Patent Publication Number: US-2021169399-A1

Title: Device and Method for Detecting Uterine Activity

Description:
FIELD 
     The present invention relates generally to a sensor device and, more particularly, to a sensor device and method for detecting uterine activity. 
     BACKGROUND 
     Detecting and analyzing uterine activity during pregnancy can yield significant information concerning the condition of the fetus and the advancement of labor. Such monitoring can be especially important during difficult pregnancies which present an increased risk to the health of the fetus. During the second and third trimesters, pregnant women may experience early contractions commonly referred to as Braxton Hicks contractions. Although such contractions do not indicate that labor has begun, it can be difficult for pregnant women to discern the difference between Braxton Hicks contractions and contractions present during first stage labor. As such, it may be desirable to detect such contractions and the frequency at which they occur to determine whether the woman has in fact entered labor 
     Various devices are generally known for measuring contraction frequency, duration, intensity, and resting tone of the user. These devices may be placed either internally or externally on the patient&#39;s abdomen to detect changes in uterine pressure. One example internal device is an intra-uterine pressure catheter. Such catheters may be placed inside the uterus, alongside the fetus, to measure the pressure generated by uterine contractions. However, internal devices are invasive and can be difficult to use. Some known external devices include internal pressure transducers and are placed proximate a pregnant woman&#39;s abdomen. Upon impingement by the abdomen during a contraction, an internal pressure of the device rises and is measured. However, it would be desirable to provide a device having an improved sensor for detecting uterine activity. 
     SUMMARY 
     Generally, a device is provided having a sensor for detecting uterine activity of a pregnant user. The device may be positioned externally abutting the user&#39;s abdomen, and includes a housing defining an inner cavity with a circuit board positioned therein. The circuit board includes at least one slot defining a cantilever portion thereof having an attached end and a free end with the sensor positioned proximate the attached end. An actuator may be coupled to the free end of the cantilever portion such that movement of the actuator (e.g., as a result of a contraction) causes the cantilever portion to flex and the sensor to detect a resulting strain on the cantilever portion. The strain detected by the sensor or the strain detected over a period of time may thereafter be used to determine, for example, whether a contraction has occurred or whether the user has entered labor. 
     The circuit board including the cantilever portion and the sensor may include additional circuitry and components for converting, processing, conditioning, and/or communicating a signal representative of the detected strain on the cantilever portion. In some forms, the circuit board includes a signal converter, a controller, and communication circuitry. Such components may be electrically connected via wires, connectors, traces, or the like. For example, the sensor may be electrically connected to a signal converter such that an analog signal representative of strain detected by the sensor may be converted to a digital signal for the controller. The controller may then cause the communication circuitry to communicate the digital signal representative of the detected strain to a computing device, such as a remote computing device or a mobile communication device (which may include a computing device). 
     A processor of the remote computing device or mobile communication device may be configured to determine whether one or more contractions have occurred based at least in part on a comparison between the signal representative of the detected strain of the cantilever portion and a threshold. Further, either the remote computing device or mobile communication device may determine whether the user has entered the first stage of labor based on, for example, a measured time interval between detected contractions. Communication circuitry of the computing device may be configured to communicate information corresponding to detected contractions to, for example, a mobile communications device. The communication circuitry may also be configured to communicate a notification or alert to a mobile communication device of the user or other person or device upon the computing device determining that the user has entered the first stage of labor, or whether the measured contractions are a “false alarm” (i.e., Braxton Hicks contractions, or other muscle contractions). 
     Alternatively, the circuit board may include a processor configured to determine whether the user has entered into first stage labor, and the communication circuitry of the board may be configured to communicate information or data corresponding to detected contractions and to communicate a notification or alert to a mobile communication device. 
     Additionally, the circuit board may include one or more apertures positioned proximate the attached end of the cantilever portion and sized to receive fasteners therethrough for coupling the circuit board to the housing. Alternatively, a portion of the circuit board proximate the attached end of the cantilever portion may be anchored to the housing by other means, such as an adhesive, clips, or screws. This coupling is configured to promote increased stability of the circuit board near the attached end of the cantilever portion as the free end thereof is flexed or otherwise displaced by the actuator causing the cantilever portion to flex. 
