Abstract: A system and method for wireless communication. The system can include a transmitter that transmits a data signal having a time period without data transmission. The system can also include a receiver including a first antenna, a second antenna, a switch that activates one of the first antenna and the second antenna, and a processor that estimates a first signal-to-noise ratio for the first antenna and a second signal-to-noise ratio for the second antenna during the time period without data transmission. The processor can control the switch to select one of the first antenna and the second antenna based on a comparison between the first signal-to-noise ratio and the second signal-to-noise ratio.

Abstract: A method and technique for the continuous, non-invasive measurement of blood pressure. The blood pressure measurement technique of the present invention utilizes ultrasound measurements to determine the diameter of the blood vessel in which the blood pressure is being measured as well as the flow rate of blood at both an input point and an output point along the blood vessel. The system utilizes a transmission line model to relate various blood vessel measurements with electrical components. The transmission line model, in combination with data management techniques including state variable representations and Kalman filtering, is used to develop a blood pressure measurement in real time.

Abstract: A continuous, non-invasive fetal heart rate measurement is produced using one or more ultrasonic transducer array patches that are adhered or attached to the mother. Each ultrasound transducer array is operated in an autonomous mode by a digital signal processor to obtain data from which fetal heart rate information can be derived. Each ultrasonic transducer array patch comprises a multiplicity of subelements that are switchably reconfigurable to form elements having different shapes, e.g., annular rings. Each subelement comprises a plurality of interconnected cMUT cells that are not switchably disconnectable. The use of cMUT patches will provide the ability to interrogate a three-dimensional space electronically (i.e. without mechanical beam steering) with ultrasound, using a transducer device that is thin and lightweight enough to stick to the patient's skin like an EKG electrode.

Abstract: A continuous, non-invasive fetal heart rate measurement is produced using one or more ultrasonic transducer array patches that are adhered or attached to the mother. Each ultrasound transducer array is operated in an autonomous mode by a digital signal processor to obtain data from which fetal heart rate information can be derived. Each ultrasonic transducer array patch comprises a multiplicity of subelements that are switchably reconfigurable to form elements having different shapes, e.g., annular rings. Each subelement comprises a plurality of interconnected cMUT cells that are not switchably disconnectable. The use of cMUT patches will provide the ability to interrogate a three-dimensional space electronically (i.e. without mechanical beam steering) with ultrasound, using a transducer device that is thin and lightweight enough to stick to the patient's skin like an EKG electrode.

Abstract: A system and method for wireless communication. The system can include a transmitter that transmits a data signal having a time period without data transmission. The system can also include a receiver including a first antenna, a second antenna, a switch that activates one of the first antenna and the second antenna, and a processor that estimates a first signal-to-noise ratio for the first antenna and a second signal-to-noise ratio for the second antenna during the time period without data transmission. The processor can control the switch to select one of the first antenna and the second antenna based on a comparison between the first signal-to-noise ratio and the second signal-to-noise ratio.

Abstract: Ultrasound is used to provide input data for a blood pressure estimation scheme. The use of transcutaneous ultrasound provides arterial lumen area and pulse wave velocity information. In addition, ultrasound measurements are taken in such a way that all the data describes a single, uniform arterial segment. Therefore a computed area relates only to the arterial blood volume present. Also, the measured pulse wave velocity is directly related to the mechanical properties of the segment of elastic tube (artery) for which the blood volume is being measured. In a patient monitoring application, the operator of the ultrasound device is eliminated through the use of software that automatically locates the artery in the ultrasound data, e.g., using known edge detection techniques. Autonomous operation of the ultrasound system allows it to report blood pressure and blood flow traces to the clinical users without those users having to interpret an ultrasound image or operate an ultrasound imaging device.

Abstract: A location system and method for determining the location of a tagged item in a facility. In one embodiment, the location system includes a plurality of room transmitters designed to be located throughout the facility. Each room transmitter has a unique signature. The system also includes at least one item or location tag affixed or otherwise associated with an item. Each tag is operable to send a signal having information related to the signature of a room transmitter within the reception range of the tag and information related to the identity of the tag. Signals from the tags are received by one or more locating receivers. Each locating receiver is operable to determine the identity of an item tag and the likely location of the item tag within the facility based upon the signal from that tag. The invention also provides a method of locating an item in a facility.

Abstract: A communication apparatus for allowing a first remote asset to communicate with wayside device, a second remote asset, a remote facility and a central operations facility, the apparatus comprising a local area network module for sending and receiving a communication over a short range using a local area network, a wide area network module for sending and receiving a communication over a long range using a wide area network, a control module to control communications sent and received over at least one of said local area network and said wide area network, and a coordinate module to coordinate a communication sent and received from a sensor wherein the apparatus passes the communication between the first remote asset and at least one of the wayside device, the second remote asset, the remote facility and the central facility based on at least one of a coverage area, latency, and a predetermined function.

Abstract: A communication system for communicating utility data from a utility distribution network comprises a transmitter for transmitting the utility data. The transmitter comprises a processor that modulates the utility data into a plurality of carrier frequencies. A modulator is connected to the processor and receives the modulated utility data. The modulator modulates the modulated utility data in the AM frequency band forming multi-tone modulated data wherein the transmitter transmits the multi-tone modulated data/transmitted information in the AM frequency band. The communication system also comprises a receiver that receives the transmitted information. The receiver comprises a demodulator that receives the transmitted information and demodulates the transmitted information into a received signal. A processor is connected to the demodulator and receives the demodulated information.

Abstract: A location system and method for determining the location of a tagged item in a facility. In one embodiment, the location system includes a plurality of room transmitters designed to be located throughout the facility. Each room transmitter has a unique signature. The system also includes at least one item or location tag affixed or otherwise associated with an item. Each tag is operable to send a signal having information related to the signature of a room transmitter within the reception range of the tag and information related to the identity of the tag. Signals from the tags are received by one or more locating receivers. Each locating receiver is operable to determine the identity of an item tag and the likely location of the item tag within the facility based upon the signal from that tag. The invention also provides a method of locating an item in a facility.

Abstract: A synthetic aperture ultrasonic imaging system for imaging a target with a resolution limited by a designated aperture. A phased array of nonuniformly spaced ultrasound transducers having an average inter-transducer spacing which is greater than a .lambda./2 Nyquist spacing for the transducers is used for imaging in a manner so as to either obtain a desired point spread function which is unattainable by a single image taken by the nonuniformly spaced transducers or to provide coarray equivalence to a phased array of transducers which are uniformly spaced at the .lambda./2 Nyquist spacing for the designated aperture. Coarray equivalence makes possible the technique of applying amplitude weightings to each of the nonuniformly spaced ultrasound transducers during transmit and receive modes and by forming a number of component images which when added together form a sum image substantially equivalent to a single image formed by a scan beam of the uniformly spaced transducers with the designated aperture.