Abstract:
A system, device and apparatus for measuring electrolytes, where an electrical charge is applied to a measurement portion to draw ions from a liquid to a gel-solution via at least one electric field. The gel-solution containing the extracted ions is excited with light of a predetermined wavelength from an emitter. A receiver detects the illumination of the ions as a result of the excited gel-solution, and a processor converts the detected intensities of the illumination to a biologically useful value representing ionic concentration.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application incorporates by reference and claims the benefit of U.S. Provisional Patent Application No. 61/731,039, filed Nov. 29, 2012 to Izadian et al., titled “Dielectric Electrolyte Measurement Device.” 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure is directed to electrolyte processing and measurement. More specifically, the present disclosure is directed to systems, apparatuses and methods for utilizing electric field forces to separate electrolytes and measuring electrolyte concentrations using light radiation. 
       BACKGROUND 
       [0003]    Chemically, electrolytes are substances that become ions in solution and acquire the capacity to conduct electricity. Among other areas, electrolytes are present in the human body, and the balance of the electrolytes in the human body is essential for normal function of cells and organs. Common electrolytes measured in blood testing include sodium, potassium, chloride, and bicarbonate. 
         [0004]    Sodium (Na+) is a major positive ion (cation) in fluid outside of cells. Sodium regulates the total amount of water in the body and the transmission of sodium into and out of individual cells also plays a role in critical body functions. Many processes in the body, especially in the brain, nervous system, and muscles, require electrical signals for communication. The movement of sodium is critical in generation of these electrical signals. Too much (e.g., hypernatremia) or too little (e.g., hyponatremia) sodium therefore can cause cells to malfunction, and extremes in the blood sodium levels (too much or too little) can be fatal. Potassium (K+) is a major positive ion (cation) found inside of cells. The proper level of potassium is essential for normal cell function. Among the many functions of potassium in the body are regulation of the heartbeat and the function of the muscles. A seriously abnormal increase in potassium (e.g., hyperkalemia) or decrease in potassium (e.g., hypokalemia) can profoundly affect the nervous system and increases the chance of irregular heartbeats (arrhythmias), which, when extreme, can be fatal. 
         [0005]    Typically, electrolytes are measured by a process known as potentiometry. This method measures the voltage that develops between the inner and outer surfaces of an ion selective electrode. The electrode (membrane) is typically made of a material that is selectively permeable to the ion being measured. This potential is measured by comparing it to the potential of a reference electrode. Since the potential of the reference electrode is held constant, the difference in voltage between the two electrodes is attributed to the concentration of ion in the sample. 
         [0006]    However, in certain cases, electrolyte measurement devices do not adequately separate the electrolytes for measurement, and may experience dissociation issues when electrolytes are in water, since water molecules are dipoles and the dipoles orient in an energetically favorable manner to solvate the ions. Accordingly, improvements are needed in electrolyte measurement devices to better measure electrolytes such as potassium, and to expand the applicability of electrolyte measurement to devices such as portable electrolyte measurement devices, hand-held dialysis devices, forced accelerated dialysis and even water filtration. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which: 
           [0008]      FIG. 1  illustrates an exemplary device for measuring electrolytes under one embodiment; 
           [0009]      FIG. 2  illustrates a device measurement portion configuration for measuring electrolyte concentrations in a sample under another exemplary embodiment; 
           [0010]      FIG. 2A  illustrates an arrangement of electrolytes under one exemplary voltage condition for the embodiment of  FIG. 2 ; 
           [0011]      FIG. 2B  illustrates an arrangement of electrolytes under another exemplary voltage condition for the embodiment of  FIG. 2 ; 
           [0012]      FIG. 2C  illustrates a configuration for illuminating and measuring electrolytes from  FIG. 2B  under one exemplary embodiment; 
           [0013]      FIG. 3A  illustrates one exemplary view of a disposable tip for collecting and measuring electrolytes under another embodiment; and 
           [0014]      FIG. 3B  illustrates another exemplary view of the disposable tip if  FIG. 3A  for collecting and measuring electrolytes. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 1  illustrates an exemplary device  100  for measuring electrolytes under one embodiment, where device  100  comprises a processor/microchip arrangement  101  that may include a central processing unit (CPU), memory and all other required components (not shown for purposes of brevity) for interfacing with other device blocks or peripherals as is known in the art. Under a preferred embodiment, the memory will contain a conversion table for relating recorded light intensity to electrolyte concentration, as is discussed in greater detail below. Processor  101  may provide additional commands and instructions to device blocks and/or peripherals, such as a signal to trigger unit  102  for applying a charge to separate the ions in  103 , and to the photodiode emitter  104  to expose gel containing at least a portion of sample  105  to a light of a specific wavelength. Processor  101  may be activated via on/off command  109  and measure command  110 , provided by dedicated hardware (e.g., switch, button) or by integration via touch screen or other suitable devices. 
