Abstract:
A method of using a sensor device for measuring a concentration of a substance within a sample includes inserting a tip portion of a sensor into a sample. The sensor has an optical transmission member having a first end and a second end. The second end has the tip portion attached thereto and an active material incorporated within the tip portion. The active material is capable of interacting with a substance within the sample. The method includes producing a reflected beam of light from the interaction of the active material with the substance within the sample, the reflective beam of light having a second wavelength different from the first wavelength. The method includes determining the concentration of the substance based on the reflected beam of light.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This is a continuation-in-part of U.S. patent application Ser. No. 09/729,611, filed on Dec. 4, 2000 which is a continuation of U.S. patent application Ser. No. 09/100,295 filed Jun. 19, 1998, now U.S. Pat. No. 6,157,442. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates generally to a sensor device and more particularly to a micro optical sensor device which may be employed in a variety of sensor applications to monitor, sense, or measure a concentration of a material within a sample.  
         [0003]     There are numerous applications in which a device is used to monitor or detect a concentration of material within a substance. For example, it may be required to know the concentration of a chemical in a sample of material such as knowing the concentration of sodium, calcium, or some other chemical composition in a sample. Monitoring or detecting a concentration of a substance typically requires a set up of relatively complex, sensitive, and expensive equipment or instrumentation. Sometimes space requirements make it difficult to use the set up of complex equipment and it would be advantageous to have equipment which has small dimensions and is easily transportable. Additionally, such complex equipment may not provide results which are of a high resolution.  
         [0004]     One known and important application for monitoring a concentration of a material within a sample deals with checking blood glucose for diabetics. There are at least two known techniques for monitoring blood glucose levels in humans. The two techniques are invasive which involves extracting samples with the use of needles or syringes and noninvasive. Typically, for the invasive method, a patient employs a small lancet device which is used to prick or puncture a finger. Blood is then collected onto a strip which has incorporated therein a chemical reagent. The strip is then placed inside of a device that optically reads the chemical reaction of the blood on the strip and converts this to a blood glucose level. It has been found very important to control glucose levels in diabetics to reduce any complications associated with diabetes. Many samples or finger pricks may be required to be taken for analysis during the course of a day. Self monitoring of blood glucose by a patient is therefore very important in the treatment of diabetes. Since finger pricking or lancing is required for self monitoring levels of glucose in a patient, many patients avoid this because it is painful and inconvenient. Therefore, a less invasive procedure would be desirable. The other methods, which have been termed noninvasive, typically involve a device which uses near infrared light to detect blood glucose levels. These devices measure a glucose concentration in blood or an organism&#39;s tissue by use of an optical device without the need to collect blood or fracturing a part of the organism&#39;s tissue. Although these devices use noninvasive methods, in that no blood is collected, none of these devices have been commercially accepted or viable.  
         [0005]     The present invention is designed to obviate and overcome many of the disadvantages and shortcomings associated with the prior use of complex testing and monitoring equipment. Additionally, the present invention is simple to use, provides extremely quick results and high resolution, and is easily transportable. The present invention uses relatively inexpensive components which result in a commercially viable product. Further, the micro optical fiber sensor device of the present invention is relatively noninvasive since it does not require the drawing of blood and provides immediate results which does not require related blood processing such as centrifugation, storage, transportation, and other time consuming testing.  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention is a sensor device for measuring a concentration of a substance within a sample which comprises a sensor comprising an optical transmission member having a first end and a second end, the second end having a tip portion attached thereto and an active material incorporated within the tip portion, the tip portion adapted to be inserted into a sample, the active material capable of interacting with a substance within a sample, a light source coupled to the first end of the sensor for emitting a beam of light into and through the sensor and into a sample, the emitted beam of light having a wavelength and the active material interacting with a substance within a sample to change the wavelength of the emitted beam of light to produce a reflected beam of light and the sensor for transmitting the reflected beam of light out of the second end thereof, means for receiving the reflected beam of light from the second end of the sensor for producing a signal indicative of the reflected beam of light, and a processor for receiving the signal indicative of the reflected beam of light and for processing the signal to determine the concentration of a substance within a sample.  
