Patent Application
20130211270
1. Technical Field
This invention relates generally to sensors, and more particularly to biometric sensors.
Sporting enthusiasts and athletes play, practice, and train for the sports in which they participate. It would be beneficial to have devices and methods to more effectively monitor their activities.
The accompanying figures, where like reference numerals refer to identical or functionally similar elements throughout the separate views and which together with the detailed description below are incorporated in and form part of the specification, serve to further illustrate various embodiments and to explain various principles and advantages all in accordance with the present invention.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
Before describing in detail embodiments that are in accordance with the present invention, it should be observed that the embodiments reside primarily in combinations of method steps and apparatus components related to biometric monitoring with an electronic monitoring device employing reflected interferometry communication. Any process descriptions or blocks in flow charts should be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps in the process. Alternate implementations are included, and it will be clear that functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved. Accordingly, the apparatus components and method steps have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.
It will be appreciated that embodiments of the invention described herein may be comprised of one or more conventional processors and unique stored program instructions that control the one or more processors to implement, in conjunction with certain non-processor circuits, some, most, or all of the functions of electronic biometric monitoring described herein. The non-processor circuits may include, but are not limited to, a radio receiver, a radio transmitter, signal drivers, clock circuits, power source circuits, and user input devices. As such, these functions may be interpreted as steps of a method to perform biometric monitoring. Alternatively, some or all functions could be implemented by a state machine that has no stored program instructions, or in one or more application specific integrated circuits (ASICs), in which each function or some combinations of certain of the functions are implemented as custom logic. Of course, a combination of the two approaches could be used. Thus, methods and means for these functions have been described herein. Further, it is expected that one of ordinary skill, notwithstanding possibly significant effort and many design choices motivated by, for example, available time, current technology, and economic considerations, when guided by the concepts and principles disclosed herein will be readily capable of generating such software instructions and programs and ICs with minimal experimentation.
Embodiments of the invention are now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.” Relational terms such as first and second, top and bottom, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, reference designators shown herein in parenthesis indicate components shown in a figure other than the one in discussion. For example, talking about a device (10) while discussing figure A would refer to an element, 10, shown in figure other than figure A.
Embodiments of the present invention provide an electronic monitoring device that includes one or more biometric sensors and a communication device. In one embodiment, the electronic components are coupled to, or alternatively integrated in, a mouth guard. Examples of biometric sensors include force sensors and temperature sensors. Electronic monitoring devices configured in accordance with embodiments of the invention are configured to provide biometric data to a receiver in real time. Through the use of reflected interferometry communication, embodiments described herein provide advantages over prior art solutions in that large power supplies and high-powered radio transceivers need not be incorporated into the monitoring device. This advantage allows the mouth guard to be smaller and lighter, more resembling traditional mouth guards worn by athletes.
In one embodiment, the electronic monitoring device is configured as a mouth guard suitable for protecting an athlete's teeth during sporting activities. One or more biometric sensors can then be attached to or integrated with the mouth guard. A communication module, operable with the biometric sensor, then includes an antenna, a controller and a switch. The switch is responsive to the controller and is operative to change a radar cross section of the antenna by selectively altering a load impedance of the antenna. The controller is configured to receive biometric data and/or signals from the biometric sensor. The controller then, upon receiving radio frequency signals from a transceiver, is configured to backscatter received radio frequency signals by modulating the received radio frequency signal by controlling the switch to encode output from the biometric sensor into a backscattered return signal.
When configured as a system, the electronic monitoring device can be used with one or more remote radio frequency transceivers. A monitoring module is operable with the one or more radio frequency transceivers. One or more monitoring devices can be given, for example, to one or more athletes competing in an activity on an athletic field. In one embodiment, the one or more radio frequency transceivers are each configured to transmit a radio frequency signal. They then receive a backscattered return signal from the each of the monitoring devices. In one embodiment, the backscattered return signals comprise multi-path, and frequently indirect path, return signals. The backscattered return signals in one embodiment have an output from the biometric sensor modulated therein due to the controller of a particular monitoring device switching the switch. In another embodiment, the backscattered return signals also include a unique identifier so the identity of a particular athlete can be determined when multiple monitoring devices are in use. Further, when multiple radio transceivers are in use, embodiments of the invention can determine the location of each monitoring device in real time as well.
Embodiments of the invention accordingly provide a method of monitoring anatomical motion and activity. In one embodiment, this includes providing one or more users with mouth guards. Each mouth guard can include a biometric sensor and a switch operable to change a radar cross section of an antenna of the mouth guard by selectively altering a load impedance of the antenna. A coach, parent, or other person can then monitoring biometric activity of the user by transmitting, with one or more transceivers, a radio frequency signal and receiving backscattered return signals having output of the biometric sensor encoded therein. This method can be used to monitor for critical biometric events, including potential overheating, dehydration, and concussions or trauma due to impact, just to name a few.
Embodiments of the invention contemplate that monitoring head motion and vital signs in physical activities provides valuable information that can lead to the prevention of medical problems during the physical activity and in the future. The electronic monitoring devices configured in accordance with the description below allow monitoring, in one embodiment, of head motion dynamics such as impulsive and translational force in three dimensions, impulsive and smooth rotational forces in two dimensions, and head orientation in three dimensions. In addition, some embodiments of the electronic monitoring devices described below can be used to monitor other vital signs such as ambient mouth temperature, heart rate, and mouth moisture. Embodiments of the invention are suitable for monitoring health diagnostics data, taking scientific measurements, and recording statistics for sports and physical activities.
