Abstract:
A system, apparatus and method for saliva-conductance based hydration sensors and for a wireless network comprising hydration sensors and base stations. The hydration sensors include electrodes, a means of measuring saliva conductance, a processor, memory and wireless controllers. The hydration sensors output user hydration status based on the conductance of the user&#39;s saliva. Saliva conductance is correlated with ion concentration of saliva, which is a biomarker for dehydration. Thus, saliva conductance can be a proxy for dehydration. The hydration sensors may be used in active or hostile conditions, e.g., military use. Symptoms of dehydration are delayed: fatigue and impaired judgment can occur before a user realizes he/she is dehydrated. The hydration sensors indicate dehydration to a user, thus encouraging a user to hydrate and prevent dehydration-related injuries. Data from hydration sensors may be used in determining supply delivery logistics in hostile or inaccessible terrain.

Description:
BACKGROUND 
     Field of invention 
       [0001]    Embodiments of the present disclosure relate generally to fluid conductance measurements and, more specifically, to determining hydration levels in animals. 
       Description of Related Art 
       [0002]    Many individuals suffer from dehydration, which could be largely prevented by maintaining proper hydration levels. Those in extreme environments are particularly prone to hydration-related issues due to heat, dangerous levels of physical activity, inability to judge the severity of potential dehydration, and lack of continuous water access. Crucially, the symptoms of dehydration are often delayed: fatigue and impaired judgment can occur well before an individual is able to prevent dehydration and associated symptoms. While dehydration can be treated by increased water consumption, extreme environment conditions make proper hydration status difficult to accurately and objectively monitor. 
         [0003]    Publications disclose methods and devices that determine the hydration status of individuals through variegated means. Conventional methods, some of which are considered industry standards for measuring dehydration, include urine and blood chemical composition analysis, plasma osmolality, as well as body weight differential analysis due to water loss. These methods are impractical due to their invasiveness and interference with in-field activities, such as may be found in military use. 
         [0004]    One such device uses ultrasonic sensing to measure hydration levels of tissue. Ultrasonic velocity may be used as an indicator of tissue hydration and thus overall hydration status. This is accomplished by positioning two ultrasonic transducers at a fixed distance away from each other across the tissue of interest. By measuring the time it takes for an ultrasonic pulse to travel the known distance, one can then calculate the ultrasonic velocity. However, such a device has not been proven to be sensitive enough to detect the minor changes in tissue hydration due to fluid loss. Also, the correlation between tissue hydration and overall hydration status is not well documented. Finally, such a device would not be suitable in field settings because the device would not be operational in vigorously active conditions, such as outdoors or in combat settings. 
         [0005]    Another device for measuring hydration uses saliva flow rate due to capillary action. It is known that the rate of flow into a water-permeable material is correlated to saliva concentration. However, this device includes several drawbacks to in-field use; one such drawback is that it takes several minutes to take a measurement. This device includes a timing apparatus that keeps track of the time elapsed during measurement. Thus, a saliva-flow rate device is impractical to use in outdoor or extreme environments. 
         [0006]    Another method for determining hydration levels includes analyzing sodium concentration in saliva. This method includes mixing saliva with a second solution to make a third solution, followed by dipping a chemically-treated piece of paper into the third solution. The user must then wait for the chemicals deposited on the paper to change in color, based on absorption of the third solution of the paper and mixture with the chemicals deposited on the paper. Clearly, such a method is cumbersome, time-consuming and is not appropriate for in-field, real-time hydration measurements. 
         [0007]    An additional method of hydration sensing includes determining saliva osmolarity using a bench top device known as a freezing-point depression osmometer. Similar to methods and devices listed above, this method does not provide for a portable means of hydration level testing. Rather, this method is slow and cumbersome, in part due to requirements that the user perform chemical analysis using a non-portable osmometer. 
         [0008]    As the foregoing illustrates, what is needed in the art is a simple, portable, accurate and fast method of determining hydration levels in humans and other animals. 
       SUMMARY 
       [0009]    Disclosed herein is a system including: a wireless network comprising hydration sensors and base stations. The hydration sensors include two or more electrodes, a means of measuring saliva conductance, a processor, memory and wireless controllers. The hydration sensors can output hydration status data of the users. The base station coordinates hydration status data between each of the hydration sensors. 
         [0010]    Embodiments according to the present disclosure may use saliva conductance as a biomarker for dehydration. In one embodiment, a user may deposit a saliva sample into a collector which has exposed electrodes at the base of the collector. In another embodiment, the user may simply place the hydration sensor into the mouth and effectuate electrode contact with the user&#39;s saliva. 
         [0011]    Once the saliva makes contact with these electrodes, embodiments according to the present disclosure may determine conductance using the electrodes. Then, embodiments according to the present disclosure may process the conductance and determine hydration status of the user. Finally, embodiments according to the present disclosure may provide an output indicating hydration status. 
         [0012]    Embodiments according to the present disclosure may provide for a lightweight, portable and nonintrusive form factor that causes minimal interference with field activity. Such field activity may include military combat conditions or vigorously active use generally. Embodiments according to the present disclosure may also provide for simple, straightforward use and real-time measurement capability to help ensure compliance among users. Finally, embodiments according to the present disclosure may allow for ease of integration into existing equipment, such as installation onto catheters included with popular hydration sport backpacks, and other portable hydration systems. 
         [0013]    Indeed, numerous, variegated uses of embodiments according to the present disclosure are possible, including but not limited to: (1) militaries could monitor hydration levels of soldiers in order to determine logistics (e.g., where to deliver more water/supplies); (2) hospitals and researchers could include hydration sensing as part of a standard list of vital sign checkups, to gather clinical trial data as well as determine the efficacy of being well-hydrated or under-hydrated on various treatments; (3) pharmaceutical companies could gather clinical trial data on how hydration affects the efficacy and side effects of drug therapy; (4) athletics could determine hydration levels during gameplay and thus control water intake vs. urination, thus influencing on- vs. off-court time; (5) outdoor enthusiasts could figure out how much water they are using and how much water they need to use and share their data on social media; (6) wearable device manufactures could encourage more water usage, share data on social media, and incorporate hydration sensors according to embodiments of the present disclosure as part of the wearable device; (7) pilots and astronauts could monitor their hydration status as part of vital sign tracking and (8) doctors could recommend additional hydration therapy to their patients who have a hydration sensor according to embodiments of the present disclosure. 
         [0014]    The construction and method of operation of the invention, however, together with additional objectives and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1A  illustrates an exploded view of a dehydration sensor, according to one embodiment of the present disclosure; 
           [0016]      FIG. 1B  illustrates an exploded view of a dehydration sensor, according to one embodiment of the present disclosure; 
           [0017]      FIG. 2  illustrates a circuit diagram, according to one embodiment of the present disclosure; 
           [0018]      FIG. 3  illustrates a cloud computing environment, according to one embodiment of the present disclosure; 
           [0019]      FIG. 4  illustrates a flow diagram of method steps for determining hydration levels, according to one embodiment of the present disclosure; 
           [0020]      FIG. 5A  illustrates a graph indicating saliva conductance vs. saliva osmotic concentration in human subjects, according to one embodiment of the present disclosure; 
           [0021]      FIG. 5B  illustrates a graph indicating saliva conductance vs. saliva osmotic concentration in human subjects, according to one embodiment of the present disclosure; 
           [0022]      FIG. 5C  illustrates a graph indicating saliva conductance vs. saliva osmotic concentration in human subjects, according to one embodiment of the present disclosure; 
           [0023]      FIG. 5D  illustrates a graph indicating saliva conductance vs. saliva osmotic concentration in human subjects, according to one embodiment of the present disclosure; 
           [0024]      FIG. 6  illustrates a hydration sensor integrated into military equipment, according to one embodiment of the present disclosure; 
           [0025]      FIG. 7A  illustrates an integrated hydration sensor and hydration catheter, according to embodiments according to the present disclosure; 
           [0026]      FIG. 7B  illustrates an integrated hydration sensor and hydration catheter, according to embodiments according to the present disclosure; 
           [0027]      FIG. 8A  illustrates an integrated hydration sensor and hydration catheter, according to embodiments according to the present disclosure; 
           [0028]      FIG. 8B  illustrates an integrated hydration sensor and hydration catheter, according to embodiments according to the present disclosure; 
           [0029]      FIG. 9  illustrates an integrated hydration sensor and hydration catheter and reservoir, according to embodiments according to the present disclosure; and, 
           [0030]      FIG. 10  illustrates a hydration sensor attached to a hydration bottle system, according to one embodiment of the present disclosure. 
       