         [0007]     Another example of the present invention is a sensor device for measuring a concentration of a substance within a sample which comprises a sensor comprising an optical transmission member having a first end and a second end, the second end having a tip portion attached thereto and an active material incorporated within the tip portion, the tip portion adapted to be inserted into a sample, the active material capable of interacting with a substance within a sample, a light source for emitting a beam of light of a preselected wavelength with the light source being coupled to an optical device capable of transmitting the beam of light Therethrough, the transmitted beam of light being directed into the first end of the sensor, through the sensor and out of the second end into a sample, the active material interacting with a substance within a sample to change the wavelength of the transmitted beam of light to produce a reflected beam of light and the sensor for transmitting the reflected beam of light from the second end, through the sensor, and out of the first end thereof, the optical device being further capable of reflecting the reflected beam of light, means for receiving the reflected beam of light which is reflected by the optical device for producing a signal indicative of the reflected beam of light; and a processor for receiving the signal indicative of the reflected beam of light and for processing the signal to determine the concentration of a substance within a sample.  
         [0008]     A further example of the present invention is a sensor device for measuring a concentration of a substance within a sample which comprises a sensor comprising an optical transmission member having a first end and a second end, the second end having a tip portion attached thereto and a first and a second active material incorporated within the tip portion, the tip portion adapted to be inserted into a sample, the first active material capable of interacting with a first substance within a sample and the second active material capable of interacting with a second substance within a sample, a light source coupled to the first end of the sensor for emitting a beam of light into and through the sensor and into a sample, the emitted beam of light having a wavelength and the first active material interacting with a first substance within a sample to change the wavelength of the emitted beam of light to produce a first reflected beam of light, the second active material interacting with a second substance within a sample to change the wavelength of the emitted beam of light to produce a second reflected beam of light, and the sensor for transmitting the first and second reflected beams of light out of the second end thereof, means for receiving the first and second reflected beams of light from the second end of the sensor for producing a first signal indicative of the first reflected beam of light and a second signal indicative of the second reflected beam of light, and a processor for receiving the first and second signals and for processing the first and second signals to determine the concentration of a first substance within a sample and the concentration of a second substance with a sample.  
         [0009]     In light of the foregoing comments, it will be recognized that a principal object of the present invention is to provide an improved sensor device which is hand held, portable, and easy to operate.  
         [0010]     Another object of the present invention is to provide a sensor device which has a tip portion of an extremely small size so that when it is inserted into a hand of a patient little or no sensation will be produced or detected.  
         [0011]     A further object of the present invention is to provide a sensor device which is of simple construction and design and which can be easily employed with highly reliable results.  
         [0012]     Another object of the present invention is to provide a sensor device which is accurate and provides readings in a short time span.  
         [0013]     A still further object of the present invention is to provide a sensor device which is compact in design and is easily transportable for personal use.  
         [0014]     These and other objects and advantages of the present invention will become apparent after considering the following detailed specification in conjunction with the accompanying drawings,  
         [0015]     wherein:  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a perspective view of a micro optical sensor device constructed according to the present invention;  
         [0017]      FIG. 2  is a block diagram of the micro optical sensor device constructed according to the present invention;  
         [0018]      FIG. 3  is a perspective view of a tip portion of the micro optical sensor device shown in  FIG. 1 ;  
         [0019]      FIG. 4  is a schematic view of the micro optical sensor device of the present invention being employed to sense a concentration in a sample;  
         [0020]      FIG. 5  is a block diagram of a second embodiment of the micro optical sensor device constructed according to the present invention;  
         [0021]      FIG. 6  is perspective view of the sensor device of  FIG. 5  illustrated monitoring a concentration of glucose in a hand of a patient; and  
         [0022]      FIG. 7  is a block diagram of a third embodiment of the micro optical sensor device constructed according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]     Referring now to the drawings, wherein like numbers refer to like items, number  10  identifies a preferred embodiment of a micro optical sensor device constructed according to the present invention. As illustrated in  FIG. 1 , the device  10  comprises a pencil or pen shaped body  12  which includes a tip portion  14 , a central body portion  16 , and an end cap  18 . The central body portion  16  further includes a display device  20 , such as an LED (light emitting diode) type display or an LCD type display, for displaying information. The end cap  18 , which may be removable from the central body portion  16 , is used to allow access into the interior of the central body portion  16 . Batteries (not shown) can be inserted into the central body portion  16  to supply power to the device  10 , as will be explained. The central body portion  16  may also include an ON/OFF switch  22  which may be used to operate the device  10 . Other switches (not shown) may be incorporated into the central body portion  16  to further control the device  10 . Additionally, the central body portion  16  houses electronic circuitry and other components which will be illustrated and explained in further detail herein. The device  10  is sized and shaped to be a hand held type device which is portable and preferably is the size and shape of a pencil or a pen.  
