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RFID Systems for Enhanced Shopping Experiencesby Walter Reade and Jeff Lindsay |
The following article was published July 24, 2004 on IP.com as Article 21115D.
Nov. 10, 2003
A condition monitoring system is proposed that employs radio frequency identification (RFID) technology and other recent advances in information management to provide improved multi-sensor condition monitoring systems relative to what is currently available on the market. In addition to tracking user states over time, the improved systems can employ RFID technology or related tools to obtain information about the user�s environment (e.g., objects being used or objects located near the user, location of the user, etc.). By combining information about the environment and the types of objects with which the user interacts, much more detailed information about the physical state and physical response of the user can be obtained for improved health diagnostics, exercise planning, safety monitoring, etc.
Further proposed improvements include:
Several companies have developed wearable biosensors that can monitor and record variables pertaining to the condition of the wearer (heart rate, heat flux, galvanic skin response, etc.). Typically, these devices communicate with a computer to transmit data, such as time histories of physical performance. In some cases, a wearable sensor can also obtain radio-transmitted signals from a scale to record the weight of the user. For some products, proprietary algorithms are said to be capable of integrating multiple physiological variables from the wearable sensor to predict caloric expenditure and other factors pertaining to health. For example, various sensor measurements are said to permit estimation of calories burned and basal metabolic rate, detection of the onset of ovulation, determination of the user�s stress level, and so forth.
The interest in biosensor monitoring has even extended to the area of computer games. One gaming product, The Wild Divine by The Wild Divine Project (Eldorado Springs, Colorado), provides biosensors worn on the fingers for monitoring details of pulse and galvanic skin response as a biofeedback tool. In playing the game, the user must complete a number of tasks requiring adjusting the user�s biological state. The game is said to help users learn to relax and find inner peace.
While a variety of commercial products can detect different user states, such as exercise versus sleep, there is typically no direct way of recording information about the environment of the user. There is a need to improve wearable biosensor systems to provide better information about the environment of the user.
Some systems are limited to input from a single part of the body, such as from the fingers or from the forearm, which might not provide adequate information regarding the state of the user�s entire body. Further, commercial sensors can be large and bulky, discouraging users from wearing them. An improved system is needed that improves comfort and convenience to the user. Further, typical systems include rigid devices that are held against the body, possibly causing discomfort in use. For example, the system described in U.S. Patent No. 6,527,711, issued March 4, 2003 to Stivoric et al., requires wrapping means to hold a rigid frame containing a pre-shaped section in place against the human body. Improved systems are needed that do not require a rigid frame against the body or wrapping means, both of which can be uncomfortable in use.
Among previous proposals regarding wearable biosensors to monitor health conditions are those U.S. military has developed. For example, clothing with sensors to detect injuries or other health factors are discussed by E.J. Lind et al., "A Sensate Liner for Personnel Monitoring Applications," available at https://www.ilcdover.com/etextiles/docs/SensateLinerGarment.pdf. Sensors are physically connected with electrical and fiber optic connections woven into the garment that can detect the penetration of bullets and other health-related conditions such as temperature, heart rate, respiration, etc.
Examples of wearable biosensors, many of which can be adapted for use with the improvements described hereafter, are found in H. Asada, P.A. Shaltis, A. Reisner, S. Rhee, and R. Hutchinson, "Mobile Monitoring with Wearable Photoplethysmographic Biosensors," IEEE Engineering in Medicine and Biology Magazine - A Special Issue on Wearable Sensors/Systems and Their Impact on Biomedical Engineering, May/June 2003, pp. 28-40. Asada et al. discuss wearable sensors such as those for heart rate, blood pressure, arterial oxygen saturation, arterial blood pressure, temperature, respiratory rate, and cardiac output. Wearable electrocardiogram devices are said to represent the most mature wearable biosensor technology. Less conventional but still potentially useful sensors for monitoring users can include acoustic sensors, electrochemical sensors, optical sensors, bioanalytic sensors, electromyography, electroencephalography, and so forth. Asada et al. note that postprocessing of sensor data using various algorithms can provide real-time analysis or offline analysis of recorded data. Despite noting several limitations, they conclude that wearable biosensors will become an important platform for future health care.
Other wearable patches are discussed in the article "Wearable Sensor Patches for Physiological Monitoring" at https://www.nasatech.com/Briefs/Feb00/NPO20651.html. Patches like bandage strips can communicate wirelessly with handheld portable units. The patches do not contain batteries but, like RFID tags, return a radio signal when a signal from a reader is received. Adhesive patches using microelectromechanical (MEMS) technology are further discussed in the associated technical support file at https://www.nasatech.com/TSP2/rf.php?getfile=NPO20651.
Brian Clarkson and Alex Pentland�s article, "Predicting Daily Behavior via Wearable Sensors," Vismod TR#540, July 2001, available at https://web.media.mit.edu/~clarkson/
isensed/isensed.Dec.01.2001.pdf, discusses a bulky system of multiple sensors (e.g., camera, microphone, gyros) for tracking user activities and for providing a data journal of time-synchronized sensor data.
Patents discussing wearable biosensor systems include U.S. Pat. No. 6,527,711, issued March 4, 2003 to Stivoric et al. Patents describing wearable electrodes or patches for use on the human body that can be adapted for the present invention, include U.S. Pat. No. 4,657,023, "Self-adhering Electrode," issued April 14, 1987 to Kuhn.
Several improvements are proposed for wearable sensor technology to improve the condition monitoring system. In particular, RFID can be applied to enhance the performance of the condition monitoring system. In one embodiment, the wearable sensor includes a disposable or reusable RFID reader that the user wears or carries to allow nearby objects with RFID chips to be identified and read, and to permit interaction with other objects. A portable RFID reader associated with the user scans the environment and detects objects that are likely to be relevant to the user�s physiological state or that are desirable to track for other reasons (e.g., determining the location of the user in time, verifying that user performed certain tasks, and so forth). A central hub associated with the user (e.g., a wearable electronic processor embedded in an article of clothing or worn attached to user or carried in a purse or other object near the user) can serve as the RFID reader and can receive information from one or more sensors and can send information about external objects and sensor data to a remote computer or data storage device, optionally after preprocessing of the data has been performed by the central hub. The RFID reader can send a wireless signal to another unit interfaced with a computer, or can write the information (e.g., an electronic product code read from a nearby RFID chip) into memory that can later be downloaded to a computer.
