications may be made to the embodiments described in this disclosure, and the general principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the scope of the present disclosure is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with this disclosure, the principles and novel features disclosed herein.

[0184] Certain features that are described herein in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while various features may be described above as acting in a particular combination, and may even be initially claimed as such, one or more features from a claimed combination may in some cases be removed from the combination, and the claimed combination may be directed to subcombinations or variations of the subcombination.

[0185] Similarly, although operations are depicted in the figures in a particular order, such operations need not be performed in the particular order shown, or sequentially, to achieve desirable results, nor need all depicted operations be performed. Furthermore, the figures may schematically depict one or more exemplary processes in the form of a flow diagram. However, other operations not shown may be incorporated into the illustrative process depicted in the schematic. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the depicted operations. Furthermore, the separation of various system components in the above-described embodiments should not be construed as requiring such separation in all embodiments. Furthermore, other embodiments are within the scope of the following claims. In some cases, the operations recited in the claims can be performed in a different order and still achieve desirable results.

Claims

1. 1. An electronic device for monitoring a physiological signal of a user, comprising: The electronic device a housing for receiving a circuit board; the housing further includes a rigid shell surrounding the flexible frame and forming a periphery of at least a portion of the housing; a button formed within the opening in the flexible frame; the button is configured to be manually depressed into the flexible frame by a user; The electronic device also an electrode configured to detect a physiological signal when engaged with a surface of a user; electronic equipment.

2. further including flexible wings extending from the housing; The electronic device of claim 1 .

3. a trace layer coupled to the flexible wing and configured to transmit electronic signals from the electrode to a circuit board; the trace layer includes a polymer body extending from a first contact area disposed adjacent the electrode to a second contact area disposed adjacent the circuit board; 3. The electronic device of claim 2.

4. The trace layer is a conductive material disposed on a first side of the polymer body and having a first conductance; a resistor disposed on the first side of the polymer body, intersecting the conductive material between the first contact area and the second contact area, the resistor having a second conductance; The electronic device of claim 3 .

5. the first conductance is greater than the second conductance such that the resistance adds resistance between the first contact area and the second contact area; 5. The electronic device of claim 4.

6. the trace layer includes one or more vias extending through the polymer body of the trace layer and filled with a conductive material; the one or more vias electrically connect a conductive material disposed on a first side of the polymer body to a conductive material disposed on a second side opposite the first side; 5. The electronic device of claim 4.

7. the via is disposed in the second contact area; 7. The electronic device of claim 6.

8. The electrode comprises a hydrogel electrode, the first contact area includes a hole extending through a center of the first contact area to allow moisture to evaporate from the hydrogel electrode through the flexible wings; 5. The electronic device of claim 4.

9. a first contact area disposed on the electrode; 5. The electronic device of claim 4.

10. the first contact area includes a hole surrounding the electrode such that the electrode is concentrically disposed within the hole; The electrodes are configured to be electrically connected to the periphery of the hole.

5. The electronic device of claim 4.

11. a first contact area disposed on a bottom side of the trace layer and a second contact area disposed on a top side of the trace layer; 5. The electronic device of claim 4.

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