Patent Publication Number: US-2023140973-A1

Title: Systems and methods for measuring ecg data and respiratory data for a patient

Description:
FIELD 
     The present disclosure generally relates to systems and methods for measuring ECG data and respiratory data for a patient. 
     BACKGROUND 
     Electrocardiograms and the devices that generate these waveforms (also referred to as ECG devices or ECGs) are essential tools in medicine, used frequently within clinical and hospital settings to monitor, diagnose, and treat heart conditions. In particular, electrical activity from a patient&#39;s heart is collected via electrodes placed on the skin in specific regions of the body. This electrical activity is also referred to herein as cardiac electrical activity. The cardiac electrical activity is communicated from the electrodes to an electronics device via wires. The electronics device, or another device connected thereto, processes the cardiac electrical activity from the electrodes to measure ECG data (e.g., via comparison between particular electrodes) and to create an ECG waveform. The electronics device or other device connected thereto may also perform other actions based on the cardiac electrical activity, such as generating alarms, creating notifications or displays, and the like in a manner known in the art. 
     The number of electrodes and wires connected to the patient varies according to the configuration of the ECG device. Common configurations known in the art include: (1) 3-lead, which uses 3 electrodes positioned on the right arm, left arm, and left leg; (2) 5-lead, which uses 5 electrodes positioned on the right arm, right leg, left arm, left leg, and one on the chest; (3) 6-lead, which uses 6 electrodes positioned on the right arm, right leg, left arm, left leg, and two on the chest; and (4) 12-lead, which uses 10 electrodes comprised of four limb leads (right arm, right leg, left arm, left leg) and six chest leads commonly referred to as V 1 -V 6 . The six chest leads of a conventional 12-lead ECG are positioned with V 1  being at the 4th intercostal space on the right sternum, V 2  being at the 4th intercostal space on the left sternum, V 3  being midway between V 2  and V 4 , V 4  being at the fifth intercostal space at the mid-clavicular line, V 5  being at the fifth intercostal space at an anterior axillary line (same horizontal level as V 4 ), and V 6  being at the fifth intercostal space at a mid-axillary line (same horizontal level as V 4 ). One example of a 12-lead ECG device in the market is the Carescape One produced by GE Healthcare®. 
     Some ECG device are also configured to measure respiratory data representing the breathing characteristics of the patient. The respiratory data is also derived by measuring electrical activity on the skin of the patient (separately referred to as respiratory electrical activity), which in systems and methods presently known in the art is collected from the same electrodes used for collecting the cardiac electrical activity for generating the ECG waveform. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts that are further described below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. 
     One example of the present disclosure generally relates to a system for measuring ECG data and respiratory data for a patient. The system includes at least four ECG wires configured to communicate a first set of cardiac electrical activity from the patient. A respiratory wire distinct from the at least four ECG wires is configured to communicate respiratory electrical activity from the patient. An electronics device is electrically coupled to the at least four ECG wires and to the respiratory wire. The electronics device is configured to measure the ECG data based on the first set of cardiac electrical activity from the at least four ECG wires, and to measure the respiratory data based on the respiratory electrical activity from the respiratory wire. 
     In certain examples, the five ECG wires and the respiratory wire are each configured to be electrically coupled to the patient via electrodes, and a respiratory electrode associated with the respiratory wire is unshared with any of the electrodes associated with the at least four ECG wires. 
     In certain examples, the electronics device receives an additional electrical activity measured on an abdomen of the patient, and the electronics device measures the respiratory data by comparing the respiratory electrical activity to the additional electrical activity. In further examples, the additional electrical activity is communicated via one of the at least four ECG wires. 
     In certain examples, the respiratory electrical activity is measured closer to a left armpit of the patient than to a sternum of the patient. 
     In certain examples, the respiratory wire is a first respiratory wire and the respiratory electrical activity is a first set of respiratory electrical activity measured in a first location on the patient and communicated by the first respiratory wire. A second respiratory wire is also included and is configured to communicate a second set of respiratory electrical activity measured in a second location on the patient, where the electronics device receives additional electrical activity measured on the patient, and where the electronics device measures the respiratory data based on comparison of both the first set of respiratory electrical activity and the second set of respiratory electrical activity to the additional electrical activity. 
     Certain examples further include electrodes by which the at least four ECG wires and the respiratory wire receive the cardiac electrical activity and the respiratory electrical activity from the patient, respectively, where one of the electrodes is configured to communicate with two separate wires among the respiratory wire and the at least four ECG wires. 
     In certain examples, the electronics device includes a first electronics device electrically coupled to the at least four ECG wires and the respiratory wire, and a second electronics device electrically coupled to additional ECG wires configured to communicate the cardiac electrical activity measured from the patient, where the ECG data is measured based on the cardiac electrical activity from the at least four ECG wires and also from the additional ECG wires. In further examples, the additional ECG wires are leads V 2  through V 6  in a conventional 12-lead ECG configuration. 
     Another example of the present disclosure generally relates to a method for measuring ECG data and respiratory data for a patient. The method includes electrically coupling at least four ECG wires to the patient to communicate a first set of cardiac electrical activity from the patient, where one of the at least four ECG leads is positioned on an abdomen of the patient. The method further includes electrically coupling a respiratory wire to the patient to communicate respiratory electrical activity from the patient, electrically coupling the at least four ECG wires and the respiratory wire to an electronics device. The method further includes configuring the electronics device to measure the ECG data based on the first set of cardiac electrical activity from the at least four ECG wires, and to measure the respiratory data based on the respiratory electrical activity from the respiratory wire. 