In addition to improving information handling, we also propose a system with improved comfort in which bulky single-site sensors with rigid pods and wrapping means are broken up into multiple small components such as biosensors embedded in flexible patches that can be comfortably attached to a variety of body sites. For example, instead of using a durable wearable armband, low-cost disposable sensors in small flexible patches can be used in one or more locations on the body. The patches can include flexible electronic circuits and a flexible thin-film or thick-film battery embedded in a flexible matrix, further adapted for wireless communication with at least one other device such as a central hub. The central hub can receive data from the sensors and transmit the data to another data storage and analysis device. Alternatively, the patches can include a small rigid battery such as a watch battery or can employ energy harvesting techniques to extract usable energy from radio waves or other ambient sources, including body heat or motion from the body of the wearer. Principles of energy harvesting from radio waves are discussed at https://www.rfidjournal.com/article/view/177 and at https://www.rfidjournal.com/article/articleprint/168/-1/3/.
The scope of the systems of the present invention can be expanded to include groups of individuals, such as a crew in a production facility, or non-human subjects, such as pets, livestock, wild animals, and the like.
The patches generally include a flexible matrix material and one or more sensors cooperatively associated with the flexible matrix (e.g., attached to a surface of the matrix, fully or partially embedded therein, connected to the matrix, etc.). The matrix can include an elastomeric material or flexible polymer, including natural or synthetic materials. Useful elastomeric compounds that can be included in a flexible biosensor patch include thermoplastic vulcanizates (TPVs) such as Santoprene�, thermoset rubbers, neoprene, silicone compounds, hydrogels, fluoroelastomers, polyurethanes such as aliphatic thermoplastic urethane or ATPU from Bayer Corp. (Pittsburgh, Pennsylvania), metallocene polyolefins such as polyethylene, particularly metallocene polyethylene foams, and the like. Biodegradable polymers can also be used as a flexible matrix or as an adhesive component. Exemplary biodegradable polymers include those derived from starch, cellulose, or other polysaccharides, gelatin and related proteinaceous materials, polylactic acids and their derivatives, the PHA copolymers of U.S. Pat. No. 6,569,990, issued May 27, 2003 to I. Noda, and the like.
In one embodiment, the flexible material is a body-conforming foam such as the "temper foam" developed for astronaut seats and the related Tempur� foam material distributed by Tempur-Pedic, Inc. Such foam includes open sphere-shaped cells that are viscoelastic and can conform to body contours. Other known foams, including high internal phase emulsion (HIPE) materials, can also be used.
A wide variety of known patch materials can be considered. For example, the patches marketed by LecTec, Inc. (Minnetonka, Minnesota) can be modified by associating them with sensors, MEMS, and other devices. Association can be by embedding a device within the patch material, placing a device on a surface of the patch such as the body-side surface or the away-from-body surface, or by placing only a portion of the device in or on the patch, such as placing one or more conductive leads from a galvanic skin response sensor into the patch material, or by incorporating one element of a multi-element sensor into a single patch.
The sensors of the present invention can detect one or more analytes. Analytes can be any compound or material associated with the physiological condition of a subject, including proteins, DNA, antibodies, enzymes, amino acids, lipids, salts, toxins, man-made organic and inorganic compounds, and the like, including analytes known to be presence in any body fluids such as saliva, blood, urine, feces, menses, sweat, tears, and the like.
The sensors use in the condition monitoring system of the present invention can include any suitable biosensor or other sensor for any analyte or condition, including the sensors discussed in U.S. Patent Application Serial No. 10/277170, filed Oct. 21, 2002. Sensors can respond to thermal, chemical, electrical, biological, biochemical, physical, or mechanical properties. Other sensor systems of use in the present invention include those referenced in U.S. Pat. No. 6,527,711, issued March 4, 2003 to Stivoric et al., or any of the biosensors proposed in the following U.S. patent applications (to the degree said sensors can be made functional): Serial No. 09/299,399, filed April 26, 1999; Serial No. 09/517,441, filed March 2, 2000; and Serial No. 09/517,481, filed March 2, 2000, the contents of which are believed to have been published at least in part in WO 00/65347, published Nov. 2, 2000 by Hammons et al.; WO 00/65348, published Nov. 2, 2000 by Roe et al.; and WO 00/65083, WO 00/65084; and WO 00/65096, each published Nov. 2, 2000 by Capri et al. The biosensor can also include any of the technologies discussed in U.S. Pat. No. 6,186,991, issued Feb. 13, 2001 to Roe et al., U.S. Patent No. 6,501,002, issued Dec. 31, 2002 to Roe et al., U.S. Patent No. 6,570,053, issued May. 27, 2003 to Roe et al.; U.S. Patent No. 6,501,002, issued Dec. 31, 2002 to Roe et al. and in the U.S. Patent Applications Serial Nos. 09/342,784 and 09/342,289, both filed June 29, 1999 in the name of Roe et al, and both of which are related to the disclosure published as WO 01/00117 on Jan. 4, 2001. The biosensor can also be any of those discussed in U.S. Pat. No. 5,468,236, issued to D. Everhart, E. Deibler, and J. Taylor. The wearable devices of the present invention can also include biosensors for disease states or nutritional conditions, including cancer, diabetes, malnutrition, and the like.
Miniaturized sensors suitable for placement within small adhesive patches (e.g., less than about 5 cm in diameter and less than about 1 cm in thickness, more specifically less than about 2 cm in diameter and less than about 0.5 cm in thickness) can be used, including MEMS pressure sensors, load cells, accelerometers, and the like.