         [0024]     With reference now to  FIG. 2 , a block diagram of the circuitry and components of the device  10  is shown. The device  10  includes a light source  30  which may be an LED, a laser, a laser diode, or other excitation source. The light source  30  is adapted to project a beam of light  32  into an optical transmission member  34 . The optical transmission member  34  transmits a beam of light  36  to a tip device  38  which is part of the tip portion  14 .  
         [0025]     The optical transmission member  34  and the tip device  38  can be any device capable of transmitting light. For example, a portion of fiber optic is used in the preferred embodiment. Various types of organic polymers such as polystyrene, PMMA, polycarbonate, SAN, polyacrylonitrile and SU-8 epoxy resins can also be used. The optical transmission member can also be an inorganic alkoxysilane or a form of glass such as lead borosilicate or fused silica. The optical transmission member can be any combination of these light transmitting materials.  
         [0026]     The beam of light  36  passes through the tip device  38  and a reflected beam of light  40  can be reflected back from a sample (not shown) through the tip device  38  to a detector  42 . The reflected beam of light  40  typically has a wavelength or a frequency which is different than the wavelength or frequency of the beam of light  36 . The detector  42  is in turn connected to a computer  44  via an electrical connection such as a wire  46 . The detector  42  provides electrical signals over the wire  46  to the computer  44 . The computer  44  may consists of, by way of examples, a microprocessor, a microcontroller, an ASIC chip, or any other known equivalent device which is capable of processing electrical signals. The computer  44  is further operatively connected to a power supply  48 , such as batteries, by a wire  50 . The computer  44  may also connected to the display device  20 , the switch  22 , and the light source  30  although such connection is not illustrated in  FIG. 2 . Additionally, the computer  44  may also be connected to other switches (not shown) which may be provided with the device  10 . In this manner, the additional switches are used to further control or operate other functions of the device  10 .  
         [0027]     The tip device  38  is shown in greater detail in  FIG. 3  and is preferably a small device on the order of microns in diameter. The tip device  38  may be constructed as is disclosed in U.S. Pat. Nos. 5,361,314 and 5,627,922. For example, the tip device can be prepared by several processes such as heat pulling, acid and/or solvent etching, laser micro-machining, laser post processing, E-beam micro-machining, injection molding, corona or electrical arcing, ultra-sound modification, high impact/high temperature powder crushing, grinding, masked lithography/etching, and micro-stereo lithography. In particular, in the preferred embodiment the tip device  38  includes a non-tapered portion  60  and a tapered portion  62  which is coated with an opaque material  64 . Other shapes and configurations can also be used. The tip device  38  further includes a first end  66  and a second end  68 . The second end  68  further has a tip or portion  70  of material which is adhered thereto. The tip  70  is chemically treated which enables the tip  70  to interact with the sample to be detected. Properties of the sensor or tip device  38  may vary dependent upon the sample and the chemical or substance to be detected by the device  10 . As constructed, the tip device  38  allows for the beam of light  36  to pass through the first end  66 , the second end  68 , and the tip portion  70  and the reflected beam  40  is allowed to pass through the tip portion  70 , the second end  68 , and the first end  66 .  
         [0028]     As indicated above, the tip device  38  is extremely small on the order of one-thousandth the width of a human hair and because of this size it can be inserted through gaps in most cells or through the membrane of a cell without damaging the cell. The tip  70  may be bathed in chemical coatings selected to react with biological compounds such as acid, calcium, oxygen, glucose, potassium, sodium, or any other material to be detected. The beam of light  36  which is transmitted through the tip device  38  glows with its brightness and color varying according to the concentration of the target chemical. The portion  70  is a photochemical sensor which is less than ten microns in diameter. Again, the portion  70  is small enough that it can pass through the membrane of a cell to monitor the concentration and nature of chemicals within the cell.  
         [0029]     The tip device  38  may have specific chemical sensitivities based upon the properties of a dye matrix. A dye may be chemically activated by a different chemical compound which enables sensing of a specific chemical property within a sample or a substance. The tip device.  38  provides for enhanced sensitivity, selectivity, and stability when detecting a concentration within a sample or substance. The tip portion or device  38  may comprise a biologically active compound that is immobilized in an environment that is optically reactive. Additionally, the biologically active compound can, in itself, be optically active. The sensor device  10  interacts with the substance or sample to detect a specific chemical or concentration within the substance.  