     In some forms, the actuator may be formed as a generally annular button that may be positioned proximate the user&#39;s abdomen. The body mass index (BMI) or body type of a user may require an actuator having a correspondingly appropriate size and configuration (e.g., an axial length and/or surface area for contacting the abdomen). As such, the present disclosure likewise provides alternative actuators that may be selectively coupled to the device and interchangeable such that the user may select a desired actuator to be used. Likewise, a kit may be provided including a device without an actuator attached, one or more embodiments of actuators, and a fastener for selectively coupling the actuators to the device. 
     A method for detecting uterine activity is additionally provided including the steps of providing a sensor device as disclosed above and detecting the strain on the cantilever portion via the sensor. Thereafter, the method may include communicating a signal representative of the detected strain on the cantilever portion to a remote computing device or mobile communication device and determining whether a contraction has occurred based at least in part on a comparison between the detected strain and a threshold. Based at least in part on a measured time interval between detected contractions, the computing device may be configured to determine whether the user has entered the first stage of labor. Optionally, the method may further include the step of communicating a notification signal to a mobile communication device of the user or another person upon determining that labor has begun. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front perspective view of an example uterine activity sensor device showing a housing thereof; 
         FIG. 2  is a rear perspective view showing the actuator; 
         FIG. 3  is a top plan view of the device shown in  FIG. 1 ; 
         FIG. 4A  is a view of the front side (i.e., the side facing away from a patient user) of the uterine activity sensor device of  FIG. 1  with the rear side of the housing removed to show a circuit board disposed in an inner cavity thereof; 
         FIG. 4B  shows the rear side of the housing that was removed in  FIG. 4A  looking from inside the housing; 
         FIG. 5  is a perspective view of the front side of the device in  FIG. 4A  showing the circuit board flipped over and revealing a power source electrically coupled thereto; 
         FIG. 6A  is a front view of the circuit board shown in  FIGS. 4A and 5  showing the cantilever portion and a sensor positioned proximate an attached end thereof; 
         FIG. 6B  shows an alternative embodiment of the cantilever portion of the circuit board, with the cantilever portion disposed at an angle; 
         FIG. 6C  shows another alternative embodiment of the cantilever portion of the circuit board; 
         FIG. 6D  shows yet another alternative embodiment of the cantilever portion of the circuit board; 
         FIG. 7  is a perspective view of a portion of the circuit board showing part of an actuator coupled to the free end of the cantilever portion in a resting state; 
         FIG. 8  is a perspective view, showing the part of the actuator in  FIG. 7  being displaced in an axial direction and deforming the cantilever portion; 
         FIG. 9  is a perspective view showing a band coupled to the device of  FIG. 1 ; 
         FIG. 10A  is a perspective view showing the device in  FIG. 2  with an alternative embodiment of the actuator; 
         FIG. 10B  is a perspective view showing the device in  FIG. 2  with another alternative embodiment of the actuator; 
         FIG. 11  is a block diagram of the uterine activity sensor device shown in  FIG. 1 ; 
         FIG. 12  is a block diagram showing communication functionality of the uterine activity sensor device of  FIG. 1 ; 
         FIG. 13  is a flowchart showing an example of a method of using a sensor device for detecting uterine activity; and 
         FIG. 14  is an example kit including a uterine activity sensor device, interchangeable actuator embodiments, and an example fastener. 
     
    
    
     Terms of orientation are for convenient reference to the drawings and are not intended to limit the orientation of the sensor device in use. 
     DETAILED DESCRIPTION 
     Referring now to the drawings, and more particularly  FIGS. 1-3 , a sensor device  100  is provided having a housing  102  defining an inner cavity therein. As illustrated, the housing  102  of the device  100  includes a front side  104  and a back side  106  (i.e., the user-facing side) that may be coupled together to form the housing  102 . For example, as shown in  FIG. 2 , the back side  106  of the housing  102  may be coupled to the front side  104  via fasteners  108  positioned in corners of the back side  106 . In other forms, the front and back sides  104 ,  106  may be snap-fit together. 
