A Five-Channel Weighted Real-Time Algorithm for High-Density Electrodes Spike Sorting.

With the application of high-density neural probes, a neuron can be detected by multiple adjacent probes, and the traditional single-channel spike sorting is no longer suitable. In this paper, we propose a five-channel weighted real-time spike sorting algorithm based on template-matching to process neural signals recorded by high-density probes. This work uses the signals of the center channel and the adjacent four channels to form a five-channel template by weighting, and employs a modified OSort algorithm with unsupervised learning to update the template. We implemented automatic online spike sorting, and tested it with both ground truth recordings and simulated datasets. The experiments show that our algorithm utilizing the information of adjacent channels has a higher sorting accuracy than traditional single-channel spike sorting. The average sorting accuracy reaches 89%, compared to 78% for single-channel.

Efficient lead immobilization by bio-beads containing Pseudomonas rhodesiae and bone char.

Mineralization of lead ions (Pb2+) to pyromorphite using phosphorus-containing materials is an effective way to remediate lead (Pb) contamination. Bone char is rich in phosphorus, but its immobilization of Pb2+ is limited by poor phosphate release. To utilize the phosphorus in bone char and provide a suitable growth environment for phosphate-solubilizing bacteria, bone char and Pseudomonas rhodesiae HP-7 were encapsulated into bio-beads, and the immobilization performance and mechanism of Pb in solution and soil by bio-beads were investigated. The results showed that 137 mg/g of phosphorus was released from bone char in the presence of the HP-7 strain. Pb2+ removal efficiency reached 100 % with an initial Pb2+ concentration of 1 mM, bone char content of 6 g/L, and bio-bead dosage of 1 %. Most Pb2+ was immobilized on the surface of the bio-beads as Pb5(PO4)3Cl. The soil remediation experiments showed a 34 % reduction in the acid-soluble fraction of Pb. The bio-beads showed good stability in long-term (30 d) soil remediation. The present study shows that bone char can be turned into an efficient Pb immobilization material in the presence of phosphate-solubilizing bacteria. Thus, bio-beads are expected to be used in the remediation of Pb-contaminated environments.

A Flexible and Miniaturized Chest Patch for Real-time PPG/ECG/Bio-Z Monitoring.

We proposed a lightweight and wearable chest patch for real-time monitoring of three vital signals, photoplethysmography (PPG), electrocardiography (ECG), and bioimpedance (Bio-Z). It comprises a flexible electrode patch and a miniaturized wireless signal acquisition module. Heart rate (HR), heart rate variability (HRV), and blood pressure (BP) can be extracted from the raw signals. The flexible electrode patch is comfortable for the user while maintaining stable contact with human skin, guaranteeing the wearability. Size of the signal acquisition module is only 17.3mm×14.5mm×9mm, and it weighs only 3.2g, including an 80mAh lithium polymer battery, which keeps the entire patch working for more than 4 hours. A host controller, involving a graphic user interface (GUI) is developed to receive and visualize the data from the chest patch. The proposed device successfully collected three vital signals with high signal quality and showed its potential in healthcare applications.