The sensors can be provided with disposable batteries, including flexible thin-film batteries such as the battery products of Power Paper Ltd. of Einat, Israel (see PowerPaper.com). Thin, flexible, disposable batteries can be incorporated into the products of the present invention in a variety of forms, such as armbands, shoe pads, patches that are placed on the body, etc. Other suitable thin-film batteries for RFID sensors and other sensors of the present invention include those of Infinite Power Solutions (Golden, Colorado). As described at https://www.rfidjournal.com/article/
articleview/411/1/1/, these batteries can be less than 5 mm thick with an output of 4 volts and a capacity of about 200 micro-amp hours per square centimeter. Other known methods can be used for recharging batteries by collecting ambient energy from vibration, motion, or temperature gradients, or by using an RF power source.
The sensors can be worn on the body, near the body, against the body, or at least partially inside the body or body opening. By way of example, a sensor can be placed inside or on an absorbent article such as a bed bad, a diaper, a sanitary napkin, facial tissue, ostomy bag, tampon, disposable garment, incontinence product, and so forth. It can also be an electrode, optical device, or other instrument, preferably miniaturized, that can respond to health indicators from the user�s body.
One useful technology that can be applied to wearable biosensors is "polytronics" � the use of semiconductor polymers, including transparent plastics and other plastics, that are doped to provide semiconductor functionality. Information about polytronics is provided in the article, "Polytronics: Rolling out the Chips," Fraunhofer Magazine, Jan. 2002, available at https://www.fraunhofer.de/fhg/archiv/magazin/pflege.zv.fhg.de/
english/publications/df/df2002/magazine1-2002-08.pdf. Coupled with laminated paper batteries or other thin-film batteries (e.g., those of PowerPaper Ltd. In Israel), plastic-based electronics offer the potential to provide a multitude of analytical and sensor technologies in low-cost, disposable forms, and in devices that are substantially free of metal.
In a related embodiment, flexible electronic circuitry can be used. Flexible circuitry can include films and can be laminated including printed conductive inks, flexible semiconductors or solid miniature semiconductor chips joined to other components with flexible electronics. By way of example, Poly-Flex Circuits, Inc. (Cranston, Rhode Island) manufactures a variety of useful flexible circuit assemblies and transponders for RFID labels. Both active and passive RFID technologies are described at https://www.polyflex.com/rfid.htm. Exemplary conductive inks useful for making RFID transponders includes Parmod� conductive inks made by Parelec, Inc. (Rocky Hill, NJ), with exemplary information provided at https://www.parelecusa.com/parelec3/index.html and information regarding the printing of antennas for RFID circuits provided at https://www.parelecusa.com/parelec3/products/Images/RFID.pdf.
Biosensors can also be selected from those that read an optical signal. Near-infrared analysis of compounds on or in the skin or components in body fluids, membranes, and other parts of the body can be considered. Indium gallium arsenide (InGaAs) detectors represent one class of near-infrared sensor technology that can be applied (see, for example, "Advanced Near-Infrared Cameras: Successful Application in the 900-to-1700 nm Band," Photonics Tech Briefs, May 2003, printed in NASA Tech Briefs, May 2003, pp. 1A-4A).
Sensors helpful for weight management can include near-infrared light technology for fat estimation, including the technology and devices marketed at www.futrex.com; bioelectrical impedance analysis (BIA) wherein electrical impedance across limbs or other parts of the body is measured (see, for example, https://www.futrex.com/nih.html) , including BIA applied by instrumented scales (e.g., those marketed by Tanita Corp. of Arlington Heights, Illinois, such as the TBF-611 Personal Body Fat Monitor/Scale) or other devices that can be in electronic communication with the condition monitoring system of the present invention, and other known methods.
In preferred embodiments, the bulky, rigid pods of some commercial system are replaced with smaller, flexible patches that can be placed in multiple locations on the body. The location of each patch can be predetermined and specified in a map or other instructions provided to the user, or can be customized by the user. For customized applications, the locations of each patch can be entered as data by the user into a computer system by typing, speaking through a voice-to-text system, or by automated means in which a camera observes the locations of added patches. Information about the position of the patches on the body can be important in interpreting the results (e.g., normal skin temperature varies across the body, and accelerometer signals during exercise will vary widely depending on the location). Thus, a computer program associated with the condition monitoring of the present invention can provide means for customizing sensor location, or means for allowing some choices to be made about the location of sensors or the number of sensors deployed, and can provide means for the user to identify the sensor location. The interpretation of sensor data can be adapted to the details of the location (e.g., accelerometer data from a hand will be interpreted differently that from a foot in terms of computing calories burned).
The sensors of the present invention can be attached to the body by any known means, though means that do not cause discomfort or undue constraint of motion are preferred. Adhesive patches can be adhered to the skin on any portion of the body. Sensors can also be implanted into the body, swallowed, or attached to the body by piercing (e.g., pierced body jewelry including one or more sensors, such as a photodetector attached to an ear ring or heat flux sensor embedded in jewelry adapted to be worn in a pierced navel or other portion of the body suitable for piercing). In addition, sensors can be placed in earpieces (e.g., a Delphi earpiece sensors system with three minute accelerometers for each ear of a race car driver is described by Gary Legg in "MEMS Sensors Rev Their Engines," Design News, Vol. 58, No. 7, May 5, 2003, pp. 73-76), mouthpieces, articles of clothing such as a shirt, sock, undergarment, hat, shoes, pants, and the like, or provided in jewelry such as rings or in accessories such as sunglasses. A ring-like biosensor for measuring pulse and possibly other parameters is described in B.-H. Yang and Sokwoo Rhee, "Development of the Ring Sensor for Healthcare Automation," Robotics and Autonomous Systems, 30 (3) (2000) pp. 273-81, available at https://www.mit.edu/people/sokwoo/RASJrnl.pdf and also described by Sokwoo Rhee et al. in "Modeling of Finger Photoplethysmography for Wearable Sensors," d'Arbeloff Laboratory for Information Systems and Technology, MIT, at https://www.mit.edu/people/sokwoo/EMBS99Model.pdf. Another ring is described in the article, "Medical Mood Ring" at https://www.technologyreview.com/articles/prototype60404.asp, which refers to the work of Harry Asada and Phillip Shaltis of MIT (for details, see https://www.mit.edu/people/pshaltis/ring_sensor.htm). Other wearable sensors that can be used are described in H. Asada, P.A. Shaltis, A. Reisner, S. Rhee, and R. Hutchinson, "Mobile Monitoring with Wearable Photoplethysmographic Biosensors," IEEE Engineering in Medicine and Biology Magazine - A Special Issue on Wearable Sensors/Systems and Their Impact on Biomedical Engineering, May/June 2003, pp. 28-40. Wound care devices such as bandages can also include sensors according to the present invention.
