Development of hemorheology: perspective in instrumentation development

New viscometers for blood viscometry, improved intravital microscope, and related instruments, which are capable of measuring important rheological factors for microcirculatory research were developed and applied for hemorheological studies. As the results, four major determinants of the suspension viscosity were determined and the role of suspension viscosity of the blood as a function of microcirculatory flow was clarified. Meanwhile, the use of fluorescence microscopy and digitized video microscopic techniques has allowed the investigation of the structure and function of cells at the level of the single intact living cell. In addition, the developments and applications of laser confocal microscopy provided for not only three-dimensional image construction, but also four-dimensional image construction. In recent years, the dramatic advances in molecular biology and instrumental technology have made it possible to probe the structural and functional bases of cellular events at the molecular level. The ultimate understanding of biorheological behavior is dependent upon a molecular basis. In the future, the use of molecular biological techniques and nanotechnology (e.g., laser tweezers, atomic force microscopy and near-field microscopy, etc.) will allow the understanding of normal and abnormal rheological properties of cells, tissues, organs, and systems at the molecular level, and will contribute to progress in biomedical science.