Qst tool

1. Introduction Quantitative sensory testing (QST) is defined as a psychophysical set of methods that neurologically examines somatosensory function.30 Many sophisticated quantitative sensory tests provide information on the nociceptive transduction, transmission, or modulation from all aspects of the somatosensory system. Through the understanding of the pathophysiology of pain and the afferent fibers (Aβ, Aδ, and C) activated by the test stimulus (mechanical or thermal), QST can aid in the evaluation of hypersensitivity and hyposensitivity phenomena in patients.8 Despite its poor prognostic and predictive value, in combination with other recommended core outcomes, QST may contribute to better-informed and individualized therapy.9,12 Limitations of laboratory-based QST (LQST) include the cost of the apparatus, complexity in training, lack of portability, and the time required for testing. Therefore, studies have turned to implement more routine clinical screening and profiling of pain mechanisms in chronic pain patients by developing a simple-to-use and clinically applicable, bedside tool-kits.20–22,28,31 Other studies are also turning to implement a qualitative component to QST to add valuable information contributing to the detection of sensory abnormalities.5 Cost-effective bedside QST tools have been developed and tested in pediatric and adult populations, such as von Frey filaments, an artist or foam brush, Neurotips, cotton swabs, a 10-mL syringe with a blocked tip, ice, or metal rods.20–22,31 Although bedside tool-kits can extend use of QST to an inpatient unit or outpatient clinic, there is an unmet need for developing a mobile or home QST (HQST) tool-kit that could be used in a patient's home or at other locations far from specialized centers. The COVID-19 pandemic showed the importance of innovation in providing remote methodologies for clinical care and research. Therefore, the objective of this study was to develop an HQST tool-kit that is cost-effective for repeated measures across time, easy to use for all age ranges including children and adolescents, and able to assess changes in sensory and pain processing. However, its safety and tolerability was first needed to be tested in young adults, aligning with procedures investigating new medical drugs or devices. The primary aim of this study was to determine whether QST measurements using

CTT, cold tolerance threshold; DMA, dynamic mechanical allodynia; H-, home; HQST, home QST; HPS, heat pain sensitivity; HPT, heat pain threshold; HPTol, heat pain tolerance; HTT, heat tolerance threshold; L-, laboratory; LQST, laboratory-based QST; MDT, mechanical detection threshold; MPT, mechanical pain threshold; PinPS, pinprick pain sensitivity; PPT, pressure pain threshold; PrePS, pressure pain sensitivity; SMA, static mechanical allodynia; SMD, static mechanical detection; VDS, vibration detection sensitivity; VDT, vibration detection threshold; WDT, warm detection threshold; WUR, wind-up ratio. 3.3. Safety and tolerability No adverse events relating to HQST tool-kit were reported. The HQST tool-kit did not evoke visible signs of skin injury. Nine participants reported their pain intensity equal to or greater than 5/10 during the pinprick sensitivity test using the sharp end of the Neurotip. One of those 9 participants only conducted 1 trial instead of 3. Zero participants tolerated the frozen syringe less than 30 seconds. Three participants tolerated the hand warmer at the lowest heat level less than 30 seconds. Five participants tolerated the hand warmer at the medium heat level less than 30 seconds. One participant refused to conduct the heat tolerance test at the medium heat level because of reporting their skin as sensitive. 3.4. Participants' comments The overall acceptability of the HQST home tool-kit was high with an average score of 44.2 ± 4.3 on our questionnaire (Fig. 3). Qualitative analysis of the comments extracted from the questionnaire lead to multiple themes identified across the 7 domains. Sample statements from the distinct themes can be found in the Supplemental Material (available at 3.: Questionnaire on the safety and satisfaction of the home QST tool-kit. The 10 questions are split into 7 domains: affective attitude (1-2), burden (3-5), perceived effectiveness (6), intervention coherence (7), opportunity costs (8), self-efficacy (9), and ethicality (10). The data are presented as box plots in which the thick black line represents the median, the edge of the boxes represent the 25% to 75% interquartile range, and the whiskers represent the largest/smallest values within 1.5 IQR above/below the upper/lower quartiles. IQR, interquartile range; QST, quantitative sensory testing.Of the 20 comments on how