     In certain examples, the one of the five ECG wires positioned on the abdomen of the patient provides a additional electrical activity, where the respiratory wire is positioned closer to a left armpit of the patient than to a sternum of the patient, and where the electronics device measures the respiratory data by comparing the respiratory electrical activity to the additional electrical activity. 
     In certain examples, the respiratory wire is a first respiratory wire and the respiratory electrical activity is a first set of respiratory electrical activity measured in a first location on the patient and communicated by the first respiratory wire, further comprising electrically coupling a second respiratory wire to the patient to communicate a second set of respiratory electrical activity measured in a second location on the patient, wherein the electronics device receives additional electrical activity measured on the patient, and wherein the electronics device measures the respiratory data based on comparison of both the first set of respiratory electrical activity and the second set of respiratory electrical activity to the additional electrical activity. 
     Certain examples further include positioning electrodes on the patient by which the at least four ECG wires and the respiratory wire receive the cardiac electrical activity and the respiratory electrical activity therefrom, respectively, where one of the electrodes is configured to communicate with two separate wires among the respiratory wire and the at least four ECG wires. 
     In certain examples, the electronics device includes a first electronics device electrically coupled to the at least four ECG wires and the respiratory wire, and a second electronics device electrically coupled to additional ECG wires configured to communicate the cardiac electrical activity measured from the patient, where the ECG data is measured based on the cardiac electrical activity from the at least four ECG wires and also from the additional ECG wires. In further examples, the additional ECG wires are leads V 2  through V 6  in a conventional 12-lead ECG configuration. 
     Another example according to the present disclosure generally relates to a system for measuring ECG data for a patient. A first electronics device is configured to be electrically coupled to the patient via a first set of ECG wires to receive a first set of cardiac electrical activity from the patient. A second electronics device is configured to be electrically coupled to the patient via a second set of ECG wires to receive a second set of cardiac electrical activity from the patient. A monitoring device is configured to communicate with the first electronics device and the second electronics device, where the monitoring device is configured to measure the ECG data for the patient based on the first set of cardiac electrical activity received from the first electronics device when communication is absent from the second electronics device, and where the monitoring device is configured to measure ECG data for the patient based on both the first set of cardiac electrical activity received from the first electronics device and the second set of cardiac electrical activity received from the second electronics device when communication is present from both the first electronics device and the second electronics device. 
     In certain examples, the monitoring device is configured to measure ECG data for the patient based on both the first set of cardiac electrical activity and the second set of cardiac electrical activity when at least one of the first set of ECG wires and at least one of the second set of ECG wires are electrically coupled to the patient via a shared electrode positioned thereon. IN further examples, the shared electrode provides additional electrical activity for both the first set of ECG wires and the second set of ECG wires, and measuring the ECG data includes comparing each of the first set of cardiac electrical activity and the second set of cardiac electrical activity to the additional electrical activity. 
     In certain examples, the first electronics device is further configured to be electrically coupled to the patient via a respiratory wire configured to measure respiratory electrical activity for the patient, where the respiratory wire is distinct from the first set of ECG wires, and where the monitoring device is further configured to measure respiratory data for the patient based on the respiratory electrical activity received from the respiratory wire. 
     Certain examples further relate to methods for using the systems presently disclosed, including electrically coupling the first set of ECG wires to the patient via electrodes, where one of the electrodes is positioned on an abdomen of the patient. 
     Various other features, objects and advantages of the disclosure will be made apparent from the following description taken together with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is described with reference to the following drawings. 
         FIG.  1    is perspective view of a system according to the present disclosure in-use for measuring ECG data for a patient; 
         FIG.  2    depicts a first configuration of a system according to the present disclosure for measuring ECG data (here providing 5-lead ECG data), also measuring respiratory data; 
         FIG.  3    is a schematic view of an example control system such as may be incorporated within the systems disclosed herein; 
         FIG.  4    depicts a second configuration of a system according to the present disclosure for measuring ECG data (here providing 12-lead ECG data); 
         FIG.  5    depicts a third configuration of a system according to the present disclosure for measuring ECG data (here providing 12-lead ECG data); 
         FIG.  6    depicts a fourth configuration of a system according to the present disclosure similar to  FIG.  4   , also measuring respiratory data; 
         FIG.  7    is a flow chart for a first example of a method for measuring ECG data according to the present disclosure; 
         FIG.  8    is a flow chart for a second example of a method for measuring ECG data according to the present disclosure; 
         FIG.  9    is a perspective view of an example of a removable/passthrough connector such as shown in  FIG.  2   ; and 
         FIG.  10    is a top view of a removable/passthrough connector similar to that of  FIG.  9    with a removable portion connected thereto. 
