CP-Net: Instance-aware part segmentation network for biological cell parsing.

Instance segmentation of biological cells is important in medical image analysis for identifying and segmenting individual cells, and quantitative measurement of subcellular structures requires further cell-level subcellular part segmentation. Subcellular structure measurements are critical for cell phenotyping and quality analysis. For these purposes, instance-aware part segmentation network is first introduced to distinguish individual cells and segment subcellular structures for each detected cell.

Modeling and Compensation of Positioning Error in Micromanipulation.

In order to improve the positioning accuracy of the micromanipulation system, a comprehensive error model is first established to take into account the microscope nonlinear imaging distortion, camera installation error, and the mechanical displacement error of the motorized stage. A novel error compensation method is then proposed with distortion compensation coefficients obtained by the Levenberg-Marquardt optimization algorithm combined with the deduced nonlinear imaging model. The compensation coefficients for camera installation error and mechanical displacement error are derived from the rigid-body translation technique and image stitching algorithm.

A Nitrocellulose Paper-Based Multi-Well Plate for Point-of-Care ELISA.

Low-cost diagnostic tools for point-of-care immunoassays, such as the paper-based enzyme-linked immunoassay (ELISA), have become increasingly important, especially so in the recent COVID-19 pandemic. ELISA is the gold-standard antibody/antigen sensing method. This paper reports an easy-to-fabricate nitrocellulose (NC) paper plate, coupled with a desktop scanner for ELISA, which provides a higher protein immobilization efficiency than the conventional cellulose paper-based ELISA platforms.

Microengineered platforms for characterizing the contractile function of in vitro cardiac models.

Emerging heart-on-a-chip platforms are promising approaches to establish cardiac cell/tissue models in vitro for research on cardiac physiology, disease modeling and drug cardiotoxicity as well as for therapeutic discovery. Challenges still exist in obtaining the complete capability of in situ sensing to fully evaluate the complex functional properties of cardiac cell/tissue models. Changes to contractile strength (contractility) and beating regularity (rhythm) are particularly important to generate accurate, predictive models.

Advances in sperm analysis: techniques, discoveries and applications.

Infertility affects one in six couples worldwide, and fertility continues to deteriorate globally, partly owing to a decline in semen quality. Sperm analysis has a central role in diagnosing and treating male factor infertility. Many emerging techniques, such as digital holography, super-resolution microscopy and next-generation sequencing, have been developed that enable improved analysis of sperm motility, morphology and genetics to help overcome limitations in accuracy and consistency, and improve sperm selection for infertility treatment.

A microdevice platform for characterizing the effect of mechanical strain magnitudes on the maturation of iPSC-Cardiomyocytes.

The use of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) as an in vitro model of the heart is limited by their structurally and functionally immature phenotypes. During heart development, mechanical stimuli from in vivo microenvironments are known to regulate cardiomyocyte gene expression and maturation. Accordingly, protocols for culturing iPSC-CMs have recently incorporated mechanical or electromechanical stimulation to induce cellular maturation in vitro; however, the response of iPSC-CMs to different mechanical strain magnitudes is unknown, and existing techniques lack the capability to dynamically measure changes to iPSC-CM contractility in situ as maturation progresses.

Electrical impedance-based contractile stress measurement of human iPSC-Cardiomyocytes.

Heart failure fundamentally results from loss of cardio myocyte contractility. Developing new methods that quantify the contractile stress of the human cardiomyocyte would facilitate the study of the molecular mechanism of heart failure and advance therapy development, to improve the current five year survival for these patients. The measurement of cellular electrical impedance measurement was recently applied to monitor cardiomyocyte beating rate and rhythm, for the study at cellular maturation, and for drug screening.

Magnetic Measurement and Stimulation of Cellular and Intracellular Structures.

From single-pole magnetic tweezers to robotic magnetic-field generation systems, the development of magnetic micromanipulation systems, using electromagnets or permanent magnets, has enabled a multitude of applications for cellular and intracellular measurement and stimulation. Controlled by different configurations of magnetic-field generation systems, magnetic particles have been actuated by an external magnetic field to exert forces/torques and perform mechanical measurements on the cell membrane, cytoplasm, cytoskeleton, nucleus, intracellular motors, The particles have also been controlled to generate aggregations to trigger cell signaling pathways and produce heat to cause cancer cell apoptosis for hyperthermia treatment. Magnetic micromanipulation has become an important tool in the repertoire of toolsets for cell measurement and stimulation and will continue to be used widely for further explorations of cellular/intracellular structures and their functions.