Patent Publication Number: US-2020281496-A1

Title: Sensor assembly for patient monitoring systems

Description:
The subject matter disclosed herein relates generally to patient monitoring systems. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present techniques, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     A patient in a medical setting, such as an infant in a neonatal intensive care unit (NICU), may be monitored using various types of sensors. For example, the patient may be monitored via one or more electrodes that are positioned (e.g., via adhesive) on the patient&#39;s skin to generate an electrocardiogram (ECG) and/or to monitor cardiac parameters of the patient. 
     BRIEF DESCRIPTION 
     Certain embodiments commensurate in scope with the originally claimed disclosure are summarized below. These embodiments are not intended to limit the scope of the claimed disclosure, but rather these embodiments are intended only to provide a brief summary of possible forms of the disclosure. Indeed, embodiments may encompass a variety of forms that may be similar to or different from the embodiments set forth below. 
     In one embodiment, a sensor assembly includes a substrate and an electrode positioned on a first side of the substrate. The electrode is configured to obtain data indicative of one or more physiological parameters of a patient, and the electrode includes a conductive portion arranged in a lattice structure. 
     In one embodiment, a sensor assembly includes a substrate having a textile and an electrode positioned on a first side of the substrate, wherein the electrode is configured to obtain data indicative of one or more physiological parameters of a patient. The sensor assembly also includes an attachment portion configured to mate with a corresponding attachment portion of a wire to enable transfer of the data to a data acquisition unit, wherein the attachment portion is oriented relative to the substrate to be exposed on a second side of the substrate that is opposite the first side of the substrate. 
     In one embodiment, a method of manufacturing a sensor assembly includes forming an electrode on a first side of a substrate, wherein the substrate is a textile, the electrode is configured to obtain data indicative of one or more physiological parameters of a patient, and the electrode includes a conductive portion arranged in a lattice structure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a block diagram of a patient monitoring system, in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a schematic diagram of a sensor assembly that may be used in the patient monitoring system of  FIG. 1 , wherein the sensor assembly includes a substrate and an electrode array on a first side of the substrate, in accordance with an embodiment of the present disclosure; 
         FIG. 3  is a cross-sectional side view of a connector that may be used in the sensor assembly of  FIG. 2 , wherein the cross-section is taken within line  3 - 3  of  FIG. 2  and the connector is in a first orientation relative to the substrate of the sensor assembly, in accordance with an embodiment of the present disclosure; 
         FIG. 4  is a cross-sectional side view of a connector that may be used in the sensor assembly of  FIG. 2 , wherein the connector is in a second orientation relative to the substrate of the sensor assembly, in accordance with an embodiment of the present disclosure; 
         FIG. 5  is a schematic diagram of a first side and a second side of a substrate of a sensor assembly that may be used in the patient monitoring system of  FIG. 1 , wherein connector assemblies are positioned on the second side of the substrate, in accordance with an embodiment of the present disclosure; 
         FIG. 6  is a schematic diagram of the first side of the sensor assembly of  FIG. 5 , in accordance with an embodiment of the present disclosure; 
         FIG. 7  is a cross-sectional side view of a first connector that may be used in the sensor assembly of  FIGS. 5 and 6 , wherein the cross-section is taken within line  7 - 7  of  FIG. 6 , in accordance with an embodiment of the present disclosure; 
         FIG. 8  is a cross-sectional side view of a second connector that may be used in the sensor assembly of  FIGS. 5 and 6 , wherein the cross-section is taken within line  8 - 8  of  FIG. 6 , in accordance with an embodiment of the present disclosure; 
         FIG. 9  is a schematic diagram of a sensor assembly that may be used in the patient monitoring system of  FIG. 1 , wherein the sensor assembly includes connector assemblies that are arranged to position connectors proximate to one another, in accordance with an embodiment of the present disclosure; 
         FIG. 10  is a schematic diagram of a sensor assembly that may be used in the patient monitoring system of  FIG. 1 , wherein the sensor assembly includes an electrode array that facilitates diagnostic monitoring, in accordance with an embodiment of the present disclosure; 
         FIG. 11  is a schematic diagram of a sensor assembly that may be used in the patient monitoring system of  FIG. 1 , wherein the sensor assembly includes an electrode array with multiple electrodes and conductive pathways, in accordance with an embodiment of the present disclosure; 
         FIG. 12  is a schematic diagram of an electrode with a rectangular lattice structure, which may be used with the patient monitoring system of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 13  is a schematic diagram of an electrode with a square lattice structure, which may be used with the patient monitoring system of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 14  is a schematic diagram of an electrode with a triangular lattice structure, which may be used with the patient monitoring system of  FIG. 1 , in accordance with an embodiment of the present disclosure; 
         FIG. 15  is a schematic diagram of a sensor assembly that may be used in the patient monitoring system of  FIG. 1 , wherein the sensor assembly includes a substrate and an electrode array and various other sensors on a first side of the substrate, in accordance with an embodiment of the present disclosure; and 
         FIG. 16  is a schematic diagram of a marker assembly that may be used in the patient monitoring system of  FIG. 1  to facilitate placement of a patient relative to an electrode array of a sensor assembly, in accordance with an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. One or more specific embodiments of the present embodiments described herein will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     Embodiments of the present disclosure relate generally to patient monitoring systems, and more particularly, to a sensor assembly for patient monitoring systems. The sensor assembly may include a substrate and an electrode array, and the electrode array may include one or more electrodes that are configured to obtain data indicative of one or more physiological parameters (e.g., heart rate, respiratory rate) of the patient. The substrate may be a textile, and the one or more electrodes may be coupled to or integrally formed with the substrate. For example, the one or more electrodes may be formed from conductive threads that are woven into (e.g., embroidered onto) the substrate. The one or more electrodes may be stretchable and biocompatible, and the sensor assembly may be disposable and/or capable of being sterilized (e.g., submerged in cleaning fluid). 