    
    
     DESCRIPTION 
     Generality of Invention 
       [0031]    This application should be read in the most general possible form. This includes, without limitation, the following: 
         [0032]    References to specific techniques include alternative and more general techniques, especially when discussing aspects of the invention, or how the embodiment might be made or used. 
         [0033]    References to “preferred” techniques generally mean that the inventor contemplates using those techniques, and thinks they are best for the intended application. This does not exclude other techniques for the invention, and does not mean that those techniques are necessarily essential or would be preferred in all circumstances. 
         [0034]    References to contemplated causes and effects for some implementations do not preclude other causes or effects that might occur in other implementations. 
         [0035]    References to reasons for using particular techniques do not preclude other reasons or techniques, even if completely contrary, where circumstances would indicate that the stated reasons or techniques are not as applicable. 
         [0036]    Furthermore, the invention is in no way limited to the specifics of any particular embodiments and examples disclosed herein. Many other variations are possible which remain within the content, scope and spirit of the invention, and these variations would become clear to those skilled in the art after perusal of this application. 
       DETAILED DESCRIPTION 
       [0037]    Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
         [0038]    References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure or characteristic, but every embodiment may not necessarily include the particular feature, structure or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one of ordinary skill in the art to effect such feature, structure or characteristic in connection with other embodiments whether or not explicitly described. Parts of the description are presented using terminology commonly employed by those of ordinary skill in the art to convey the substance of their work to others of ordinary skill in the art. 
       System Elements 
       [0039]    
       FIG. 1 
     