     
    
    
     DETAILED DISCLOSURE 
     It is generally known in the art to use the electrodes measuring ECG data to also make dual vector impedance measurements of respiratory data, for example as described in U.S. Pat. Nos. 7,351,208 and 10,405,765, and U.S. Patent Application Publication No. 2019/0380620. However, the present inventors have recognized that the systems and methods presently known in the art provide inaccurate respiratory data measurements and are generally problematic. For example, low signal amplitude and/or motion artifacts using devices and methods presently known in the art may cause inaccurate respiration rate. A false indication of central apnea is also possible, particularly if the electrodes locations are not optimized to have the strongest signal amplitudes. 
     In addition, the present inventors have recognized problems when using medical devices and methods presently known in the art, specifically when needing to transition between ECG measuring configurations. For example, in certain cases a patient may be connected to a 5-lead or 6-lead ECG system for a relatively long period of time, such as for extended monitoring (which could range from a hours to several days). In contrast, a 12-lead ECG (which provides much more detailed information regarding the electrical activity of the heart) is typically connected for only short-term collection. For example, a patient arriving at an intensive care unit (ICU) may be checked for possible cardiac issues using a 12-lead ECG, which may require only a few minutes of monitoring or be continued for a few hours. Once the initial monitoring with 12-lead ECG is completed, additional monitoring may be continued using a 5-lead ECG setup. It is also common that a patient already connected to a 5-lead or 6-lead ECG requires a full 12-lead ECG for additional data collection, but will then be subsequently returned back to the 5-lead or 6-lead ECG configuration again. In this scenario, a caregiver must fully remove the entire 5-lead or 6-lead ECG setup from the patient to complete a 12-lead ECG study, then remove the entire 12-lead ECG setup to reapply the 5-lead or 6-lead ECG setup again. 
     The positioning and removing of electrodes, connecting of wires, and configuration of electronics devices connected thereto is time-consuming for the caregiver, uncomfortable and/or disruptive to the patient, and increases the delay for collecting the additional 12-lead ECG data measurements for the patient (also increasing the time until the patient is restored to the previous configuration). The process also generates additional material cost and waste for multiple rounds of using electrodes, causes additional skin irritation, generates additional wear and tear on the wires, and increase the risk of human error in the placement and connection of the electrodes due to repeated efforts and working under time constraints. 
       FIG.  1    shows an example configuration of a system  30  for measuring ECG data (and in certain examples, respiratory data) according to the present disclosure. The system  30  includes an electronics device  60  that receives electrical activity from electrodes positioned on a patient  1 , as discussed further below. The electronics device can also be referred to as a medical device. The patient  1  may be positioned in a bed  14  as shown, or, due to the flexibility offered by the presently disclosed system  30  (discussed further below), may be free to move, e.g., using a wireless configuration discussed below. 
     In the example shown, the electronics device  60  communicates via a connection  28  to a separate monitoring device  20 , which here has a display device  22  for displaying ECG data  24  and respiratory data  26  collected by the system  30 . The connection  28  may be physical, such as wires within a wire harness, and/or wireless, for example using a protocol known in the art (e.g., Bluetooth®, Wi-Fi, or others). The electronics device  60  and/or monitoring device  20  may also communicate with additional devices or systems, such as a central monitoring station or an Electronic Medical Record (EMR) known in the art, for example to display, archive, and/or further process the information collected by the system  30 . 
       FIG.  2    shows one configuration for measuring both the ECG data and respiratory data for another patient  1 . The figure shows the patient&#39;s left shoulder  2 , right shoulder  4 , and abdomen  10 . Additional notable landmarks for reference include the left armpit  6 , sternum  8 , and navel  12 .  FIG.  2    further shows a number of electrodes  50  coupled to the skin of the patient  1 , which may be electrodes presently known in the art unless otherwise stated. The electrodes  50  create electrical signals based on electrical activity present on the surface of the skin, in this case as cardiac electrical activity generated by the beating of the heart, and/or as respiratory electrical activity generated by the patient&#39;s breathing. One or more of the electrodes  50  is also used in certain examples as a ground to equalize the potential between the patient and the electronics ground, as is customary in ECG measurement, whereby the electrical activity measured by this electrode is also referred to as additional electrical activity. 
     For the ease of reference, certain electrodes  50  used exclusively for measuring ECG data are shown in solid black (here also labeled as electrodes  51 A,  51 C, and  51 D). Other electrodes  50  used exclusively for measuring respiratory data are shown in solid white (here also labeled as electrode R 1 ), and those for both ECG data and respiratory (here electrode  51 B, R 2 , and also electrode G, R 3 ) in black and white stripes. However, the actual electrodes  50  used for each purpose (e.g., measuring cardiac, respiratory, and/or additional electrical activity) may be functionally the same, subject to further distinctions described below. It should be recognized that different numbers of electrodes  50  may also be used, for example omitting electrode  51 C for a four-lead ECG configuration. 
     With continued reference to  FIG.  2   , the electrical signals produced by the electrodes  50  responsive to the electrical activity are then communicated to an electronics device  60  via wires  32  connected therebetween. The wires  32  may be connected to the electronics device  60  and to the electrodes  50  via different methods known in the art, and/or in a manner described further below. It should be recognized that various types of wires  32  known in the art may be used, including shielded and non-shielded, different gauges, and the like. The wires  32  may also be bundled together in a variety of ways, and should thus be broadly considered as individual conductive pathways between points. In certain instances, the wires  32  are separately referred to as ECG wires  34  or respiratory wires  40  to clarify which type of electrical activity is communicated thereby. However, the actual wires used may be the same for any of the types of electrical activity discussed herein (e.g., cardiac, respiratory, and ground). The example shown in  FIG.  2    includes five ECG wires  34  (four connecting to electrodes  51 A- 51 D, and one to the ground electrode G), indicating a 5-lead ECG configuration. The electronics device  60  then processes the electronic signals received from the five ECG wires  34  in a manner known in the art to produce the desired ECG data. It should be recognized that the electronics device  60  may also or alternatively communicate these electronic signals to another device (e.g., a monitoring device  20 ) for processing. 