     In some embodiments, neither the substrate nor the one or more electrodes are adhered to the patient&#39;s skin via adhesive. Instead, the substrate may be wrapped around the patient or the patient may lie down on the substrate to place the one or more electrodes into direct contact with the patient&#39;s skin without an adhesive or other intermediary substrate or composition facilitating contact. The one or more electrodes may include a lattice structure (e.g., open cell structure, non-solid structure, non-continuous structure, or framework) to limit a contact area between the one or more electrodes and skin of the patient. Thus, the disclosed systems and methods may be especially useful for patients with sensitive skin, such as infants in a neonatal intensive care unit (NICU). While the disclosed embodiments are presented in the context of the NICU to facilitate discussion, it should be appreciated that the disclosed embodiments may be adapted for use with various different types of patients in medical and non-medical settings. 
     With the foregoing in mind,  FIG. 1  is a block diagram of a patient monitoring system  10 . As shown, the patient monitoring system  10  may include a sensor assembly  12  having a substrate  14  with a first side  16  (e.g., patient-contacting side; first surface) and a second side  18  (e.g., second surface) that is opposite the first side  16 . The substrate  14  may be a textile, which may be a flexible material formed from a network of natural or synthetic fibers. As used herein, the term textile may include any of a variety of fabrics and/or paper materials. Furthermore, the substrate may be a blanket, an article of clothing, a diaper, and/or a cover for a mattress or other patient-supporting surface (e.g., a fabric sheet or a disposable paper cover). In some embodiments, the substrate  14  may be a patch that is configured to couple (e.g., temporarily couple via adhesive and/or fasteners, such as snaps, clips, hook and loop fasteners) to another object. For example, the substrate  14  may be a piece of cloth or a piece of paper that is configured to couple to a blanket, an article of clothing, a diaper, a cover for a mattress or other patient-supporting surface, or other object via fasteners  19 . As noted above, the disclosed embodiments may be particularly useful for infants, and thus, it should be appreciated that the substrate  14  may be sized for use in an incubator that is configured to house an infant in the NICU (e.g., the substrate may be a fitted sheet for a mattress of an incubator). 
     The sensor assembly  12  may also include an electrode array  20  having one or more electrodes  22  that are positioned on (e.g., exposed on) the first side  16  of the substrate  14 . The one or more electrodes  22  may be positioned on the first side  16  of the substrate  14  via any of a variety of techniques. For example, the one or more electrodes  22  may be formed by printing conductive ink (e.g., silver-based ink) onto a film, which is then bonded onto the substrate  14  (e.g., via lamination). In some embodiments, the one or more electrodes  22  may be formed by weaving conductive threads (e.g., silver-based threads) into the substrate  14  (e.g., weaving conductive threads to form the substrate  14  and/or embroidering conductive threads through the substrate  14 ). In some embodiments, the one or more electrodes  22  may be formed by coupling one or more pieces of conductive fabric (e.g., having a conductive coating or made with conductive threads) onto the substrate  14 , such as via stitching, adhesive, and/or fasteners (e.g., snaps, clips). In some such embodiments, the one or more pieces of conductive fabric may be etched to remove conductive portions (e.g., to remove the conductive coating) to form multiple separate electrodes  22  and/or to provide a lattice structure for the one or more electrodes  22 , as discussed in more detail below. 
     During a monitoring session, the sensor assembly  12  may be positioned so that the one or more electrodes  22  contact an appropriate region of a patient. For example, the substrate  14  may be positioned on a patient-supporting surface (e.g., a mattress or a table), and the patient may lie down on top of the substrate  14  with the one or more electrodes  22  under a torso of the patient. As shown, one or more bumps  28  (e.g., protrusions, puffs, relief structures) may be positioned along the second side  18  of the substrate  14  to push the one or more electrodes  22  into the skin of the patient. The one or more bumps  28  may be integrally formed with the substrate  14  (e.g., woven as part of the substrate  14 ) or may be pieces of fabric, elastomer, or other material that are coupled to the substrate  14  via stitching, adhesive, and/or fasteners (e.g., snaps, clips, hook and loop fasteners). 
