This paper presents the development of a wireless magnetic field sensor consisting of a three-layer thin-film giant magnetoimpedance sensor and a surface acoustic wave device on one substrate. The goal of this integration is a passive and remotely interrogated sensor that can be easily mass fabricated using standard microfabrication tools. The design parameters, fabrication process, and a model of the integrated sensor are presented together with experimental results of the sensor.

Objectives: Autism spectrum disorders (ASD) are pervasive developmental disorders.The prevalence of ASD has risen sharply in the last few years, reaching 1 in 68. Previous studies have found that abnormal auditory processing is the most common and one of the early sensory abnormalities in ASD children, which may relate to clinical manifestations such as poor language ability, pitch and voice intonation, and insensitivity or hypersensitivity to sound. Mismatch negativity (MMN) is considered as an optimal electrophysiological indicator in the pre-attentive central processing of acoustic change detection. Previous MMN studies on ASD were limited to children and adults older than five. This may be related to the difficulty for young children to cooperate with MMN recording in the awake state. Meta-analysis study indicated mixed findings on MMN latencies and amplitudes in ASD, possibly due to the different stimulation types and age ranges. This is the first study to record cotical auditory evoked potentials(CAEPs) and MMNs induced by frequency change in ASD children constrained from 2 to 5 years old. Method: MMNs were recorded from eighteen ASD children and typical controls during sleeping. The oddball paradigm for approximately 15-min lengths was given with standard (80%, 1000 Hz, 40-millisecond duration) and frequency deviant (20%, 2000 Hz, 40-millisecond duration). The presentation rate was 1.1 per second. A total of 750 stimuli were presented to each subject to obtain at least 150 deviant stimuli.The CAEP latencies and amplitudes were labeled.MMN areas were calculated based on the marked latencies and amplitudes. The latencies and amplitude of CAEPs and the latency, amplitude, and area of MMNs were recorded. Results: Our data showed that the latencies of MMN were significantly longer, and the amplitudes were significantly smaller in ASD children than those in typical controls. Due to the MMN representing the integrity of the primary auditory cortex and its auditory pathway projecting to the hippocampus, prolonged MMN response in ASD children may be related to the lack of mature axons in the deeper cortex and prolonged myelination. Conclusions: This is the first study that reported MMN response characteristics evoked by acoustic stimulation with a 100% frequency rise at 1kHz in young ASDs during sleepness. Findings from the current research indicate that MMN recording could be reliably recorded in young children with ASD at an early age to assess auditory discrimination function. There is much work to be done to further the scientific underpinning of this measurement. Studying young ASD children is essential to understand the impact of the sound encoding process on language development. Future directions should focus on understanding the association between auditory processing characteristics and ASD core symptomatology (namely, social communication and restricted/repetitive behaviors), independent of language development levels. This research was supported by the National Natural Science Foundation;China (Grant Number: 82000974), Science, Technology and Innovation Commission of Shenzhen Municipality (JCYJ20190809174405505), and Shenzhen Maternity & Child Healthcare Hospital Science Foundation (Grant Number: FYA2018011) to CL This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.