Abstract: A system to recharge a battery including a first current-voltage source to generate a first signal, a second current-voltage source to generate a second signal, a first inductor-capacitor circuit to generate the first DC current-voltage signal using the first signal, a second inductor-capacitor circuit to generate the second DC current-voltage signal using the second signal, wherein the first and second inductor-capacitor circuits are spaced apart by a predetermined distance. The system also includes a temperature sensor adapted to generate temperature data during the charging operation, and control circuitry configured to: (i) determine whether the first temperature data is out-of-specification, and (ii) generate one or more control signals to adjust the first and second DC current-voltage signals, in response to the first temperature data being out-of-specification.

Abstract: A system and technique for determining a state of charge (SOC) of a battery having at least two terminals and at least one silicon-based anode, or other anode materials exhibiting hysteretic voltage-SOC dependence such as tin-based anodes (whether partial or full dependence). The system and technique determines whether the battery is in a charge mode or a discharge mode of operation, measures a terminal voltage of the battery, and determines the SOC of the battery using (a) a first predetermined relationship between (i) the terminal voltage of the battery and (ii) the SOC of the battery when the battery is in a charge mode, and (b) a second predetermined relationship between (i) the terminal voltage of the battery and (ii) the SOC of the battery when the battery is in a discharge mode. In one embodiment, the terminal voltage is an equilibrium voltage of the battery.

Abstract: A system to recharge a battery including a first current-voltage source to generate a first signal, a second current-voltage source to generate a second signal, a first inductor-capacitor circuit to generate the first DC current-voltage signal using the first signal, a second inductor-capacitor circuit to generate the second DC current-voltage signal using the second signal, wherein the first and second inductor-capacitor circuits are spaced apart by a predetermined distance. The system also includes a temperature sensor adapted to generate temperature data during the charging operation, and control circuitry configured to: (i) determine whether the first temperature data is out-of-specification, and (ii) generate one or more control signals to adjust the first and second DC current-voltage signals, in response to the first temperature data being out-of-specification.

Abstract: Circuitry and techniques to measure, at the battery's terminals, characteristic(s) of the charging signal applied to the battery/cell during the recharging operation and, in response to feedback data which indicates the charging signal is out-of-specification, control or instruct the charging circuitry to adjust characteristic(s) of the recharging signal (e.g., the amplitude of the voltage of and/or current applied to or removed from the battery during the charging operation). For example, a rechargeable battery pack comprising a battery, and controllable switch(es), a current meter and voltmeter, all of which are fixed to the battery. Control circuitry generates control signal(s) to adjust a current and/or voltage of the charging signal using the feedback data from the current meter and/or voltmeter, respectively.

Abstract: A system to recharge a battery including a first current-voltage source to generate a first signal, a second current-voltage source to generate a second signal, a first inductor-capacitor circuit to generate the first DC current-voltage signal using the first signal, a second inductor-capacitor circuit to generate the second DC current-voltage signal using the second signal, wherein the first and second inductor-capacitor circuits are spaced apart by a predetermined distance. The system also includes a temperature sensor adapted to generate temperature data during the charging operation, and control circuitry configured to: (i) determine whether the first temperature data is out-of-specification, and (ii) generate one or more control signals to adjust the first and second DC current-voltage signals, in response to the first temperature data being out-of-specification.

Abstract: A device including an RF transceiver coupled to receive signals from an antenna; and a micro-controller coupled to the RF transceiver periodically scanning for a wakeup signal and measuring a signal strength is provided. The micro-controller may use the signal strength to update a count value in a bin of a histogram. The micro-controller may also decrement histogram values periodically, and direct the RF transceiver to respond to the wakeup signal if the count value in the histogram is lower than a threshold value. Further according to some embodiments disclosed herein a system for avoiding over polling in wireless communications may include a tag and a reader. The reader may transmit a wakeup signal periodically and the tag may operate as the device disclosed above. Also, a method for using a device and a system as above is provided.