Embodiments of the invention are especially useful in monitoring forceful impacts to the head that may occur in sporting activities. Recent studies suggest that measuring impacts to the head with linear accelerations in excess of 96.1 G's or rotational accelerations in excess of 5582.3 rad/s2 correlate with concussion incidences. Accordingly, embodiments of the invention can be used as concussion monitoring devices in high-impact sports such as football and rugby. In such sports, mouth guards are standard equipment. By configuring the electronic monitoring device as a mouth guard, the athlete can be monitored without altering standard equipment. Such monitoring is beneficial in sports with head impacts such as football, hockey, rugby, soccer, boxing, and mixed martial arts. The measurement of head acceleration can be used as a diagnostic for detecting concussions, muscle strain, neck injuries, and internal bruises. Medical procedures for diagnosing concussions are performed immediately after a severe blow to the head or neck. Symptoms such as headache, dizziness, nausea, or loss of consciousness typically indicate a concussion. Further testing such as x-ray, CT scan, or neurological testing can diagnose a concussion. The data from embodiments of the invention are unique in that it is measured data of the hit instead of a symptom of the hit.
A secondary use of embodiments of the invention is as an accurate scientific measurement tool. Embodiments can be used to scientifically measure linear or rotational acceleration and biometric data. Embodiments described below can feasibly contain any number of biometric sensors that measure vital signs such as heart rate, temperature, moisture level, or blood pressure. In addition, any biometric data that can be measured using a pair of electrodes connected to the roof of the mouth, the tongue, or teeth can be measured by providing one or more exposed electrodes along the surface of the mouth guard.
Another use for embodiments of the invention includes simply recording biometric data during physical activity. Embodiments of the invention can track and store biometric data over the course of the physical activity for later reporting. Coaches, trainers, and athletes can use the information for optimizing physical performance or in any other optimization.
Turning now to
The mouth guard 101 has coupled thereto—integrated therein—a biometric sensor 106 and a communication device 107. In this illustrative embodiment, the biometric sensor 106 is integrated into the body of the mouth guard 101, while the communication device 107 is disposed along a surface 108 of the mouth guard 101. In other embodiments, both the biometric sensor 106 and the communication device 107 can be disposed along the surface 108 of the mouth guard 101. In still other embodiments, the biometric sensor 106 and the communication device 107 can be integrated into the body of the mouth guard 101. Note that while a single biometric sensor 106 is shown in
The biometric sensor 106 can be configured as any of a number of different types of sensors. For example, in one embodiment, the biometric sensor comprises a linear acceleration detector. In another embodiment, the biometric sensor 106 comprises a rotational acceleration sensor. In another embodiment, the biometric sensor 106 comprises both a linear acceleration detector and a rotational acceleration sensor. In another embodiment, the biometric sensor 106 comprises a temperature sensor. In another embodiment, the biometric sensor 106 comprises a moisture sensor. In another embodiment, the biometric sensor 106 comprises a heart rate sensor. In another embodiment, the biometric sensor 106 comprises a respiration sensor. Of course, combinations of these sensors can be used as well. Moreover, those of ordinary skill in the art will recognize that other types of biometric sensors can be used instead of, or in addition to, the sensors listed above. Accordingly, the list is intended to be illustrative only, and is not limiting. For example, other types of biometric sensors include microelectromechanical (MEMS) type impact sensors, MEMS accelerometers, and/or miniature weighted cantilevers fitted with miniature strain-gauge elements, piezoelectric membranes, or force-sensitive resistors.
In one embodiment, the biometric sensor 106 comprises a linear acceleration sensor, a rotational acceleration sensor, or a combination thereof. The communication device 107 is operable with the biometric sensor and receives sensed acceleration data from the biometric sensor via a communication bus 109. A radio frequency transceiver, which will be explained in more detail with reference to
In one embodiment, the acceleration detectors of the biometric sensor 106 are configured to monitor linear acceleration and/or rotational acceleration in three Cartesian dimensions. This monitoring is used in one embodiment to monitor for concussions in athletes. With a Cartesian plane being defined by X, Y, and Z coordinates, linear acceleration of the head of a user who has the mouth guard 101 in his mouth can be measured in the x, y, and z axes. Rotational acceleration around the x, y, and z axes can also be measured using a convention corresponding to the “right-hand rule”. As is known in the art, the right hand rule defines a convention when one points the right-hand thumb in the positive linear direction of the axis, and then wraps the right-hand fingers around the axis in the positive direction of rotation for that axis.
When force is applied to a user wearing the mouth guard 101, the measured linear and rotational acceleration vectors are represented as:
A.sub.lin=a.sub.x*x.sub.vect+a.sub.y*y.sub.vect+a.sub.z*z.sub.vect; (EQ. 1)
and
A.sub.rot=a.sub.x*Omega.sub.x+a.sub.y*Omega.sub.y+a.sub.z*Omega.sub.z; (EQ. 2)
where x.sub.vect, y.sub.vect, and z.sub.vect are the linear basis vectors that point in the positive x, y, and z directions respectively, and the rotational basis vectors Omega.sub.y, Omega.sub.y, and Omega.sub.z point in the positive rotation directions around the x, y, and z axes respectively. The amount of “head jerk” resulting from an impact force can be measured as well by taking the derivative of measured acceleration versus time as follows:
Jerk.sub.lin=d/dt(A.sub.lin); and (EQ. 3)
Jerk.sub.rot=d/dt(A.sub.rot). (EQ. 4)
Significant magnitudes of head jerk can correspond to probable incidence of concussion. For example, a sudden hit to the head between the left eye and left ear may cause both linear and rotational acceleration. Significant linear acceleration would be measured in the negative y and z directions, and significant rotational acceleration would be measured around the z axis. The biometric sensor 106, in one embodiment, detects this acceleration, and delivers signals corresponding thereto to the communication device 107. The communication module then delivers this data to radio frequency transceivers by backscattering return signals having output of the biometric sensor encoded therein. When other sensors are included in the biometric sensor 106, other data can be reported in the same way, including but not limited to, heart rate, moisture content, and mouth temperature.