     As is discussed further below, ground electrodes G may serve two functions (and thus in certain examples are also labeled as R 3 ). First, the ground electrode G is used for equalizing the potential between human body and the electronics device  60 . In the context of measuring ECG data, the additional electrical activity measured by the ground electrode G may not contribute to any of the measurements, whereby the ECG data is instead measured using differential amplifiers all individually referenced to electrode  50  positioned on the right arm (for example). In the context of impedance or respiratory data, the respiratory data may be measured between an electrode positioned to measure respiratory electrical activity (e.g., positioned on the right arm) and another electrode positioned to measure respiratory electrical activities, which is in certain examples the ground electrode G used for measuring the ECG data. Since the ground electrode G also serves the function of measuring respiratory electrical activity, it may also be labeled as electrode R 3  (see  FIG.  2   ) to clarify that it measures respiratory electrical activity rather than functioning as a ground in this context. In this manner, the ground electrode G may have two different functions: equalizing potentials at low frequencies, and serving as another pole for the impedance measurement at higher frequencies. 
     The example  FIG.  2    also includes respiratory wires  40 ,  42  connecting the electrode R 2  used for measuring respiratory electrical activity to the electronics device  60 . In the specific configuration shown, the connection to the electrode  51 A is a removable/passthrough connector  56  specifically developed by the present inventors. In addition to electrically coupling the electrode  51 A to the ECG wire  34  for communication of signals from the cardiac electrical activity to the electronics device  60 , the removable/passthrough connector  56  allows signals from the respiratory electrical activity of the electrode R 1  to be electrically coupled to the respiratory wire  40  between the electrode  51 A and the electronics device  60 . The removable/passthrough connector  56  is designed such that the cardiac electrical activity received at the electrode  51 A remains electrically isolated from the respiratory electrical activity received at the electrode R 1 . 
     In this manner, the presently disclosed system  30  including the removable/passthrough connector  56  allows the addition of the electrode R 1  simply by plugging the shared wiring harness containing both the respiratory wire  40  and the ECG wire  34  into the electronics device  60 . This shared wiring harness is then connected to the electrode  51 A via the removable/passthrough connector  56  (which may snap/socket or clamp on in manners known in the art), leaving the ECG wire  34  and the respiratory wire  40  electrically isolated, and also the electrodes  51 A and R 1  electrically isolated. It should be recognized that the electronics device  60  is also distinct from others presently known in the art, at least in that the connection for the shared wiring harness must separately receive connections for both the ECG wire  34  and the respiratory wire  40 . Additional information regarding the removable/passthrough connector  56  is provided below and shown in  FIGS.  9  and  10   . 
     It should be recognized that while the above-referenced configuration is practical and cost-effective, others are also contemplated by the present disclosure. For example, the present disclosure also contemplates configurations having a separate respiratory wire  40  between the electrode R 1  and the electronics device  60 , rather than the shared harness and removable/passthrough connector  56  of  FIG.  2   . 
     With continued reference to the example of  FIG.  2   , the electrode  51 B used for collecting cardiac electrical activity has a dual purpose of serving as a second electrode for respiratory data, and is thus also referred to as electrode R 2 . In this manner, dual vector impedance respiratory data can be collected by measuring the signals from the respiratory electrical activity between the electrodes R 1  and R 2 , and between the electrodes R 2  and R 3 . In certain examples, slightly different carrier frequencies are used for each of the two vector impendence measurements such that the measurements are independent of each other. For example, the frequency used for ECG data may be measured in hertz (e.g., below 150 Hz), whereas the frequency used for respiratory data may be measured in the tens of kilohertz, (e.g., between 10 and 100 kHz). 
     In systems and methods presently known in the art, the ground electrode is customarily placed on the right leg of the patient. Through experimentation and development, the present inventors have discovered that re-positioning the electrode G for ground (which here is also the electrode R 3 ), specifically to the abdomen  10  of the patient  1 , yields an improved signal from the respiratory electrical activity versus positioning in customary locations. For example, positioning the electrode G, R 3  on the abdomen vertically approximately level to the navel  12 , and near but to the left of the navel  12 , provided particularly accurate readings of respiratory data. 
     In certain examples, it is advantageous to place the electrodes  50  where breathing efforts cause with maximum movement. For example, the upper abdomenal region is generally favorable, at or above navel level. In examples in which one electrode  50 , R 3  is shared for both respiratory and cardiac electrical activity, it is advantageous to position the electrode  50 , R 3  specifically slightly to the right from navel (rather than to the left) to optimize the ECG signal amplitude. 