     Once assembled, the housing  102  includes a front portion  110 , a rear portion  112 , an upper portion  114 , a lower portion  116 , and two side portions  118 ,  120 . The housing  102  and portions  110 ,  112 ,  114 ,  116 ,  118 ,  120  thereof preferably include rounded or filleted edges such that the device  100  may be comfortably handled and worn by a user. In addition, the housing  102  is shown having a generally arcuate configuration with the front side  104  having a generally convex shape and the back side  106  having a generally concave shape such that it may generally conform to the abdomen of the user for further improved comfort and effective actuation of an actuator  136  caused by uterine activity. In some forms, the housing  102  may be about 3 inches wide (width W), 2 inches tall (height H), and 0.7 inches thick (thickness T). These example dimensions are provided herein for the purpose of describing the device  100 , however, the housing  102  may be formed in a variety of different sizes and shapes. 
     As illustrated, the housing  102  may include openings  122  in the form of slots  124  extending through the front and back sides  104 ,  106  for receiving, for example, a belt or strap for securing the device  100  to the abdomen of the user. The slots  124  are shown adjacent the portions  118 ,  120  of the housing, but may alternatively be positioned in other locations. In other embodiments, the device  100  may include openings  122  having different shapes or configurations for receiving belts or straps of different sizes and shapes. 
     The device  100  may include one or more switches or controls, such as switch  126  for turning the device  100  on and off. In order to inhibit accidental actuation of the switch  126 , a switch guard  128  may be positioned on the back side  106  of the housing  102  such that the abdomen of the user does not inadvertently or unintentionally contact the switch  126  while the device  100  is being worn. As shown, the switch guard  128  is formed integral with the back side  106  of the housing, but in alternative forms may be a separate component coupled thereto. Additionally, one or more indicators  130  such as light emitting diodes (LEDs)  132  may be positioned on the upper portion  114  of the housing  102  and electrically connected to circuitry of the device  100  to indicate an operating status thereof. For example, illumination of the LEDs  132  may indicate to a user that the device  100  is on or off, whether a battery is low, or in other forms may indicate whether the device  100  is successfully paired with a separate device (e.g., a mobile communication device of the user). A charging port  134  may likewise be positioned on the upper portion  114  of the housing  102  and electrically connected to a power source  160  (shown in  FIG. 5 ) of the device  100  to facilitate recharging. Of course, the switch  126 , switch guard  128 , LEDs  132 , and charging port  134  may be positioned at any suitable location on the housing  102  and need not necessarily be placed on the upper portion  114  as shown. 
     As shown in  FIG. 2 , the actuator  136  may extend through an aperture  138  (shown in  FIGS. 4B and 14 ) in the back side  106  of the housing  102  and may be coupled to a cantilever portion  140  of a circuit board  142  (shown in  FIG. 4A ) disposed in the inner cavity. In the illustrated form, the actuator  136  may be coupled to the cantilever portion  140  via a fastener  144  such as a bolt, nut, screw, nail, or the like. Alternatively, the actuator  136  may be coupled to the free end using an adhesive or other fastening means. 
     As illustrated in  FIG. 4A , the back side  106  of the housing  102  has been separated from the front side  104  to show the inner cavity thereof and a first side  146  of the circuit board  142  disposed therein. The circuit board  142  includes apertures  139  for receiving fasteners  108  for attaching the front side  104  to the back side  106  of the device  100 . The cantilever portion  140  of the circuit board  142  is illustrated including an attached end  148  and a free end  150 . By one approach, the attached end  148  is integral with the circuit board  142  and the free end  150  may include a bore  137  ( FIGS. 7 and 8 ) for receiving the fastener  144  ( FIG. 14 ) to couple the free end  150  to the actuator  136  as described above. In such forms, the free end  150  or a portion thereof is generally aligned with the aperture  138 . For example, the threaded fastener  144  may be advanced through an opening of the actuator  136 , advanced through the aperture  138 , and secured to the bore  137  on the free end  150  of the cantilever portion  140 . In some forms, the bore  137  may be threaded for accepting a corresponding threaded fastener. The bore  137  may be a separate structure attached to the free end  150  of the cantilever portion as shown in  FIGS. 7 and 8  or may alternatively be formed as a threaded aperture through cantilever portion  140 . In still other forms, a fastener such as a threaded fastener may extend from the free end  150  of the cantilever portion  140  and the actuator  136  may include a threaded aperture therethrough such that the actuator may be coupled to the free end  150  by a threaded fastener. 