     In the illustrated embodiment, the one or more electrodes  22  are communicatively coupled to a data acquisition unit  24  via one or more wires  26  (e.g., electrical wires or any suitable conductor). The one or more electrodes  22  may generate signals indicative of physiological parameters (e.g., heart rate, respiration rate) of the patient, and the one or more wires  26  may carry the signals to the data acquisition unit  24 . The data acquisition unit  24  may process the signals to calculate a heart rate of the patient and/or a respiratory rate of the patient via any suitable processing techniques. For example, in some embodiments, the data acquisition unit  24  may process the signals to generate an ECG waveform. In some such cases, the heart rate and/or the respiration rate may be derived from the ECG waveform. The respiration rate may be obtained in various other ways. For example, a low current may be provided to electrodes positioned across the patient&#39;s chest and to electrodes positioned across the patient&#39; abdomen, and resistance changes measured over time may indicate the respiration rate (e.g., two channel respiration rate monitoring). In some such cases, the same electrodes  22  may be used for both heart rate monitoring and respiration rate monitoring (e.g., alternating between heart rate monitoring and respiration rate monitoring over time). Alternatively, the sensor assembly  12  may include some electrodes  22  that are used for heart rate monitoring and other electrodes  22  that are used for respiration rate monitoring. 
     As shown, the data acquisition unit  24  may be an electronic computing system having a communication device  30 , a processor  32 , a memory/storage device  34 , and/or an output device  36 . The memory/storage device  34  may include one or more tangible, non-transitory, computer-readable media that store instructions executable by the processors  32  and/or data to be processed by the processor  32 . For example, the memory/storage device  34  may include random access memory (RAM), read only memory (ROM), rewritable non-volatile memory such as flash memory, hard drives, optical discs, and/or the like. Additionally, the processor  32  may include one or more general purpose microprocessors, one or more application specific processors (ASICs), one or more field programmable gate arrays (FPGAs), or any combination thereof. The processor  32  may instruct the output device  36  to display the ECG waveform, the heart rate, and/or the respiration rate, for example. 
     The communication device  30  may enable the data acquisition unit  24  to communicate with a remote computing system  38  via various protocols, such as various wired or wireless communication protocols. In some embodiments, the data acquisition unit  24  may relay raw data or processed data to the remote computing system  38 . The remote computing system  38  may be an electronic computing system having a communication device  40 , a processor  42 , a memory/storage device  44 , and/or an output device  46 . These components of the remote computing system  38  may have any of the features discussed above with respect to the communication device  30 , the processor  32 , the memory/storage device  34 , and/or the output device  36  of the data acquisition unit  24 . Thus, the remote computing system  38  may process the data (e.g., in the manner discussed above with respect to the data acquisition unit  24 ) and/or display the data for visualization by a medical professional, for example. 
       FIG. 2  is a schematic diagram of an embodiment of the sensor assembly  12  with the substrate  14  and the electrode array  20 . As shown, the electrode array  20  includes four electrodes  22  on the first side  16  of the substrate  14 . In the illustrated embodiment, the electrodes  22  are physically spaced apart from one another, arranged in parallel lines, and each of the electrodes  22  has a rectangular shape. For use with an infant, the electrodes  22  may be spaced apart from one another by approximately 1 centimeter (or between about 0.5 to 1.5 centimeters), and the electrodes  22  may be have a length of approximately 10 centimeters (or between about 5 to 15 centimeters) and a width of approximately 1 centimeter (or between about 0.5 to 1.5 centimeters). However, it should be appreciated that the sensor assembly  12  may include any number of electrodes  22  (e.g., 1, 2, 3, 4, 5, 6, 7, 8 or more) with any of a variety of sizes, any of a variety of shapes, and any of a variety of configurations. Furthermore, multiple sensor assemblies  12  with substrates  14  of different characteristics (e.g., different sizes and/or configurations, such as various sizes of patches, blankets, clothing, and/or covers) and/or with electrodes  22  of different characteristics (e.g., different numbers, sizes, shapes, arrangements, and/or contact ratios) may be provided as a kit to a medical facility for use with patients having different characteristics (e.g., medical needs, skin condition, sizes). For example, for use with an adult, the electrodes  22  may be spaced apart by approximately 4 centimeters (or between about 3.5 to 5.5 centimeters), and the electrodes  22  may have a length of approximately 25 centimeters (or between about 15 to 50 centimeters and a width of approximately 2 centimeters (or between about 1.5 and 3 centimeters). 