     In systems and methods presently known in the art, impedance or respiratory data measurements are measured between two ECG electrodes. Consequently, the the caregiver cannot move the shared ECG and respiratory electrode to a position to improve the quality of the incoming signal for the respiratory electrical activity. Specifically, this relocation would distort the ECG data from being positioned in a non-standard location. Accordingly, the present disclosure provides examples of systems and methods in which a ground electrode is used for measuring the respiratory data (rather than an ECG electrode), whereby this ground electrode can be placed freely without ditorting ECG signals. 
     Additionally, the present inventors have discovered that by using a separate electrode R 1  to collect the non-ground respiratory electrical activity of the patient  1  (in  FIG.  2   , for the first vector impedance measurement), yielded more accurate results than re-using an electrode also used for measuring ECG data. However, this is not a limitation of the presently disclosed systems and methods, and one or more of the vector impedance measurements may include an electrode  50  also used for ECG data (e.g., see electrode R 2  in  FIG.  2   ). Moreover, the ECG data and respiratory data need not share a common electrode G, R 3 , and need not include wires  32  that are connected directly to the electrode G, R 3 . For example,  FIG.  2    shows only the ECG wire  34  being directly connected to the electrode G, R 3 , with the respiratory data obtaining this additional electrical activity via the electronics device  60  connected to both the ECG wire  34  and the respiratory wires  40 ,  42 . 
     Through experimentation and development, the present inventors have further discovered a particularly advantage in positioning one of the electrodes  50  for measuring respiratory data (here, electrode R 1 ) as shown in  FIG.  2   . Specifically, the present inventors have identified improvement from placing the electrode  50  horizontally closer to the left armpit  6  than to the sternum  8 . In certain examples, this location is further defined as coinciding with the customary location of the V 6  electrode in a 12-lead ECG (discussed further below). The present inventors have specifically noted that positioning the electrode R 1  in this manner—and also as a dedicated electrode (though not required)—yields a strong, accurate signal representing the respiratory electrical activity of the patient  1 . 
       FIG.  2    also shows that the system  30  is configured to be portable, having an electronics device  60  that can move with the patient  1 . In the example shown, the electronics device  60  is retained on the patient via a belt  70  (e.g., by a clip, hook and loop fastener, or other methods known in the art). This allows the patient  1  to move about while the system  30  collects the ECG and/or respiratory data, which is both convenient, and in some cases necessary for testing protocols (e.g., a cardiac stress test). Additional flexibility is provided when the connection  28  between the electronics device  60  and the external monitoring device  20  (see  FIG.  1   ) is wireless. 
     The electronics device  60  of  FIG.  2    may be or may incorporate a control system CS 100  such as shown in  FIG.  3   , whereby the wires  32  constitute the input devices CS 99  thereto and the monitoring device  20  ( FIG.  1   ) constitutes an example of output device CS 101 . The control system CS 100  receives and processes the electrical signals received from the wires, which may be passed to an output device CS 101 , and/or processed via a processing system CS 110  to generate the ECG data for the patient (e.g., as a waveform displayed on a display device). 
     It should be recognized that the electronics device  60  and the monitoring device  20  may be incorporated into a single device, or subdivided from the examples discussed herein while preserving the same function. Likewise, there may be multiple control systems configured like the control system CS 100  of  FIG.  3   , for example in each electronics device  60  and the monitoring device  20 . In certain examples, the control system CS 100  of the electronics devices  60  merely communicate the electrical activity received from the electrodes  50  to the monitoring device  20 , whereby a control system CS 100  thereon processes this electrical activity to generate the ECG data, ECG waveforms, notifications, and the like. 
     As stated above,  FIG.  3    depicts an example of a control system CS 100  such as may be incorporated within the system  30 , here specifically within the electronics device  60 . Certain aspects of the present disclosure are described or depicted as functional and/or logical block components or processing steps, which may be performed by any number of hardware, software, and/or firmware components configured to perform the specified functions. For example, certain embodiments employ integrated circuit components, such as memory elements, digital signal processing elements, logic elements, look-up tables, or the like, configured to carry out a variety of functions under the control of one or more processors or other control devices. The connections between functional and logical block components are merely examples, which may be direct or indirect, and may follow alternate pathways. 
     In certain examples, the control system CS 100  communicates with each of the one or more components of the system  30  via a communication link CL (e.g., wires  32  and connections  28  in  FIGS.  1  and  2   ), which can be any wired or wireless link. The control module CS 100  is capable of receiving information and/or controlling one or more operational characteristics of the system  30  and its various sub-systems by sending and receiving control signals via the communication links CL. In one example, the communication link CL is a controller area network (CAN) bus; however, other types of links could be used. It will be recognized that the extent of connections and the communication links CL may in fact be one or more shared connections, or links, among some or all of the components in the system  30 . Moreover, the communication link CL lines are meant only to demonstrate that the various control elements are capable of communicating with one another, and do not represent actual wiring connections between the various elements, nor do they represent the only paths of communication between the elements. Additionally, the system  30  may incorporate various types of communication devices and systems, and thus the illustrated communication links CL may in fact represent various different types of wireless and/or wired data communication systems. 