     In a preferred embodiment, the cantilever portion  140  is defined by a three-sided slot, such as slot  152 , formed in the circuit board  142  so the cantilever portion  140  may bend or flex upon application of force to the free end  150  thereof. As illustrated, the cantilever portion  140  is of a generally rectangular shape, however, the cantilever portion  140  may also have other shapes as described in further detail below. The circuit board  142  also may include one or more apertures, such as apertures  154  positioned proximate the attached end  148  of the cantilever portion  140  that receive fasteners therethrough for coupling, or anchoring, the circuit board  142  to the housing  102  (e.g., through threaded apertures  156  shown in  FIG. 5 ). So configured, the circuit board  142  is anchored at the attached end  148  of the cantilever portion  140  using fasteners (not shown) to promote increased stability of the attached end  148  while allowing the free end  150  to be flexed by the actuator  136 . Alternatively, a portion of the circuit board  142  proximate the attached end  148  of the cantilever portion  140  may be anchored to the housing by other means, such as, for example, an adhesive, clips, or screws. 
     In  FIG. 5 , the circuit board  142  has been flipped over such that a second side  158  thereof is visible, and to additionally show the power source  160  for the device  100  positioned in the inner cavity and electrically coupled to the circuit board  142  via wires  162 . In the preferred form, the second side  158  of the circuit board  142  includes a sensor  164  for detecting the resulting strain on the cantilever portion  140  when the free end  150  thereof is displaced by the actuator  136 . The sensor  164  may be printed directly on the circuit board  142  or may alternatively be affixed thereto (e.g., via soldering). In one embodiment, the sensor  164  is configured for detecting strain near the attached end  148  of the cantilever portion  140  where stress concentrations will be the highest. In other embodiments, sensor  164  may be placed closer toward the free end  150  to achieve a desired sensitivity of the sensor  164  to flexing of the free end  150  of the cantilever portion  140 . In still other embodiments, multiple sensors  164  may be positioned on or proximate to cantilever portion  140  for detecting a strain on the cantilever portion  140 . 
     In a preferred embodiment, the sensor  164  may comprise a strain gauge  166 . For example, the strain gauge  166  may be a foil strain gauge that is affixed to and moves with the cantilever portion  140  of the circuit board  142  such that the resistance across the foil strain gauge changes as the cantilever portion  140  is flexed. In other embodiments, the strain gauge  166  may comprise a silicon strain gauge bonded to the circuit board  142  proximate the attached end  148 , or a polymer printed onto cantilevered portion  140  and/or another portion of circuit board  142 , to measure strain in a similar manner. Various characteristics and parameters of the strain gauge  166  may be varied such as the resistance and size thereof. In some forms, the strain gauge  166  may include a resistance between about 120 to about 350 ohms. So configured, and as described in further detail below, the resistance of the strain gauge  166  changes when the cantilever portion  140  is flexed, thus changing the voltage of an analog signal representative of the uterine activity causing the cantilever portion  140  to flex. 
     As shown, the circuit board  142  includes a signal converter  168 , a controller  170  (e.g., a microcontroller or microprocessor), and communication circuitry  172 . The signal converter  168  may function as an analog-to-digital (A/D) converter and is configured to receive an analog signal from the sensor  164  corresponding to the strain on the cantilever portion  140 . The signal converter  168  may then convert the analog signal to a digital signal for processing by the controller  170 . In some forms, the signal converter  168  may be an HX711 load cell IC that is used to interface the strain gauge  166  and the controller  170 . 
     The controller  170  is configured to process the signal received from the signal converter  168  and cause the communication circuitry  172  to communicate a corresponding signal to a remote computing device  174  or mobile communication device  176  (shown in  FIG. 12 ). In some forms, the communication circuitry  172  is configured to communicate and relay a digital signal representative of the sensed strain to one or both of the remote computing device  174  and the mobile communication device  176  for additional processing. The communication circuitry  172  may in some forms utilize a short-range communication protocol such as, for example, Zigbee, Z-Wave, Bluetooth (or Bluetooth Low Energy (BLE)), Near Field Communications (NFC), Long Terminal Repeat (LTR), Wi-Fi, WiMAX, or other proprietary or public wireless communication methods. By one approach, the communication circuitry  172  includes a universal asynchronous receiver/transmitter (UART). 
