TWI440863B - Impedance measurement equipment and systems - Google Patents

Description

Impedance measurement equipment and system

The invention relates to a measuring device and system, in particular to an impedance measuring device and system.

The literature "H. Kalv Φ y, L. Frich, S. Grimnes, Impedance-based tissue discrimination for needle guidance . Physiol. Meas., 2009. 30: p. 129-140" discloses two conventional impedance measurements system.

Referring to FIG. 1, a first conventional impedance measuring system includes a first electrode 11 in the form of a flat plate, a second electrode 12 in the form of a needle, a signal generator 13, a current detector 14, and a voltage. Detector 15. The first and second electrodes 11, 12 are used to contact a solution 19 to be tested. The signal generator 13 is electrically connected to the second electrode 12 for outputting an alternating voltage signal having a frequency of 100 kHz and a root mean square amplitude of 30 mV to the second electrode 12. The current detector 14 is electrically connected between the first electrode 11 and the signal generator 13 for detecting the magnitude of the current flowing through the first electrode 11 to generate a current detecting signal. The voltage detector 15 is electrically connected between the first and second electrodes 11, 12 for detecting the magnitude of the voltage between the first and second electrodes to generate a voltage detection signal.

Therefore, according to the current detection signal and the voltage detection signal, the magnitude and phase of the measured impedance can be obtained. The measured impedance includes an impedance of the solution 19 to be tested between the first and second electrodes 11, 12 and an electrode polarization impedance (EPI) of the second electrode 12.

Referring to FIG. 2, a second conventional impedance measuring system includes a first electrode 21 in the form of a flat plate, a second electrode 22 in the form of a needle, a third electrode 23 in the form of a flat plate, an amplifier 24, and a The signal generator 25, a current detector 26 and a voltage detector 27. The first to third electrodes 21 to 23 are used to contact a tissue 29. The amplifier 24 has an inverting input electrically coupled to the third electrode 23, a non-inverting input, and an output electrically coupled to the first electrode 21. Signal generator 25 is electrically coupled to the non-inverting input of amplifier 24 for outputting an AC voltage signal having a frequency of 100 kHz and a root mean square amplitude of 30 mV to the non-inverting input of amplifier 24. The current detector 26 is electrically connected between the second electrode 22 and the signal generator 25 for detecting the magnitude of the current flowing through the second electrode 22 to generate a current detecting signal. The voltage detector 27 is electrically connected between the second and third electrodes 22, 23 for detecting the magnitude of the voltage between the second and third electrodes 22, 23 to generate a voltage detection signal.

Therefore, according to the current detection signal and the voltage detection signal, the magnitude and phase of the measured impedance can be obtained. The measured impedance includes the impedance of the tissue 29 between the second and third electrodes 22, 23 and the polarization of the second electrode 22. Then, the type of the tissue 29 can be identified based on the magnitude and phase of the impedance.

However, both of the above conventional impedance measurement systems must use a voltage detector, which increases the cost.

Accordingly, it is an object of the present invention to provide an impedance measuring apparatus that does not require the use of a voltage detector.

Therefore, the impedance measuring device of the present invention is adapted to be electrically connected to a first electrode and a second electrode, and includes a signal generator, a current detector and a processor. The signal generator is electrically coupled to the first electrode for outputting a one-step voltage signal to the first electrode. The step voltage signal transitions from a first voltage to a second voltage. The current detector is electrically connected between the second electrode and the signal generator for detecting a magnitude of a current flowing through the second electrode to generate a current detection signal. The processor is electrically connected to the current detector to receive the current detection signal, and according to the current detection signal and the difference between the first voltage and the second voltage, a capacitance value is obtained, as follows:

Wherein, C is the capacitance value, T is a preset integral time, I (t) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage.

Another object of the present invention is to provide an impedance measuring apparatus that does not require the use of a voltage detector.

Therefore, the impedance measuring device of the present invention is adapted to be electrically connected to a first electrode, a second electrode and a third electrode, and includes an amplifier, a signal generator, a current detector and a processor. The amplifier has an inverting input electrically coupled to the third electrode, a non-inverting input, and an output electrically coupled to the first electrode. The signal generator is electrically coupled to the non-inverting input of the amplifier for outputting a one-step voltage signal to the non-inverting input of the amplifier. The step voltage signal transitions from a first voltage to a second voltage. The current detector is electrically connected between the second electrode and the signal generator for detecting a magnitude of a current flowing through the second electrode to generate a current detection signal. The processor is electrically connected to the current detector to receive the current detection signal, and according to the current detection signal and the difference between the first voltage and the second voltage, a capacitance value is obtained, as follows:

Wherein, C is the capacitance value, T is a preset integral time, I (t) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage.

It is yet another object of the present invention to provide an impedance measurement system that does not require the use of a voltage detector.

Therefore, the impedance measuring system of the present invention comprises a first electrode, a second electrode, a third electrode, an amplifier, a signal generator, a current detector and a processor. The amplifier has an inverting input electrically coupled to the third electrode, a non-inverting input, and an output electrically coupled to the first electrode. The signal generator is electrically coupled to the non-inverting input of the amplifier for outputting a one-step voltage signal to the non-inverting input of the amplifier. The step voltage signal transitions from a first voltage to a second voltage. The current detector is electrically connected between the second electrode and the signal generator for detecting a magnitude of a current flowing through the second electrode to generate a current detection signal. The processor is electrically connected to the current detector to receive the current detection signal, and according to the current detection signal and the difference between the first voltage and the second voltage, a capacitance value is obtained, as follows:

Wherein, C is the capacitance value, T is a preset integral time, I (t) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

