Three-dimensional magnetic camera for the characterization of magnetic manipulation instrumentation systems for electrophysiology procedures

Abstract

We present a three-dimensional magnetic camera consisting in an array of 64 CMOS integrated monolithic three-dimensional Hall-Effect sensors. The camera covers a 40x40x40 mm3 volume and performs a synchronous sampling at 100 samples per second of each of the 64 three-dimensional magnetic flux density signals. Recent results in the design of magnetic manipulation instrumentation systems for e.g. electrophysiology procedures or magnetic particle imaging have shown that an extensive use of calculations and finite element method simulations is done during the development. In practice, there is a lack of suitable configurable magnetic camera to perform experimental magnetic field mapping and verify simulation results. Magnetic field and field gradients determine respectively the force and torques applied to the manipulated object and shall therefore be precisely known for an accurate steering of the object. The new magnetic camera described in this paper has to our knowledge no commercial equivalent. It answers to the need of experimental characterization of magnetic manipulation systems and offers the designers some new experimental performance assessment capabilities. The camera is both suited for small object manipulation where the steering field reaches a magnitude of about 1 mT and for electrophysiology applications where the magnetic steering of catheters requires a magnetic flux density that typically can reach up to 150 mT. Based on Hall-Effect, the magnetic camera could be easily adapted to reach even larger dynamic ranges and could fulfill the requirements of magnetic manipulation of objects using a MRI magnetic field.