     As shown, a marker  48  (e.g., indicator) may be provided on the substrate  14  to facilitate placement of the patient relative to the electrodes  22 . For example, the marker  48  may indicate a location at which the patient&#39;s head should be placed to position the patient&#39;s torso on top of the electrodes  22 . In the illustrated embodiment, upon placing the patient&#39;s head on the marker  48 , the electrodes  22  extend horizontally across the patient&#39;s torso (e.g., from a left side to a right side of the patient). While the illustrated sensor assembly  12  may be configured for use with the electrodes  22  extending horizontally across the patient&#39;s torso, it should be appreciated that the sensor assembly  12  may be configured for use with the electrodes  22  extending vertically across the patient&#39;s torso (e.g., from a chest portion to an abdomen portion of the patient&#39;s torso). 
     In some embodiments, one or more of the electrodes  22  may include a lattice structure  50  (e.g., open cell structure, non-solid structure, non-continuous structure, or framework). Thus, one or more of the electrodes  22  do not form solid conductive surfaces that contact the skin of the patient, but instead, the conductive portions are separated by non-conductive portions (e.g., conductive ink, wires, or fabric are spaced apart from one another by non-conductive fabric or film). Accordingly, a contact area between the electrodes  22  and the skin of the patient is reduced as compared to other types of electrodes with solid conductive surfaces. 
     In order to transmit signals to the data acquisition unit  24  ( FIG. 1 ), each of the electrodes  22  is electrically coupled to one of the wires  26  via a respective connector  52 . Each of the connectors  52  may be a conductive connector or fastener, such as a snap, a clip, or a magnet. For example, each of the connectors  52  may include a first portion  54  (e.g., first connector portion) that is coupled to a respective electrode  22  and the substrate  14  (e.g., via riveting or sewing) and that is configured to mate with a second portion  56  (e.g., second connector portion) that is positioned at an end portion of the wire  26 . When the first and second portions  54 ,  56  are mated (e.g., joined or interlocked by securing the second portion  56  to the first portion  54 , as shown by arrow  58 ), the signals may be transmitted from the electrode  22  through the connector  52  to the wire  26 . In the illustrated embodiment, the first portion  54  of the connector  52  is oriented so that the wire  26  is positioned on and extends along the first side  16  of the substrate  14  when the first and second portions  54 ,  56  are mated. 
     The connectors  52  are merely exemplary, and the electrical connections between the electrodes  22  and the wires  26  may be made in any of a variety of ways. For example, the connections may be made on a single layer (e.g., the first side  16  of the substrate  14 ) by extending conductive pathways (e.g., conductive fabric, conductive thread) from the electrodes  22  to the edge of the substrate  14  for connection to the wires  26 . The conductive pathways, the wires  26 , and/or any connectors (e.g., the connectors  52 ) on the first side  16  of the substrate  14  may be covered (e.g., by a non-conductive material, such as a printed dielectric or a second substrate material), or at least portions of these structures that are likely to be contacted by the patient may be covered to be electrically isolated from the patient. 
       FIG. 3  is a cross-sectional side view of one of the connectors  52  taken within line  3 - 3  of  FIG. 2 . As shown, the connector  52  includes the first portion  54  that is coupled to the electrode  22  and the substrate  14  and the second portion  56  that is positioned at an end portion of the wire  26 . The first and second portions  54 ,  56  are mated to electrically couple the electrode  22  to the wire  26 . In the illustrated embodiment, the connector  52  is a snap, and the first portion  54  includes a body  60  that extends through the electrode  22  and the substrate  14 . For example, the body  60  may be punched through (e.g., puncture) the electrode  22  and the substrate  14 , and then prongs  62  extending from the body  60  may be bent as shown by arrow  64  to secure the first portion  54  to the electrode  22  and the substrate  14 . However, it should be appreciated that the first portion  54  may be coupled to the electrode  22  via any suitable technique that places the first portion  54  into contact with the electrode  22  and exposes an attachment portion  66  (e.g., key, slot, magnet) of the first portion  54  on the first side  16  of the substrate  14  to enable the first and second portions  54 ,  56  to be mated to one another. For example, the first portion  54  may not extend through the electrode  22  and the substrate  14 . Instead, the first portion  54  may be positioned on the electrode  22  and secured to the electrode  22  and/or the substrate  14  via stitching. While the attachment portion  66  of the first portion  54  is illustrated as a key (e.g., protrusion) that engages with a slot of the second portion  56 , it should be appreciated that the attachment portion  66  may include other features, such as a slot that engages with a key of the second portion  56  or a magnet that couples to another magnet of the second portion  56 . 
     As noted above, in  FIGS. 2 and 3 , the first portion  54  of the connector  52  is oriented so that the wire  26  is positioned on and extends along the first side  16  of the substrate  14  when the first and second portions  54 ,  56  are mated. However, the first portion  54  of the connector  52  may be oriented so that the wire  26  is positioned on and extends along the second side  18  of the substrate  14  when the first and second portions  54 ,  56  are mated.  FIG. 4  is a cross-sectional side view of one of the connectors  52  with the first portion  54  oriented in this way. 
