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Hiroshi Nakase,1,2 Shinji Sakuma,3 Takumi Fukuchi,4 Takuya Yoshino,1,5 Kohta Mohri,3 Kohei Miyata,3,6 Hironori Kumagai,6 Ken-Ichiro Hiwatari,6 Kazufumi Tsubaki,6 Tetsuya Ikejima,6 Etsuo Tobita,6 Meiying Zhu,7 Kevin J Wilson,7 Kay Washington,8 John C Gore,7,9–13 Wellington Pham7,9–12,14 1Division of Endoscopy, Kyoto University Hospital, Kyoto, Japan; 2Department of Gastroenterology and Hepatology, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan; 3Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Osaka, Japan; 4Gastroenterology and Hepatology, Osakafu Saiseikai Nakatsu Hospital, Osaka, Japan; 5Division of Inflammatory Bowel Disease, Digestive Disease Center, Kitano Hospital, Osaka, Japan; 6Advanced Materials R&D Laboratory, ADEKA Corp., Tokyo, Japan; 7Department of Radiology, Vanderbilt University Institute of Imaging Science, 8Division of Gastrointestinal and Hepatic Pathology, Vanderbilt School of Medicine, 9Department of Radiology and Radiological Sciences, 10Department of Biomedical Engineering, 11Vanderbilt Ingram Cancer Center, Vanderbilt School of Medicine, 12Vanderbilt Brain Institute, 13Molecular Physiology and Biophysics, 14Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, TN, USA Abstract: The Thomsen–Friedenreich (TF) antigen represents a prognostic biomarker of colorectal carcinoma. Here, using a nanobeacon, the surface of which was fabricated with peanut agglutinin as TF-binding molecules, we demonstrate that the nanobeacon is able to detect TF antigen in frozen and freshly biopsied polyps using fluorescence microscopy. Our results provide important clues about how to detect aberrant colonic tissues in the most timely fashion. Given the versatile application method for this topical nanobeacon, the protocol used in this work is amenable to clinical colonoscopy. Moreover, the prospects of clinical translation of this technology are evident. Keywords: TF antigen, fluorescence colonoscopy, nanobeacon, colorectal cancer

The authors have presented a pulse frequency modulation (PFM) amorphous wire CMOS IC magneto-impedance (MI) sensor for the purpose of omitting the A/D converter in the electronic compass for mobile phone application by counting the output square wave voltage width with the number of timing pulses of the microprocessor. Elimination of A/D converters is useful for downsizing, speed up and cost cutting in the mobile phone electronic compass. However, output stability of the PFM-MI sensor should be improved by canceling the fluctuation of sensor circuit parameter (R, C) with temperature variation. They recently constructed a pulsewidth modulation (PWM) amorphous wire CMOS IC MI sensor on the basis of the PFM-MI sensor detecting the pulse duty ratio proportional to the applied magnetic field strength, in which the sensor circuit parameter (R, C) are canceled in the sensor output equation for the improvement of the magnetic field sensing stability to temperature variation. Index Terms--Amorphous wire, magneto-impedance (MI), magnetic sensor, pulsewidth modulation (PWM).

The magneto-impedance (MI) effect is a phenomenon in which the voltage induced by a high frequency current source in a ferromagnetic wire changes with the application of an external field. A giant MI effect was found in amorphous magnetic wires having a composition of [([Fe.sub.0.06][Co.sub.0.94]).sub.72.5][Si.sub.12.5][B.sub.15] and a magnetostriction of ([-10.sup.-7]). The amplitude of the wire voltage decreased by 40% at 1 MHz, 60% (600 kHz) and 50% (150 kHz), for wires having diameters 30 [[micro]meter], 50 [[micro]meter] and 124 [[micro]meter], respectively, under the influence of an external longitudinal field of about 10 Oe (800 A/m). A highly sensitive and quick-response field sensor was constructed using a 200 MHz resonant multivibrator bridge-circuit combining two MI-effect elements of 1 mm length with two field effect transistors (FET). Highly sensitive flux detection was carried out by using the small MI sensor head on a rotary encoder magnet having 512 poles and a diameter of 30 mm. Discussion of a mechanism for the MI effect considers the skin effect in an amorphous wire with high circumferential anisotropy.

New high performance micro magnetic heads and sensors are presented utilizing the giant magneto-impedance (GMI) in the Co-rich amorphous wire. Typical performances or advantageous features of the head and sensor are as follows; (i) head size can be reduced to about 1 mm maintaining a flux detection sensitivity of about [10.sup.-5] Oe, (ii) a rapid response. with the cut-off frequency of 20 [similar to] 30 MHz using a wire current of 200 [similar to] 300 MHz, (iii) high temperature stability of about 0.01 %FS/[degree] C with a maximum operating temperature of about 180 [degrees] C using a negative feedback loop in the sensor circuit, and (iv) small power consumption of less than 10 mW using a self-oscillation circuit, in which a MI element voltage decreases to zero (100 % change) with an external field of about 2 Oe. The basic properties and mechanism of the GMI, the head construction, the sensor construction principle, sensor circuits and sensing applications are discussed.