While acceleration can be measured with a biometric sensor 106 that is integrated into a body of the mouth guard 101, some other information requires exposed measurement terminals. Turning now to
To enable more efficient temperature sensing, in one embodiment the temperature sensor 221 is operative with a first biometric sensor terminal 223 that has a surface exposed to a surface 208 of the mouth guard 201. When the mouth guard 201 is placed in the mouth of a user, the first biometric sensor terminal 223 can rest against the roof of the mouth in this illustrative embodiment to better detect temperature. Similarly, in one embodiment the moisture sensor 22 is operative with a second biometric sensor terminal 224 that has one or more surfaces exposed to the surface 208 of the mouth guard 201. The second biometric sensor terminal 224 can thus sense moisture in the mouth. Note that while the first biometric sensor terminal 223 and the second biometric sensor terminal 224 are disposed on an upper surface in this illustrative embodiment, it will be clear to those of ordinary skill in the art having the benefit of this disclosure that other configurations could also be used. For example, one or both of the first biometric sensor terminal 223 and the second biometric sensor terminal 224 could be disposed on a first sidewall 203 of the mouth guard 201, a second sidewall 204 of the mouth guard 201, or on a floor 205 of the mouth guard 201 as well.
Turning now to
In other embodiments, the generator 330 can be replaced by a battery. Such a battery can be coupled to the biometric sensors 306,336 and the communication device 307. In some embodiments, the batteries are rechargeable, such as via a wireless charging device. However, due to the low power consumption of the communication device 307, in other embodiments the battery will be a primary use battery. When the primary use battery is depleted, the electronic monitoring device 300 will simply be discarded.
In yet other embodiments, the generator 330 can be replaced with a power harvester. As will be described below, in one or more embodiments the communication device 307 communicates by backscattering received radio frequency waves. The power harvester allows the electronic monitoring device 300 to function without batteries. One example of a suitable power harvester is described in D. Dobkin's book, “The RF in RFID. Passive UHF RFID in Practice,” published by Elsevier in 2008. Using the power harvester, power for the biometric sensors 306,336 and the communication device 307 can be harvested from an un-modulated signal received at an antenna of the communication device 307.
In this illustrative embodiment, one biometric sensor 306 is disposed along a front portion of the mouth guard 301. This biometric sensor 306, in this illustrative embodiment, would be proximately located with the incisors of a user when the mouth guard 301 is placed in the user's mouth with the user's upper teeth disposed in the channel 302. Biometric sensor 336 is disposed at a different area of the mouth guard 301.
In this illustrative embodiment, biometric sensor 306 comprises a three-axis accelerometer configured to detect acceleration along three orthogonal linear axes. Operable with biometric sensor 306 is a three-axis gyroscope 331 and a control circuit 332 that are disposed on a flexible substrate 333 that is integrated into the mouth guard 301. The three-axis accelerometer, in one embodiment continually monitors acceleration and outputs an impact-warning signal when acceleration is measured in excess of 90 G. In one embodiment, the three-axis gyroscope 331 is configured to resolve six thousand or more degrees per second. In one embodiment, each of biometric sensor 306, the communication device 307, and the flexible substrate 333 are disposed on the first sidewall 303, which is outside the user's teeth. This helps to ensure that the user's teeth do not interfere with backscattering signals from the communication device 307.
As described above, the three-axis accelerometer and gyroscope 331 can be configured to determine a rate of acceleration of the mouth guard 301. Additionally, these devices can determine orientation of the mouth guard 301 in time. By correlating acceleration and position, the electronic monitoring device can not only the fact of an impact of a particular magnitude has occurred, but also the direction of the impact from the direction of movement of the gyroscope 331. These data can be used to calculate a vector representative of a combined direction and magnitude of the acceleration experienced by the electronic monitoring device 300. In some instances the calculated vector may be along a straight line, while in other instances the calculated vector may be curvilinear, rotational, or combinations thereof.
While a three-axis accelerometer is one explanatory biometric sensor 306, it will be clear to those of ordinary skill in the art that embodiments of the invention are not so limited. For example, in another embodiment, biometric sensor 306 comprises three linear accelerometers. Moreover, gyroscope 331 may not be required.
Turning now to
In the illustrative embodiment of
Examples of the controller 404 disposed in the communication device 107 and control circuit 403 coupled to the transceiver 405 include a microprocessor configured to execute instructions stored in an on-board or separately coupled memory. Alternatively, each of the controller 404 and control circuit 403 can be configured as programmable logic, an ASIC, or combinations thereof. The radio transceiver 401 can even be configured such that the control circuit 403 is disposed in a portable computer or other electronic control device that is electrically coupled with the transceiver 405. In at least some instances, the controller 404 and control circuit 403 will be implemented using one or more microprocessors, implemented to execute one or more sets of pre-stored instructions. However in some instances all or portions of the controller could be implemented in hardware, where exemplary forms include one or more sequential state machines and/or various logic circuitry, including discrete logic elements, programmable gate array elements, or VLSI circuitry. It will be obvious to those of ordinary skill in the art having the benefit of this disclosure that other alternative implementations involving various forms of software programming and hardware elements can be used to implement embodiments of the present invention without departing from the teachings herein.