         [0040]      FIGS. 1A and 1B  illustrate an exploded view of a dehydration sensor, according to one embodiment of the present disclosure. As shown, the hydration sensor  100  includes a housing  102 , a printed circuit board (PCB)  104 , a cover plate  106 , a cable  108 , a stem  110 , and a saliva conductance tester  112 . By way of example and not limitation, saliva conductance tester  112  may take the form of mouthpiece  113 , or saliva collector cap  111 . In some embodiments, saliva conductance tester  112  may be disconnected and swapped with other types of saliva conductance testers  112  mentioned herein. 
         [0041]    PCB  104  may be contained within housing  102 , and beneath cover plate  106 , which serve to protect PCB  104 , among other functions. The circuitry in PCB is shown in detail in  FIG. 1B . PCB  104  may include but is not limited to the following components connected to a bus  114 : oscillator  116 , differential amplifier  118 , AC/DC converter  120 , antenna  122 , bluetooth circuit  124 , battery  126 , microcontroller  128 . Bus  114  may also be connected to but not limited to the following components: positive electrical lead  130 , negative electrical lead  132  and optionally, data leads  134 . Data leads  134  may contain one or more distinct electrical connections. The interactive functionality of many of the elements comprising PCB  104  will be discussed in the detailed description for  FIG. 2 . ( 41 ) In some embodiments, housing  102  and/or cover plate  106  may be coupled to cable  108 . In further embodiments, PCB  104  may be electrically connected to cable  108 . By way of example and not limitation, PCB  104  may be electrically connected to cable  108  through one or more of the following components: positive electrical lead  130 , negative electrical lead  132  and optionally, data leads  134 . 
         [0042]    In some embodiments, cable  108  may be coupled to stem  110  and saliva conductance tester  112 . In further embodiments, stem  110  and/or saliva conductance tester  112  are electrically connected to PCB  104  through one or more of the following components: positive electrode  130 , negative electrode  132  and optionally, data leads  134 . 
         [0043]    Stem  110  may have LEDs  136 . In some embodiments, LEDs  136  may serve to indicate to the user levels of hydration, power on/off status, battery charge and other functions. Alternatively, LEDs  136  may be disposed on housing or cover plate  102  or  106  (not illustrated). 
         [0044]    Saliva conductance tester  112  may be attached to positive electrode  138  and negative electrode  140 . In some embodiments, positive electrode  138  and negative electrode  140  serve to test the conductance of saliva in proximity to saliva conductance tester  112 . In some embodiments, positive electrode  138  and negative electrode  140  and other electrodes or saliva conductance measurement means described herein may be made of gold, platinum, copper, conductive polymer, carbon or the like. In one embodiment, mouthpiece  113  may be engulfed in saliva such that the saliva makes contact with both electrodes  138  and  140  such that an electrical current may flow through the saliva, thus allowing conductance to be determined. In other embodiments, both electrodes  138  and  140  may be structurally sound such that both electrodes  138  and  140  are resistant to crushing forces (e.g., biting). 
         [0045]    As mentioned above, saliva conductance tester  112  may take the form of saliva collector cap  111 . Saliva collector cap  111  may include saliva deposition chamber  162 , well  164 , stem  110 , and positive electrode  168  and negative electrode  170 . Positive electrode  168  and negative electrode  170  are similar to positive electrode  138  and negative electrode  140 , respectively. In one embodiment, saliva may be deposited in saliva collector cap  111  such that saliva makes contact with both electrodes  138  and  140  such that an electrical current may flow through the saliva, thus allowing conductance to be determined. 
         [0046]    The above illustration provides many different embodiments or embodiments for implementing different features of the invention. Specific embodiments of components and processes are described to help clarify the invention. These are, of course, merely embodiments and are not intended to limit the invention from that described in the claims. 
       Processing System 
       [0047]    The methods and techniques described herein may be performed on a processor-based device. The processor-based device will generally comprise a processor attached to one or more memory devices or other tools for persisting data. These memory devices will be operable to provide machine-readable instructions to the processors and to store data. Certain embodiments may include data acquired from remote servers. The processor may also be coupled to various input/output (I/O) devices for receiving input from a user or another system and for providing an output to a user or another system. These I/O devices may include human interaction devices such as keyboards, touch screens, displays and terminals as well as remote connected computer systems, modems, radio transmitters and handheld personal communication devices such as cellular phones, “smart phones”, digital assistants and the like. 
         [0048]    The processing system may also include mass storage devices such as disk drives and flash memory modules as well as connections through I/O devices to servers or remote processors containing additional storage devices and peripherals. 
         [0049]    Certain embodiments may employ multiple servers and data storage devices thus allowing for operation in a cloud or for operations drawing from multiple data sources. The inventor contemplates that the methods disclosed herein will also operate over a network such as the Internet, and may be effectuated using combinations of several processing devices, memories and I/O. Moreover any device or system that operates to effectuate techniques according to the current disclosure may be considered a server for the purposes of this disclosure if the device or system operates to communicate all or a portion of the operations to another device. 
         [0050]    The processing system may be a wireless device such as a smart phone, personal digital assistant (PDA), laptop, notebook and tablet computing devices operating through wireless networks. These wireless devices may include a processor, memory coupled to the processor, displays, keypads, WiFi, Bluetooth, GPS and other I/O functionality. Alternatively, the entire processing system may be self-contained on a single device. 
         [0051]    The methods and techniques described herein may be performed on a processor-based device. The processor-based device will generally comprise a processor attached to one or more memory devices or other tools for persisting data. These memory devices will be operable to provide machine-readable instructions to the processors and to store data, including data acquired from remote servers. The processor will also be coupled to various input/output (I/O) devices for receiving input from a user or another system and for providing an output to a user or another system. These I/O devices include human interaction devices such as keyboards, touchscreens, displays, pocket pagers and terminals as well as remote connected computer systems, modems, radio transmitters and handheld personal communication devices such as cellular phones, “smart phones” and digital assistants. 
         [0052]    The processing system may also include mass storage devices such as disk drives and flash memory modules as well as connections through I/O devices to servers containing additional storage devices and peripherals. Certain embodiments may employ multiple servers and data storage devices thus allowing for operation in a cloud or for operations drawing from multiple data sources. The inventors contemplate that the methods disclosed herein will operate over a network such as the Internet, and may be effectuated using combinations of several processing devices, memories and I/O. 
         [0053]    The inventors further contemplate integration of embodiments of the present disclosure a network of nodes that are capable of performing some processing, gathering sensory information and communicating with other nodes in the network. Such wireless sensor nodes may include devices, vehicles, buildings and other items embedded with electronics, software, sensors, and network connectivity that enables the nodes to collect and exchange data (sometimes referred to as “Internet of Things” (IoT) or a wireless sensor network). In these embodiments, the inventors contemplate, by way of example and not limitation, a hydration sensor communicating with one or more hydration sensors and a base station. Said base station may coordinate data between the one or more hydration sensors. Administrators of the base station may use this data to inform the users to take or omit action, including but not limited to, hydrate. Further description of such embodiments are described herein. 
         [0054]    The processing system may be a wireless device such as a smart phone, personal digital assistant (PDA), laptop, notebook and tablet computing devices operating through wireless networks. These wireless devices may include a processor, memory coupled to the processor, displays, keypads, WiFi, Bluetooth, GPS and other I/O functionality. 
       FIG.  2   
       [0055]      FIG. 2  illustrates a circuit diagram, according to one embodiment of the present disclosure. As shown, circuit  200  includes but is not limited to: oscillator  202 , amplifier  204 , AC/DC converter  205 , microcontroller  206 , wireless controller  124  (previously shown in  FIG. 1B ), battery  210 , leads  212  (including poles alpha and beta), and antenna  122  (previously shown in  FIG. 1B ). 
         [0056]    The role of oscillator  202  is to generate an alternating current in the form of a sine wave, however, those skilled in the art will appreciate that there are numerous other methods of generating an oscillating or sinusoidal current. By way of example and not limitation, oscillator  202  may take the form of a Wien bridge oscillator, as shown. While some embodiments, a single oscillating sine current may be used to take conductance measurements, other embodiments of the present disclosure use a broad frequency or multifrequency current (i.e., a combination of currents of varying frequency). In this manner, such currents may allow for saliva conductance measurements to be less affected by frequency-dependent confounders. 
         [0057]    The role of amplifier  204  is to amplify the conductance of tested saliva. 
         [0058]    However, those skilled in the art will appreciate that there are numerous other methods of amplifying an electrical signal. By way of example and not limitation, amplifier  204  may take the form of an operational amplifier. 
         [0059]    Resistor R 10  represents saliva resistance. Poles alpha and beta represent the electrical connection to positive and negative conductance electrodes (such as positive electrode  138 , negative electrode  140 , and other electrodes described herein). In some embodiments, these electrodes assess the conductance of saliva to be tested. It is known in the arts that, as the conductance changes, resistance changes proportionately. Thus, in combination with amplifier  204  as pictured, amplification changes according to equation B.01, below: 
         [0000]        A   B   =R   8   /R   10 +1   Eq 2.1
 
         [0060]    Variables for Eq 2.1 are provided in Table 2.1, below: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 2.1 
               