Even with wireless data transmission, sensors themselves typically require some form of wiring to join power sources and sensing elements or other components. For wearable sensors, it can be useful to include highly flexible wiring systems or even stretchable wiring. One approach for stretchable wiring is described in "Stretchy Wires Form Bendy Circuits," Nature Science Update, March 14, 2004, available online at https://www.nature.com/nsu/040308/040308-13.html:
Christopher Chen at Johns Hopkins University, Baltimore, and his co-workers built rubbery circuits out of several squashed but extendable gold wires. These are 20 times thinner than a human hair and wrapped in a springy polymer. The wires can be stretched by over half their initial length without loss of electrical conductivity.
Other details are given in D.S. Gray, J. Tien, and C.S. Chen, Advanced Materials, Vol. 16, No. 5, pp. 393-97 (March 2004).
RFID refers to the use of radiofrequency signals to automatically read codes from objects to identify the objects. For the purposes of this disclosure, RFID will be understood to encompass any practical electromagnetic frequency range (as used herein, RFID can be considered synonymous with the term electromagnetic identification or EMID). RFID technology enables microscopic (or larger) chips to be placed in objects, allowing the objects to be identified by wireless means. A typical RFID chip can contain an electronic product code that uniquely identifies the product (not just the product type, but a unique ID code for the individual product). A radio signal generated by a wearable sensor device can result in passive response signals from nearby RFID chips (the chips are coupled with antennas that can use the energy of the radio signal to generate a weaker radio signal in response that conveys the electronic product code for the article). Alternatively, products can include active RFID tags that have their own energy source and that actively emit a signal that could be read by known commercial systems (or another reader that can send information to the commercial device or to the computer used with the system). RFID telemetry can therefore be used to transmit sensor data to readers and from thence to central computers, if desired.
Generally, RFID tags consist of a semiconductor, a coiled, etched, or stamped antenna, a capacitor, and a substrate on which the components are mounted or embedded. A protective covering is typically used to encapsulate and seal the substrate. Inductive or passive smart tags have been introduced by Motorola under the name "BiStatix." A detailed description of the BiStatix device can be found in U.S. Patent No. 6,259,367 B1. Another commercial source of suitable smart tags is Alien Technology Corporation of Morgan Hill, California, under the technology name FSA (Fluidic Self-Assembly). With the FSA process, tiny semi-conductor devices are assembled into rolls of flexible plastic. The resulting "smart" substrate can be attached or embedded in a variety of surfaces. The smart tag technology under development at the Auto-ID Center at the Massachusetts Institute of Technology (Cambridge, Massachusetts) can also be used within the scope of the present invention. Further information on smart tags and related technology is discussed in U.S. Patent No. 6,451,154, "RFID Manufacturing Concepts," issued Sep. 17, 2002 to Grabau et al.; U.S. Patent No. 6,354,493, "System and Method for Finding a Specific RFID Tagged Article Located in a Plurality of RFID Tagged Articles," issued Mar. 12, 2002 to Mon; PCT publication WO 02/48955, published June 20, 2002; U.S. Patent No. 6,362,738, "Reader for Use in a Radio Frequency Identification System and Method," issued Mar. 26, 2002 to Vega; D. McFarlane, "Auto-ID Based Control," White Paper for the Auto-ID Centre Institute for Manufacturing, University of Cambridge, Cambridge, United Kingdom, Feb. 1, 2002; Chien Yaw Wong, "Integration of Auto-ID Tagging System with Holonic Manufacturing Systems," White Paper for the Auto-ID Centre Institute for Manufacturing, University of Cambridge, Cambridge, United Kingdom, Sept. 2001; and A.A. Zaharudin et al., "The Intelligent Product Driven Supply Chain," White Paper for the Auto-ID Centre Institute for Manufacturing, University of Cambridge, Cambridge, United Kingdom, Feb. 1 2002, available as paper "CAM-AUTOID-WH-005.pdf" at https://www.autoidlabs.com/whitepapers/.
Other RFID technologies believed to be of value for the present invention include the I*CODE chips and readers of Philips Semiconductor (Eindhoven, The Netherlands); the RFID tags of Sokymat (Lausanne, Switzerland); and the RFID technology of Texas Instruments (Dallas, Texas) including their TI*RFID systems.
Gemplus (Gemenos, France) provides RFID smart tags (sometimes called "smart labels") and smart cards employing RFID technology that can be used as smart tags. They also market interfaces, antennas, scanners and software that can be adapted for use with smart tags.
With RFID or other smart tag technology, a vendor can associate a unique ID code with a batch of raw materials, and enter physical property data into a database in which the data is associated with the ID code. When the raw material shipment is received, an RFID scanner can automatically scan the RFID chip and retrieve the associated information from the database, verify that usable raw material has been received at the correct facility, provide quality information to be associated with a quality database, and so forth.
It is to be understood that many other technologies are potential substitutes for the RFID embodiments discussed herein. For example, RFID readers could be replaced with optical scanners, image analysis devices, arrays of chemical detection devices, and the like to allow other technologies for reading identification means to be applied.