The transceiver 405 of the radio transceiver 401 is responsive to the control circuit 403 and is configured to transmit a radio frequency signal 415. Where multiple radio transceivers are used in an application, the radio frequency signal 415 transmitted by each radio transceiver may be unique. For example, in one embodiment, each radio frequency signal 415 transmitted may be offset from the others by a predetermined phase. In another embodiment, each radio frequency signal 415 transmitted may have a different frequency or characteristic waveform. In one embodiment, the transmitted radio frequency signal 415 has a center frequency of about 915 MHz, about 2.45 GHz, or about 5.7 GHz. These frequencies are well suited to embodiments of the invention in that they represent the unlicensed scientific and medical bands of 915 MHz, 2.45 GHz, and 5.7 GHz, respectively, having wavelengths of 30 centimeters, 12 centimeters, and 5 centimeters respectively. It will be clear to those of ordinary skill in the art having the benefit of this disclosure, however, that embodiments of the present invention are not limited to these frequencies, as any number of radio frequency bands may work as well.
The communication device 107 receives this radio frequency signal 415 at its antenna 406. In one embodiment, the antenna 406 comprises a slot antenna suitable for receiving radio frequency communication. In one embodiment, the antenna 406 comprises an inverted-F antenna.
The switch 408 of the communication device 107 then, in response to a control signal from the controller 404, switches in accordance with biometric data signals 418 received from the biometric sensor (106). In one embodiment, the switch 408 switches between the two loads 410,412, thereby changing the radar cross-section of the antenna 406. This change in radar cross section serves to modulate or encode the biometric data signals 418 into a backscattered return signal 416 that is backscattered from the antenna 406. The transceiver 405 then receives this backscattered return signal 416 having the biometric data modulated therein. By reading the biometric data, the control circuit 403 is able to determine biometric information about the user wearing the electronic monitoring device.
A biometric evaluation device 407 then processes the biometric information. A modeling device 409 can then receive information from the biometric evaluation device 407 to create diagnostic models from the data. Illustrating by example, the modeling device 409 can translate linear and/or rotational forces from the biometric data signals 418 to a center of mass of an athlete's head. The modeling device 409 can then deliver 411 to a display so that a coach, parent, or medical professional can view a graphical representation of the linear and/or rotational forces on the athlete's head. In some embodiments, the coach, parent, or medical professional can also see graphical representations of the athlete's temperature, oral moisture, heart rate, or other vital signals. In one or more embodiments, the biometric evaluation device 407 includes an injury warning device. The injury warning device can generate alerts when the biometric data signals correspond to thresholds representative of injury to the athlete. In one embodiment, the injury warning device is connected across a network like the Internet to a medical record system to draw data corresponding to injuries.
Turning now to
In addition to having a mouth guard 501, the explanatory electronic monitoring device 500 of
Turning now to
Turning now to
As with previous embodiments, the monitoring device 703 comprises a biometric sensor and a communication module. The communication module is operable with the biometric sensor and includes an antenna, a controller, and a switch. The switch is responsive to the controller. The switch is operative to change a radar cross section of the antenna by selectively altering a load impedance of the antenna.
As shown in
The monitoring module 702 then processes the received data and delivers it, wired or wirelessly, to one or more monitoring devices. Said differently, the monitoring module 702 is configured to collect the output from the biometric sensor, received by the radio frequency transceiver 701 as a backscattered return signal, and present indicia corresponding thereto on a display of a monitoring device. In one embodiment, the indicia comprise data corresponding to an impact event detected by the biometric sensor of the monitoring device 703. The indicia can further comprise a concussion warning. The monitoring devices can include a tablet 707, a mobile device 708, or a computer 709. Other monitoring devices can be used as well, as will be obvious to those of ordinary skill in the art having the benefit of this disclosure.
In one or more embodiments, the biometric monitoring system 700 can be used to aggregate head-acceleration information received from the monitoring device 703. To facilitate ease of monitoring, the monitoring module 702 of the radio frequency transceiver can be in wireless communication with one or more of the monitoring devices to allow coaches, parents, and/or spectators to monitor not only monitor head acceleration of the various players, but temperature information, hydration information, body temperature information, heart rate information, and other vital information for each player. In one or more embodiments, the monitoring module 702 is operable with a server, network, or other electronic device that serves as an intermediate device between the radio frequency transceiver and the monitoring devices. Additional processing capabilities can be integrated into the server or other electronic device as well. The monitoring device can include its own processor, user interface, local memory, and one or more communication components. The monitoring module 702 receives information from the monitoring device 703 and optionally makes that data available to the monitoring devices.
In one or more embodiments, the monitoring module may be in wired or wireless communication with a medical system or medical records database via communication with the same over a public or private data network. The medical system can optionally receive the biometric information detected by the monitoring device for analysis in conjunction to stored athlete information or medical records.
