A Detection System For Magnetic Nanoparticles Based On Magnetoresistive Sensor

Tumor has been a serious threat to human health, and chemotherapy is the main method to cure the tumor. But the application of traditional chemotherapy drugs is restricted because they damage normal cells while killing tumor cells. Magnetic Targeted Drug Delivery System is the most promising means of chemotherapy, for the magnetic drugs in it can localize to the tumor tissue and then release in the role of external magnetic field, this will improve the drug concentrations of tumor location, reduce side effects and improve the treatment effect. Magnetic Targeted Drug Delivery System is one of the most promising cancer treatments.Magnetic Targeting Drug Delivery system is a hotspot research area in the field of medicine, which is still at the research stage. The detection of distribution of magnetic drug in target zone is an importance standard to evaluate Magnetic Targeting Drug Delivery system, which is a meaningful research. The common detections include in vitro detection and in vivo detection. The methods of in vitro detections are atomic absorption spectrometer detection and (ultra) high-performance liquid chromatography detection, microscope inspection, X-ray imaging, etc. The methods of in vivo imaging detection are magnetic resonance imaging, emission computed tomography imaging, etc. In vitro detection needs to collect specimens and only reflects the drug distribution at one point. Besides, in vivo detection requires large and expensive imaging equipment so it is unfit for long time detection.Based on the analysis of these methods above, we proposed a method of magnetic positioning, which is used to obtain the distribution of magnetic nanoparticles and then indirectly reflect the distribution of magnetic drug. Design of magnetoresistive sensor based magnetic detection system. Using magnetoresistive sensor magnetic field information is collected,and the magnetic field signal is converted to voltage signals with different amplitudes. Differential output voltage signals are transferred to the amplification and filtering by the multi-channel analog signal conditioning circuit. A/D conversion is performed after amplification. And then the data will be transmitted to the host computer through the serial port. Using LabVIEW graphical programming to receive serial data and calculate magnets’ position on the basis of the magnetic dipole model using Particle Swarm Optimization algorithm and Levenberg-Marquardt algorithm. In order to display magnetic location information and source trajectory in real-time, a graphical user interfaces was developed.Research and experiments showed that the system has some characteristics such as small volume and low-cost, the location information of single magnetic source and two magnetic source can be show real-timely.