               
                   
                   
               
             
             
               
                   
                 A B   
                 Gain of Amplifier 204 
               
               
                   
                 R 8   
                 Resistance of R 8   
               
               
                   
                 R 10   
                 Resistance of R 10   
               
               
                   
                   
               
             
          
         
       
     
         [0061]    Thus, saliva conductance is proportional to amplifier gain from amplifier  204 . 
         [0062]    In terms of enhancing saliva conductance measurements, it is important to take into account the following factors: electrode material and resistivity, electrode spacing (e.g., spacing between poles α and β ) as well as electrode surface contact area. The measured conductance is inversely related to the distance between the electrodes. Specifically, the conductance of saliva in siemens can be determined using Equation 2.2: 
         [0000]        G=A   S /(ρ L )   Eq 2.2
 
         [0063]    The variables used in Equation 2.2 are provided in Table 2.2: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                 TABLE 2.2 
               
               
                   
                   
               
             
             
               
                   
                 G 
                 Conductance (e.g., of saliva) 
               
               
                   
                 A S   
                 Electrode surface area 
               
               
                   
                 ρ 
                 Resistivity of saliva 
               
               
                   
                 L 
                 Electrode spacing 
               
               
                   
                   
               
             
          
         
       
     
         [0064]    By way of example and not limitation, an electrode spacing of 7 mm, surface area of 4.15 mm 2 , and the use of carbon electrodes may be successful in saliva conductance measurements. 
         [0065]    The role of AC/DC converter  205 , is to convert an alternating current (AC) into a direct current (DC) acceptable to a microcontroller or the like. However, those skilled in the art will appreciate that there are various methods of converting AC to DC. By way of example and not limitation, AC/DC converter  205  may take the form of a full-wave diode bridge rectifier, as shown. 
         [0066]    The role of microcontroller  206  is to process the DC signal from AC/DC converter  205  into an output useful to the user, among other functions. However, those skilled in the art will appreciate that there are various methods of processing data. In one embodiment, microcontroller  206  outputs hydration levels based on the DC signal from AC/DC converter  205 . In other embodiments, microcontroller  206  transmits hydration level data to the user via wireless controller  124 , described below. 
         [0067]    The role of wireless controller  124 , is to propagate a wireless signal through spacetime to other devices. However, those skilled in the art will appreciate that there are variegated methods of transmitting a signal at different frequencies at different effective distances. By way of example and not limitation, wireless controller  124  may take the form of a combined bluetooth circuit and antenna. The role of antenna  122 , is to generate an alternating current in the form of a sine wave, however, those skilled in the art will appreciate that there are numerous other methods of generating an oscillating or sinusoidal current. 
         [0068]    Battery  210  provides power to circuit  200  such that circuit  200  is operational to perform saliva conductance testing. Those skilled in the art will recognize that there are numerous means of powering circuits, including electrical outlet power, inductive power, solar power and the like. Furthermore, those skilled in the art will recognize that circuits such as  200  will need a minimum of sustained and continuous power to operate, based on the load that circuit  200  causes on the power source. 
         [0069]    Leads  212  may include poles alpha (α) and beta (β). In one embodiment, one or more of leads  212  are connected to a saliva conductance testing device (not pictured), such as saliva conductance tester  112 . 
         [0070]    By way of example and not limitation, suppose oscillator  202  has been configured to output an alternating current in the form of a sinusoidal wave with an amplitude of one volt (1V). Furthering the example, resistors are selected such that R 8  is 2 kiloohms (kΩ). In keeping with this example, resistor R 10  may represent the resistance (inverse conductance) of a user&#39;s saliva, which may have a resistance of 1 kΩ. If one uses a negative feedback amplifier as amplifier  204 , the ratio of the amplitude of the output wave to the amplitude of the input wave from the oscillator will be governed by Equation B.1 above. The gain provided by such an amplifier is shown in Equation 2.3, below. 
         [0000]        A   B =(2 kΩ/1 kΩ)+1=3.   Eq. 2.3
 