In one embodiment, the monitoring module 702 includes thresholds that can be set to generate alerts based upon certain types of data. For example, the monitoring module 702 can be configured to determine when a diagnostic, such as head acceleration for example, has exceeded a predetermined threshold. When this occurs, the monitoring module 702 can provide an alert that the acceleration event that exceeded the threshold. Such alerts can be useful in determining when a particular athlete has sustained a concussion. Similar alerts can be set for temperature, to alert when an athlete is overheating, for moisture, to alert when an athlete is becoming dehydrated, or based upon other monitored vital signs.
The general method steps used in the biometric monitoring system 700 of
Beginning at step 801, a user to be monitored is provided a mouth guard comprising a biometric sensor and a switch operable to change a radar cross section of an antenna of the mouth guard by selectively altering a load impedance of the antenna. At step 802, the user places the mouth guard in their mouth and begins an activity.
Steps 803-806 then describe the steps of monitoring biometric activity of the user. At step 803, one or more transceivers transmit a radio frequency signal. At step 804, the one or more transceivers receives backscattered return signals having output of the biometric sensor encoded therein due to the switching of the switch in the mouth guard.
At step 805, the monitoring module receives data from the radio frequency transceiver. In one embodiment, the data comprises information corresponding to a linear force and/or a rotational force applied to the athlete. The monitoring module may normalize this data or otherwise process the same to determine impact information. Examples of impact information include a peak force, a rate of change of the force, and a magnitude or other characteristic of the force. The monitoring module may extrapolate acceleration and rotational forces from the data.
At optional step 806, a modeling module can use the processed data from the monitoring module to generate a model of the forces on a human skull. Such a model will be shown in more detail below in
While being described as generally applicable to monitoring athletes, those of ordinary skill in the art having the benefit of this disclosure will recognize that the method 800 of
Turning now to
The monitoring device 903 of this system 900 can be used to help diagnose concussions by measuring the linear and rotational accelerations on the football helmet 992 of the football player. Advantageously, embodiments of the present invention can accomplish this with greater accuracy than prior art systems, such as the HITS system manufactured by Simbex. In this illustrative embodiment, in addition to acceleration measurements, mouth temperature is measured with a temperature sensor, and heart rate is measured with exposed electrodes. Each of these sensors is configured as a biometric sensor of the monitoring device 903.
In this embodiment, the communication device 907 of the monitoring device 903 comprises a passive wireless device that communicates with the base station using wireless backscatter communications. In this embodiment, backscattering refers to the reflection of impinging signals with an alternating reflection coefficient signaling a message. A schematic block diagram of the components of the communication device 907, i.e., the components of the passive wireless device, is shown in
Once powered, the baseband logic of a controller 908 of the communication device 907 reads the one or more biometric sensors of the monitoring device 903. A switch then modulates a reflector. When one or more of the radio frequency transceivers 901,991 needs to communicate information to the communication device 907 an optional envelope detector 993. The envelope detector 993 is configured to demodulate any commands sent to the communication device 907 by the radio frequency transceivers 901,991. In one embodiment, both the biometric sensor and the communication device 907 are integrated into the monitoring device 903 to prevent any corrosion from saliva or accidental swallowing.
The controller 908 and switch, which can be integrated in a single integrated circuit, causes the radar cross section of the antenna 906 to alternate between connections to two or more distinct reflective loads 910,912. The control and timing of the load modulator's switch is performed by the controller's baseband logic in accordance with signals received from the biometric sensor. In one embodiment, the controller's baseband logic can be implemented in a mixed-signal IC using complementary metal-oxide-semiconductor (CMOS) technology. A discrete logic device such as the Texas Instruments MSP430 series microprocessor can be used as well. The baseband logic device receives data from the biometric sensor, in one embodiment, in analog form using an analog-to-digital converter. In another embodiment, the baseband logic receives the data in digital form. For example, in one embodiment an STMicroelectronics LIS3LV02DQ linear accelerometer can be used as the biometric sensor to communicate acceleration measurements digitally via a data connection to the controller 908.
In this illustrative embodiment, to provide a completely passive communication device, an energy harvester 914 is included as the power source. The energy harvester 914 converts ambient energy from the environment into electrical energy for the components of the monitoring device 903. Examples of suitable energy harvester devices include a radio frequency rectifier or charge pump, a vibration harvester, or acoustic harvester. The envelope detector 993, where included, is typically a rectifying circuit that is built from diodes and capacitors. The baseband logic of the controller 908, the energy harvester 914, the envelope detector 993, and even the biometric sensor, be it one or more accelerometers, one or more gyroscopes, or one or more other sensors can all be contained within an integrated circuit. However, a discrete component implementation is feasible as well.
As shown in
The plurality of radio frequency transceivers 990 provide an unmodulated incoming signal 905. Energy from the incoming signals 905 is then harvested for DC power by the energy harvester 914. The antenna 906 then modulates and reflects a backscattered return signal 996. There is a wide variety of signal configurations that can be used, but in one embodiment, the incoming signals 905 and the backscattered return signals 996 correspond to the rules of the Federal Communications Commission (FCC) for the designed frequency band. Any of the radio frequency transceivers 901,991 can transmit incoming signals 905 multiple times per second. The monitoring module 902 of one of the radio frequency transceivers 901 can analyze received data, and then save and report the data to the user or a medical professional, coach, or personal trainer.
