University of Washington

Massachusetts Institute of Technology

Carnegie Mellon University

Academia Sinica

Shyamnath Gollakota

Joshua R Smith

Vamsi Talla

Aaron N Parks

Bryce Kellogg

Rajalakshmi Nandakumar

Dina Katabi

Vikram Subramaniam Iyer

Angli Liu

Vincent Liu

Nathaniel F Watson

Saman Naderiparizi

Mehrdad Hessar

Shwetak N Patel

Fadel Adib

Sidhant Gupta

Ching-Ju Lin

David Wetherall

Arka Majumdar

Ali Najafi

Srinivasan Seshan

Sawyer Fuller

Elyas Bayati

Ben Ransford

Qifan Pu

Kate Ching-Ju Lin

Wei-Liang Shen

Johannes James

Yogesh M Chukewad

Systems and methods of identifying medical disorders in one or more subjects are disclosed herein. In one embodiment, sound is transmitted toward a subject and at least a portion of the sound reflected by the subject and is acquired as echo data. The acquired echo data is used to generate a motion waveform having a plurality of peaks detected therein. At least a portion of the plurality of peaks may be indicative of movement of the subject. One or more medical disorders in the subject can be identified based on, for example, time durations and/or amplitude changes between peaks detected in the motion waveform.

Systems and methods of identifying motion of a subject

An aerial robot system may include an aerial robot having an airframe, a piezo actuator, a wing connected to the piezo actuator, and a photovoltaic cell. The system may further include a laser source configured to emit a laser beam oriented toward the photovoltaic cell for conversion by the photovoltaic cell into electrical energy. The aerial robot may further include a boost converter connected to the photovoltaic cell and configured to raise a voltage level of the electrical energy, and a signal generator connected to the boost converter and configured to generate an alternating signal. The piezo actuator is connected to the signal generator to move according to the alternating signal to cause the wing to move in a flapping motion to generate aerodynamic force that moves the robot. Methods for manufacturing aerial robots and corresponding electronics are also disclosed herein.

Untethered flying micro-robots

Examples described herein include systems, devices, and methods for backscattering carrier signals in accordance with pixel values of an image and/or video. Signals having a property proportionate to pixel values may be converted into a pulse-containing waveform having pulses whose widths and/or duty cycles are determined based on the pixel values. Backscatter transmitters may backscatter a carrier signal in accordance with the pulse-containing waveform to provide the pixel values to a receiver. In this manner, video transmission at low power and/or battery-free operation may be provided.

Image and/or video transmission using backscatter devices

Systems and methods for wirelessly transmitting power across a room or space are disclosed herein. One such system is comprised of a power receiving element positioned to receive wireless power transfer, comprised of a power receiving cell and a retroreflector positioned proximate the power receiving cell, and a power transmission element configured to wirelessly transmit power towards the power receiving element. The power transmission element includes an optical power transmitter configured to emit a first laser beam with a first power density towards the receiving cell, a guard beam emitter positioned proximate the optical power transmitter and configured to emit a second laser beam with a second power density towards the retroreflectors, a light detector positioned proximate the guard beam emitter and configured to detect light reflected by the retroreflectors, and an interlock system configured to interrupt power transmission when a decrease in light incident from the retroreflectors is detected.

Systems and methods for wireless power transmission

Examples described herein include devices and systems utilizing backscatter communication to generate transmissions in accordance with wireless communication protocols. Examples are described including single sideband operation, generation of a carrier wave using Bluetooth, downlink communication to a backscatter device, and combinations thereof.

Backscatter devices including examples of single sideband operation

Examples described herein include devices and systems utilizing backscatter communication to directly generate transmissions in accordance with wireless communication protocols that can be decoded existing devices. Examples include devices that generate 802.11b transmissions using backscatter communication. Examples of network stacks are described which may facilitate backscatter devices to coexist with other devices (e.g. in the ISM band), without incurring, or reducing a need for, the power consumption or carrier sense and medium access control operations.