     As described in further detail below, such a digital signal may be communicated to a remote computing device  174  or mobile communication device (e.g., a device associated with a healthcare professional or other third party) to provide information regarding the status of the user&#39;s pregnancy or to provide an alert in case of emergency or other time sensitive events. 
     In some embodiments, the circuit board  142  may include a global positioning system (GPS) chip (not shown) to provide GPS data indicative of a location of the device  100 . Additionally or alternatively, the communication circuitry  172  may include a subscriber identity module (SIM) card such that the device  100  may be interfaced over a mobile telephony network. In some forms a SIM card is included on circuit board  142 . The SIM card and controller  170  may be configured such that the location of the device  100  may be determined via the telephony network using, for example, triangulation of signals received from cell towers. 
     The power source  160  positioned in the inner cavity is electrically coupled to the circuit board  142  via wires  162  to provide power to the various components thereof (e.g., signal converter  168 , controller  170 , and communication circuitry  172 ). In some embodiments, the power source  160  is a rechargeable lithium ion battery, which may be electrically coupled to the charging port  134  such that the device  100  does not require replacement of the power source  160 . In other forms, the device  100  may be configured to receive replaceable batteries, for example, AA or AAA batteries. Additionally, the power source  160  may be coupled to one of the LEDs  132  visible on the upper portion  114  of the housing  102  to indicate whether the power source  160  is running low on power, and a recharge or replacement is required. 
     Referring to  FIG. 6A , the circuit board  142  may be a printed circuit board (PCB) including various electrical components. In some forms, the material properties of the circuit board  142  may affect the flexing characteristics of the cantilever portion  140 . For example, the thickness of the circuit board  142 , the type of glass mat utilized, the lamination of the layers (e.g., the “stack up”), whether copper layers are included, the direction of the fibers in the glass mat with respect to the slot  152 , the positioning of the apertures  154  for anchoring to the housing  102  the portion of the circuit board  142  proximate the attached end  148  of cantilever portion  140 , etc., may all affect the stiffness, linearity, elastic limit, and fatigue of the circuit board  142  and cantilever portion  140  thereof. In one embodiment, the circuit board  142  is formed of glass fibers woven in both direction X and direction Y as illustrated in  FIG. 6A , and the at least one slot defining the cantilever portion is preferably formed parallel to the woven fibers such that the slot is generally aligned therewith. In one embodiment, the circuit board  142  may be formed of FR4 epoxy glass and have a thickness of about 1.6 mm. The circuit board material and properties may be selected to provide the desired stiffness and other properties mentioned above of the cantilever portion  140  such that it may bend or flex about attached end  148 . In addition to the properties of the circuit board material and the orientation of the cantilever portion  140  with respect to the weave of the fibers in the circuit board, the size and shape of the cantilevered portion  140  may also be selected to obtain desired strain measurements and/or sensitivity of the sensor  164  to uterine activity. 
     Referring to  FIG. 6B , an alternative circuit board  142 ′ is shown having an alternate arrangement of a cantilever portion  140 ′. As illustrated, the cantilever portion  140 ′ is positioned at an angle with respect to the weave of the circuit board  142 ′ in contrast with the cantilever portion  140  in  FIG. 6A  shown extending generally parallel to the weave of the circuit board  142  in directions X and Y. In some embodiments, slot patterns formed in the circuit board  142 ′ to define the cantilever portion  140 ′ can be selected to provide the desired stiffness or flexing properties thereof. The free end  150 ′ is sized and shaped to permit coupling to the actuator  136 . 