The frequency bands used for communications will typically be an industrial, scientific, and medical (ISM) band, which allow use of the spectrum by unlicensed users by the FCC. Possible frequency bands and their communications standards may include, but are not limited to:
ISO 18000-3: Air interface standard for 13.56 MHz;
ISO 18000-4: Air interface standard for 2.45 GHz;
ISO 18000-6: Air interface standard for 860 to 940 MHz;
ISO 18000-7: Air interface standard for 433.92 MHz;
IEEE 802.15.1: “Bluetooth” standard for 2.4 GHz;
IEEE 802.15.1: Wireless personal area networks coexisting with wireless local area networks at 2.4 GHz or 5.8 GHz;
IEEE 802.15.4: Low-rate wireless personal area networks for semi-passive tags or long-battery life tags on which the Zigbee specification is based; and
Dash-7: tags consuming less than 1 mW operating at 433.92 MHz.
As shown in
In this embodiment, forces from the hit are measured in a three-dimensional Cartesian coordinate system used to measure both linear and rotational acceleration. As indicated by the direction of the arrow 994, the biometric sensor will detect significant linear acceleration components in the negative y and z directions. In addition, the head of the athlete 904 will experience significant rotational acceleration in the negative z direction and slight rotation in the positive y direction from this force. The monitoring module 902 receives this data and models the impact on a coordinate system and head 995. This information, which includes a resulting vector 997, can then be presented on a monitoring device.
Turning now to
In one or more embodiments, medical information 1005 received from a medical service as described above that corresponds to the athlete can be displayed as well. Other biometric information, including temperature information 1006, hydration information 1007, and heart rate and/or respiration information 1008 can also be presented.
In one or more embodiments, information 1009 identifying the coach, trainer, or parent can be presented as well. The modeled impact information 1002 can be shown in analog or numeric form, depending upon which is more efficient at informing a coach, trainer, or health care provider the magnitude of the most recent impact. In one or more embodiments, the same information can be delivered to a server or other device disposed near the playing field.
To this point, biometric monitoring has been described. However, as noted in the discussion of the information that can be presented on the display 1001, in one or more embodiments, identification and location of a particular player can be presented as well. Location and identification information can be especially useful when multiple monitoring devices are being deployed. For example, in a typical football game, there may be 100 or more monitoring devices being used, with 22 on the field at any one time. Accordingly, it can be advantageous to be able to identify individual players when monitoring biometric data.
Turning first to
The transceiver 1105 of the radio transceiver 1101 is responsive to the control circuit 1103 and is configured to transmit a radio frequency signal 1115. Where multiple radio transceivers are used in an application, the radio frequency signal 1115 transmitted by each radio transceiver may be unique. For example, in one embodiment, each radio frequency signal 1115 transmitted may be offset from the others by a predetermined phase. In another embodiment, each radio frequency signal 1115 transmitted may have a different frequency or characteristic waveform.
The communication device 1102 receives this radio frequency signal 1115 at its antenna 1106. In one embodiment, the antenna 1106 comprises a slot antenna suitable for receiving radio frequency communication. The switch 1108 of the communication device 1102 then, in response to a control signal from the controller 1104, switches. In the embodiment above shown in
A location determination module 1107, which may be configured in software as executable code or in hardware as programmable logic, is then configured to compare the received backscattered return signal 1116 with the transmitted radio frequency signal 1115 to make location determination estimates. In one embodiment, the location determination module 1107 is configured to determine the location of the communication device 1102 by determining a phase shift between the transmitted radio frequency signal 1115 and the backscattered return signal 1116 to determine a distance between the communication device 1102 and the radio transceiver 1101. In another embodiment, the location determination module 1107 is configured to determine a signal strength of the backscattered return signal 1116 and compare it with the signal strength of the transmitted radio frequency signal 1115 to determine a distance between the communication device 1102 and the radio transceiver 1101. Where multiple radio transceivers are disposed about the area of interest, these distances can be used in a triangulation method to determine a location estimation of each communication device.
In one embodiment, the location determination module 1107 is configured to determine both a first location determination and a second location determination. The first location determination can be a coarse location estimate, while the second location determination can be a fine location estimate. Each location determination can be made using the same backscattered return signals 1116. For example, presuming three or more radio transceivers are disposed about an area of interest, in one embodiment the first location determination can be made by triangulating distances from the three or more radio transceivers using the signal strength of each backscattered return signal received by each radio transceiver. In one embodiment, the second location determination can be made by triangulating distances from the three or more radio transceivers using the phase shift between transmitted radio frequency signals and the backscattered return signals received by each radio transceiver.
Where multiple radio transceivers are used, the corresponding control circuits can be combined into a single control circuit or may otherwise be integrated into a single device. For example, each radio transceiver 1101 may include an output 1111 suitable for coupling to a general-purpose computer, application specific device, or user interface.
Where multiple radio transceivers 1101 are used to determine the location of any one communication device 107, in one embodiment each radio transceiver 1101 is capable of receiving a backscattered return signal 1116 from each other radio transceiver. Said differently, while radio transceiver 1101 may emit its own, unique radio frequency signal 1115, it may receive backscattered return signals from multiple other radio transceivers. This configuration can have advantages in some applications, as advanced location determination techniques can be applied to the plurality of received signals.
In other applications, however, it may be desirable to only receive a return signal that corresponds to the signal delivered from the transceiver 1105. One way to accomplish this is by including an optional filter 1113 configured to pass some backscattered return signals while blocking others. For example, where each radio transceiver transmits a radio frequency signal of a different frequency, the radio transceiver 1101 can be equipped with the optional filter such that only the backscattered return signal 1116 having the unique identifier modulated therein that corresponds to the radio frequency signal 1115 transmitted by radio transceiver 1101 will be received, as other backscattered return signals will be blocked.