     The control system CS 100  may be a computing system that includes a processing system CS 110 , memory system CS 120 , and input/output (I/O) system CS 130  for communicating with other devices, such as input devices CS 99  and output devices CS 101  (e.g., a monitoring device  20 , an Electronic Medical Record, and/or other external devices (e.g., smart phones or tablets), which may also or alternatively be stored in a cloud  102 . The processing system CS 110  loads and executes an executable program CS 122  from the memory system CS 120 , accesses data CS 124  stored within the memory system CS 120 , and directs the system  30  to operate as described in the present disclosure. 
     The processing system CS 110  may be implemented as a single microprocessor or other circuitry, or be distributed across multiple processing devices or sub-systems that cooperate to execute the executable program CS 122  from the memory system CS 120 . Non-limiting examples of the processing system include general purpose central processing units, application specific processors, and logic devices. 
     The memory system CS 120  may comprise any storage media readable by the processing system CS 110  and capable of storing the executable program CS 122  and/or data CS 124 . The memory system CS 120  may be implemented as a single storage device, or be distributed across multiple storage devices or sub-systems that cooperate to store computer readable instructions, data structures, program modules, or other data. The memory system CS 120  may include volatile and/or non-volatile systems, and may include removable and/or non-removable media implemented in any method or technology for storage of information. The storage media may include non-transitory and/or transitory storage media, including random access memory, read only memory, magnetic discs, optical discs, flash memory, virtual memory, and non-virtual memory, magnetic storage devices, or any other medium which can be used to store information and be accessed by an instruction execution system, for example. 
       FIG.  4    shows another configuration for a system  30  configured to measure ECG data, this time not showing electrodes for measuring respiratory data. The system  30  includes the same ECG wires  34  connected to a first electronics device  61  as shown in  FIG.  2   , which is also referred to as a first set of ECG wires communicating a first set of cardiac electrical activity. In the configuration of  FIG.  4   , a second set of ECG wires communicating a second set of cardiac electrical activity has been added to the first set. Specifically, this includes additional electrodes  50  and additional ECG wires  36  connected to a second electronics device  61  as the second set of ECG wires communicating the second set of cardiac electrical activity. The electrodes  50 , ECG wires  34 ,  46 , and first and second electronics devices  61 ,  62  may be functionally the same between the first and second sets unless otherwise noted. 
     By adding the second set of ECG wires  36  to the first set of ECG wires  34  from  FIG.  2   , the system  30  is expanded from a 5-lead ECG configuration to a full, 12-lead ECG setup. This allows the caregiver to conduct the more extensive analysis and testing of a full 12-lead ECG, without requiring the removal of the electrodes  50  already in position from the previous 5-lead ECG monitoring associated with the first set of ECG wires. By utilizing the existing electrodes of the 5-lead ECG in the 12-lead ECG, time and effort is saved, the cost of materials is reduced, the patient remains more comfortable, and human error is reduced, as discussed above. 
     In the example shown in  FIG.  4   , the first and second sets of ECG wires  34 ,  36  have a shared or common ground electrode G, which in this case has two removable connector  52  (e.g., clamps or snaps). However, it should be recognized that separate ground electrodes may be used. 
     A similar configuration having the same placement of electrodes  50  is shown in  FIG.  5   . The system  30  of  FIG.  5    includes electrodes  50  having three different types of connectors for connecting wires  32  thereto. In particular, some electrodes (e.g., electrode  51 C) are connectable to a single wire  32  via removable connector  52  (e.g., a snap or clamp as known in the art). Other electrodes  50  have fixed connectors  54 , meaning they are hard-wired or permanently coupled to the wire  32  (e.g., electrodes V 2 -V 6 ), and still further electrodes  50  have both a fixed connector  54  and a removable connector  52  (e.g., electrode  51 B). The present inventors have recognized that utilizing fixed connectors  54  allows at least some of the wires  32  within the 12-lead ECG to be made as a simplified and disposable assembly (e.g., the electrodes V 2 -V 6  being connected as a single, fixed unit, ensuring proper placement therebetween), whereby electrodes  50  having both a fixed connector  54  and a removable connector  52  allows the user to subsequently add on to the already placed electrode, such as electrode  51 B. Configuring electrode  51 B to be a fixed connector  54  for the first set of cardiac electrical activity, while providing the removable connector  52 , allows the same electrode  51 B to later be used for a second set of cardiac electrical activity as needed (thereby reducing time, cost, and patient discomfort). It should be recognized that the particular configuration of fixed connectors  54  and removable connectors  52  may vary from that shown. 
     The ECG data received at the first and second electronics devices  61 ,  62  may be combined together (e.g., within either one of the electronics devices  60 , for example via a wired or wireless connection therebetween), and/or may be passed independently to output devices (CS 101 ,  FIG.  3   ) for combination thereon. For example, a monitoring device ( 20  of  FIG.  1   ) may be configured to select between 5-lead and 12-lead configurations, receiving, processing, and/or displaying the corresponding ECG data on the display device  22  accordingly. This selection may also be made by the monitoring device  20  automatically based on whether or not it is communicating with one or two electronic devices  60 , for example. In certain examples, the system  30  may be configured to generate and transmit an alarm or notification on the display device  22  or a third party devices (e.g., a text message or other communication to a third party device, such as a caregiver smart phone) when one of the electronic devices  60  is connected to the patient  1  and receiving electrical activity therefrom, but the monitoring device  20  is configured such that that electrical activity is not being stored, used, and/or displayed, for example. The same alarms or notifications may also be provided when the monitoring device  20  is in a mode (e.g., 12-lead ECG mode), but not receiving electrical activity from all necessary electronic devices  60 . Specific details regarding which of the electronics devices  60  is not communicating with the monitoring device  20 , and/or any wires between the electronics devices  60  and the electrodes  50  may also be included in the alarms and notifications to aid in troubleshoot or reconfiguring the system  30 . 