Backscatter devices and network systems incorporating backscatter devices

Examples of backscatter systems, device, and techniques are described herein. Example backscatter devices may utilize CSS modulation to provide backscatter signals including CSS signals (e.g., LoRa packets). Utilizing CSS modulation may advantageously allow for backscatter communication over wide areas. Examples of backscatter devices described herein may toggle the impedance of the backscatter device between multiple (e.g., eight) impedances to reduce and/or eliminate higher order harmonic components in the backscatter signal (e.g., third and fifth harmonic components).

Backscatter systems, devices, and techniques utilizing CSS modulation and/or higher order harmonic cancellation

Examples described herein include backscatter devices which may transmit orthogonal frequency division multiplexing (OFDM) signals. Techniques for complex analog backscatter are described. Examples of impedance circuitry are described which may be used to provide real and imaginary components of impedance in accordance with inphase and quadrature bits.

Backscatter devices and systems providing backscattered signals including OFDM packets

Systems and methods of identifying medical disorders in one or more subjects are disclosed herein. In one embodiment, sound is transmitted toward a subject and at least a portion of the sound reflected by the subject and is acquired as echo data. The acquired echo data is used to generate a motion waveform having a plurality of peaks detected therein. At feast a portion of the plurality of peaks may be indicative of movement of the subject. One or more medical disorders in the subject can be identified based on, for example, time durations and/or amplitude changes between peaks detected in the motion waveform.

Apparatuses, systems, ambient RF backscatter transceivers, and methods for communicating using MIMO and spread spectrum coding of backscattered ambient RF signals are described. An example system may include an ambient RF backscatter transceiver that include an antenna configured to receive a backscattered ambient radio frequency (RF) signal, and a receiver coupled to the antenna. The receiver may be configured to demodulate the backscattered ambient RF signal using one of multiple input, multiple output multiplexing demodulation or spread spectrum code demodulation to retrieve the first data. The backscattered ambient RF signal may be generated by backscattering an ambient RF signal at a first frequency. The ambient RF signal may be configured to provide other data at a second frequency.

Apparatuses, systems, and methods for communicating using MIMO and spread spectrum coding in backscatter of ambient signals

Apparatuses, systems, ambient backscatter transceivers, and methods for modulating a backscatter of an ambient RF signal are described. An example system may include an ambient backscatter transceiver comprising an antenna that is configured to receive a backscattered ambient radio frequency (RF) signal. The ambient backscatter transceiver is configured to demodulate the backscattered ambient RF signal to retrieve first data. The backscattered ambient RF signal is generated by backscattering an ambient RF signal at a first frequency. The ambient RF signal is encoded with modulated to provide second data at a second frequency.

Ambient backscatter transceivers, apparatuses, systems, and methods for communicating using backscatter of ambient RF signals

Examples described herein include wireless transmitters configured for power transmission. Example wireless transmitters may insert power packets into wireless communications such that power harvesting circuitry may harvest sufficiently continuous power from the wireless communication signals. Example power harvesting circuitry is configured to harvest power across multiple wireless communication channels. Example chargers are described which may harvest power from wireless communication signals (e.g. Wi-Fi signals).

Power transmission using wireless communication signals

Example devices described herein include endpoint devices which may communicate with an access point device by modulating a channel associated with the wireless communication to encode transmit data. The channel modulation may be performed by utilizing a switch to control an impedance of an antenna at the endpoint device to either reflect or absorb wireless network communication signals received by the endpoint device. The access point device may extract the transmit data by decoding changes in the channel caused, at least in part, by the modulation. Access point devices may transmit a pattern of packets&#x2014;the presence or absence of which may correspond with transmit data. Endpoint devices may decode this data by using an energy detector to differentiate between the presence or absence of a packet.

Growing community of inventors

Seattle, WA, United States of America

Shyamnath Gollakota