Probo No.56 Details Probo No.56 Details

Technical Paper

Study of spatial filter for magnetocardiography measurements without a magnetically shielded room

Author Advantest Laboratories, Ltd. Yuji Ogata others
Summary Magnetocardiography (MCG) is an effective modality for clinical application and health monitoring due to non-contact measurement and mapping of heart activity at high spatial resolution. A superconducting quantum interference device (SQUID) magnetometer is usually used for measuring MCG signals. However, a SQUID magnetometer has high running cost due to the liquid helium. Moreover, measuring MCG signals inside a magnetically shielded room (MSR) can be costly. Therefore, we developed a 64-channel magneto-impedance (MI) sensor system that does not require an MSR. However, the MCG measurement has very high noise level without an MSR. In this paper, we discuss the signal processing techniques of various noise reduction methods to decrease very loud noises. In particular, we investigated three spatial filter conditions that decrease correlated noises among the 64-channel signals to achieve a high peak value of MCG signals.
By using a spatial filter that uses the average of the circumference channels and gradient, the distortion of MCG signals can be reduced. The average reduction in amplitude of the R wave as a result of using a spatial filter was 4.5 pT. Furthermore, the signal to noise ratio (SNR) of the P wave was 29.1 dB, while that of the R wave was 42.3 dB, and clear MCG signals were obtained when using the spatial filter that uses the average of the circumference
channels and the gradient. Finally, we successfully measured the MCG signals without an MSR.
Key Words magnetocardiography, magneto-impedance sensor, signal processing, spatial filter

Development of High Voltage General-purpose Pin-Electronics

Author PE Core Engineering Section, 4th R&D department Technology Development Division, Technology Development Group ATE Business Group Hitoshi Nakamura others
Summary Currently, there is a demand in Automated Test Equipment (ATE) to test both high-speed/low-voltage amplitude devices manufactured in advanced processes and low-speed / high-voltage amplitude devices manufactured in legacy processes by a pin-electronics equipment. However, it is difficult to achieve both the operating speed over than 1Gbps and the wide I/O range over than 10Vpp, due to the trade-off between breakdown voltage and parasitic capacitance of transistor.
We achieved the improvement of the trade-off in the general-purpose pin-electronics by using the LDMOS process.
Key Words Pin-electronics, operating speed, I/O voltage range, Lateral Diffused MOS (LDMOS) process

Technical Description

High-speed Image Processing by GPU

Author MD Software Section 2, 1st Software Department Software Division, T2000 Business Unit ATE Business Group Chiezo Saito
Summary By using CPU and GPU together, we have increased the speed of the filter function that is often used in imaging tests. This feature is provided by the Image Processing Library (IPL) in T2000 CMOS Image Sensor Solution.
Next IPE, our new image processing engine that is currently in development, is about six times faster than IPE3 (Image Processing Engine 3), an existing engine.
Key Words Not Specified