         [0071]    (64) Thus, the gain provided by A B  may be 3, and therefore the output wave from the amplifier may constitute a 3V peak-to-peak sinusoidal wave, in keeping with the above example. Those skilled in the art will understand that converting an alternative current to a direct current may be a process that is less than perfectly efficient. In the exemplary full wave rectifier provided in circuit  200  (namely, AC/DC converter  205 ) a voltage drop may occur due to the diodes constituting the full-wave rectifier bridge of AC/DC converter  205 . Furthering the example above, after passing through the AC/DC converter  205 , the output may be different and varies based on the configuration of the rectifier. It is worth pointing out in the example that, depending on the resistance (conductance) of the saliva (in this example, R 10 ), this DC signal may change in voltage, as affected by amplifier  204 . 
         [0072]    Continuing the example above, this DC signal may then be fed into, for example, a set of LEDs (not pictured). Those skilled in the art will understand that an increase in voltage may be used to power additional components, such as LEDs. In this example, additional LEDs may be lit based on voltage levels. Thus, one LED may be lit for voltages under 1V, a second LED may be lit for voltages under 2V, and the like. In this manner, saliva conductance may be indicated to the user through a selection of a number or color of LEDs. Those skilled in the art will understand that LEDs are merely one method of indicating a voltage output, a digital or analog readout, ammeter, voice callout, color change, screen display, and the like, and any and all means known in the art for representing or displaying information such as conductance and the like are contemplated. 
         [0073]    Thus, one embodiment could be described as follows: two or more electrodes as described herein, a means of measuring saliva conductance; non-transitory memory, a power source and a processor. 
       FIG.  3   
       [0074]      FIG. 3  illustrates a cloud computing environment, according to one embodiment of the present disclosure. As shown,  FIG. 3  illustrates a functional block diagram of a client server system  300  that may be employed for some embodiments according to the current disclosure. In  FIG. 3 , a server  310  is coupled to one or more databases  312  and to a network  314 . The network may include routers, hubs and other equipment to effectuate communications between all associated devices. A user accesses the server by a computer  316  communicably coupled to the network  314 . The computer  316  includes a sound capture device such as a microphone (not shown). Alternatively the user may access the server  310  through the network  314  by using a smart device such as a telephone or PDA (mobile device)  318 . Mobile device  318  may connect to the server  310  through an access point  320  coupled to the network  314 . Mobile device  318  includes a sound capture device such as a microphone. 
         [0075]    Conventionally, client server processing operates by dividing the processing between two devices such as a server and a smart device such as a cell phone or other computing device. The workload is divided between the servers and the clients according to a predetermined specification. For example in a “light client” application, the server does most of the data processing and the client does a minimal amount of processing, often merely displaying the result of processing performed on a server. 
         [0076]    According to the current disclosure, client-server applications are structured so that the server provides machine-readable instructions to the client device and the client device executes those instructions. The interaction between the server and client indicates which instructions are transmitted and executed. In addition, the client may, at times, provide for machine readable instructions to the server, which in turn executes them. Several forms of machine readable instructions are conventionally known including applets and are written in a variety of languages including Java and JavaScript. 
         [0077]    Client-server applications also provide for software as a service (SaaS) applications where the server provides software to the client on an as needed basis. 
         [0078]    In addition to the transmission of instructions, client-server applications also include transmission of data between the client and server. Often this entails data stored on the client to be transmitted to the server for processing. The resulting data is then transmitted back to the client for display or further processing. 
         [0079]    One having skill in the art will recognize that client devices may be communicably coupled to a variety of other devices and systems such that the client receives data directly and operates on that data before transmitting it to other devices or servers. Thus data to the client device may come from input data from a user, from a memory on the device, from an external memory device coupled to the device, from a radio receiver coupled to the device or from a transducer coupled to the device. The radio may be part of a wireless communications system such as a Wi-Fi or Bluetooth receiver. Transducers may be any of a number of devices or instruments such as thermometers, pedometers, health measuring devices and the like. 
         [0080]    A client-server system may rely on “engines” which include processor-readable instructions (or code) to effectuate different elements of a design. Each engine may be responsible for differing operations and may reside in whole or in part on a client, server or other device. As disclosed herein a display engine, a data engine, an execution engine, a user interface (UI) engine and the like may be employed. These engines may seek and gather information about events from remote data sources. 
         [0081]    In some embodiments according to the present disclosure, hydration sensors discussed herein may communicate with elements of network  314  through antenna  122  and wireless controller  124 , or the like. In some embodiments, hydration sensors discussed herein may communicate with mobile device  318  through a bluetooth connection or other means known in the art. The contents of any communications may include but are not limited to: information relating to hydration levels of the user, water storage locations, water intake recommendations and the like, according to embodiments according to the present disclosure. In this manner, users of hydration sensors discussed herein and system administrators overseeing network  314  may make better-informed decisions relating to user hydration. More specific examples of enhanced decision making based on hydration levels and cloud-based communications 
         [0082]    For example, a military setting may require strategic rationing and location of water, and such activities may be optimized through the use of embodiments according to the present disclosure, such as hydration sensors discussed herein. Specifically, decision makers of military supply logistics could deliver or relocate supplies based on water consumption/hydration levels by members of the military, as water is consumed. Furthermore, future such deliveries/relocations could be based on current consumption and hydration data recoded by embodiments according to the present disclosure in an effort to prevent supply shortages in the field. This future logistical planning may be easier to execute as locations vary in hostility. For example, if hydration sensors described herein record user water consumption as higher than current water storages accommodate for in a currently low-risk area, decision-makers may react accordingly by delivering more water while said areas are still low-risk. This is especially important if said areas are expected to become high-risk to members of the military. Such future logistical planning can be done in anticipation of these areas becoming actively hostile, making for safer and more effective supply delivery. 
         [0083]    In another example, doctors, patients and researchers alike may benefit from hydration level monitoring and hydration level data sharing. Specifically, embodiments according to the present disclosure such as hydration sensors discussed herein may allow doctors to assess the hydration level of their patients as part of a standard vital sign check. Furthermore, the speed and portability of embodiments according to the present disclosure allow for unobtrusive and repeated usage of hydration sensors discussed herein such that hydration level monitoring, including real-time cloud storage of such data, may be done throughout the patient&#39;s stay. In keeping with the example, such cloud-stored hydration level data between one or more patients may be helpful for doctors to determine whether patients are properly hydrated, whether hydration levels are indicative of symptoms of unknown afflictions (thus potentially enhancing a physician&#39;s diagnosis), and the like. Researchers may benefit as well, in determining whether and how hydration levels affect various afflictions and patients alike, thus potentially enhancing clinical trial data. In addition, embodiments according to the present disclosure may assist pharmaceutical companies in determining the effects of hydration levels on the efficacy of medical drug therapy on patients. 