     In some forms, the at least one slot  152 ′ may be cut in the circuit board  142 ′ to form a cantilever portion having the desired size, shape, and width such that various characteristics thereof (e.g., stiffness and Young&#39;s Modulus) may be achieved. For example, as shown in  FIG. 6C , the cantilever portion  140 ″ of circuit board  142 ″ may be defined by slot  152 ″ to form a generally trapezoidal shape.  FIG. 6D  illustrates still another form of the cantilever portion  140 ′″ in which the cantilevered portion  140 ′″ has a paddle-like shape with a smaller width proximate the attached end thereof and a greater width proximate the free end. Other shapes, sizes, and orientations are within the spirit and scope of the present invention. 
       FIGS. 7 and 8  illustrate a cut-away view of the cantilever portion  140  of the circuit board  142  showing an at-rest state ( FIG. 7 ) of the free end  150  of the cantilever portion  140  and a flexed state ( FIG. 8 ) in which the free end  150  has been pushed downward by the actuator  136  (shown in  FIGS. 2, 3, and 14 ). The actuator  136  and fastener  144  coupling the actuator  136  to a bore  137  have been omitted from  FIGS. 7 and 8  for clarity and ease of illustration. As shown, the sensor  164  in the form of a strain gauge  166  is positioned on the side  158  of the circuit board  142  opposite the side from which actuator  136  protrudes. Sensor  164  is positioned proximate the attached end  148  of the cantilever portion  140 . As the free end  150  is flexed between the states shown in  FIGS. 7 and 8 , the resistance of the strain gauge  166  changes due to the physical stretching of a conductor positioned therein. An analog signal representative of the voltage or current resulting from this change in resistance is received by the signal converter  168 . 
     As shown in  FIG. 9 , a belt  176  may be coupled to the device  100  via the slots  124  to secure the device  100  (and actuator  136 ) against the abdomen of the user. The belt  176  may be formed of an elastic or stretchable material such that the device  100  will be held with the actuator  136  securely pressed against the abdomen without unduly restricting blood flow in the area. Additionally, the belt  176  may optionally include a liner on an interior face thereof to minimize or inhibit transmission of radiation to the abdominal area of the user. In other embodiments, the housing  102  of the device  100  may not include the openings  122  and the device  100  may, for example, alternatively be secured to the abdomen of the user via an adhesive or be integrated into clothing such as a shirt of the user. 
     As described above, the actuator  136  may be formed having different sizes and shapes to accommodate users having a range of body types and body mass indexes (BMIs). Various alternative embodiments of the actuator may be interchangeable such that the user may select an actuator suitable for their comfort level and body type (e.g., their individual BMI) and attach it to the device  100  before the device  100  is secured to the abdomen. Examples of alternative forms are illustrated in  FIGS. 10A and 10B . Referring to  FIG. 10A , an alternative actuator  136 ′ is shown having an annular shape similar to actuator  136 , but having an increased axial length to protrude farther out from the front side  106  of housing  102  and a smaller surface area relative thereto, which may be suitable, for example, for users having a higher than average BMI. In  FIG. 10B , another alternative actuator  136 ″ is shown having a shorter axial length relative to other actuators  136 ,  136 ′ and a larger surface area for contacting the abdomen of users, for example, those users having a lower than average BMI. Thus, the actuator may have various shapes and sizes. Regardless of shape and size, the actuator is coupled to the free end  150  of the cantilever portion  140  such that uterine activity may be sensed. 
     An example of the operation of the device  100  for monitoring uterine activity and assessing whether the user has entered the first stage of labor will now be described with respect to  FIGS. 11 and 12 . Specifically,  FIG. 11  is a schematic diagram illustrating the main components of the device  100 , and  FIG. 12  is a schematic diagram illustrating an example of a communication scheme for the device  100 . As described above, the device  100  is configured to be worn by a user such that at least the actuator  136  of the back side  106  of the housing  102  is in contact with the user&#39;s abdomen to detect uterine activity (e.g., a contraction). Upon occurrence of a contraction, the user&#39;s abdomen will move outward and inward, causing the actuator  136  to deflect the free end  150  of the cantilever portion  140  of the circuit board  142 . The resistance of the strain gauge  166 , which in one embodiment is proximate the attached end  148  of the cantilever portion  140 , changes as the free end  150  is deflected by actuator  136 , and an analog voltage or current signal that is a function of the resistance of strain gauge  166  is converted by the signal convertor  168  into a digital signal for the controller  170 . The controller  170  may then cause the communication circuitry  172  (e.g., a Bluetooth® chip) to communicate a digital signal representative of the detected uterine activity to, for example, the remote computing device  174  (e.g., a cloud computing device) or to the mobile communication device  176 , or both. The remote computing device  174  comprises a processor  179  and communication circuitry  183 . In some embodiments, the remote computing device  174  may comprise or may be communicatively connected to a mobile communication device  176  of the user. For example, the mobile communication device  176  may comprise a smart phone, a tablet, or device of the user connected to the device  100  (e.g., via a network  175  such as the internet, or a short-range communication protocol) and may include a processor  177  and communication circuitry  181 . 