     As shown in  FIG. 4 , the connector  52  includes the first portion  54  that is coupled to the electrode  22  and the substrate  14  and the second portion  56  that is positioned at an end portion of the wire  26 . The connector  52  is a snap, and the first portion  54  includes the body  60  that extends through the electrode  22  and the substrate  14 , and the body  60  is oriented to expose the attachment portion  66  of the first portion  54  at the second side  18  of the substrate  14 . The first and second portions  54 ,  56  are mated to electrically couple the electrode  22  to the wire  26 . As noted above, the connector  52  may have various forms and it should be appreciated that the first portion  54  may be coupled to the electrode  22  via any suitable technique that places the first portion  54  into contact with the electrode  22  and exposes the attachment portion  66  of the first portion  54  on the second side  18  of the substrate  14 . Such a configuration may block interference between the wires  26  and other equipment and/or between the wires  26  and the patient. 
       FIGS. 5 and 6  are schematic diagrams of an embodiment of the sensor assembly  12  that illustrates the electrode array  20  on the first side  16  of the substrate  14  and multiple connector assemblies  70  on the second side  18  of the substrate  14 . To facilitate discussion, the first side  16  of the substrate  14  and the second side  18  of the substrate  14  are shown separately and side-by-side in  FIG. 5 . In the illustrated embodiment, the electrode array  20  includes four electrodes  22  that have a rectangular shape, are arranged in parallel lines, and are physically spaced apart from one another. However, it should be appreciated that the sensor assembly  12  may include any number of electrodes  22  (e.g., 1, 2, 3, 4, 5, 6, 7, 8 or more) with any of a variety of sizes, any of a variety of shapes, and any of a variety of configurations. The substrate  14  may include the marker  48  and/or one or more of the electrodes  22  may include the lattice structure  50 . 
     In order to transmit signals to the data acquisition unit  24  ( FIG. 1 ), each of the electrodes  22  may be electrically coupled to one of the wires  26  via one of the connector assemblies  70 . Each of the connector assemblies  70  may include a first connector  72 , a conductor  74  (e.g., conductive pathway), and a second connector  76 . The first connector  72  may be a conductive connector or fastener, such as a rivet, grommet, pin, snap, clip, thread, that is in contact with the electrode  22  positioned on the first side  16  of the substrate  14  and the conductor  74  positioned on the second side  18  of the substrate  14 . The conductor  74  may be any of a variety of conductors (e.g., flex circuit, wire, conductive ink, conductive fabric, thread) that can be coupled to the second side  18  of the substrate  14  (e.g., via printing, stitching, adhesive, lamination, and/or fasteners). The conductor  74  extends from the first connector  72  toward an edge  78  of the substrate  14 . 
     The second connector  76  may be a conductive connector or fastener, such as a snap, a clip, or a magnet, which is configured to electrically couple the conductor  74  to the wire  26 . For example, each of the second connectors  76  may include a first portion  80  (e.g., first connector portion) that is coupled to the conductor  74  and the substrate  14  (e.g., via riveting or sewing) and that is configured to mate with a second portion  82  (e.g., second connector portion) that is positioned at an end portion of the wire  26 . When the first and second portions  80 ,  82  are mated (e.g., joined or interlocked by securing the second portion  82  onto the first portion  80 , as shown by arrow  84 ), the signals may be transmitted from the electrode  22  through the connector assembly  70  to the wire  26 . 
     In the illustrated embodiment, the connector assemblies  70  enable the wires  26  to be coupled at the second side  18  of the substrate  14 , which may block interference between the wires  26  and other equipment and/or between the wires  26  and the patient. The connector assemblies  70  may also enable the electrodes  22  to be positioned on a central portion of the substrate  14  without extending along the first side  16  of the substrate  14  to the edge  78  of the substrate  14 , while still enabling the wires  26  to be connected proximate to the edge  78  of the substrate  14 . Such a configuration may limit the size of the electrodes  22  to reduce discomfort to the patient and/or may facilitate coupling the wires  26  to the other components of the sensor assembly  12  without disturbing the patient positioned on top of the electrodes  22 , for example. 
       FIG. 7  is a cross-sectional side view of one of the first connectors  72  taken within line  7 - 7  of  FIG. 6 . As shown, the first connector  72  is in contact with the electrode  22  positioned on the first side  16  of the substrate  14  and the conductor  74  positioned on the second side  18  of the substrate  14 . In the illustrated embodiment, the first connector  72  is a rivet that may be punched through (e.g., puncture) the electrode  22  to secure the first connector  72  to the electrode  22 , the substrate  14 , and the conductor  74 . However, as noted above, the first connector  72  can be any of a variety of connectors or fasteners, such as a grommet, pin, snap, clip, and/or thread. 