         [0084]    In another example, embodiments according to the present disclosure could be used to naturally and safely enhance athlete performance through hydration level monitoring. For example, a water cooler or other hydration unit may include embodiments according to the present disclosure, such as hydration sensors discussed herein. Thus, when players hydrate, their hydration levels can be monitored and stored in the cloud. In this manner, player hydration levels can be tracked and allow for enhanced decision making by coaches, athletic trainers, and the like. 
         [0085]    In another example, athletes or outdoor activity enthusiasts may carry embodiments according to the present disclosure such as hydration sensors discussed herein and record and trade hydration level data through social media, similar to the manner in which wearable device users do. In this manner, wearable device manufacturers, sports drinks manufactures and the like may use embodiments of the present disclosure to encourage more hydration and share their products enhanced with embodiments according to the present disclosure. 
         [0086]    Thus, one system embodiment could be described as follows: a wireless network of hydration sensors, in which the hydration sensors include two or more electrodes, a means of measuring saliva conductance, a processor, non-transitory storage containing processor-based instructions, and a means of wireless communications, in which the non-transitory storage contains processor-based instructions operable for determining hydration levels, in which the hydration sensors are operable to output hydration status data; and a base station, in which the base station coordinates hydration status data between the hydration sensors. 
       FIG.  4   
       [0087]      FIG. 4  illustrates a flow diagram of method steps for determining hydration levels, according to one embodiment of the present disclosure. Although the method steps are described in conjunction with  FIGS. 1-10 , persons skilled in the art will understand that any system configured to perform the method steps, in any order, falls within the scope of the present invention. The steps in this method are illustrative only and do not necessary need to be performed in the given order they are presented herein. Some steps may be omitted completely. 
         [0088]    The method begins at a step  402 , a user depositing a sample of the user&#39;s saliva in contact to electrodes described herein, such electrodes may be part of saliva conductance tester  112  or catheters described herein. 
         [0089]    At a step  404 , a current is generated (in some embodiments, by oscillator  202 ) and sent to electrodes described herein. In some embodiments, this current is an alternating current or a multifrequency current. In this step, the generated current is transmitted from one electrode, through the saliva deposited, and collected by the second electrode. 
         [0090]    At a step  406 , the return current is accepted by a microcontroller or the like. 
         [0091]    In this step, a return current may be sent to an AC to DC converter. In some embodiments, this return current is an alternating current. In these embodiments, the return current is converted into a direct current. 
         [0092]    At a step  408 , the microcontroller determines saliva conductance based on the return current and/or return voltage. 
         [0093]    At a step  410 , the microcontroller compares saliva conductance to a master data table. The master data table may contain but is not limited to one or more of the following: saliva conductances and hydration levels. 
         [0094]    At an optional step  412 , the microcontroller compares saliva conductances to data from an auxiliary data table. The auxiliary data table may contain but is not limited to one or more of the following: hydration levels, osmolarity, osmolality, ion concentration, body weight, body weight differential data due to water intake, gender, age, ethnicity, medical history data, fitness levels (such as body mass index and the like), urine data, and blood data. In some embodiments, data from auxiliary data table may be reflective of the user. 
         [0095]    At a step  414 , the microcontroller determines hydration level. 
         [0096]    At a step  416 , the microcontroller outputs an indication of the hydration status, after which the method ends. 
       FIG.  5   
       [0097]      FIG. 5  illustrates graphs indicating saliva conductance vs. osmotic concentration in human subjects, according to embodiments of the present disclosure. More specifically, Graph  5 A shows a linear regression plot of empirical data taken from the saliva of seven human test subjects. Discussed herein are various methods of measuring human hydration levels, followed by a discussion of interpreting saliva conductance data as a means of determining hydration level, according to embodiments according to the present disclosure. 
         [0098]    Using ionic concentration as a means of determining hydration status will be discussed. Those skilled in the art know that saliva consists of, among other things, ions and biological components (e.g., mucin). Measuring the concentration of ions in saliva from an individual may provide a determination of the individual&#39;s hydration status. However, measuring ionic concentration directly can be cumbersome, time-consuming and difficult, especially in outdoor or during vigorous activity conditions. As conventionally known, an ion selective electrode may be used to test for ionic concentration, but such a device may require tuning and individual measurements for each type of ion to be measured. This is impractical for use during in-field saliva ion measurement due to the fact that saliva contains numerous, variegated ion types. Furthermore, a ion selective electrode is a bench-top measurement system best suited for laboratory use, rather than in-field (e.g., military field or outdoor) use. 
         [0099]    According to embodiments according to the present disclosure, conductance may be an indirect measure of a solution&#39;s osmolarity, and conductance may be a sensing modality that can be much more easily translated into a portable device. 
         [0100]    Discussed herein is the correlation between saliva conductance and hydration. A dehydrated subject is likely to produce saliva that contains less water (dehydrated saliva) than saliva from a hydrated subject (hydrated saliva). This saliva is likely to be higher in ion concentration with ions, and more conductive. Thus, a saliva sample&#39;s ion concentration may be electrically determined through conductance. More specifically, a percent change in conductance relative to a hydrated state may be used to detect the onset of dehydration. 
         [0101]    Using conductance as an indirect measure of osmolarity is possible due to the correlation between these two metrics, as shown in Graph  5 A, which shows a linear regression plot of conductance measurements versus osmolarity. More specifically, Graph  5 A illustrates seven data points that each correspond to two human saliva samples taken from individuals. One sample was taken prior to exercise, and a second sample taken after exercise. In this study, exercise was 45 minutes of vigorous activity. 
         [0102]    Each pair of saliva samples was tested for conductance and ion concentration. Then the conductance values post-exercise were subtracted from the conductance values pre-exercise for each pair of saliva samples. Similarly, the ion concentration values post-exercise were subtracted from the conductance values pre-exercise for each pair of saliva samples.  FIG. 5A  shows the percent change for ion concentration versus conductance changes. Importantly, a clear trend emerged, with the square of a correlation coefficient R 2  of 0.9159. Based on this correlation coefficient, changes in the Y values (conductance) can be partly attributed to the changes in the X values (ion concentration) for each pair of saliva samples, pre- and post-exercise. It is important to note that a correlation coefficient value of 0.9159 clearly indicates a trend, considering the degree of variability in contents and quality of actual biological saliva samples and error that may occur in empirical testing generally. 