     The monitoring device  20  may be part of the system  30  itself, and/or may contain a control system CS 100  such as that shown in  FIG.  3    for receiving, processing, displaying, and performing other functions using the ECG data measured by the electronic devices  60  (whether one or two electronics devices). It should be recognized that in this example, the monitoring device  20  may be different than those presently known in the art, particularly to provide the connectivity and processing of information coming from the electronic devices  60  presently disclosed. 
       FIG.  6    shows another system  30  similar to that shown in  FIG.  4   , but now also configured to measure respiratory data. In the example shown, electrode V 6  used for measuring ECG data (here, connected as a fixed connector  54  to a wire  36  within the second set of ECG wires  36  to the second electronics device  62 ) also includes a removable connector  52  for connecting a respiratory wire  40 . In this manner, electrode V 6  also serves as electrode R 1 , being positioned near the left armpit  6  as identified by the present inventors to be particularly advantageously. The electrode  51 B used for both the first and second sets of ECG wires  32 ,  34  is also used as the respiratory electrode for the second vector impedance and is thus also labeled as electrode R 2 . In this example, a separate respiratory wire  40  is not provided, instead obtaining this respiratory electrical activity from the wire  32  already connected to the first electronics device  61 . 
       FIGS.  7  and  8    are flow charts of example methods  200  and  300  for measuring ECG data according to the present disclosure, respectively, for example using one of the systems  30  described above. While the present flow charts reflect a 4-lead ECG setup, other numbers of leads are also contemplated by the present disclosure. In particular,  FIG.  7    provides for electrically coupling (in step  202 ) four (or more) ECG wires to the patient to communicate a first set of cardiac electrical activity (one of the ECG leads positioned on an abdomen). Step  204  provides for electrically coupling a respiratory wire to the patient to communicate respiratory electrical activity. Step  206  provides for electrically coupling the four (or more) ECG wires and the respiratory wire to an electronics device. Steps  208  and  210  provide for configuring the electronics device to measure the ECG data based on the first set of cardiac electrical activity, and configuring the electronics device to measure the respiratory data based on the respiratory electrical activity from the respiratory wire. 
     In the method  300  of  FIG.  8   , step  302  provides for electrically coupling a first set of ECG wires to the patient to communicate a first set of cardiac electrical activity (one of the first set of ECG wires being electrically coupled to an electrode positioned on the patient). Step  304  provides for electrically coupling a second set of ECG wires to the patient to communicate a second set of cardiac electrical activity (one of the second set of ECG wires being electrically coupled to the one of the first set of ECG wires that is electrically coupled to the electrode positioned on the patient). Steps  306  and  308  include electrically coupling the first set of ECG wires to a first electronics device, and electrically coupling the second set of ECG wires to a second electronics device. In step  310 , the ECG data is measured based on both the first set of cardiac electrical activity and the second set of cardiac electrical activity. 
       FIGS.  9  and  10    show an example of a removable/passthrough connector  56  according to the present disclosure, which as described may be used to enable systems  30  according to the present disclosure to be easily expanded with the addition of a second electronics device  60  and associated electrodes  50  as needed. The removable/passthrough connector  56 , and/or the removable portion  52  connectable thereto, may be reusable or disposable depending on the application. Likewise, the removable/passthrough connector  56  is not limited to use with the systems  30  and methods described herein, not to ECG contexts. Other exemplary uses include electromyography (EMG), electroencephalography (EEG), or any other systems or devices in which wires are connected to contacts (by way of non-limiting example, electrodes). In the example shown, the removable/passthrough connector  56  comprises a first connector  400  and a second connector  500  that share a joint body  399 . The first connector  400  extends to a first end  401  having a clamp  402  designed for clamping to an electrode positioned on the skin of the patient in a customary manner. Specifically, the clamp  402  includes contacts  404  supported by support arms  408  and separated by an opening  406 . The opening  406  may be temporarily increased, for example to remove the first connector  400  from an electrode, by pressing pinch arms  410  together in the customary manner, thereby reducing a gap  420  therebetween. 
     The joint body  399 , and particularly within the first connector  400 , is resilient such that when the pinch arms  410  are not pressed together, the opening  406  between the clamps  402  corresponds to the size and shape of the electrode to be clamped onto. The lengths  414 ,  416  of the pinch arms  410  and the support arms  408 , respectively, are designed to provide the necessary leverage for an operator to easily open the clamp  402  when desired, which is also a function of the resiliency of the materials selected. It should be recognized that the clamp  402  may be biased in the closed position shown in  FIGS.  9  and  10    by other methods known in the art, including through the use of springs. 
     In the example shown, the height  412  of the first connector  400  also varies, here being less at the clamp  402  than at the pinch arms  410 . This provides for additional surface area where the user presses the pinch arms  410  together, but also a low enough provide to engage a customary electrode. Likewise, the first end  401  of the first connector  400  may be offset forward from the first end  501  of the second connector  500  by an offset  512 . This ensures that the first end  501  of the second connector  500  does not interfere with the connection and disconnection of the first connector. 