A related wireless technology within the scope of the present invention is Surface Acoustic Wave (SAW) technology. For example, InfoRay (Cambridge, Massachusetts) markets a passive smart tag that is said to achieve long ranges (up to 30 meters) using a Surface Acoustic Wave (SAW) device on a chip coupled with an antenna. The SAW device converts a radio signal to an acoustic wave, modulates it with an ID code, then transforms it to another radio signal that is emitted by the smart tag and read by a scanner. The ID code of the smart tag is extracted from the radio signal. RFSAW, Inc. (Dallas, Texas) also provides minute Surface Acoustic Wave (SAW) RFID devices that can be used within the scope of the present invention.
Known principles for using RFID in medical applications are discussed by D.L. Brock in "Smart Medicine: The Application of Auto-ID Technology to Healthcare," White Paper from the Auto-ID Center at MIT, Cambridge, Massachusetts, Feb. 1, 2002, available as paper "MIT-AUTOID-WH-010.pdf" at https://www.autoidlabs.com/whitepapers/.
RFID technology can be used in multiple aspects of the present invention. For example, RFID tags can be used to identify a user (e.g., the condition monitoring system would include an RFID scanner that reads a chip associated with a user to obtain needed information to retrieve or write information to medical or insurance records, to retrieve information about the health and background of the user, etc.), preferably with security features such as a password or biometric identification means to verify user identity. Active or passive RFID tags can also be used to wirelessly transmit information from sensors in the sensor patches to a central hub (e.g., a device worn as a belt buckle, or a PDA or other device associated with the user, or a more remote device such as a computer). The transmission of sensor data from a central hub associated with a user to a computer or from the various sensors associated with the user to a central computer can be done wirelessly via RFID chips that are read by RFID readers. The readers can be distributed throughout a building or other area such that signals from the sensors on the user are continuously monitored by distributed readers and made available on one or more servers or other storage devices, allowing the data to be processed and displayed. Alternatively, data processing can be done on a small processor worn or carried by the user. In any case, passive RFID tags can be read by multiple readers, or active tags can be by one or more readers, to provide information containing sensor data to a central hub or to others. In addition to providing sensors data from the user, this system can also track the location of the user.
RFID signals can convey information about objects that are near the user, and these objects can be recorded, particularly if they are interacting with the wearer in a way that could affect health, calorie burn, and other factors. For example, exercise equipment can include active RFID signal generating systems that identify the machine and optionally carry information about use of the machine (speed, distance, time, etc.) to create more detailed exercise records for the user.
An extensive portfolio of information about a user can be obtained by tracking through RFID means the objects that a user interacts with, and correlating that to biosensor information about the condition of the user. For example, when a user is sitting on a couch and the TV is on, or when a user is holding video game controllers, an RFID reader associated with the user can detect the user�s proximity to these objects. Biosensor signals are then tracked, allowing the user to later review heart rate, calorie usage, and other biological factors during watching television or playing video games, and compare this to information obtained during physical exercise. RFID analysis will permit tracking of time spent in sedentary activities and what the activities probably were. The user can then review his or her health status as a function of activity, and can customize designations of activities based on proximity to other RFID chips (i.e., creating a category called "Resting" that is characterized by being adjacent to an RFID chip in a couch while the TV is on).
Figure 1. Flow chart showing one approach for associating RFID data pertaining to external objects with physiological data from a condition monitoring system.
When objects of interest are determined to be near the user, the user can be given an option to acknowledge that the object of interest is being use or should be tracked. This can be done by prompting the user for a yes/no type of input when the object is identified. Alternatively, the user can later provide instructions about which object information to retain in an already compiled record from the condition monitoring system of the present invention. Certain classes of objects, whose presence was recorded, can be deleted after the fact in such embodiments.
Objects that can be of interest could include items such as exercise equipment, refrigerators, food dispensing devices and vending machines, televisions, beds, automobiles, lawn mowers, power tools, computers, video games, and the like.
In one embodiment, eating utensils can be provided with sensors that can monitor attributes about water, beverages, and foods consumed by the user. For example, sensors can monitor temperature and pH of fluids and foods, salt content, and so forth. One example of a proposed device for monitoring foods is the "Intelligent Spoon" from the MIT Media Lab, described at https://cac.media.mit.edu:8080/contextweb/
project?name=Intelligent_Spoon.
A wireless mesh network can be created by integrating various objects with the wearable sensor system. For example, wireless mesh technology from Dust Incorporated (Berkeley, California--see https://www.dust-inc.com/) can be integrated with the systems of the present invention. In the Dust Incorporated model, various sensors ("motes") gather information that is shared across a resilient, self-healing wireless network using a number of battery-operated communication nodes. These nodes, however, could be powered with RF harvesting to provide constant power without the need for battery replacement, or could be connected to AC circuits. The powered nodes could communicate via wireless signals with active sensors, passive sensors, passive RFID tags, or active or semi-active RFID tags.
Improved Applications of Condition Monitoring Units
The condition monitoring units of the present invention can be used in any known application for wearable biosensor products or for other known condition monitoring applications. New applications can also be considered. For example, a condition monitoring unit can be used to track operator activity levels in a production facility, and the physical data pertaining to the operator (e.g., respiration rate, calories burned, average and maximum velocity, distance traveled, changes in pulse or respiration rate, etc.) can be obtained and correlated with production results such as quality level, production rate, operator error, down time, production rate, etc. Such data can be mined and interpreted with neural networks or other features to specify standards of performance, or to predict the possibility of quality or production problems and take corrective steps.
While past applications of condition monitoring units have focused on individual use, the condition monitoring units of the present invention can also be used for group monitoring. Such applications include:
� tracking shift workers in a production setting;
� tracking the health of an athletic team during play;
� tracking the health of children in a day care center, with group information being available to the caretakers and, optionally, child-specific information made available to parents or guardians for real-time monitoring;
� tracking the status of students in a class; and
� tracking the health and activities of inmates, prisoners, and parolees.