       FIG. 8  is a cross-sectional side view of one of the second connectors  76  taken within line  8 - 8  of  FIG. 6 . As shown, the second connector  76  electrically couples the conductor  74  to the wire  26 . The second connector  52  includes the first portion  80  that is coupled to the conductor  74  and the substrate  14  and the second portion  82  that is positioned at an end portion of the wire  26 . The first and second portions  80 ,  82  are mated to electrically couple the conductor  74 , and thus the electrode  22 , to the wire  26 . In the illustrated embodiment, the second connector  76  is a snap, and the first portion  80  includes a body  86  that extends through the conductor  74  and the substrate  14 . For example, the body  86  may be punched through (e.g., puncture) the conductor  74  and the substrate  14 , and then prongs  88  extending from the body  86  may be bent as shown by arrow  90  to secure the first portion  80  to the conductor  74  and the substrate  14 . However, it should be appreciated that the first portion  80  may be coupled to the conductor  74  via any suitable technique that places the first portion  80  into contact with the conductor  74  and exposes an attachment portion  92  (e.g., key, slot, magnet) of the first portion  80  on the second side  18  of the substrate  14  to enable the first and second portions  80 ,  82  to be mated to one another. For example, the first portion  80  may not extend through the conductor  74  and the substrate  14 . Instead, the first portion  80  may be positioned on the conductor  74  and secured to the conductor  74  and/or the substrate  14  via stitching. While the attachment portion  74  of the first portion  80  is illustrated as a key (e.g., protrusion) that engages with a slot of the second portion  82 , it should be appreciated that the attachment portion  74  may include other features, such as a slot that engages with a key of the second portion  82  or a magnet that couples to another magnet of the second portion  82 . 
     As noted above, in  FIGS. 5-8 , the first portion  80  of the second connector  76  is oriented so that the wires  26  are coupled at the second side  18  of the substrate  14  when the first and second portions  80 ,  82  are mated. However, the first portion  80  of the second connector  76  may be oriented so that the wires  26  are coupled at the first side  16  of the substrate  14  when the first and second portions  80 ,  82  are mated. Such a configuration may enable the size of the electrodes  22  and conductive components on the first side  16  of the substrate  14  to be limited to reduce discomfort to the patient, while still enabling the connection to the wires  26  proximate to the edge  78  of the substrate  14  to reduce interference with and/or disturbance to the patient positioned on top of the electrodes  22 , for example. 
     Various other arrangements of the electrodes  22  and/or the connector assemblies  70  are envisioned. For example,  FIG. 9  is a schematic diagram of an embodiment of the sensor assembly  12  with the connector assemblies  70  arranged to position the second connectors  76  proximate to one another. More specifically, in the illustrated embodiments, two of the conductors  74  have a bend  100  (e.g., L-shape) so that the four second connectors  76  are all arranged in a central region  102  proximate to the edge  78  of the substrate  14 . Thus, instead of being aligned in a single line as shown in  FIGS. 5 and 6 , the second connectors  76  are arranged in a square pattern (e.g., at four corners of a square). Such a configuration may block interference between the wires  26  and other equipment and/or between the wires  26  and the patient, for example. 
       FIG. 10  is a schematic diagram of an embodiment of the sensor assembly  12  with the electrode array  20  having six electrodes  22  in another configuration. As shown, the electrode array  20  includes a first end electrode  22 ,  110 , a second end electrode  22 ,  112 , and four central electrodes  22 ,  114  positioned between the first end electrode  22 ,  110  and the second end electrode  22 ,  112 . The electrodes  22  are physically separate from one another and may be coupled to the wires via any of the techniques disclosed herein (e.g., the connectors  52  of  FIGS. 2-4 , the connector assembly  70  of  FIGS. 5-9 ). Furthermore, the substrate  14  may include the marker  48  and/or one or more of the electrodes  110 ,  112 ,  114  may include the lattice structure  50 . The illustrated sensor assembly  12  may be used for diagnostic monitoring (e.g., may provide more detailed and/or reliable data indicative of cardiac function and/or respiration rate) and/or may enable two channel respiration rate monitoring. 
       FIG. 11  is a schematic diagram of an embodiment of the sensor assembly  12  with the electrode array  20  having multiple electrodes  22  in another configuration. The electrodes  22  are physically separate from one another and may be coupled to the wires via any of the techniques disclosed herein (e.g., the connectors  52  of  FIGS. 2-4 , the connector assembly  70  of  FIGS. 5-9 ). In the illustrated embodiment, the connections include conductive pathways  116  (e.g., conductor, conductive fabric, conductive thread) that extend from the electrodes  22  toward the edge of the substrate  14  (or at least away from an area that is configured to be positioned under or to otherwise contact the patient) for connection to the wires. The conductive pathways  116 , the wires, and/or any connectors (e.g., the connectors  52 ) used on the first side  16  of the substrate  14  may be covered (e.g., by a non-conductive material, such as a printed dielectric or a second substrate material), or at least portions of these structures that are likely to be contacted by the patient may be covered to be electrically isolated from the patient. Only some of the electrodes  22  and the conductive pathways  116  are numbered in  FIG. 11  for clarity. 