     With continued reference to  FIGS.  9  and  10   , the joint body  399  further includes the second connector  500 , which is electrically isolated from the first connector  400  as discussed above. The second connector  500  extends from a first end  501  and includes a contact  502  for electrically engaging with a removable portion  520  when connected thereto. In the example shown, the contact  502  is a male-end nipple, which may be the same or similar to the male contact of an electrode presently known in the art (including that which the clamp  402  of the first connector  400  is configured to engage). The contact  502  extends upwardly by a height from a floor  506  on which the removable portion  520  rests when connected to the second connector  500 . Walls  508  also extend upwardly from the floor  506  having a height  510  from the bottom of the second connector  500 . 
     The walls  508  are sized and shaped to correspond to the sides  526  of the removable portion  520  such that the removable portion  520  is secure therein and prevented from accidental removal (e.g., shear forces from catching on other wires, equipment, and the like). The walls  508  also provide increased electrical safety for the patient, effectively shielding the contact  502  from accidental contact with other electrical devices. Likewise, the walls  508  serve as a mistake-proofing mechanism to ensure that only the intended removable portion  520  is connected to the second connection  500  (via the corresponding shapes and sizes thereof). 
     The walls  508  also provide for cable management of the wires  32  for the removable/passthrough connector  56 . In particular, a gap  509  is formed between the walls  508 , in this example generally opposite the first end  501  of the second connector  500 . The gap  509  is the only opening through which the respiratory wires  40  (or other wires in other contexts) may extend when the removable portion  520  is engaged within the second connector  500 . In this example, this alignment via the gap  509  causes the respiratory wire  40  connected to the removable portion  52  to be aligned in parallel to the wires  32  embedded within the joint body  399 . It should be recognized that these wires  32  are electrically coupled to the contacts  404 ,  502  of the first connector  400  and the second connector  500 , respectively, via internal wires  421 . The internal wires  421  may be integrally formed within the joint body  399  as an overmold in a manner known in the art, for example. In certain examples (e.g.,  FIG.  9   ), internal wires  421  may run internally to connect the wires  32  with the contacts  404  and/or  502 . In other examples (e.g.,  FIG.  10   ), the wires  32  may be connected to an internal wire  421  that is in turn connected to the contacts  404 ,  502  via a conductive plate  422 , for example. In the example shown, the conductive plate  422  forms the contacts  404  of the first connector  400 . 
     With continued reference to  FIGS.  9  and  10   , the walls  508  of the removable portion  520  extend between an outside  522  and an inside  524 , here forming a generally cylindrical shape. As shown in  FIG.  9   , a second contact  530  is provided on or within the inside  524  of the removable portion  520 . In this example, the second contact  530  is generally circular and has a diameter  533  and depth  535  corresponding to the diameter  503  and height  505  of the first contact  502  such that a snap-type connection is formed therebetween, for example as used with snap-type electrode connections in the art. It should be recognized that the actual conductive portion of the second contact  530  may not mirror the complete cylindrical shape of the opening defined by the diameter  533  and depth  535  defined within the removable portion  520 . In this manner, the removable portion  520  is electrically coupled to the removable/passthrough connection by forcing the inside  524  against the floor  506  of the joint body  399 . Likewise, the removable portion  520  may be removed (e.g., when no longer needed), but pulling the removable portion  520  in a direction normal to the floor  506 . 
     It should be recognized that the contacts  530 ,  502  of the removable portion  520  and the second connector  500  within the joint body  399  may be reversed, and/or other types of connections may be substituted to provide the similar functionality. The present inventors have noticed multiple benefits of using removable/passthrough connectors  56 , including but not limited to use within the systems  30  described above. In particular, the removable/passthrough connectors  56  described above are unobtrusive and provide for fast and easy connection and disconnection of the removable portion  520  as needed. Each of the first connector  400  and second connector  500  are also very intuitive to caregivers, requiring no special training and allowing instant identification of whether either connector is properly connected. 
     In this manner, the systems and methods disclosed herein provide for an improved workflow, improved flexibility, and improved accuracy of measuring ECG and respiratory data in patients. Furthermore, less equipment is needed at a care facility as there is no longer a need to have both 5-lead ECG devices for long-term monitoring versus 12-lead ECG devices for short-term testing, for example. 
     The functional block diagrams, operational sequences, and flow diagrams provided in the Figures are representative of example architectures, environments, and methodologies for performing novel aspects of the disclosure. While, for purposes of simplicity of explanation, the methodologies included herein may be in the form of a functional diagram, operational sequence, or flow diagram, and may be described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance therewith, occur in a different order and/or concurrently with other acts from that shown and described herein. For example, those skilled in the art will understand and appreciate that a methodology can alternatively be represented as a series of interrelated states or events, such as in a state diagram. Moreover, not all acts illustrated in a methodology may be required for a novel implementation. 
     This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. Certain terms have been used for brevity, clarity, and understanding. No unnecessary limitations are to be inferred therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes only and are intended to be broadly construed. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have features or structural elements that do not differ from the literal language of the claims, or if they include equivalent features or structural elements with insubstantial differences from the literal languages of the claims.