         [0103]    Since conductance is closely related to osmolarity (as described above), conductance of saliva may be used as an approximation of saliva&#39;s osmolarity, according to embodiments according to the present disclosure. In this manner, osmolality, and thus user hydration level may be approximated through conductance measurements of the user&#39;s saliva. 
         [0104]      FIG. 5  also illustrates Graphs  5 B,  5 C and  5 D, each indicating saliva conductance vs. saliva osmotic concentration pre- and post-exercise in three human subjects, one subject for each of the Graphs  5 B-D. As shown, Graphs  5 B-D reflect the results of an experimental trial in which volunteer subjects were asked to dehydrate themselves by exercising without drinking water. Saliva samples were collected both before exercising and after exercising, and subject body weight was also measured before and after exercise to determine the percent change in body weight due to water loss. 
         [0105]    Pre-workout hydration results for the three subjects are shown in Groupings  520 ,  540  and  560 , respectively. Post-workout hydration results for the three subjects are shown in Groupings  530 ,  550 ,  570 , respectively. A distinct clustering can be seen between pre-workout and post-workout samples. These clusterings evidence the same trend of correlated saliva osmolarity to subject dehydration, further bolstering the concept that user hydration level may be approximated through conductance measurements of the user&#39;s saliva. 
       FIG.  6   
       [0106]      FIG. 6  illustrates a hydration sensor integrated into military equipment, according to one embodiment of the present disclosure. As shown,  600  includes catheter  602  and backpack  604 . In some embodiments catheter  602  may be a standard hydration catheter known in the art, and backpack  604  may contain a separate compartment for a removable, handheld hydration sensors as discussed herein. In this manner, a user may check their hydration levels as needed. In further embodiments, hydration level data may be wirelessly uploaded into the cloud or act as a node in a wireless sensor network or IoT network, as described herein. 
         [0107]    Catheter  602  allows for fluid flow, as shown by the arrow in inset  640 . In some embodiments, catheter  602  may be multifunction catheter  700 , multifunction catheter  800 , multifunction catheter  902 , or any hydration catheter described herein. It should be noted that  FIG. 6  is meant to illustrate exemplary uses of hydration sensors discussed herein, and should not be read as limiting; thus other embodiments described in this patent application not pictured here may be used in military and other settings.  FIG. 7   
         [0108]      FIGS. 7A and 7B  illustrate an integrated hydration sensor and hydration catheter, according to embodiments according to the present disclosure. As shown,  FIG. 7A  includes multifunction catheter  700 , which houses a hydration tube  702 , and positive electrode  704  and negative electrode  706 , and optionally, data leads  705  (not pictured). Hydration tube  702  allows fluid flow, as demonstrated by the arrow inside hydration tube  702 .  FIG. 7B  illustrates multifunction catheter  700  from another view. The hydration catheter also includes hydration catheter well  708 , and saliva deposition chamber  710 . Finally, hydration catheter well  708  has hydration catheter well floor  709 , hydration well opening  707 , and saliva deposition chamber  710  has saliva deposition chamber floor  711 . Optionally, multifunction catheter  700  may include a locking mechanism (not shown) and/or a flexible enclosure (not shown) to limit fluid discharge, as known in the art. In some embodiments, positive electrode  704  and negative electrode  706 , and optional data leads  721  (not pictured) may be electrically connected to hydration sensors discussed herein, through electrical connections  705  and  707 . In other embodiments, positive electrode  704 , negative electrode  706  and other elements shown in the Figure may be structurally sound such that these elements are resistant to crushing forces (e.g., biting). 
         [0109]    Conventionally, catheters may be attached to reservoirs stored in “hydration backpacks,” which are often used in athletic or extreme environments, including but not limited to, outdoor sports, (e.g., cycling, hiking or climbing) and military combat. In this manner, a hydration backpack user may sip water or other fluids stored in the reservoir contained in the hydration backpack. The user sips fluid by means of suction through multifunction catheter  700 . 
         [0110]    Saliva deposition chamber  710  is similar to saliva deposition chamber  162  in that saliva deposition chamber  710  may be used to test the conductance of saliva deposited in saliva deposition chamber  710 , according to embodiments according to the present disclosure. Saliva deposition chamber  710  differs from saliva deposition chamber  162  in that saliva deposition chamber  710  is mounted in proximity to hydration catheter well  708 . Positive electrode  704  and negative electrode  706  serve to test the conductance of saliva deposited. In this manner, a user may deposit saliva in saliva deposition chamber  710 , which allows hydration sensors discussed herein to determine the conductance of the deposited saliva. In this manner, hydration sensors (as discussed herein) may avoid reading the conductance of other fluids, which may be beneficial to accuracy of saliva conductance measurements. 
       FIG.  8   
       [0111]      FIGS. 8A and 8B  illustrate an integrated hydration sensor and hydration catheter, according to embodiments according to the present disclosure. As shown,  FIG. 8A  includes multifunction catheter  800 , which houses a hydration tube  802 , and positive electrode  804  and negative electrode  806 , and optionally, data leads  821  (not shown). Hydration tube  802  allows for fluid flow, as demonstrated by the arrow inside hydration tube  802 . Positive electrode  804  and negative electrode  806  may be electively connected to hydration sensors described herein through electrical connections  803  and  805 .  FIG. 8B  illustrates multifunction catheter  800  from another view. Multifunction catheter  800  also includes integrated hydration/saliva well (multifunction well)  808 . Multifunction well  808  has hydration well opening  807 . 
         [0112]    Optionally, multifunction catheter  800  may include a locking mechanism (not shown) and/or a flexible enclosure (not shown) to limit fluid discharge, as known in the art. In some embodiments, positive electrode  804  and negative electrode  806 , and optional data leads  805  are electrically connected to hydration sensors discussed herein. 
         [0113]    Multifunction well  808  is similar to saliva deposition chamber  162  in that saliva deposition chamber  810  may be used to test the conductance of saliva deposited in multifunction well  808 . Positive electrode  804  and negative electrode  806  serve to test the conductance of saliva deposited. In this manner, a user may deposit saliva in multifunction well  808 , which allows hydration sensors discussed herein to determine the conductance of the deposited saliva. 
         [0114]    According to embodiments of the present disclosure, multifunction well  808  differs from saliva deposition chamber  162  in that multifunction well  808  serves as both a location for the user to deposit saliva for conductance testing by hydration sensors discussed herein, as well as a location for dispensing fluid through hydration tube  802 . In some embodiments, positive electrode  804  and negative electrode  806  and hydration well opening  807  share the same “floor,” specifically, multifunction well floor  809 . In other words, multifunction well floor  809  has hydration well opening  807  in proximity to positive electrode  804  and negative electrode  806 . 
         [0115]    In some embodiments, automatic testing of saliva may be performed by hydration sensors discussed herein before or after the user sips fluids through hydration catheter  800 . Conveniently, in this manner, a user may not be required to separately test the user&#39;s saliva for dehydration; hydration levels may be automatically determined as part of the user&#39;s regular use of hydration catheter  800 . 
         [0116]    In further embodiments, hydration sensors discussed herein may detect that the user did not hydrate enough with a previous sip, and thus hydration sensors discussed herein may encourage the user to sip more fluids. Beneficially, in this mariner, injuries dehydration may be avoided or mitigated. Such encouragement may occur through through means of lit LEDs, voice reminders or other means known in the art. 
         [0117]    In even further embodiments, hydration sensors discussed herein may detect that the user may have over-hydrated with a previous sip, and thus hydration sensors discussed herein may discourage the user from imbibing more fluids. Beneficially, in this manner, hydration sensors discussed herein may assist the user in rationing fluid use by conserving onboard fluids stored in reservoir (not pictured). Such discouragement may occur through means of lit LEDs, numerical displays, voice reminders or other means known in the art. 