         [0016]    Once device  100  is activated and processor  101  triggers the device, light receiver  106  is configured to capture light reflected from sample  105  after exposure and may convert the reflected light to one or more voltage values. Signal-conditioning unit  107  converts the measured voltage to the signal readable by processor  101 . As the voltage is stabilized, processor  101  will calculate an accurate ion concentration from its stored tables and will trigger a display of the value. Display  108  is configured to display the measured ion concentration. 
         [0017]    Turning to  FIG. 2 , an exemplary configuration is provided for a measurement portion  200  of device  100  for measuring electrolytes. Here, a top electrode  202  is coupled to an anode of a battery or cell  209 . The cathode of cell  209  is coupled to conductive layer  207  where conductive layer  207  will serve to draw ions in its direction when cell  209  draws power. Additionally, conductive layer  207  is preferably made from a transparent conducting oxide such as indium tin oxide (ITO). ITO is particularly advantageous, due to its electrical conductivity and optical transparency, as well as the ease with which it can be deposited as a thin film. As with all transparent conducting films, a compromise may be made between conductivity and transparency, since increasing the thickness and increasing the concentration of charge carriers will increase the material&#39;s conductivity, but decrease its transparency. Under a preferred embodiment, the ITO conductive layer  207  may be between 750-1250 Å, and may be deposited by electron beam evaporation, physical vapor deposition, or a range of sputter deposition techniques known in the art. Conductive plastics and other transparent conductive layers can also be used. 
         [0018]    Dielectric material  206  is preferably deposited between conductive layer  207  and electrode  202  as shown in  FIG. 2  to polarize resulting electrical fields between electrode  202  and conductive layer  207  in order to provide dielectric polarization. Because of this polarization, layer  207  will assist in displacing positive charges (ions) toward the field and shifting negative charges in the opposite direction. In a preferred embodiment, dielectric material  206  is comprised of a chemical vapor deposited polymer such as parylene and may be 0.5-2.0 μm thick. Under one embodiment, the parylene may be deposited as a passivation coating. A glass membrane  208  is provided on the other side of conductive layer  207  to enclose measurement portion  200 . Other transparent dielectric material can also be used with proper thickness to act as dielectric layer. Transparent wax material can also be used. 
         [0019]    During electrolyte measurement, a sample is provided in  203 , which may come from a disposable tip (described in detail below) or from a cartridge or other suitable medium for carrying liquids. Sample  203  is separated by membrane  204 , which is preferably a dialysis membrane that separates sample  203  from spilling over contacts and covering gel-solution  205 . Under a preferred embodiment, gel-solution  205  is a fluorescing solution for assisting in light radiation. Under one embodiment, solution  205  comprises agarose or other suitably porous medium. Agarose is particularly suitable due to it hysteresis qualities and gel stability at temperatures near human body temperatures. Additionally, solution  205  may comprise a chemical buffering agent, such as sodium (Na) HEPES, as well as an emulsifier, such as microcrystalline cellulose (MCC). Under another embodiment, solution  205  specifically comprises 1% agarose, 5 mm Na HEPES, and 40 μm MCC. It is understood by those skilled in the art that other materials and mixture concentrations may be used depending on the needs of the designer. 
