MAGNETIC SYSTEM FOR MEDICAL INSTRUMENT

摘要

An instrument (100) monitors the coagulation of coagulable fluid blood, blood fraction or a control (514) by combining (101) the coagulable fluid (514) with particles which are affected by a magnetic field so that the particles become suspended relatively freely in the fluid. A time-varying magnetic field (2 Hz) causes the particles to be reori- ented as the magnetic field varies. The reorientation changes as the fluid (514) coagulates owing to the fluid's (514's) changing viscosity. An electromagnet (140) creates the time-varying magnetic field. The electromagnet (140) includes a core (150) comprising a first leg (148), an electrically conductive coil (144) for creating a time-varying magnetic flux in the core (150), and a return (152) for the time-varying magnetic flux. The first leg (148) and the flux return (152) together comprise a generally E-shaped core (150) of ferromagnetic material. A bobbin (146) is provided on the first leg (148) and the electrically conduc- tive coil (144) is wound on the bobbin (146).