         [0030]     With reference now to  FIGS. 1, 2 , and  4 , the operation of the device  10  will be explained in detail. In order to operate the device  10 , the on/off switch  22  is pressed to initialize the device  10 . Once powered, the device  10  may be inserted into a sample  80  to test for a particular concentration of material within the sample  80 . As shown in  FIG. 4 , the sample to be tested is a liquid  82  in a beaker  84 . The tip portion  70  is inserted into the liquid  82  and at this point in time a beam of light, such as the beam of light  36 , is transmitted into the liquid  82 . With the tip portion  70  being in contact with the liquid  82 , the liquid  82  reacts chemically with the tip portion  70  and the color of the chemical composing the sensor device  10  changes. As a result of this change, the color of the light reflected back into the tip portion  70  changes, such as reflected beam of light  40 , as compared to the beam of light  36 . The amount of this change can be quantified by the detector  42 . Once quantified signals are provided to the computer  44  which performs a calculation to determine the concentration of the particular chemical being sensed and the result may be displayed in the display  20 .  
         [0031]     In further detail and again with reference to  FIGS. 1, 2 , and  4 , once the device  10  is actuated by pressing the switch  22 , the beam of light  32  is sent from the light source  30  through the optical transmission-member  34  which transmits the beam of light  36  through the tip device  38  into the liquid  82 . The reflected beam of light  40  is reflected from the liquid  82  into the tip device  38  to the detector  42 . The detector  42  provides signals to the computer  44  and the computer  44  determines the concentration of a particular chemical within the liquid  82 . This process may be termed photochemical optical fiber sensing. Additionally, the chemical properties of the tip portion  70  of the sensor portion  14  may be changed to react with another chemical to detect some other chemical within a sample. Further, instead of changing the chemical properties of the tip portion  70 , it may only be necessary to change the light source  30  to detect some other chemical within a sample.  
         [0032]      FIG. 5  illustrates another preferred embodiment of a sensor device  100  which comprises a computer  102  which is connected to a light source  104  by a wire  106 . The light source  104  operates to provide light, represented by a light beam  108 , to be projected at an optical device  110 . The optical device  110  may be a mirror which allows light, which is represented by a light beam  112 , of a particular or predetermined wavelength or frequency to pass through the device  110  to be directed at an optical transmission member  114 . The optical transmission member  114  is connected to a connector device  116  and the optical transmission member  114  passes light, such as light beam  118 , through to the connector device  116 . A beam of light  120  is transmitted from the connector device  116  to a sensor device  122 . The sensor device  122  is similar to the tip portion or device  38  which was shown in  FIGS. 2 and 3 . Light, such as light beam  124 , which may be reflected back from a sample (not shown) and through the sensor device  122 , is directed to the connector device  116 . A light beam  126  is transmitted from the connector device  116  to the optical transmission member  114 . The optical transmission member  114  in turn directs a light beam  128  to the optical device  110 . The optical device  110  provides a light beam  130  of a particular or predetermined wavelength or frequency to be directed at an optical detector device  132 . The optical detector  132  is connected by a wire  134  to the computer  102  and provides signals to the computer  102 . The computer  102  is operatively programmed to use the signals provided from the optical detector  132  to calculate or determine the concentration of a substance within a sample.  
         [0033]     Referring now to  FIG. 6 , the sensor device  100  is further shown comprising a pencil like body  150  which includes a central body portion  152 , an end cap  154 , and a tip portion  156 . The central body portion  152  has a display  158  for displaying information such as glucose concentration. An ON/OFF switch  160  is also included in the central body portion  152  for controlling operation of the sensor device  100 . The sensor device  100  is illustrated having the tip portion  156  inserted into a hand  162  of a patient. As has been previously discussed, the tip portion  156  is of an extremely small size and because of its small size insertion of the tip portion  156  into the hand  162  will produce little or no sensation. The other components of the sensor device  100 , which were discussed with reference to  FIG. 5 , are all housed within the central body portion  152 .  