In another embodiment, such as to reduce multipath distortion, the optional filter 1113 can be configured to block signals that are unmodulated, while passing those that have been modulated by the communication device 1102. Such a filter 1113 helps to reduce both noise and distortion that can affect location determination.
Where multiple radio transceivers are used, and further where multiple communication devices are used, one or more of the radio transceivers may include an optional object modeling module 1109. The object modeling module 1109 may be configured in software as executable code or in hardware as programmable logic. While shown in
In one embodiment, the object modeling module 1109 is configured to model a multi-dimensional shape of an object. Recall from above that while the communication device 107 can be integrated into a mouth guard, it can also be integrated into other devices, including bandages, or stickers for application to the skin. It can also be integrated into pads and equipment, shoes or other objects. Presuming that a subject has a plurality of monitoring devices is disposed along their body, the object modeling module 1109 can map the shape of the object from the determined location of each monitoring device, using an interpolation algorithm to create surfaces between the location of each monitoring device. For example, in one embodiment, the object modeling module 1109 can map the shape of the object by linearly connecting the locations of each monitoring device. In another embodiment, a higher order function may be used to connect the monitoring device locations to form the multidimensional shape of the object.
Turning now to
In the illustrative embodiment of
As also noted above, in one embodiment each radio frequency signal 1115, 1215, 1217, 1219 is unique. For example, each radio frequency signal 1115, 1215, 1217, 1219 may have its phase or frequency offset from each of the other radio frequency signals as indicated in
The communication device 1102 of the present invention is unique, in that it backscatters each of the radio frequency signals 1115, 1215, 1217, 1219 by switching between two loads 1110,1112 coupled to the antenna 1106. This communication device 1102 is inexpensive to manufacture in that it does not require any RF components such as matching circuits, transmission lines, and the like. Its largest component is generally the antenna 1106. However, the antenna 1106 merely receives and reflects incident power from each radio frequency signal 1115, 1215, 1217, 1219, thereby modulating a unique identifier associated with the communication device 1102 (as well as the biometric data from a biometric sensor (not shown)) into the backscattered return signals 1116, 1216, 1218, 1220. The physical form factor of the antenna 1106 is scalable with frequency. Experimental testing has shown that a 5.7 GHz antenna can be manufactured to be 2 centimeters or less in length.
In the illustrative embodiment of
In the illustrative embodiment of
Upon reflection, each backscattered return signal 1116, 1216, 1218, 1220 travels to the receiver of each radio transceiver 1101, 1201, 1203, 1205. When each radio transceiver 1101, 1201, 1203, 1205 receives each backscattered return signal 1116, 1216, 1218, 1220, components of the location determination module 1107 (neglecting operation the biometric processing components since they have been described above) operating in each radio transceiver 1101, 1201, 1203, 1205 may determine a distance between the radio transceiver and the communication device 1102. As noted above, this can be done in various ways.
Turning now briefly to
Turning now back to
In one embodiment, the first location determination is based upon received signal strength fingerprinting technology. Radio transceivers 1101, 1201, 1203, 1205 that are closer to the communication device 1102 receive stronger signals, while more distant radio transceivers 1101, 1201, 1203, 1205 receive weaker signals. Each communication device 1102 has a unique combination of signal strengths that can be used to provide the location estimate. Further, the backscatter link is lossier than conventional free-space wireless links. The additional propagation loss can be used it increase accuracy determination when the signals are triangulated. Such technology is known in the art and has been used, for example, in cellular communication systems to determine the location of a caller dialing 911. Such technology is illustratively set forth in a paper by N. Patwari, A. Hero III, M. Perkins, N. Correal, and R. O'Dea, entitled “Relative Location Estimation in Wireless Sensor Networks,” IEEE Transactions on Signal Processing, vol. 51, no. 8, pp. 2137-48, August 2003, http://dx.doi.org/10.1109/TSP.2003.814469, which is incorporated herein by reference. Location determination based upon signal strength measurements is also illustratively described in a paper by R. Yamamoto, H. Matsutani, H. Matsuki, T. Oono, and H. Ohtsuka, entitled “Position Location Technologies Using Signal Strength in Cellular Systems,” IEEE VTS 53rd Vehicular Technology Conference, Spring, 2001. Proceedings (Cat. No. 01CH37202), vol. vol. 4, pp. 2570-4, 2001, http://dx.doi.org/10.1109/VETECS.2001.944065, and a paper by J. Zhu, Indoor/Outdoor Location of Cellular Handsets Based on Received Signal Strength,” Georgia Tech PhD Dissertation, June 2006, http://www.propagation.gatech.edu/Archive/PG_TR—060515_JZ/PG_TR—060515_JZ.pdf, both of which are incorporated herein by reference. The system 1200 of
A second, more accurate location estimate can be achieved using phase shift between the transmitted radio frequency signals 1115, 1215, 1217, 1219 and the backscattered return signals 1116, 1216, 1218, 1220. Each radio transceiver 1101, 1201, 1203, 1205 has a corresponding signal path defined between it and the communication device 1102. The path from each radio transceiver 1101, 1201, 1203, 1205 to the communication device 1102 will introduce a phase change in the transmitted and backscattered wave that is proportional to the total path link. For example, if the signal path from radio transceiver to communication device is 5.83 meters, and the radio frequency being used is 5.7 GHz, 3 centimeters of phase difference will be introduced into as the wave travels from the radio transceiver to the communication device. This corresponds to a phase difference of 144 degrees. A corresponding amount of phase difference will be introduced on the return trip. Thus, each radio transceiver 1101, 1201, 1203, 1205 will measure a different amount of phase shift due to the location of the communication device 1102.