A comprehensive analysis of magneto-impedance (MI) phenomena in Co-rich amorphous materials is presented on the basis of skin effect in combination with dynamical magnetization processes. We consider a MI effect for which the domain walls are perpendicular to the current and field direction. Thus, the magnetization induced by current proceeds via both the wall movement and moment rotation. The magnetic responses of impedance in wires and films have some common features and can be understood from the same mechanism. The sensitivity of the magnetic response in a small sample (1 mm length and a few micrometer thickness) is about 10%/Oe in wires and 5%/Oe in films. The model describes well the existing experimental data for moderate frequencies. There is some quantitative discrepancy for the case of a very strong skin effect, where the position dependence of basic magnetostatic parameters is important.

Analysis of recent experimental results on magneto-impedance and magneto-inductive effects in amorphous alloys shows that the magneto-impedance effect originates from an electromagnetic source and is utilized in soft magnetic conductors. Total wire impedance varies with circumferential permeability via the penetration depth, and causes a large magneto-impedance effect at strong skin effect. Soft magnetic materials with perpendicular domain walls and current and external field direction register the most sensitive magneto-impedance effect.

Magneto-Inductive effect (MI-effect, for short) means a phenomenon of change of an inductance L for an external magnetic field Hex in a ferromagnetic wire element magnetized with a wire ac current I(sub ac). When a I(sub ac) is applied through a ferromagnetic wire, a voltage e(sub tot) is induced between both ends of the wire which has two voltage components: a voltage e(sub R) of R(sub w)I(sub ac) (R(sub w): electric resistance of the wire) and a voltage e(sub L) of dphi(sub c)/dt (phi(sub c): a circumferential flux at the cross section of the wire). e(sub L) is detected by subtraction e(sub R) from e(sub tot) using a simple resistor circuit. The amplitude /e(sub L)/ of e(sub L) decreases with increasing /H(sub ex)/ due to the decrease of L. That is, /e(sub L)/ is an amplitude-modulated wave with /H(sub ex)/. The waveform of /H(sub ex)/ is detected using a simple demodulator with a diode and a capacitor. A sensitive MI element is constituted using a slightly negative magnetostrictive amorphous wire (a-wire, for short). The rate of change of /e(sub L)/ at a folded 5-mm long a-wire element was about 50% for /H(sub ex)/ of 10 Oe (800 A/m). The a-wire MI element is expected as new sensitive magnetic heads (MI heads) for accurate rotary encoders, hard disks, and various magnetic cards.

An accurate stationary low-speed and torque control system for induction motors (IM) with a secondary current ([I.sub.2]) signal feedback loop is presented, in which a sensitive and stable micromagnetic (MI) sensor is set inside a drilled shaft hole to detect a slip frequency (sf) magnetic field proportional to an endring circular current. A finite impulse response digital low-pass filter (FIR-DLPF) is introduced to separate the [I.sub.2] signal from slightly higher frequency drive current [I.sub.1] signal at a low speed IM operation for such as the steel sheet rolling spread control. Accurate stationary low speed (45 r/min) control with error less than 1.11% and stationary torque (1.3 N*m at 45 r/min) control with error less than 0.76% for a 1.5 kW, 4-pole IM through 83 min operation were obtained, respectively. Index Terms--Accurate low-speed control, induction motor, micromagnetic (MI) sensor, secondary current feedback.

A new frequency-modulation-type magnetoimpedance (MI) sensor using amorphous wire and a complimentary metal-oxide-semiconductor (CMOS) multivibrator is presented. The normal switching mode (mode I) with the alternative saturation and off states in the p-MOSFET and n-MOSFET maintains a stable multivibrator oscillation and simultaneous CMOS unsaturation state mode (mode II) generates a sensitive MI effect. A 50%/Oe change in the oscillation frequency versus external dc magnetic field was obtained. A linear sensor characteristic is obtained using a negative feedback through a frequency-voltage converter. Index Terms--Amorphous wire, CMOS multivibrator, frequency modulation, magnetoimpedance (MI), magnetic sensor.

Two methods for obtaining asymmetrical magnetoimpedance characteristics in Co-based negative magnetostrictive amorphous wires were studied in terms of the surface impedance tensor. The first approach involved a wire having a helical anisotropy and subjected to an ac current superposed with a dc current. In the other method, the asymmetric voltage response was obtained by applying the ac current in series through the wirer and the coil mounted on it. These kinds of asymmetrical magnetoimpedance was found to be important for developing autobiased linear magnetoimpedance sensors.

