A rapid quantitative determination method of Luteinizing hormone with gold immunochromatographic strip.

Measurement of Luteinizing hormone (LH) levels is of great importance in guidance for pregnancy, diagnosis of ovarian diseases and evaluation of clinical effect. Gold immunochromatographic strip(GICS) assay is a rapid, simple, low-costs, and on-site technology. Quantitative detection of GICS has advantage over the traditional qualitative or semi-quantitative strip assay. In this paper, we developed a novel quantitative detection method for GICS based on smart-phone. First, smart-phone was used to acquire GICS image. Then, we applied the canny edge detection operator to extract the reading window from GICS image, and the fuzzy c-means (FCM) clustering algorithm to locate the test and control lines in the reading window. In order to reduce environmental interference, luminance compensation based on color constancy algorithms was applied. Finally, the property of the developed quantitative method is demonstrated by the detection of LH sample and clinical serum sample. Experimental results revealed that this method could achieve a low detection limit of 1.0 mIU/mL in a linear range from 1.0 to 125.0 mIU/mL. Furthermore, the proposed method could be used for the determination of clinical serum samples and its corresponding correlation coefficients were 0.964. Results showed that this novel method could be an effective tool for the rapid quantitative determination of LH.

Research on the synchronous detection of neuronal signals under a nerve stimulation system control.

Deep brain stimulation (DBS) provides a recognized research intervention for neurological disease currently. However, there is a lack of traditional electrical stimulator to observe neuronal firing activity synchronously. The aim of the present study was to realize concurrent detection of neuronal signals better under a nerve stimulation system control. Herein, we designed an integrated software, which could control not only neuro-stimulator but also detection instrument at the same time. Moreover, the actual stimulation signals applied to the experiment object could be collected back to data acquisition card and in consistent with the electrophysiological signals. As to basic performance of self-building stimulator, the accuracy of output square signal was verified to be greater than 99.05 % with the change of voltage amplitude. Practicably, combined with homemade microelectrode array (MEA) detecting device, medial forebrain bundle (MFB) DBS effects were observed significantly through the changes of electrophysiological signals in caudate putamen (CPu) of Sprague-Dawley (SD) rat, and the signal-to-noise ratio (SNR) was 5:1 after stimulation. Therefore, the comprehensive nerve stimulation system, which consists of neuro-stimulator and integrated software, could be widely used in the field of neuroscience research with high precision and synchronization.

A model-based method to measure baroreflex sensitivity.

This paper proposes a model-based method to quantitatively measure baroreflex sensitivity in autonomic nervous regulation of cardiovascular system. The method measures the continuous blood pressure and heart rate in orthostatic scenario, models dynamics of the baroreflex firing rate, solves parameters by optimization of measured blood pressure and heart rate variations. With this model, we can get the baroreflx sensitivity (BRS) inner indicators to evaluate the status of the autonomic nervous regulation system. Experimental results have shown the validation of the quantitative measures and the effectiveness of the method.

Research on neural information detecting system measuring neuroelectricity in hippocampus in vivo and dopamine in vitro based on microelectrode array.

Concurrently detecting the electrical activity of neurons and neurotransmitter release signals, will have a great significance in understanding the working mechanism of the brain. This paper describes a neural information detecting system based on microelectrode array(MEA) measuring neuroelectricity in hippocampus in vivo and dopamine(DA) in vitro. The detecting system contains of electrophysiological headstage, electrochemical headstage, microprocessor, electrophysiological signal amplifier, data acquisition module and neural signal analysis software. In electrophysiological test, the neural information detecting system was applied to detect neuroelectricity in hippocampus of SD rat with 16-channel microelectrode array in vivo. Active potentials were captured. The amplitude of the recorded neural spikes reached 182.90 µV, and signal to noise ratio was 7:1. For measure dopamine as neurotransmitter, there was a good linear relationship between response current and concentration of dopamine from 10nM to 18.88µ with correlation coefficient of 0.9974. Electrophysiological experiment and electrochemical experiment demonstrate the capability of the neural information detecting system to capture dual mode neural signal, which provides a convenient way to study dual mode operating mechanism of neural system.

An implantable microelectrode array for dopamine and electrophysiological recordings in response to L-dopa therapy for Parkinson's disease.

Dual-mode multielectrode recordings have become routine in rodent neuroscience research. However, robust and reliable application of acute, multielectrode recording methods in brain especially for in vivo research remains a challenge. In patients with Parkinson's disease (PD), the efficacy of L-dopa therapy depends on its ability to restore Dopamine (DA) neurotransmission in the striatum. In this paper, We describe a low cost thin film 16 sites implantable microelectrode array (MEA) chip fabricated by standard lithography technology for in vivo test. In urethane anesthetized rats, the MEA probes were implanted acutely for simultaneous recording of local field potentials, spikes, and L-dopa therapy evoked dopamine overflow on the same spatiotemporal scale. We present a detailed protocol for array fabrication, then show that the device can record Spikes, LFPs and dopamine variation in real time. Across any given microelectrode, spike amplitudes ranged from 80 to 300 µν peak to peak, with a mean signal-tonoise ratio of better than 5:1. Calibration results showed the MEA probe had high sensitivity and good selectivity for DA. Comparison with existing methods allow single mode recording, our neural probes would be useful for examining specific spatiotemporal relationships between electrical and chemical signaling in the brain.