Turning briefly to
To illustrate by way of example, a phase difference measurement at 5.7 GHz at 72 degrees would yield a hyperbolic surface in three dimensions that is indicative of a total path length change of 4.36 meters from radio transceiver to communication device. Neighboring hyperbolic surfaces would correspond to total path lengths of 4.31 meters and 4.41 meters, respectively.
Location of the communication device 1102 can then be resolved by using multiple phase measurements from the multiple backscattered return signal measurements. Each phase measurement results in a series of hyperbolic surfaces that can be intersected with others to eventually produce a reliable and sufficiently accurate location estimation of the communication device 1102.
Using the four-radio transceiver system shown in
Turning back to
In one embodiment, the location determination module 1107 is configured to determine location both from the course location estimate using signal strength and the fine location estimate using phase change. By using both determination methods, the effects of noise, interference, and multiple signal paths can be overcome. For example, using the course location estimate, a “sphere of likelihood” can first be determined. Next, the hyperboloids of the fine location estimate may only be drawn in within the sphere of likelihood, thereby reducing the computation associated with an accurate location determination.
In one embodiment, where both fine and course location determinations are used, a carrier frequency for the radio frequency signals 1115, 1215, 1217, 1219 will be selected such that the sphere of likelihood determined from the course location determination would include 3 or 4 hyperboloids. Generally speaking, lowering the carrier frequency of the radio frequency signals 1115, 1215, 1217, 1219 results in longer wavelengths, which in turn leads to hyperboloids that are father apart.
Turning now to
At step 1401, a plurality of radio frequency signals are transmitted from a plurality of radio transceivers. In one embodiment, the radio frequency signals are transmitted continuously while the method 1400 is being executed, although intermittent transmission is also possible. In one embodiment, the radio frequency signals are transmitted on a one-to-one basis from each radio transceiver, such that each radio transceiver transmits one radio frequency signal. In one embodiment, four radio transceivers are used to transmit four radio frequency signals into an area of interest. The radio frequency signals can each be unique. For example, in one embodiment, each radio frequency signal is transmitted with one of a unique frequency, a unique phase shift, or combinations thereof.
At step 1402, each radio transceiver receives one or more backscattered return signals from one or more communication devices disposed within one or more biometric monitoring devices. As described above, in one embodiment, each communication device has a switch capable of selectively reflecting and modulating each of the transmitted radio frequency signals to encode an identifier that is unique to the communication device, and also to encode biometric data, therein. In one embodiment, the switch toggles between a high impedance load and a low impedance load in accordance with a unique identification code and/or biometric data to modulate the identifier and biometric information into the radio frequency signal and reflect and return it to the plurality of transceivers as one or more backscattered return signals.
At step 1403, the method 1400 receives the biometric data and further determines the location of the one or more communication devices from information derived from the one or more backscattered return signals. For example, in one embodiment, the method 1400 uses triangulation techniques to determine the location of the one or more communication devices at step 1403. As shown in
At step 1502 and step 1504, as described above, the triangulation can be performed using the relative signal strengths of the one or more backscattered signals to achieve a coarse location estimate. The signal strength of the backscattered signal can be compared to the signal strength of the transmitted radio frequency signal. As each radio transceiver determines a different relative signal strength, these differences can be triangulated to obtain a course location estimate.
At step 1503 and step 1505, as also described above, triangulation could be performed by generating a series of hyperboloids modeling the distances between each radio transceiver and each communication device to achieve a fine location estimate, where those distances are determined from a phase shift detected between each transmitted radio frequency signal and the corresponding backscattered return signal. The phase difference of the backscattered return signal, when compared to the transmitted radio frequency signal, can be used to generate the hyperboloids. The combination of the two approaches can also be used as illustrated at steps 1504,1505. One example of this is the method using the course location estimate to determine a sphere of probability with the fine location estimate pinpointing the actual location of a communication device within the sphere noted above.
Where multiple communication devices are employed, it can sometimes be advantageous to model the shape of the object to which the communication devices are affixed. For example, embodiments of the invention are well suited for biomechanical sensing, such as athletic activity, as many monitoring devices can be coupled to an athlete executing a biometric motion. As the radio transceivers of embodiments of the present invention are capable of determining the locations of each communication device while the biometric motion is being executed, it can be useful to form a visual model of the athlete by modeling surfaces between the communication devices to approximate the student on a video screen. This is especially useful for review of collisions and other impact events occurring in contact sports. Turning now back to
In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention as set forth in the claims below. Thus, while preferred embodiments of the invention have been illustrated and described, it is clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions, and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention as defined by the following claims. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. The benefits, advantages, solutions to problems, and any element(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential features or elements of any or all the claims.
This application claims priority and benefit under 35 U.S.C. §119(e) from U.S. Provisional Application No. 61/525,001, filed Aug. 18, 2011, which is incorporated by reference for all purposes. This application is a continuation-in-part of U.S. application Ser. No. 12/505,916, filed Jul. 20, 2009, which is incorporated herein by reference for all purposes, and which claims priority and benefit under 35 U.S.C. §119(e) from U.S. Provisional Application No. 61/083,974, filed Jul. 28, 2008.
| Number | Date | Country | |
|---|---|---|---|
| 61525001 | Aug 2011 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 12505916 | Jul 2009 | US |
| Child | 13588663 | US |