For example, in a production facility equipped with an intelligent manufacturing system such as that described in U.S. Patent Application No. 10/306868, "Quality Management and Intelligent Manufacturing with Labels and Smart Tags in Event-Based Product Manufacturing," filed Nov. 27, 2002 by Markham et al., process information from production and quality events is recorded and time-stamped, and used to guide subsequent use of the materials produced. The system could be further improved by incorporating condition monitoring data from operators as a quality and performance factor that can have an impact of production efficiency and quality. For example, condition monitoring devices, perhaps located in mandatory safety equipment for a crew (e.g., steel-toed boots, a hard hat, etc.), in work clothing, or in patches against the skin, could be used to track the level of motion of workers during an interval of time, and this information could be correlated with production performance. There can be a general correlation between higher motion with higher awareness and higher attention to detail, and this in turn can correlate with product quality or efficiency. Crews showing lower than desired levels of alertness or activity, as sense by condition monitoring devices on multiple individuals, can be provided with suitable encouragement or motivation to change their performance pattern as a pre-emptive effort to avert quality defects. Data mining can be used to identify other physiological conditions for groups or individuals that correlate with higher performance or quality during a shift, and steps can be taken to achieve the desired physiological conditions more frequently.
Tracking group and individual dietary habits during a shift can also be used to determine the impact of eating habits on productivity. For example, crews that make large numbers of purchases from vending machines during breaks, as detected with external object tracking features or other means, can be found to exhibit improved or diminished performance, suggesting that management might wish to modify prices or ease of access to the snacks being consumed to encourage the desired response. Comparison of production event data with condition monitoring data can, for example, show that on the average, there is a 10% higher rate of web breaks immediately after an employee returns from purchasing snacks at a vending machine, suggesting corrective measures for management to explore.
Improved Data Visualization
A daunting aspect of dealing with prolonged condition monitoring of one or more individuals is the large body of information that can be collected, particularly when many sensors are operating simultaneously. Typically, the data are presented as a series of lines in a two-dimensional plot of measurement value versus time, which can only provide limited insights into the physiological map of the human body. Further, in prior systems, the user must download data to a compute system and view results on a computer system, rather than seeing real-time results. Monitors are known that provide a continuous display of one or a handful of variables on a display screen, but these often require that the user be physically connected to a bulky device. We propose an improved system in which portable, wireless display means are used to provide visualization of multiple measurement results in real time without preventing the user from engaging in activity such as physical exercise. Such means can include virtual reality displays provided in the form of video-enabled glasses, goggles, helmets, or other display devices known in the art.
In one embodiment, one or more walls or screens in one or more rooms are provided as virtual reality display devices to provide data visualization of multiple physiological parameters. For example, a user can wear virtual reality goggles while exercising in a virtual reality "cave" having two, three, four, five, or six walls capable of providing electronic images for a virtual reality display. Virtual reality displays can be programmed using tools such as the VR JugglerTM Open Source Virtual Reality Tools available at https://www.vrjuggler.org/. Data can be displayed using any known virtual reality software, such as 3D Active Chart of RInvoice.com (Ostrava, Czech Republic).
In other embodiments, the user is provided with head-up data displays that can present key biological parameters such as pulse rate, as well as rich data environments such as virtual reality displays of three-dimensional or higher-dimensional representations of the information from the user. For example, statistics, charts, or 3-D data displays can be provided via display-enabled sunglasses, glasses, helmets, facemasks, goggles, diver�s masks, and the like, as is discussed in U.S. Patent No. 6,356,392, "Compact Image Display System for Eyeglasses or Other Head-Borne Frames," issued March 12, 2002 to M.B. Spitzer; U.S. Patent No. 6,160,666, "Personal Visual Display System," issued Dec. 12, 2000 to R.D. Rallison et al.; U.S. Patent No. 5,903,396, "Intensified Visual Display," issued May 11, 1999 to R.D. Rallison; U.S. Patent No. 6,157,291, "Head Mounted Display System," issued Dec. 5, 2000 to G.B. Kuenster et al.; U.S. Patent No. 5,886,822, "Image Combining System for Eyeglasses and Face Masks," issued March 23, 1999 to M.B. Spitzer; U.S. Patent No. 5,208,617, "Sunglasses Having Reversible Watch," issued May 4, 1993 to S. Schwartz; and U.S. Patent No. 4,867,551, "Display Projection Optical System for Spectacles or Sunglasses," issued Sept. 19, 1989 to K.T. Perera.
Exemplary products for head-up display include the products of Virtual Vision, Inc. (Redmond, Washington), such as the eGlass IITM Personal Viewer.; or the devices of the MicroOptical Corp. (Westwood, Mass.), such as the AV-1, BV-3, SV-3, SV-9, EG-7, or CV-1 viewers; or the products of I-O Display Systems (Sacramento, California), such as the X3D Viewing System or i-GlassesTM HRV. Head-up viewers can provide images directly on the lens of glasses or on other transparent surfaces, or can provide images on viewers mounted near but not directly in the normal line of sight during use of glasses or related objects. Head-up displays of data can be provided in other formats as well. A windshield or other transparent surface in front of a user can be used for display of information without requiring the user to look away from a scene being viewed, as discussed in U.S. Patent No. 6,359,737 issued March 19, 2002 to S.A. Stringfellow.
Another useful tool that can be adapted to provide rich feedback to the wearer and to enable interaction between the user and the condition monitoring system is the Media Helmet developed Tom Selker and Jeremy Arnold at the Context-Aware Computing group in the MIT Media Lab. This device is described at https://cac.media.mit.edu:8080/
contextweb/project?name=Media_Helmet. Likewise, the Media Windshield from the same group, described at https://cac.media.mit.edu:8080/contextweb/project?name=
Media_Windshield, can also be adapted as a data visualization and display tool for users of the present invention, particularly while driving or flying aircraft. Such biological feedback can be particularly valuable for truckers and pilots, for whom fatigue or drowsiness can be common problems. Biosensor data from pilots, truckers, and the like can also be recorded in devices such as the black box of an airplane to provide additional data that can be useful in understanding the causes of an accident.
Data analysis can also include processing data streams through any known filtering system or transformation system to identify key effects, remove noise, identify interactions or correlated functions, and the like. Processing with regression techniques and related data analysis techniques can be done. For example, Empirical Mode Decomposition data processing (also known as the Hilbert-Huang Transformation) can be applied to identify physical signals (see https://www.nasatech.com/Briefs/
Oct00/GSC13817.html).