     As shown in  FIG. 11 , the substrate  14  may include the marker  48  and/or one or more of the electrodes  22  may include the lattice structure  50 . The illustrated sensor assembly  12  may be used for diagnostic monitoring (e.g., may provide more detailed and/or reliable data indicative of cardiac function and/or respiration rate) and/or may enable two channel respiration rate monitoring. 
       FIGS. 12-14  illustrate various lattice structures  50  that may be utilized to form the electrodes  22  disclosed herein. In particular,  FIG. 12  illustrates one electrode  22  with the lattice structure  50  having a conductive portion  120  (e.g., conductive trusses or lines) arranged to form rectangular lattice units and defining a non-conductive portion  122  (e.g., gaps).  FIG. 13  illustrates one electrode  22  with the lattice structure  50  having the conductive portion  120  arranged to form square lattice units and defining the non-conductive portion  122 .  FIG. 14  illustrates a portion of one electrode  22  with the lattice structure  50  having the conductive portion  120  arranged to form triangular lattice units and defining the non-conductive portion  122 . 
     As shown in  FIGS. 12-14 , the non-conductive portion  122  may be occupied (e.g., filled) by the substrate  14 . However, in some embodiments, the non-conductive portion  122  may additionally be occupied by a film or other material on which the conductive portion  120  is printed or coated, for example. The lattice structure  50  may have a contact ratio, which may be defined as a first total area of the conductive portion  120  of the electrode  22  over a second total area of the electrode  22 . For example, with reference to  FIG. 12 , the contact ratio may be defined as (L*W−a*b*N)/(L*W), where L is a length of the electrode  22 , W is a width of the electrode, a is a length of each segment of the non-conductive portion  122 , b is a width of each segment of the non-conductive portion  122 , and N is a number of segments of the non-conductive portion  122 . 
     The contact ratio may be adjusted as a function of a skin condition of the patient (e.g., different sensor assemblies  12  may be appropriate for use with different patients). For example, a relatively low contact ratio (e.g., less than or equal to about 50, 40, 30, or 20 percent or between about 10 to 50, 20 to 40, or 25 to 35 percent) may be appropriate for patients with sensitive skin (e.g., pre-term infants, elderly, burn patients), while a relatively high contact ratio (e.g., greater than or equal to about 50, 60, 70, 80, or 90 percent or between about 50 to 95, 70 to 90, or 75 to 85 percent) may be appropriate for patients without particular skin sensitivity (e.g., full-term infants). As discussed above, multiple sensor assemblies  12  with substrates  14  of different characteristics and/or with electrodes  22  of different characteristics, including different contact ratios, may be provided as a kit to a medical facility. Thus, the medical professional may select an appropriate sensor assembly  12  for the patient to balance signal-to-noise ratio of the signals generated by the electrodes  22  with the skin sensitivity of the patient. 
     Furthermore, the conductive portion  120  may be have various orientations. For example, in  FIG. 12 , the conductive portion  120  includes segments that are parallel to a horizontal edge  124  of the electrode  22  and segments that are parallel to a vertical edge  126  of the electrode  22 . However, in  FIG. 13 , the segments of the conductive portion  120  are angled relative to the horizontal edge  124  of the electrode  22  and relative to the vertical edge  126  of the electrode  22 . It should also be appreciated that the lattice structure  50  may have any of a variety of forms. For example, the lattice units may have various cross-sectional shapes, such as rectangles (e.g., non-square), squares, triangles, diamonds, pentagons, hexagons, octagons, or circles. In some embodiments, the lattice structure  50  may have lattice units of multiple different cross-sectional shapes (e.g., both hexagonal and square shapes). 
     Various methods of manufacturing and use of the sensor assembly  12  are envisioned. For example, the sensor assembly  12  may be manufactured by forming the one or more electrodes  22  with the lattice structure  50  on the substrate  14 . As noted above, the one or more electrodes  22  may be formed by printing conductive ink onto a film, which is then bonded onto the substrate  14  (e.g., via lamination). The one or more electrodes  22  may be formed by weaving conductive threads into the substrate  14 , or the one or more electrodes  22  may be formed by coupling one or more pieces of conductive fabric onto the substrate  14 . In some such embodiments, the one or more pieces of conductive fabric may be etched to remove conductive portions. Next, the first portion  54  of the connector  52  or the appropriate components of the connector assembly  70  (e.g., the first connector  72 , the conductor  74 , the first portion  80  of the second connector  82 ) may be assembled onto the substrate  14 . During use, the sensor assembly  12  may be wrapped around the torso of the patient or the sensor assembly  12  may be placed under the torso of the patient. Signals from the one or more electrodes  22  may be transmitted (e.g., via the connector  52  and/or the connector assembly  70  and the one or more wires  26 ) to the data acquisition unit  24 , which may then relay data to the remote computing system  38 . 