A brain tumor position sensing method using an MI (magneto impedance) micro magnetic sensor in combination with fine magnetic particles (FMP for short) is proposed. Sensing of magnetic field generated from FMP accumulated in the brain tumor tissue would be an effective way to accurately detect the tumor position in the surgical operation. The spatial distributions of stray fields in gel samples, in which FMP were dispersed, were measured using an MI gradient-field sensor. The position of samples having FMP concentration of more than 0.1g/l was clearly detected due to the high sensitivity (2 x [10.sup.-5] Oe for a dc field) of the sensor. The spatial distributions were analyzed by a model of aligned dipole moments. The calculation results using the model were in good agreement with experimental results. Position sensing of the tumor tissue of a rat was also carried out. It was concluded that the proposed method would be useful for not only position sensing of the brain tumor but' also 3D imaging of the tumor shape.

A family of sensitive, stable and low power consumption Ml micro magnetic sensors are constructed using a CMOS IC multivibrator circuit, in which a sharp pulse train current is applied to an amorphous wire to cause the skin effect A micro field sensor having a resolution of [10.sup.6] Oe with a full scale (FS) of [+ or -] 1.50e and a nonlinearity of less than 0.2%, a cut-off frequency of [approximately]200 kHz, and a power consumption in the oscillation circuit of 0.5[approximately equal to]5 mW is obtained using a zero-magnetostrictive FeCoSiB amorphous wire of 30 [[micro]meter] diameter and 2 mm length. A differential field sensor is also constructed using a pair of amorphous wires suitable for detection of a localized field with the resolution of [10.sup.-4] Oe cancelling uniform disturbance fields such as terrestrial field. Non-contact sensing of a magnetic card surface field was demonstrated.

A giant stress-impedance (GSI) effect with the strain-gauge factor more than 1200 was found in negative magnetostrictive amorphous CoSiB wires of 30-[[micro]meter] diameter magnetized with a high frequency current or a sharp pulse current. A sensitive stress sensor is constructed using a CMOS IC multivibrator circuit in which the amorphous wire is magnetized with a sharp pulse train current. The amorphous wire GSI sensor will be applied for detection of such as pressure, tension, stream speed for liquid and gases and mechanocardiogram with the sensitivity of 5-6 times higher than that of the semiconductor stress sensors utilizing the piezo-resistance effect showing a gauge factor of about 200.

New detection of the rotor information of squirrel-cage induction motors for a stable torque control is carried out by using a highly sensitive Magneto-Impedance micro magnetic sensor. A magnetic field detected near an edge of the rotor shaft is estimated to be proportional to the rotor current with a slip frequency (psf/2) and a torque when the motor is driven with a constant V/f inverter. A stable control for the stationary torque is realized independently of the motor temperature variation.

Sensitive and quick response micro magnetic sensor for detection of a very localized field (gradient field) cancelling background disturbance field is presented using a high frequency (20 [similar to] 40 MHz) multivibrator having a pair of amorphous wire MI head of 1 [similar to] 3 mm length each. The resolution of field detection is [10.sup.-6] Oe for ac field and the cut-off frequency is about 200 kHz. Stable detection of a surface field of a densely magnetized ring magnet with 19 mm diameter and 2000 poles (30 [[micro]meter] in pole interval) for a high resolution rotary encoder was carried out with a sinusoidal waveform.

This paper presents results on magneto-impedance (MI) in a NiFe/Cu/NiFe sandwich film of 0.2 [[micro]meter] thickness, which exhibits the impedance change up to 8% for a field of 4 Oe at a frequency of 400 MHz. The effect of voltage change with the field can be especially large ([approximately]200% for 5 Oe) if the sandwich film is incorporated in a self oscillation circuit which can be directly used for magnetic sensor head applications. The comparative analysis of MI in a sandwich film and a single magnetic layer is given, demonstrating that the sandwich structure can show an increase in MI of about a factor of 6 over a single magnetic layer and the maximum MI effect occurs at frequencies of an order of magnitude lower.

An improved magnet-displacement sensor is constructed using amorphous Magneto-Inductive (MI) elements for both-eyelid movement sensing. Folded amorphous wires without any coils are fixed on a glass frame and sensitively detect a magnetic field generated from a small magnet which is adhered on a upper eyelid. These noncontact field sensors detect a delicate eyelid movement accompanied by eyeball motion of as small as 1 micrometer by cancelling disturbance fields such as the earth field. Changing of a value of a cross correlation of two time series of both eyelid was measured for two subjects with a time interval of 3 hours through 24 hours. A relation between a magnitude of the cross correlation and a sleepiness was obtained when subjects trace a light spot target which oscillates horizontally with a 0.2 Hz sinusoidal form.