Improved User Input
The current Healthwear system of Roche Diagnostics (Indianapolis, Indiana) system can detect physiological states such as exercising, but marking of many physiological states appears to be done manually by pushing a timestamp button that allows the user to mark selected times in the collected data to correspond with activities or events known to the user. Rather than merely providing a timestamp that the user must then mentally connect with a specific activity, an improved system is proposed in which audio recording and, optionally, voice recognition technology is incorporated with the condition monitoring unit to allow the user to verbally describe events, activities, places, foods, etc. In one embodiment, the user depresses a button or otherwise signals that audio recording should begin, whereupon the user speaks and the voice message is recorded (e.g., "I�m going up stairs two at a time now"). The spoken words are recorded and time-stamped for association with the data collected at or near that time. In one embodiment, speech-to-text technology is used to convert the spoken message into text that can be displayed with or associated with the physiological data at or near the time of recording.
User Identification and Security Features
If desired, the condition monitoring system can include biometric identification features to identify the user or to only permit one or more specified users to use the system. Such security features can help prevent false data from other individuals from being gathered, particularly when physiological data is needed by a third party such as an insurer, employer, parole officer, care giver, parent, and the like. For example, the wearable condition monitoring system can require that the wearer periodically place a finger on a fingerprint reading sensor, such as capacitative-based sweep sensors, single touch sensors, or entrusted sensors (see Douglas McArthur, "Finger Sensor ICs Move to Accelerated Development Path," R&D Magazine, May 2003, Vol. 45, No. 5, p. 22) to confirm the identity of the wearer. Commercial fingerprint sensors include the Fujitsu Fingerprint Sensors of Fujitsu-Europe (Dreieich-Buchschlag, Germany) described at https://www.fme.fujitsu.com/products/biometric/. Other biometric sensing technologies or personal identification technologies can be employed, including voice recognition, iris scans, palm scans, detection of RFID-enabled identify cards or implanted chips, and the like.
Patches with Changeable Tackiness or Shape
In one embodiment, the patches include a body adhesive that is temperature sensitive, such that the patch is made tacky by body heat but is substantially non-tacky when cooled. This can allow a patch to be removed painlessly by cooling the adhesive with a cooling device. Exemplary materials and cooling methods are described in U.S. Patent No. 6,572,600, "Disposable Article with Deactivatable Adhesive," issued June 3, 2003 to Roe et al. Useful polymers that become tacky when warmed are described in U.S. Patent No. 5,387,450, "Temperature-Activated Adhesive Assemblies," issued Feb. 7, 1995 to Stewart, particularly the polymers of Examples 1 and 2 therein. Some other examples of deactivatable and reversible adhesives suitable for use in the present invention are described in more detail in U.S. Patent No. 5,156,911, "Skin-Activated Temperature-Sensitive Adhesive Assemblies," issued Oct. 20, 1992 to Stewart, and U.S. Patent No. 5,648,167, "Adhesive Compositions," issued July 15, 1997 to Peck.
In another embodiment, the patch can include a shape-memory polymer that conforms to a three-dimensional body surface at body temperature but that changes shape for quick release from the body upon cooling or heating.
In another embodiment, the patch can include an LCST polymer (lower critical solution temperature) that is liquid when cold but becomes solid when warmed. LCST polymers and methods of manufacture are described in U.S. Patent No. 6,030,634, "Polymer Gel Composition and Uses Therefor," issued Feb. 29, 2000 to Wu et al.
When the critical temperature is below body temperature, the patch can be applied to the body as a viscous liquid or soft gel that can then conform to the body and solidify or more fully adhere as it is warmed to body temperature. Such patches can provide excellent contact, even on hairy skin, and can then be painlessly removed by cooling until the polymer assumes liquid form again, whereupon the polymer can be removed by suction, adsorption, wiping, flowing off the body, and the like.
Other useful polymers for adhesive patches include those of WO 02/04570, "Preparation of Hydrophilic Pressure Sensitive Adhesives Having Optimized Adhesive Properties," published Jan. 17, 2001, by M.M. Feldstein et al. The polyvinyl caprolactam (PVcap) -PEG hydrogels discussed therein are said to have an LCST of about 35�C and to be well suited for pharmaceuticals and useful as adhesives.
A commercially available product suitable for use in the adhesive patches of the present invention is the MorphTM gels of Foster-Miller/Smart Materials (Boston, Mass.), as described at https://www.foster-miller.com/pressreleases/
fm_materials_licensing_gels.htm. These gels are said to respond to pre-programmed temperatures so the gel is liquid and pliable until it reaches a desired temperature, whereafter it becomes firm, allowing it to conform to the shape of whatever surface supports the gel. The process is reversible, so the solidified gel can become liquid again when cooled.
Other means can be used to deactivate the adhesive joining a patch to the body. For example, tension can be used to crystallize portions of an adhesive when strained, reducing adhesive strength. Tension-deactivatable adhesives are available as Poster Strips with COMMANDTM Adhesive from the 3M Corp. of St. Paul, Minn. and as TESA Power Strips from Beiersdorf Corp. (Hamburg, Germany). Related adhesives are described in U.S. Patent Nos. 5,491,012; 5,626,931; and 5,626,932.
The changeable polymer, such as a temperature-sensitive polymer or other polymers that change shape or viscosity or tackiness in response to an environmental factor, can be used as an adhesive, such as an adhesive layer joining another flexible layer to the skin, or it can form the primary matrix within which sensors are embedded (in which case another material can serve as the adhesive polymer), or both.