Abstract: A system and method for eye gaze tracking without calibrated cameras, direct measurements of specific users' eye geometries, or requiring the user to visually track a cursor traversing a known trajectory. The preferred embodiment includes two uncalibrated cameras imaging the user's eye and haying on-axis lighting. The cameras capture images of a test pattern in real space as reflected from the user's cornea, which is essentially a convex spherical mirror. The invention then extracts parameters required to define a mathematical mapping between real space and image space, including spherical and perspective transformations. The invention processes subsequent images of objects reflected from the user's eye through the inverse of the mathematical mapping to determine a gaze vector and a point of regard. Alternately, a single calibrated camera may be employed with means for estimating the eye-to-camera distance. A head-mounted embodiment that may include a laser pointer is also described.

Abstract: A system and method for eye gaze tracking without calibrated cameras, direct measurements of specific users' eye geometries, or requiring the user to visually track a cursor traversing a known trajectory. The preferred embodiment includes two uncalibrated cameras imaging the user's eye and having on-axis lighting. The cameras capture images of a test pattern in real space as reflected from the user's cornea, which is essentially a convex spherical mirror. The invention then extracts parameters required to define a mathematical mapping between real space and image space, including spherical and perspective transformations. The invention processes subsequent images of objects reflected from the user's eye through the inverse of the mathematical mapping to determine a gaze vector and a point of regard. Alternately, a single calibrated camera may be employed with means for estimating the eye-to-camera distance. A head-mounted embodiment that may include a laser pointer is also described.

Abstract: A system and method for calibration-free tracking of a user's eye gaze vector and point of regard even if substantial head movement or rotation occurs. The preferred embodiment includes two synchronized interlaced cameras, each viewing the user's eye and having on-axis lighting that is alternately modulated. An image difference between lighted and unlighted images of the eye is used to identify a user's pupil. A plane containing the gaze vector is defined by rotating a base plane through the angle in a camera image plane between a pupil center, a first glint, and a second glint. The intersection of two such planes (one from each camera), defines the gaze vector. The gaze position is the intersection of the gaze vector with the object being viewed by the user. Alternate embodiments are also described.

Abstract: A system and method (and signal medium) for interactively displaying information, include a ticker display for displaying items having different views, a tracker for tracking a user's eye movements while observing a first view of information on the ticker display, and a mechanism, based on an output form the tracker, for determining whether a current view has relevance to the user.

Abstract: A system and method for calibration-free tracking of a user's eye gaze vector and point of regard even if substantial head movement or rotation occurs. The preferred embodiment includes two synchronized interlaced cameras, each viewing the user's eye and having on-axis lighting that is alternately modulated. An image difference between lighted and unlighted images of the eye is used to identify a user's pupil. A plane containing the gaze vector is defined by rotating a base plane through the angle in a camera image plane between a pupil center, a first glint, and a second glint. The intersection of two such planes (one from each camera), defines the gaze vector. The gaze position is the intersection of the gaze vector with the object being viewed by the user. Alternate embodiments are also described.

Abstract: A method and apparatus analyzes a scene to determine which pupils correspond to which subjects. First, a machine-readable representation of the scene, such as a camera image, is generated. Although more detail may be provided, this representation minimally depicts certain visually perceivable characteristics of multiple pupil candidates corresponding to multiple subjects in the scene. A machine such as a computer then examines various features of the pupil candidates. The features under analysis include (1) visually perceivable characteristics of the pupil candidates at one given time (“spatial cues”), and (2) changes in visually perceivable characteristics of the pupil candidates over a sampling period (“temporal cues”). The spatial and temporal cues may be used to identify associated pupil pairs. Some exemplary spatial cues include interocular distance, shape, height, and color of potentially paired pupils.

Abstract: A method and apparatus determine when a subject is looking at a specific target area by estimating a divergence angle between (1) the direction in which the subject is looking and (2) the direction from the subject directly to the target area. This technique accesses whether the subject is looking at a particular area. The invention may further condition this determination according to the subject's distance from the target area, because there is less tolerance for divergent angles when the subject is farther away. In one embodiment, the divergence angle is estimated using the position of a glint of light in the subject's pupil. The glint is created by a light source located in the target area. If the glint is sufficiently central to the pupil, with the camera and light source being near the target area, the subject is looking at the target area. At long distances, when the glint is not sufficiently discernable from the pupil, another technique may be employed to estimate divergence angle.