• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.773-775
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• 1998

This paper describes the highly sensitive Si Hall magnetic sensing system which can measure the earth magnetic field. Generally, the important parameters in Hall device which degrade the ability of magnetic detection are offset voltage and 1/f noise. The offset voltage and 1/f noise in Hall plates can be reduced by spinning current method. In this paper, we implement the highly sensitive Si Hall magnetic sensing system using spinning current method. As a result, the minimum detectable magnetic field is 0.1G.

• Proceedings of the Korean Magnestics Society Conference
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• 2013.12a
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• pp.77-78
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• 2013

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.721-726
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• 2007

The study relates to achievement and analysis of 3-dimensional spatial pulse wave archived by a spatially arterial pulse diagnostic apparatus (SAPDA), wherein a pulse sensing part array consists of multiple hall devices and is located over a skin contacting part which consists of a magnetic material. When a radially arterial pulse is transferred to the magnetic material, which is contacted skin that results in changes in a magnetic field of the lower part of the pulse sensing part array, the changes in a magnetic field can be detected by the commercial Hall semiconductor device of the pulse sensing part array. Finally, according to development of SAPDA, the 3-dimensionally arterial pulse waveform can be measured noninvasively by detecting the changes of the magnetic field.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.251-253
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• 2002

We have fabricated a novel Vertical Trench Hall-Effect Device sensitive to the magnetic field parallel to the sensor chip surface for non-contact angular position sensing applications. The Vertical Trench Hall-Effect Device is built on SOI wafer which is produced by silicon direct bonding technology using bulk micromachining, where buried $SiO_2$ layer and surround trench define active device volume. Sensitivity up to 150 V/AT is measured.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.17 no.1
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• pp.63-76
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• 2013

The aims of this study are to investigate a logisitic regression equation of the vacuous pulse and the replete pulse for efficacy evaluation of clip-type pulsimeter by using magnetic Hall device. To evaluate the efficacy of clip-type pulsimeter by using magnetic Hall device as sensing the minute movement of a radial artery, one research clinical trial have been performed. The number of subject was 120, the clinical data of patients did treated with a normal statistical method. The systolic peak amplitude, the reflective peak amplitude and time, and the notch peak amplitude and time are analyzed major efficacy parameters to discern the vacuous pulse and the replete pulse. The equations included of five parameters such as systolic peak amplitude, the reflective peak amplitude and time, and the notch peak amplitude and notch amplitude time for determination of the vacuous pulse and the replete pulse were deducted by statistical logistic regression method. It suggests that the logistic regression equations are possible to develop the oriental algorithm for pulse diagnosis.

• Journal of Magnetics
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• v.18 no.2
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• pp.183-187
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• 2013

Two concurrent signals of the pulse wave measured from both hands' radial artery in un-pressurization condition using the prototype model of two clip-type pulsimeters with a permanent magnet and Hall device are investigated. The phase differences of two pulse waves from 22 subjects have some distinct points according to the handedness. Thus, the propagation of the pulse wave calculated from phase difference is both fast and slow to each other. It is confirmed that this phenomenon comes from the difference of blood vessel hardness between right- and left-hand of each subject rather than a quantity of muscle.

• Journal of the Korean Magnetics Society
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• v.23 no.4
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• pp.130-134
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• 2013

The clip-type pulsimeter equipped with a magnetic sensing Hall device and the most popular body sign of the electrocardiogram (ECG) were investigated in order to analyze the pulse wave velocity (PWV). The PWV simultaneously calculated by means of time difference between the maximum peak of ECG pulse wave and the starting point of radial artery pulse wave, and distance difference between the heart position and the radial wrist position. The PWV analyzed from the clinical data was a wider scope of 5~7 m/s with an average value of 6 m/s. By the prediction of blood vessel's elasticity from the analysis of PWV, it may be useful for developing an oriental-western diagnostic medical signal device for a U-health-care system in the future.

• Journal of Magnetics
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• v.19 no.3
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• pp.255-260
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• 2014

A portable clip-type pulsimeter equipped with a magnetic sensing Hall device has been developed to raise the accuracy of oriental disease diagnosis and therapy by convergence of magnetism and oriental medicine. To improve accuracy and reliability of conventional pulsimeter due to subjective analysis of the pulse wave and measuring position dependency of the arterial pulse sensor, the fuzzy algorithm was applied to analyze the strong- and weak-pulse wave symptom. Optimal time for electronic acupuncture was calculated using fuzzy rules and interference were drawn from objective data in view of pre-treatment. Moreover, the electrical characteristics of the pain parts that respond to acupuncture point were applied in view of post-treatment to propose the scientific pulse wave algorithm and simulation experiment.

• Journal of the Korean Magnetics Society
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• v.24 no.3
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• pp.90-96
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• 2014

The magnetic field variation by the permanent magnet fluctuation positioned on a "Chwan" of wrist according to the movement of radial artery was generated. The clip-type pulsimeter equipped with a Hall device sensing magnetic field pulse movement analyzed the characteristics of pulse wave as output signals. The magnetic field curve and pulse waveform simulated by the finite element method were compared and analyzed with each other. Also, the variation of magnetic field distribution one permanent magnet investigated by the fabrication of clip-type pulsimeter simulator. This result suggests that the clip-type pulsimeter can be used the reproducible and efficacious oriental diagnostic medical instrument.

• Journal of the Korean Magnetics Society
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• v.22 no.4
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• pp.130-135
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• 2012

One prototype product of clip-type pulsimeter equipped with magnetic field sensing semiconductor Hall device after one permanent magnet attached "Chwan" position in center of a radial artery was developed. The clip-pulsimeter was composed of the hard ware system measuring to voltage signals. To measure the blood velocity, the radial artery pulsimeter is simultaneously connected the PPG (photoplethysmograph). Analysis and comparison of two pulse waves data has done obtained from a clinical test of forty subjects of 20 ages. The value of a blood velocity simultaneously measured from a radial artery puls wave and PPG is an average value of 0.8m/s. The usage of this research results is possible to store the biomedical signals for health care.