     Once the digital signal representative of uterine activity of the user is received by either the remote computing device  174  or the mobile communication device  176 , the signal may be further filtered, amplified, or conditioned for analysis and analyzed to determine whether, for example, a contraction occurred. During ordinary operation, the device  100  is configured to continuously monitor uterine activity such that multiple contractions may be detected over an interval of time, and this information processed to determine, for example, whether the user has entered the first stage of labor. So configured, such continuous monitoring may allow the detected contractions to be displayed to the user in real-time through an application on the remote computing device  174  or on the user&#39;s mobile communication device  176 . 
     The processor  177  of the mobile communication device  176  or the processor  179  of the remote computing device  174  may be configured to analyze the signal representative of the monitored uterine activity to, for example, differentiate between first stage labor contractions, ordinary muscle contractions, or Braxton-Hicks contractions. The processor may be configured to perform such differentiation based at least in part on a comparison between the signal representative of the detected uterine activity and a specified threshold relating to the magnitude, the time interval between detected uterine activity signals, or both. For example, the threshold may be based on statistical averages for uterine activity of a specific age group or population, or alternatively may be specific to the patient. In some forms, the processor  179  of the remote computing device  174  or the processor  177  of the mobile communication device  176  may be configured to record the monitored activity in a memory coupled thereto and may establish a baseline of measured values of the user. Throughout the pregnancy of the user, the processor  177  and/or  179  may be configured to update and analyze changes in the user&#39;s baseline values via a machine learning algorithm, such that the accuracy of the detection and differentiation of contractions may be improved. For example, such processors may be configured to use decision trees, thresholding, Bayesian networks, Markov chains, or artificial neural networks to analyze the detected uterine activity and determine whether first stage labor has begun based, in part, on the magnitude of and time intervals measured between the detected contractions. Additionally or alternatively, some or all of the signal processing and determining functions may be performed via the controller  170  of the device  100 . 
     In one embodiment, if the processor  179  of the remote computing device  174  or the processor  177  of the mobile communication device  176  receives signals indicating that contractions are occurring at less than four-minute intervals, for at least one minute each, lasting for at least one hour, the respective processor may determine that the user has entered labor. Such determinations may also incorporate various characteristics of the user, such as age, which may be input into a user interface associated with, for example, the remote computing device  174  or mobile communication device  176 . For example, in some cases, the age of the pregnant user may affect the frequency or duration of the contractions typically present during the first stage of labor. 
     Upon the remote computing device  174  or mobile communication device determining that first stage labor has begun, either device  174  or  176  may be configured to communicate a notification to the user or another party via the communication circuitry  183  or  181 , respectively. For example, the remote computing device  174  may be configured to cause communication of a notification signal to the mobile communication device  176  when uterine activity significantly changes relative to the threshold or falls outside of a preset range. In some forms, the mobile communication device  176  may be used by the user, a medical services provider, or a family member of the user. In response to receiving the notification signal, the mobile communication device  176  may display a message indicating that the user should seek medical attention because labor is imminent. Additionally or alternatively, the notification signal may be configured to display a graph, message, picture, etc. corresponding to detected uterine activity. In still other forms, the notification signal may be further communicated to mobile communication devices of a third-party such as a family member or healthcare professional. In embodiments where the device  100  includes a GPS chip or other circuitry for determining location (e.g., a subscriber identification module (SIM card)), the remote computing device  174  may be further configured to communicate a notification to any number of third-party devices indicating the physical location of the user upon detection that the user has entered the first stage of labor. 