         [0118]    In general, hydration sensors discussed herein may be activated such that positive electrode  804  and negative electrode  806  do not test for conductance in the presence of fluid from the reservoir. Such fluid presence may negatively impact conductance testing, causing inaccurate conductance measurements. In other embodiments, positive electrode  804 , negative electrode  806  and other elements in this Figure may be structurally sound such that these elements are resistant to crushing forces (e.g., biting). 
       FIG.  9   
       [0119]      FIG. 9  illustrates an integrated hydration sensor and hydration catheter and reservoir, according to embodiments according to the present disclosure. As shown,  FIG. 9  includes reservoir  900 , a hydration sensor as discussed herein, (by way of example and not limitation, hydration sensor  100  is shown), integrated wire/catheter tube (multifunction catheter)  902 , and integrated hydration/electrode mouthpiece (multifunction mouthpiece)  904 . Reservoir  900  includes screw cap  912 , hanger  914 , catheter mount  916  and bladder  918 . 
         [0120]    By way of example and not limitation, hydration sensor  100  is attached to reservoir  900 , but hydration sensor  100  may be located anywhere proximate to multifunction catheter  902 . Fluid may flow through multifunction catheter  902 , as indicated by the arrow within multifunction catheter  902 . 
         [0121]    As shown in inset  920 , multifunction mouthpiece  904  includes positive electrode  906  and negative electrode  908 , which may be electrically connected by electrical connections  922  and  924  to hydration sensors discussed herein, according to the present disclosure. In one embodiment, the user may partially or completely engulf multifunction mouthpiece  904  in saliva. In this manner, hydration sensors discussed herein may determine the conductance of the user&#39;s saliva. 
         [0122]    In some embodiments, positive electrode  906 , negative electrode  908  and a other elements in this Figure may be structurally sound such that these elements are resistant to crushing forces (e.g., biting). 
         [0123]    In some embodiments, automatic testing of saliva may be performed by hydration sensors discussed herein before or after the user sips fluids through multifunction catheter  902 . Conveniently, in this manner, a user may not be required to separately test the user&#39;s saliva for dehydration; hydration levels may be automatically determined as part of the user&#39;s regular use of multifunction catheter  902 . 
         [0124]    In further embodiments, hydration sensors discussed herein may detect that the user did not hydrate enough with a previous sip, and thus hydration sensors discussed herein may encourage the user to sip more fluids. Beneficially, in this mariner, injuries dehydration may be avoided or mitigated. Such encouragement may occur through means of lit LEDs, voice reminders or other means known in the art. 
         [0125]    In even further embodiments, hydration sensors discussed herein may detect that the user may have over-hydrated with a previous sip, and thus hydration sensors discussed herein may discourage the user from imbibing more fluids. Beneficially, in this manner, hydration sensors discussed herein may assist the user in rationing fluid use by conserving onboard fluids stored in reservoir (not pictured). Such discouragement may occur through means of lit LEDs, voice reminders or other means known in the art. 
       FIG.  10   
       [0126]      FIG. 10  illustrates a hydration sensor attached to a hydration bottle system, according to one embodiment of the present disclosure. As shown, hydration bottle system  1000  includes hydration sensor  1002 , which may include positive electrode  1004  and negative electrode  1006 . Hydration bottle system  1000  may include bottle  1001 , smart lid anchor  1008  and lid  1010 . Lid  1010  may be attached to smart lid anchor  1008  using strap  1012 . Smart lid anchor  1008  may be attached to bottle  1001  by screwing, gluing or other attachment means known in the art. The inventors note that numerous permutations of hydration sensors  1002 , bottles, lids, lid anchors and straps are possible, and the inventors contemplate any and all combinations of these elements. One skilled in the art will understand that embodiments of the invention are not limited to those illustrated herein. 
         [0127]    In some embodiments, positive electrode  1004  and negative electrode  1006  are electrically connected to hydration sensor  1002 . Hydration sensor  1002  may be substantially similar to hydration sensors discussed herein, such as hydration sensor  100 . In some embodiments, hydration sensor  1002  is attached to smart lid anchor  1008  temporarily by the user by affixing, screwing or by any means of attachment known in the art. In other embodiments, hydration sensor  1002  may be secured by a manufacturer to smart lid anchor  1008  by gluing or other means of attachment known in the art. In some embodiments, hydration sensor  1002  may be a thin or printable circuit (e.g., RFID or the like) that is secured or printed directly onto hydration bottle  1001  or lid  1010  by means known in the art. In some of these embodiments, these means of securing hydration sensor  1002  to hydration are liquid-proof or otherwise resistant to liquids. 
         [0128]    In some embodiments, hydration sensor  1002  may include batteries (not pictured, such as battery  210 ), may be powered by inductive charging through mutual inductance, or other means known in the art. We contemplate various charging systems, including a ‘chargeable hydration bottle’ such that a user may charge hydration sensor  1002  on in a charging station, or with a photovoltaic cell (not shown, e.g., a solar panel) or the like. Such a charging station may be combined with a hydration station. 
         [0129]    Other charging systems include a shaker charger, as shown by optional shaker charger  1020 . A shaker charger allows the user to shake ferrite core  1022  suspended in an inductive coil (not shown) in a relatively linear motion, such shaking then inducing a current appropriate for charging hydration sensor  1002  or hydration sensors discussed herein. Current induced by shaker charger  1020  may be fed through electrical connections  1024  and  1026  to contacts  1030  and  1032 . Contacts  1030  and  1032  may be electrically connected to hydration sensor  1002  when smart lid anchor  1008  is affixed to bottle  1001 . Such a shaker charger may be additionally beneficial in allowing simultaneous charging of hydration sensors  100  or hydration sensors  1100  as well as mixing, emulsifying or otherwise redistributing the contents of hydration bottle system  1000 . For example, a user could shake hydration bottle system  1000 , thereby charging hydration sensor  1002  and mixing a smoothie within hydration bottle system  1000 . 
         [0130]    In one embodiment, positive electrode  1004  and negative electrode  1006  may extend partially or completely around the circumference of the spout of smart lid anchor  1008 . In this mariner, a user may drink from hydration bottle  1002  from multiple angles, and hydration sensors discussed herein may still receive hydration level data from the user&#39;s saliva. Thus, the user is less restricted when attempting to determine the user&#39;s hydration level. 
         [0131]    The inventors also contemplate another embodiment: positive electrode  1004  and negative electrode  1006  may extend partially or completely around the circumference of the spout of hydration bottle  1002 , omitting smart lid anchor  1008  entirely. In this manner, hydration bottle  1002  would include hydration sensor  1002  on the spout of hydration bottle  1002 . 
         [0132]    In a further embodiment, lid  1010  is optional and is not required for the user of hydration sensor  1002 . In an even further embodiment, hydration sensor  1002  may be attached to contest  1030  and  1032 . In this embodiment, hydration sensor  1002  may be powered by optional shaker charger  1020 . In an alternative embodiment, smart lid anchor  1008  may contain a power source (not shown) and may function as a replacement lid anchor and optional lid. In this manner, the user may use smart lid anchor  1008  with conventional hydration bottles by simply attaching the threading of smart lid anchor  1008  to the conventional hydration bottle (by means of screwing or the like). 
         [0133]    Although the invention is illustrated and described herein as embodied in one or more specific examples, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention, as set forth in the following claims.