         [0020]    Turning to  FIGS. 2A-C , various embodiments are illustrated utilizing the configuration of  FIG. 2 . The same or similar items from  FIG. 2  are represented by the same reference numbers in  FIGS. 2A-C  and discussion of these reference numbers will not be repeated for the sake of brevity. In the example of  FIG. 2A , the embodiment is illustrated as a biological electrolyte measurement device for measuring ion concentrations. More specifically, sample  203  is comprised of blood where potassium (K+) ion concentrations are to be measured. In this example, a drop of blood (e.g., 20 μl) is placed on dialysis membrane  204 . As explained above, membrane  204  serves to enclose the blood from spilling over contacts and covering gel-solution  205  outer surface. As is shown in  FIG. 2A  the blood in sample  203  comprises potassium ( 215 ) and bilirubin ( 216 ). In order to get a more accurate measurement, potassium ions  215  should be separated from the bilirubin  216 , as bilirubin  216  absorbs light and may impede fluorescing. As the blood  203  is deposited on membrane  204 , voltage is initially set at V=0. 
         [0021]    As voltage is increased (V&gt;0) in  FIG. 2B , the DC electrical field generated from dielectric material  206  draws the K+ ions  215  and other positively charged ions into gel-solution  205 , while leaving behind bilirubin  216 . Accordingly, the applied voltage acts as a charge separation device to absorb the K+ ions and separate them from the non-polar bilirubin, thus accelerating the process of K+ separation for concentration measurement. Once the K+ ions  215  are absorbed into gel-solution  205 , an emitter  220  exposes solution  205  (containing ions  215 ) to light of a predetermined wavelength, as shown in  FIG. 2C . In one embodiment, emitter  220  may be a photodiode or other suitable device. As ions  215  fluoresce due to the light exposure, receiver  220  captures the light illumination to determine ionic concentration, where the level of illumination is correlated to the concentration of ions (i.e., higher concentration =higher illumination, and vice versa). Under a preferred embodiment, the captured illumination values are subsequently transposed, via look-up table or other suitable means, to a biologically useful ion concentration value. In one embodiment, a light wavelength of 300-500 nm may be used to excite the gel-solution  205 , and receiver  220  may be in the form of a charge-coupled device (CCD) camera or other light measurement sensors. 
         [0022]    Turning to  FIGS. 3A-B , a device incorporating measurement portion  200  discussed above, may be embodied having a disposable tip that may be used to locate a drop of blood from a human or other mammal. In this example, disposal tip may comprise several layers of material on dielectric layer to separate the charges from blood to a gel-solution. The material used for dielectric  305  and/or contact  302  should be transparent over a wide range of light wavelength, preferably from 430 nm to 670 nm The overall shape of tip  300  is shown in  FIG. 3A , where a charge separation tip comprises electrode contacts ( 302 ,  303 ) on both sides of the gel and blood (see  FIG. 3B ). Under a preferred embodiment, the negative electrode  302  connects the dielectric to a substrate. This electrode will be conductive and transparent to eliminate any beam power loss emitted from gel-potassium bonds. 
         [0023]    The disposal tip  300  is preferably a cylindrical tube that contains the charge separation elements and has empty space to hold a blood droplet. Between electrodes is a transparent conductive layer  302 , a transparent dielectric layer  305 , and gel-solution  306  (e.g., aqueous gel). Once a blood drop is located at the tip through the positive electrode  303 , the applied electric field will force the positive ions to migrate from the blood to the gel, as described above. Under one embodiment, disposal tip  300  is located on a handheld device that (1) energizes electrodes to separate charges, (2) emits specific wavelength light to the charge separated blood sample, (3) measures the reflected light from the sample, and (4) displays a potassium concentration related number. 
         [0024]    Regarding the light emitter and measurement tools, these parts of the device may be configured to hold the tip in place and make a secure connection to the electrodes. Under one embodiment, after the charge separation has occurred, a 430 nm light is emitted from a photodiode ( 307 ) to the gel. When the light hits the potassium-gel bonds, it will emit a relative light of wavelength 460-650 nm. Other wavelengths may also be used as the material may change. The intensity of the received light determines the potassium concentration. A light receiver (photo detector)  308  is configured to collect the light through a lens and will convert it to a voltage. The output voltage is related to the light intensity received by the photo detector. The emitter, tip position, and the reflected beam measurement are shown in  FIG. 3B . 
         [0025]    While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient and edifying road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the invention and the legal equivalents thereof.