     As briefly described above, various embodiments of the device  100  provided herein may be used in connection with an application on the mobile communication device  176 . For example, the device  100  may be paired to the mobile communication device  176  via Bluetooth® or other short-range communication protocols to provide real-time information to the user. In one embodiment, the user is able to access the application to view a graphical representation of real-time uterine activity measured by the device  100  as the cantilever portion  140  is flexed by the actuator  136  over time. Such an application may permit the user to share the real-time viewing of the detected uterine activity (e.g., contractions) with family and friends, or a healthcare provider. In some forms, the application may be connected to a web-based application for viewing online. 
     Referring now to  FIG. 13 , a method  1200  is shown for detecting uterine activity of a user. The method  1200  includes the steps of providing a uterine activity monitor device as described above at step  1202 , the actuator of which may be positioned proximate the abdomen of the user. At step  1204 , the device is configured to sense via a sensor such as a strain gauge strain on the cantilever portion resulting from uterine activity. The device may be configured to communicate a signal representative of the sensed strain and uterine activity to either a remote computing device, a mobile communication device, or both. 
     In some embodiments, the method  1200  may include the step  1206  of communicating a signal representative of the sensed strain to the remote computing device, and step  1208  of determining whether a contraction has occurred based at least in part on a comparison between the signal and a threshold. Optionally, at step  1210 , the remote computing device may be configured to determine whether a user has entered labor based at least in part on a time interval between detected contractions. In addition, at step  1212 , the remote computing device may be configured to communicate a notification signal based at least in part on the determination of whether the user has entered first stage labor. 
     In other forms, the method  1200  may additionally or alternatively include the step  1214  of communicating a signal representative of the sensed strain to the mobile communication device, and step  1216  of determining whether a contraction has occurred based at least in part on a comparison between the signal and a threshold. Optionally, at step  1218 , the mobile communication device may be configured to determine whether a user has entered labor based at least in part on a time interval between detected contractions. In addition, at step  1220 , the mobile communication device may be configured to communicate a notification signal based at least in part on the determination of whether the user has entered first stage labor. 
     Referring now to  FIG. 14 , a kit  1400  is provided including the uterine activity monitoring device with the fastener  144  removed and the actuator  136  detached, and further including one or more alternative actuators, such as actuators  136 ′,  136 ″, for accommodating users having different body types and BMIs. As illustrated, the back side  106  of the housing  102  includes a recessed portion  145  such that the actuators  136 ,  136 ′,  136 ″ may be partially received therein when impinged upon by the user. So configured, the recessed portion  145  permits the actuator to be seated at least partially therein when the cantilever portion  140  is in a flexed configuration (e.g., as shown in  FIG. 8 ). Optionally, the kit  1400  may include an instruction sheet or data sheet including a suggested actuator (e.g.,  136 ,  136 ′,  136 ″) for different body types and ranges of BMIs. For example, the user may obtain the kit  1400  including the different actuators  136 ,  136 ′,  136 ″ and select and attach an actuator using the fastener  144  through the aperture  138  in the housing  102 . So configured, the actuators in the kit  1400  may be interchangeable for use with the device. In some forms, the kit  1400  may include various types of fasteners as described above (e.g., a hex bolt or other fastener), and may also include a driver (e.g., a screwdriver or hex driver) corresponding with the fastener for attaching the selected actuator to the device. 
     Uses of singular terms such as “a,” “an,” are intended to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms. Any description of certain embodiments as “preferred” embodiments, and other recitation of embodiments, features, or ranges as being preferred, or suggestion that such are preferred, is not deemed to be limiting. The invention is deemed to encompass embodiments that are presently deemed to be less preferred and that may be described herein as such. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended to illuminate the invention and does not pose a limitation on the scope of the invention. Any statement herein as to the nature or benefits of the invention or of the preferred embodiments is not intended to be limiting. This invention includes all modifications and equivalents of the subject matter recited herein as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. No unclaimed language should be deemed to limit the invention in scope. Any statements or suggestions herein that certain features constitute a component of the claimed invention are not intended to be limiting unless reflected in the appended claims. Neither the marking of the patent number on any product nor the identification of the patent number in connection with any service should be deemed a representation that all embodiments described herein are incorporated into such product or service.