Therapeutic Options
The condition monitoring system can also be adapted to provide signals that direct the application of therapeutic or pharmaceutical treatments to the user and to be responsive to the physiological condition of the user as determined by analysis of sensor data. For example, insulin can be delivered based on detected glucose levels and other sensor signals. In one embodiment, a plurality of biosensor signals (rather than a single sensor) are analyzed using algorithms to determine the detailed physiological state of the user, and, in response, one or more therapeutic treatments are automatically applied. Such treatments can include delivery of a medication, application of heating or cooling to a region of the body, modification of oxygen levels or humidity levels, adjustment of room temperature, a signal calling for a caregiver to provide a treatment such as changing a wound dressing or moving a patient, alteration of the position of a hospital bed, and the like.
Drug delivery means can include polymers that are sensitive to pH, temperature, electrical signals, light, and the like, whereby a change in an external stimulus influenced by the condition monitoring system causes a change in the drug delivery means that results in delivery of therapeutic agent. Microfluidic devices can also be used to deliver therapeutic agents to the skin, mucous membranes, directly into the blood, and so forth. Exemplary drug delivery devices that can be adapted for the present invention include those of U.S. Patent No. 4,675,009, "Drug Dispensing Device for Transdermal Delivery of Medicaments," issued March 31, 1986 to Ong and Pearsons and U.S. Patent No. 6,361,790, "Method of Forming Adhesive Patch for Applying Medication to the Skin," issued March 26, 2002 to Rolf et al.
In one embodiment, iontophoresis and/or electroporation can be used to enhance drug delivery to the skin. Principles of electroporation for transdermal drug delivery are discussed at https://epore.mit.edu/~tgowrish/tgowrish/research/transdermal.html and in A.V. Badkar et al., "Enhancement of Transdermal Iontophoretic Delivery of a Liposomal Formulation of Colchicine by Electroporation," Drug Delivery, 6:111-115, 1999; S. Bose et al., "Electrically-Assisted Transdermal Delivery of Buprenophrine.," J. of Controlled Release, 73:197-203, 2001; and S.-L. Chang et al., "The Effect of Electroporation on Iontophoretic Transdermal Delivery of Calcium Regulating Hormones," J. Controlled Release, 66:127-133, 2000. A commercial device for electrically-assisted transdermal drug delivery useful for the present invention is the PowerCosmeticsTM system of Power Paper Ltd. (Einat, Israel), in which microcurrents delivered by flexible thin batteries are said to enhance transdermal drug delivery by several orders of magnitude (see https://www.powerpaper.com/2_solutions_cosmetics/1main.htm and https://www.powerpaper.com/pdf/Data_cos.pdf).
Ultrasound can also be used to promote transdermal drug delivery. Patches including a high frequency generating element such as a thin, flexible piezoelectric film can be operatively associated with a drug reservoir or material including a drug that is present against the skin, wherein application of electrical energy to the piezoelectric element can be used to enhance the transfer of the drug into the skin. Principles of ultrasonic assistance for drug delivery are discussed by L. Weimann and J. Wu in "Transdermal Drug Delivery by Sono-Macroporation" at https://www.meddevgroup.org/presentations/Ultra-sound%20%20application%20in%20%20TDD-%20short%20form.ppt and by D. Bommannan et al. in "Sonophoresis. II. Examination of the Mechanisms of Ultrasound-Enhanced Transdermal Drug Delivery," Pharm. Research, 1992; 9: 1043-1047.
Therapeutic treatments and drug delivery can also be assisted by micromechanical actuators, such as those discussed in Chang Liu and Y. Bar-Cohen, "Scaling Laws of Microactuators and Potential Applications of Electroactive Polymers in MEMS," Proceedings of SPIE's 6th Annual International Symposium on Smart Structures and Materials, March 1-5, 1999, Newport Beach, CA, 1999, available at https://ndeaa.jpl.nasa.gov/ndeaa-pub/spie99/SPIE99-3669-mems-33.PDF.
By way of example, in one embodiment, biosensors are adapted to detect the presence of bacterial infection by detecting markers for infection, including the presence or a changed concentration of certain proteins or antibodies, an increase in body temperature, etc. In response, immune-strengthening materials or antimicrobial agents can be administered automatically.
Summary
Several improvements for wearable biosensors have been proposed. Some of these improvements can generally be described in several ways, such as either of the following:
1. A system for monitoring the physiological condition of a subject, including:
a) at least one flexible patch having attachment means for holding the patch in proximity to a body surface of the subject, the at least one patch including at least one sensor adapted to obtain raw data pertaining to at least one physiological condition of the subject;
b) processing means in electrical communication with the at least one sensor for converting the raw data from the at least one sensor into human physiological output data;
c) storage means for storing at least one of the raw data from the at least one sensor and human physiological output data from the processing means;
d) object detection means for automatically detecting the presence or use by the subject of at least one object during a first time interval;
e) associating means for associating the detection of the presence or use of an object with stored data including at least one of the human physiological output data from the processing means and the raw data from the at least one sensor during a second time interval, the second time interval characterized by one of overlapping with the first time interval, being substantially contemporaneous with the first time interval, or being proximate to the first time interval such that at a pair of endpoints from both the first and second time intervals are separated by less than a predetermined length of time, the associating means adapted to provide associative data linking the presence or use of an object with human physiological output data;
f) output means in electrical communication with the processing means and the associating means for communicating the human physiological output data associative data to the user or a third party.
2. A method of automatically associating object information pertaining to the environment of a user with physiological condition data obtained via a physiological condition monitoring system, the method including:
a) obtaining physiological data pertaining to the user during an interval of time via a condition monitoring system including a plurality of sensors contained within at least one flexible section attached to the body of the user, the sensors generating signals and being in electronic communication with processing means for generating physiological data based on the signals from the sensors,
b) storing the physiological data on storage means to define a physiological history of the user during the time interval;
c) automatically identifying an object proximate to the user at a time during the time interval, wherein the proximity of the object to the user is likely to be relevant to the health or physiological state of the user, and wherein wireless signals are used to identify the object;
d) associating information pertaining to the object and the time it was identified with the physiological history of the user; and
e) correlating the physiological history of the user with the associated information pertaining to the object.
We look forward to further developments involving multiple sensor systems that can be comfortably worn on the body of a subject and that can interact with or communicate with other objects to assist the subject.
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