Abstract: A method for collaborative document editing determines a document update upload rate based on edit characteristics. The document update upload rate is used to determine when edits made via a particular user device are sent to a document collaboration server. The edit characteristics include a number of a plurality of users collaboratively editing a document, a current edit location within the document for one of the users, and the type of connection and speed of the connection between a user device and the document collaboration server. The document update upload rate can be determined in response to a change in one of the edit characteristics.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying proximity of a mobile computing device to another mobile computing device. A computing system determines that a set of mobile computing devices are geographically proximate to a first mobile computing device based on identifying that each of the mobile computing devices received a first type of signal from an emitting device for which the first mobile computing device also received the first type of signal. The computing system determines a subset of the mobile computing devices that share a physical space with the first mobile computing device based on identifying that each of the mobile computing devices emitted a second type of signal that was detected by the first mobile computing device, or detected the second type of signal that was emitted by the first mobile computing device.

Abstract: According to one aspect of the present invention, a projectile target is disclosed comprising a target having a substantially sealed chamber having a front face and a rear face with an enclosing side wall disposed intermediate. The front and rear faces are formed by membranes configured to allow a projectile to pass therethrough and then substantially seal to maintain the substantially sealed chamber. Pressure wave sensors are disposed within the chamber and are configured to detect pressure waves created by the projectile. A target controller receives signals from the pressure sensors indicative of the pressure sensed by the sensors and determines an impact point of the projectile on the front face of the target.

Abstract: In general, the subject matter described in this specification can be embodied in methods, systems, and program products for identifying proximity of a mobile computing device to another mobile computing device. A computing system determines that a set of mobile computing devices are geographically proximate to a first mobile computing device based on identifying that each of the mobile computing devices received a first type of signal from an emitting device for which the first mobile computing device also received the first type of signal. The computing system determines a subset of the mobile computing devices that share a physical space with the first mobile computing device based on identifying that each of the mobile computing devices emitted a second type of signal that was detected by the first mobile computing device, or detected the second type of signal that was emitted by the first mobile computing device.

Abstract: Head motion input devices for providing control to a computer are described.

Abstract: A method for analyzing an EKG signal in real time to produce a heart rate indication. The most recent digitized samples of the EKG are stored in a buffer and evaluated to identify each R-wave peak sample value that (a) immediately precedes and is larger that the most recently stored digital sample value, (b) is larger than any other sample value in the buffer, and (c) differs from the first sample value in the buffer by more than a predetermined threshold value. The threshold is a fraction of the rise time slope of the last peak. The real time heart rate indication is calculated from the time duration separating the last two detected peaks, but rate indications outside the range of 30–200 beats per minute, and which depart from the preceding rate indication by more than 50 percent, are discarded.

Abstract: An orientation and position tracking system in three-dimensional space and over a period of time utilizing multiple inertial and other sensors for determining motion parameters to measure orientation and position of a moveable object. The sensors, for example vibrational and angular velocity sensors, generate signals characterizing the motion of the moveable object. The information is received by a data acquisition system and processed by a microcontroller. The data is then transmitted via wireless communication to an external data reception system (locally based or a global network). The information can then be displayed and presented to the user through a variety of means including audio, visual, and tactile.

Abstract: A method for analyzing an EKG signal in real time to produce a heart rate indication. The most recent digitized samples of the EKG are stored in a buffer and evaluated to identify each R-wave peak sample value that (a) immediately precedes and is larger that the most recently stored digital sample value, (b) is larger than any other sample value in the buffer, and (c) differs from the first sample value in the buffer by more than a predetermined threshold value. The threshold is a fraction of the rise time slope of the last peak. The real time heart rate indication is calculated from the time duration separating the last two detected peaks, but rate indications outside the range of 30-200 beats per minute, and which depart from the preceding rate indication by more than 50 percent, are discarded.