         [0034]     With particular reference now to  FIGS. 5 and 6 , in operation, the tip portion  156  of the sensor device  100  is inserted into a sample, such as the hand  162 , to detect the presence of a concentration of material, such as for example glucose. Once inserted into the hand  162 , the ON/OFF switch  160  is pressed by the user to initiate operation of the sensor device  100 . Actuation of the sensor device  100  causes the computer  102  to operate the light source  104 . The light beam  108  is sent to the optical device  110  which causes the light beam  112  to be directed at the optical transmission member  114  which in turn produces the light beam  118 . The light beam  118  passes into the connector  116  and emerges as the light beam  120  which is provided to the sensor device  122 . With the sensor device  122  being in contact with the hand  162 , the sensor device  122  reacts chemically with the hand  162  and the color of the chemical composing the sensor device  122  changes. The color of the light beam  124  which is reflected back into the sensor device  122  is then directed back into the connector  116 . The beam of light  126  is transmitted from the connector  116  to the optical transmission member  114  which in turn transmits the beam of light  128  to the optical device  110 . The optical device allows the light beam  130  to be directed to the optical detector  134 . The optical detector  134  provides signals to the computer  102  which then determines the concentration of glucose within the hand  162 . The result may then be displayed in the display  158  of the sensor device  100 . Once the result is displayed, the user may remove the sensor device  100  from the hand  162  and press the ON/OFF switch  160  to turn the sensor device  100  off. The sensor device  100  may be used again to determine the glucose concentration.  
         [0035]     The sensor device  100  in actual construction is a small device and sized and shaped to be pencil like. Because of its small size the sensor device  100  may be used as a portable monitoring device. Additionally, the computer  102  may be a microprocessor chip, a customized integrated circuit chip such as an ASIC chip, or any other device which is capable of processing electrical signals. Although not shown or made reference to, a rechargeable battery or a replaceable battery may be used to power the sensor device  100 . Further both devices  10  and  100  may have incorporated therein a memory for storing information such as, for example, a log of monitoring of the patient&#39;s glucose concentration, time of day of monitoring, and date of monitoring.  
         [0036]      FIG. 7  depicts a block diagram of a third embodiment of a micro optical sensor device  200 . The sensor device  200  comprises a computer  202  which is connected to a light source  204  via a wire  206 . The light source  204  projects a beam of light  208  into a section or portion of a optical transmission member  210 . The optical transmission member  210  is connected to a tip portion or device  212  and passes a beam of light  214  to the tip device  212 . The tip portion or device  212  is similar in several respects to the tip device  38  which was illustrated in FIGS.  2  and  3 , however, the tip device  212  is different in one respect. In fabricating the tip device  212 , as discussed in U.S. Pat. Nos. 5,361,314 and 5,627,922, the tip device  212  uses a multi-dye matrix tip which is photochemically attached to the tip device  212  to form a multi-functional sensor having an extremely small size. The multi-dye configuration allows for a multi-function sensor in which each dye may be chemically activated by a different chemical compound. This enables the tip device  212  to sense, detect, or monitor more than one chemical.  
         [0037]     Since the tip device  212  is capable of monitoring two different chemicals, two different light beams, such as light beams  216  and  218 , will be reflected back from a sample and through the tip device  212 . Each of the light beams  216  and  218  are directed to a detector  220  and  222 , respectively. Although not shown, it is possible to have an optical component, such as band pass filters, placed between the tip device  212  and the detectors  220  and  222  to direct the light beams  216  and  218  to a specific detector  220  or  222 . The detector  220  is connected to the computer  202  by a wire  224  and electrical signals indicative of the concentration of a particular chemical within a sample is provided to the computer  202 . Additionally, the detector  222  is connected to the computer  202  by another wire  226  and signals indicative of another chemical within the sample are provided to the computer  202 . In this manner, the computer  202  is programmed to receive the signals from the detectors  220  and  222  and calculate or determine the concentrations of the two chemicals within the sample. Additionally, the sensor device  200  may include a display (not shown) which would display the results of the calculations. The sensor device  200  may also be provided with a power supply  228  which is operatively connected by a wire  230  to the computer  202 . Although the device  200  is depicted to show the monitoring of at least two different chemical compounds it is also contemplated that more than two chemical compounds may be sensed, detected, or monitored by the device  200  by adding additional components, as has been taught and illustrated.  
         [0038]     From all that has been said, it will be clear that there has thus been shown and described herein a micro optical sensor device which fulfills the various objects and advantages sought therefor. It will be apparent to those skilled in the art, however, that many changes, modifications, variations, and other uses and applications of the subject micro optical sensor device are possible and contemplated. All changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow.