Design of a Self-Controlled Dual-Oscillator-Based Supply Voltage Monitor for Biofuel-Cell-Combined Biosensing Systems in 65-nm CMOS and 55-nm DDC CMOS.

A supply voltage monitor (SVM) with self-controlled dual-oscillator-based architecture is proposed herein for biosensing systems combined with a biofuel cell (BFC) in this paper. The output of the BFCs can be used to monitor the biological signals while powering the BFC-combined biosensing systems. Thus, the SVM is designed to convert the change in the supply voltage (V DD) into a code. The architecture of the proposed SVM allows self-controlled periodic operation without external signals. Furthermore, the frequency subtraction technique that uses two oscillators employing gate-leakage-based architecture with different frequency sensitivities to V DD allows accurate code generation with low power consumption and a small circuit area for supply voltage monitoring. The proposed SVM is fabricated using two different CMOS process technologies, including 65-nm CMOS and 55-nm deeply depleted channel (DDC) CMOS. The implementation of the 65-nm CMOS obtains an operating V DD range of 250 mV (0.75-1 V), draws a standby power consumption of 1.4 nW at 0.75-V V DD, exhibits a resolution of 2.4 mV with a nonlinearity error of -8.4/ +12.1 mV, and occupies a circuit area of 0.0047 mm2. Meanwhile, the implementation of the 55-nm DDC CMOS for low-voltage operation achieves an operating V DD range of 300 mV (0.225-0.525 V), draws a standby power consumption of 32.5 nW at 0.25-V V DD, exhibits a resolution of 0.94 mV with a nonlinearity error of -15.2/ +14 mV, and occupies a circuit area of 0.0032 mm2.

A 65-nm CMOS Fully Integrated Analysis Platform Using an On-Chip Vector Network Analyzer and a Transmission-Line-Based Detection Window for Analyzing Circulating Tumor Cell and Exosome.

A fully integrated CMOS circuit based on a vector network analyzer and a transmission-line-based detection window for circulating tumor cell (CTC) and exosome analysis is presented for the first time. We have introduced a fully integrated architecture, which eliminates the undesired parasitic components and enables high-sensitivity, to analyze extremely low-concentration CTC in blood. The detection window was designed on the high-sensitive coplanar waveguide line. To validate the operation of the proposed system, a test chip was fabricated using 65-nm CMOS technology. Measurements were performed after adding a tiny lump of silicone or a droplet of water on its detection window. The measured results show |S_21| degradation of -1.96 dB and -6.04 dB for the silicone and the droplet, respectively, at 1.4 GHz. In addition, in another measurement using magnetic beads, it is confirmed that the proposed circuit can analyze even low concentrations of 20 beads/µL. As well as microbeads, measurement with CTCs was successfully demonstrated.

Direct Damage to a Vertebral Artery Better Predicts a Vertebral Artery Injury than Elongation in Cervical Spine Dislocation.

Cervical spine dislocation and fracture of a transverse process are isolated risk factors for vertebral artery injuries (VAIs), which can cause a life-threatening ischemic stroke. Since in vivo experiments are not possible, it has not been unclear whether damage to or extension of vertebral arteries is more predictive of a VAI. To identify the imaging characteristics associated with VAI, we analyzed 36 vertebral arteries from 22 cervical spine dislocation patients who underwent computed tomography angiography (Aug. 2008-Dec. 2014). We evaluated (1) the posttraumatic elongation of the vertebral artery and (2) the presence of fracture involving the transverse foramen. VAI was found in 20 (56%) of the 36 vertebral arteries. The rate of residual shift (vertebral artery elongation) was not markedly different between the VAI and no-VAI groups. However, the rate of >1 mm displacement into the foramen and that of fracture with gross displacement (≥2 mm) differed significantly between the groups. We found that greater displacement of fractured transverse processes with cervical spine dislocation was a risk factor for VAI. These results suggest that direct damage to the vertebral arteries by transverse process fragments is more likely to predict a VAI compared to elongation, even in cervical spine dislocation.

Early versus delayed reduction of cervical spine dislocation with complete motor paralysis: a multicenter study.

PURPOSE: Reduction of cervical facet dislocation should be performed as soon as possible to depressurize neuron cells although some randomized control studies defined early reduction as over 24 h after trauma. The purpose of this study was to define the actual time limit for early reduction in patients with complete motor paralysis. METHODS: Cervical spine dislocation patients with complete motor paralysis admitted between April 2007 and December 2014 were analyzed as retrospective cohort study. We separated the patients into three groups according to the number of hours lapsed between the trauma and reduction, within 4 h (very early group), >4-6 h (early group), and >6 h (delayed group). We compared the neurological outcomes, patient injury patterns, the arrival time at the hospital, and the injury severity score (ISS). RESULTS: Of 30 patients who enrolled, 8 (27%) were recovered to American Spinal Injury Association Impairment Scale Grades C-E. The delayed group had poorer neurological outcomes than the very early group and early group, although no significant differences were noted in the recovery rate between the very early group and early groups. The injury pattern, arrival time, and ISS were not found to be associated with the neurological outcome. CONCLUSION: Our data suggest that early (<6 h) reduction of cervical spine dislocation is associated with favorable neurological outcome as compared with those performed after 6 h.

Design and Experimental Verification of a 0.19 V 53 µW 65 nm CMOS Integrated Supply-Sensing Sensor With a Supply-Insensitive Temperature Sensor and an Inductive-Coupling Transmitter for a Self-Powered Bio-sensing System Using a Biofuel Cell.

In this paper, we present a self-powered bio-sensing system with the capability of proximity inductive-coupling communication for supply sensing and temperature monitoring. The proposed bio-sensing system includes a biofuel cell as a power source and a sensing frontend that is associated with the CMOS integrated supply-sensing sensor. The sensor consists of a digital-based gate leakage timer, a supply-insensitive time-domain temperature sensor, and a current-driven inductive-coupling transmitter and achieves low-voltage operation. The timer converts the output voltage from a biofuel cell to frequency. The temperature sensor provides a pulse width modulation (PWM) output that is not dependent on the supply voltage, and the associated inductive-coupling transmitter enables proximity communication. A test chip was fabricated in 65 nm CMOS technology and consumed 53 µW with a supply voltage of 190 mV. The low-voltage-friendly design satisfied the performance targets of each integrated sensor without any trimming. The chips allowed us to successfully demonstrate proximity communication with an asynchronous receiver, and the measurement results show the potential for self-powered operation using biofuel cells. The analysis and experimental verification of the system confirmed their robustness.

Psychometric Assessment of the Japanese Version of the Zurich Claudication Questionnaire (ZCQ): Reliability and Validity.

PURPOSE: The Zurich Claudication Questionnaire (ZCQ) is a self-administered measure to evaluate symptom severity, physical function, and surgery satisfaction in lumbar spinal stenosis (LSS). The purpose of this study is to assess the psychometric properties of the Japanese ZCQ in LSS patients. METHODS: LSS patients who are scheduled to undergo surgery were recruited from 12 facilities. Responses to several questionnaires, including the Japanese ZCQ; the visual analogue scale (VAS) to evaluate the degree of pain in the buttocks/legs, numbness in the buttocks/legs, and low back pain; the Oswestry Disability Index (ODI); and the SF-36v2, were collected before surgery and again 3 months after surgery (the post-surgery ZCQ was administered twice for test-retest reliability). For reliability, test-retest reliability was evaluated using the intra-class coefficient (ICC) and internal consistency was evaluated using Cronbach's alpha coefficient. Concurrent validity was assessed using Spearman's correlation coefficients between the Japanese ZCQ and other questionnaires. Effect size (ES) and standard response mean were calculated for responsiveness. All analyses were performed individually for the Japanese ZCQ symptom, function, and satisfaction domains. RESULTS: Data from 180 LSS patients were used in this analysis. The ICCs were 0.81, 0.89, and 0.88 and Cronbach's alpha coefficients were 0.78, 0.84, and 0.92 for the Japanese ZCQ symptom, function, and satisfaction domains, respectively. Regarding the concurrent validity, strong correlations (±0.5) were demonstrated between the Japanese ZCQ domains and the VAS leg pain, ODI, and SF-36v2 physical functioning or bodily pain, whereas correlations were approximately 0.3 in scales measuring other symptoms that are less related to symptom, function, or satisfaction domains. ESs showed high values for the ZCQ symptom and function domains (-1.73 for both). CONCLUSIONS: These psychometric assessments demonstrate that the Japanese ZCQ is a psychometrically reliable and valid measure in LSS. The Japanese ZCQ can evaluate both multi-dimensional aspects and the level of surgery satisfaction.

The efficacy of prostaglandin E1 derivative in patients with lumbar spinal stenosis.

STUDY DESIGN: Randomized controlled trial. OBJECTIVE: To examine the effect of limaprost, an oral prostaglandin (PG) E1 derivative, on health-related quality of life (HRQOL) in patients with symptomatic lumbar spinal stenosis (LSS), compared to etodolac, a NSAID. SUMMARY OF BACKGROUND DATA: Limaprost, an oral PGE1 derivative, was developed in Japan to treat numerous ischemic symptoms of thromboangiitis obliterans (TAO) and LSS. Previous studies have demonstrated the effectiveness of limaprost in the symptoms in patients with LSS. However, the evidence for effect on patient-reported outcomes, such as patient's HRQOL or satisfaction, is limited. METHODS: This study was conducted at 4 study sites in Japan. Briefly, inclusion criteria were: age between 50 and 85 years; presence of both neurogenic intermittent claudication (NIC) and cauda equina symptoms (at least presence of bilateral numbness in the lower limbs); and MRI-confirmed central stenosis with acquired degenerative LSS. Limaprost (15 microg/d) or etodolac (400 mg/d) was administered for 8 weeks. The primary outcome was Short Form (SF)-36, and the secondary outcomes were the verbal rating scale of low back pain and leg numbness, walking distance, subjective improvement, and satisfaction. RESULTS: A total of 79 participants were randomized (limaprost:etodolac = 39:40). Thirteen participants withdrew from the study (limaprost:etodolac = 5:8) and 66 completed the study (limaprost:etodolac = 34:32). Comparisons showed that limaprost resulted in significantly greater improvements in the SF-36 subscales of physical functioning, role physical, bodily pain, vitality, and mental health. Limaprost was also significantly better than etodolac for leg numbness, NIC distance, and subjective improvement and satisfaction. In the subgroup analysis stratified by symptom severity, limaprost seemed more effective for milder symptoms. No serious adverse effects were reported in either treatment group. CONCLUSION: In this study, limaprost was found to be efficacious on most outcome measures, such as HRQOL, symptoms and subjective satisfaction, in LSS patents with cauda equina symptoms.