An Integrated Wireless Power Management and Data Telemetry IC for High-Compliance-Voltage Electrical Stimulation Applications

Wirelessly Powered and Bi-Directional Data Communication System With Adaptive Conversion Chain for Multisite Biomedical Implants Over Single Inductive Link

A wirelessly powered and data communication system is presented which is implemented as a full system, designed for multisite implanted biomedical applications. The system is capable of receiving wireless power and data communication for each implant separately, using inductive links with different resonance frequencies. To achieve this, dual-band coils are presented in the system. In addition, the system supports bi-directional half-duplex data communication, utilizing amplitude and load shift keying (ASK and LSK) modulation schemes over a single inductive link. The system employs a digitally assisted active rectifier and an automatic resonance tuning system, to improve the power transfer efficiency (PTE) through various coupling coefficients, while minimizing the reverse current and power dissipation. The power control unit enables closed-loop monitoring to prevent high or low power delivery, and it can detect inefficient or excessive wireless power transmission or prevent temperature elevation by limiting the voltage to a safe level. A new structure of self-sampling separated- Vb ASK demodulator is proposed in the paper which is utilized within the data conversion chain, serving both the external and implanted units. The whole system is fabricated using a standard 180-nm 1.8/3.3 V CMOS process with a core area of 0.82 mm[Formula: see text]. The system is tested with coupled multisite inductive links and offers the maximum overall PTE of 31.2%, from the Tx coil to the implant load.

Monopolar Biphasic Stimulator With Discharge Function and Negative Level Shifter for Neuromodulation SoC Integration in Low-Voltage CMOS Process

A 16-channel monopolar biphasic stimulator chip with discharge function for biomedical applications is proposed and designed. To provide monopolar biphasic stimulus currents, the positive (6V) and the negative (-6V) voltage sources are supported to generate the desired current pulses of ±3 mA. The monopolar biphasic stimulator chip was fabricated in a 0.18-μm 1.8-V/3.3-V CMOS process with the common grounded p-type substrate. The overstress and reliability issues on the low-voltage transistors in the stimulator circuits were fully overcome by circuit design. The silicon area of each single channel only occupies 0.08 mm² and the output level of stimulus current is up to ±3 mA. By applying the discharge function, safety concern of unbalanced charge in neuro-stimulation can be dealt properly. The residual average dc current is less than 3.42 nA after discharge is activated. Moreover, this chip has also been verified with both in-vitro imitation measurement and in-vivo animal test.

A Dual-Output Reconfigurable Shared-Inductor Boost-Converter/Current-Mode Inductive Power Management ASIC With 750% Extended Output-Power Range, Adaptive Switching Control, and Voltage-Power Regulation

This paper describes a dual-output, reconfigurable integrated power management (IPM) ASIC for inductive power delivery. The proposed ASIC operates either as a current-mode (CM) rectifier or a boost converter by sharing the receiver (Rx) coil (LRx) to improve performance of inductive power transmission against the variations of Rx input power (PRx) and dual-output DC power (PL+ PHv). Conventional IPM structures either fail to generate regulated outputs (e.g., VL and VHv) when the required PL+ PHv exceeds PRx or suffer from low power-conversion efficiency (PCE) when PRx exceeds PL+ PHv due to voltage regulation and protection. To overcome these challenges, the proposed ASIC offers the unique capabilities of 1) generating multiple regulated outputs [Formula: see text] directly from LRx with single-stage conversion, 2) efficient CM operation with active rectification, enabled by adaptive switching control (ASC), 3) charging a large capacitor ( CS) with the purpose of operating as a shared-inductor boost converter (SBC), transferring energy from CS to CL and CHv, when , and 4) efficient voltage-power regulation (VPR). A proof-of-concept chip was fabricated in a 0.35-μm 2P4M standard CMOS process occupying 1.35-mm2 active area. In measurements, the proposed ASIC was able to successfully provide regulated [Formula: see text] and [Formula: see text] despite significant variations in PRx, PL, and PHv. Moreover, the chip extended the peak output power range by 750% and improved the PCE by 1.3 times and 8.1 times thanks to the ASC and VPR, respectively.

Bidirectional Information Transmission in SWIPT System with Single Controlled Chopper Receiver

The wireless power transfer (WPT) technology has the advantages of convenience, safety and reliability due to its non-metal contact power supply and has a broad application prospect in many occasions. In practical applications, the information communication between the primary and secondary side is necessary for output voltage control, load detection, condition monitoring and other functions, which makes the WPT system more intelligent and convenient. A simultaneous wireless information and power transfer (SWIPT) system with controlled chopper circuit receiver is proposed in this paper. The load voltage remains constant by adjusting the pulse width of the secondary controlled device through feedback control. The information bidirectional transmission methods and two modes are proposed, considering different application scenarios. Simulation and experiment results validate the proposed topology and the method of information bidirectional transmission.

Development of Radio-Frequency Sensor Wake-Up with Unmanned Aerial Vehicles as an Aerial Gateway

The advent of autonomous navigation, positioning, and general robotics technologies has enabled the improvement of small to miniature-sized unmanned aerial vehicles (UAVs, or ‘drones’) and their wide uses in engineering practice. Recent research endeavors further envision a systematic integration of aerial drones and traditional contact-based or ground-based sensors, leading to an aerial–ground wireless sensor network (AG-WSN), in which the UAV serves as both a gateway besides and a remote sensing platform. This paper serves two goals. First, we will review the recent development in architecture, design, and algorithms related to UAVs as a gateway and particularly illustrate its nature in realizing an opportunistic sensing network. Second, recognizing the opportunistic sensing need, we further aim to focus on achieving energy efficiency through developing an active radio frequency (RF)-based wake-up mechanism for aerial–ground data transmission. To prove the effectiveness of energy efficiency, several sensor wake-up solutions are physically implemented and evaluated. The results show that the RF-based wake-up mechanism can potentially save more than 98.4% of the energy that the traditional duty-cycle method would otherwise consume, and 96.8% if an infrared-receiver method is used.