Calculated because of different scales or paradigms being used. The pain intensity reported from a single pinprick of the Neurotip was not correlated with the laboratory-based wind-up ratio but was correlated with the pain intensity from a single 128 mN pinprick. We would hypothesize that there would be a significant correlation between the wind-up ratio when using the Neurotip or the 128 mN pinprick. Most of our healthy pain-free sample was able to tolerate the cold plastic syringe and the hand warmer at the low and medium temperature levels. Despite these thermal home tests primarily correlated with laboratory-based thermal tolerance thresholds, they may provide to be useful in episodic chronic pain conditions. Unlike LQST that may involve subjects with chronic pain being between painful episodes, the HQST offers the opportunity for repeatable measures to investigate hypoalgesia and hyperalgesia during nonpainful and painful episodes. The current home battery may provide an opportunity to subgroup individuals with “sensory loss,” “mechanical hyperalgesia,” or “thermal hyperalgesia” similar to LQST and bedside QST.2,28,38 However, based on our current findings, the HQST may only be complementary and useful when LQST or bedside QST is impossible. Although the HQST is not exactly similar to LQST, it may offer the opportunity to contribute to better-informed care, particularly for repeatable testing across time. An additional advantage of the HQST tool-kit is the active participation of the subjects in the sensory testing that helps them move from passivity to more shared responsibility in their examination.33 Participants reported high acceptability for the HQST tool-kit. However, the comments written by the participants highlight that although the tool-kit may have good implications, there is still concern for its validity and improvement is warranted. Laboratory-based QST was conducted before the HQST as an education/training session on the different possible tests used in pain research and their purpose. Although this may have had an effect on the HQST results, this order of procedures was to ensure critical feedback may be given by the participants in their safety and satisfaction questionnaire. Using video instructions before the testing may be advantageous in the future and complementary for

The wider adoption of power GaN devices at voltages above 650 V necessitates innovations in both the substrate and integration process of the lateral high-electron-mobility transistor (HEMT) and vertical DMOS devices. In this article, we highlight the development of 1,200-V p-GaN HEMTs on engineered Qromis substrate technology (QST) by a group from Imec and Aixtron.Silicon substrates are commonly used as the base for GaN epi layers in commercially available power HEMT devices rated at voltages of 650 V or less. Extending the voltage requires thicker epi layers, which becomes challenging given the high coefficient of thermal expansion mismatch between GaN and silicon. QST is a proprietary substrate technology developed by Qromis, and commercial QST substrates are available from both Qromis and Shin-Etsu Chemical. High-thermal-conductivity (170–230 W/mK) poly-aluminum nitride (AlN) ceramic core material is covered by several encapsulation layers, on top of which is a silicon dioxide (SiO2) bonding layer and a single crystalline Si(111) layer, which serves as the nucleation layer, allowing the growth of thicker epi layers that can support higher voltages. Si(111) GaN growth-ready surface can be changed to single-crystal GaN, SiC or other GaN growth-ready surfaces.The CMOS fab-friendly and Semi standard thickness 200-mm QST substrates (scalable to 300 mm), which are similar to silicon-on-insulator substrates with respect to manufacturing processing and cost, enable the fabrication of long-awaited commercial high-performance GaN power devices ranging from 100-V to 1,800-V and beyond breakdown voltages with high thermal conductivity and high mechanical strength. Furthermore, the poly-AlN core of QST substrates has better thermal conductivity than silicon and sapphire substrates. Another important feature of QST is that the substrates are assembled and manufactured in traditional CMOS fabs with energy-efficient mainstream semiconductor process tools.Currently, 200-mm QST substrates are being used by Vanguard International Semiconductor for manufacturing 650-V p-GaN (e-mode) HEMT device products for