       FIG. 15  is a schematic diagram of the sensor assembly  12  with the one or more electrodes  22  and various other sensors. The other sensors may include one or more pressure sensors  130  (e.g., strain gauges) that detect motion of the patient, one or more temperature sensors  132  (e.g., thermocouples) that detect a body temperature of the patient, and/or one or more motion sensors  134  (e.g., accelerometers) that detect motion of the substrate  14 , for example. The substrate  14  may include the marker  48 . Furthermore, one or more of the electrodes  22  and/or one or more of the other sensors may include the lattice structure  50  ( FIGS. 12-14 ). 
     Each of the one or more electrodes  22  and the other sensors may be coupled to the data acquisition unit  24  via respective wires  26 , and the one or more electrodes  22  and/or one or more of the other sensors may be coupled to the wires  26  via any of the techniques disclosed herein (e.g., the connectors  52  of  FIGS. 2-4 , the connector assembly  70  of  FIGS. 5-9 ). During a monitoring session, the sensor assembly  12  may be positioned so that the one or more electrodes  22  and the other sensors contact an appropriate region of a patient. For example, the substrate  14  may be positioned on a patient-supporting surface (e.g., a mattress or a table), and the patient may lie down on top of the substrate  14  with the one or more electrodes  22  and the other sensors under a torso of the patient. The one or more electrodes  22  and the other sensors may generate signals indicative of various physiological parameters of the patient, and the one or more wires  26  may carry the signals to the data acquisition unit  24  for processing. It should be appreciated that the data acquisition unit  24  may process the signals and provide an output (e.g., via the output device  36  in  FIG. 1 ) indicative of the physiological parameters and/or may transmit signals (e.g., raw or processed) to the remote computing system  38  ( FIG. 1 ). The signal from the motion sensors  134  (or from any other motion sensors  134  positioned on the patient or on the bed supporting the patient) may be processed and used to compensate for noise due to motion when calculating the physiological parameters of the patient. 
       FIG. 16  is a schematic diagram of an embodiment of the sensor assembly  12  having a marker assembly  148  to facilitate placement of the patient relative to the electrodes  22  of the electrode array  20 . The marker assembly  148  may be printed (e.g., screen printed) on the first side  16  of the substrate  14  or otherwise formed (e.g., woven) to be visible on the first side  16  the substrate  14 . As shown, the marker assembly  148  may include a first marker  48 ,  150  that indicates an appropriate placement of the patient&#39;s head relative to the electrodes  12 , a second marker  48 ,  152  that indicates an appropriate placement of the patient&#39;s torso relative to the electrodes  22 , and/or additional markers  48 ,  154  that indicate an appropriate placement of the patient&#39;s arms relative to the electrodes  22 . In the illustrated embodiment, the marker assembly  148  is designed to look like a bumble bee, the first marker  48 ,  150  that indicates the appropriate placement of the patient&#39;s head is shown as a head of the bumble bee, the second marker  48 ,  152  that indicates the appropriate placement of the patient&#39;s torso is shown as a torso of the bumble bee, and the additional markers  48 ,  154  that indicate appropriate placement of the patient&#39;s arms is shown as wings of the bumble bee. However, the marker assembly  48  may be any of a variety of combinations of shapes and/or may represent any of a variety of animals or characters (e.g., cartoon characters). For example, the marker assembly  48  may be designed to look like a turtle, the first marker  48 ,  150  that indicates the appropriate placement of the patient&#39;s head may be a head of the turtle, and the second marker  48 ,  152  that indicates the appropriate placement of the patient&#39;s torso may be a shell of the turtle. It should be appreciated that the marker assembly  148  may utilized in any of the sensor assemblies  12  disclosed herein, such as the sensor assemblies  12  of  FIG. 2, 5, 9-11 , or  15 . 
     Technical effects include providing a sensor assembly having a substrate (e.g., textile substrate) and an electrode array. The sensor assembly may improve patient monitoring techniques by avoiding the use of adhesives, reducing a contact area between the one or more electrodes and the patient&#39;s skin via the lattice structure, and/or by providing various connectors that enable the one or more electrodes to be coupled to the data acquisition unit with limited interference with the patient. 
     This written description uses examples to disclose the embodiments, including the best mode, and also to enable any person skilled in the art to practice the embodiments, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure 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 structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims. It should be appreciated that various features discussed with respect to  FIGS. 1-14  may be combined in any suitable manner. For example, the fasteners  19  and/or the one or more bumps  28  shown in  FIG. 1  may be incorporated into the sensor assembly  12  of  FIG. 2, 5, 9-11 , or  15 .