First preferred embodiment

Referring to Figures 3 and 4, a first preferred embodiment of the impedance measuring system of the present invention comprises a first electrode 31 in the form of a flat plate, a second electrode 32 in the form of a needle, and an impedance measuring device 33. The first and second electrodes 31, 32 are for contacting an object to be tested 39. The impedance measuring device 33 includes a signal generator 331, a current detector 332, and a processor 333. The signal generator 331 is electrically connected to the first electrode 31 for outputting a one-step voltage signal to the first electrode 31. The step voltage signal transitions from a first voltage to a second voltage, as shown by waveform 51 of FIG. The current detector 332 is electrically connected between the second electrode 32 and the signal generator 331 for detecting the magnitude of the current flowing through the second electrode 32 to generate a current detecting signal, as shown in the waveform 52 of FIG. Show. The processor 333 is electrically connected to the current detector 332 to receive the current detection signal, and obtains a capacitance value according to the current detection signal and the difference between the first voltage and the second voltage, and according to the peak value of the current detection signal A difference between a voltage and a second voltage results in a conductance value, as shown below:

G = I _P / V ₀ ,

Where C is the capacitance value, T is a preset integration time, I ( t ) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage, G is the conductance value, and I _P is the current detection The peak value of the signal.

Therefore, a characteristic of the object to be tested 39 can be identified based on the capacitance value and the conductance value, for example, type, acidity, and the like.

Second preferred embodiment

Referring to FIG. 5, a second preferred embodiment of the impedance measuring system of the present invention comprises a first electrode 41 in the form of a flat plate, a second electrode 42 in the form of a needle, a third electrode 43 in the form of a flat plate, and a Impedance measuring device 44. The first to third electrodes 41 to 43 are for contacting a sample to be tested 49. The third electrode 43 is formed with a through hole 431 through which the second electrode 42 can pass. The impedance measuring device 44 includes an amplifier 441, a signal generator 442, a current detector 443, and a processor 444. The amplifier 441 has an inverting input electrically connected to the third electrode 43, a non-inverting input, and an output electrically connected to the first electrode 41. Signal generator 442 is electrically coupled to the non-inverting input of amplifier 441 for outputting a one-step voltage signal to the non-inverting input of amplifier 441. The step voltage signal transitions from a first voltage to a second voltage. The current detector 443 is electrically connected between the second electrode 42 and the signal generator 442 for detecting the magnitude of the current flowing through the second electrode 42 to generate a current detecting signal. The processor 444 is electrically connected to the current detector 443 to receive the current detection signal, and obtains a capacitance value according to the current detection signal and the difference between the first voltage and the second voltage, and according to the peak value of the current detection signal A difference between a voltage and a second voltage results in a conductance value, as shown below:

G = I _P / V ₀ ,

Where C is the capacitance value, T is a preset integration time, I ( t ) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage, G is the conductance value, and I _P is the current detection The peak value of the signal.

Therefore, a characteristic of the object to be tested 49 can be identified based on the capacitance value and the conductance value, for example, type, acidity, and the like.

It is worth noting that this embodiment can be used for body surface measurement.

Third preferred embodiment

Referring to FIG. 6, a third preferred embodiment of the impedance measuring system of the present invention is different from the second preferred embodiment in that the second electrode 42' is disposed coaxially with the third electrode 43', and the third electrode 43' is surrounded. Second electrode 42'.

It is worth noting that this embodiment can be used for in vivo measurement with an endoscope.

In summary, the above embodiments do not require the use of a voltage detector, so the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

11. . . First electrode

12. . . Second electrode

13. . . Signal generator

14. . . Current detector

15. . . Voltage detector

19. . . Solution to be tested

twenty one. . . First electrode

twenty two. . . Second electrode

twenty three. . . Third electrode

twenty four. . . Amplifier

25. . . Signal generator

26. . . Current detector

27. . . Voltage detector

29. . . organization

31. . . First electrode

32. . . Second electrode

33. . . Impedance measuring device

331. . . Signal generator

332. . . Current detector

333. . . processor

39. . . Analyte

41. . . First electrode

42, 42’. . . Second electrode

43, 43’. . . Third electrode

44. . . Impedance measuring device

441. . . Amplifier

442. . . Signal generator

443. . . Current detector

444. . . processor

49. . . Analyte

51, 52. . . Waveform

Figure 1 is a schematic view showing a first conventional impedance measuring system;

Figure 2 is a schematic view showing a second conventional impedance measuring system;

Figure 3 is a schematic view showing a first preferred embodiment of the impedance measuring system of the present invention;

4 is a waveform diagram illustrating a step voltage signal and a current detection signal according to a first preferred embodiment of the present invention;

Figure 5 is a schematic view showing a second preferred embodiment of the impedance measuring system of the present invention; and

Figure 6 is a schematic view showing a third preferred embodiment of the impedance measuring system of the present invention.

31. . . First electrode

32. . . Second electrode

33. . . Impedance measuring device

331. . . Signal generator

332. . . Current detector

333. . . processor

39. . . Analyte

Claims (9)

An impedance measuring system comprising: a first electrode in the form of a flat plate; a second electrode in the form of a needle; a signal generator electrically connected to the first electrode for outputting a one-step voltage signal to the first An electrode, the step voltage signal transitions from a first voltage to a second voltage; a current detector electrically connected between the second electrode and the signal generator for detecting flow through the second electrode a current to generate a current detection signal; and a processor electrically coupled to the current detector to receive the current detection signal, and based on the current detection signal and the first voltage and the second The difference in voltage gives a capacitance value as follows: Wherein, C is the capacitance value, T is a preset integral time, I (t) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage. The impedance measuring system according to claim 1, wherein the processor further obtains a conductance value according to a peak value of the current detecting signal and a difference between the first voltage and the second voltage, as follows: G = I _P / V ₀ , where G is the conductance value and I _P is the peak value of the current detection signal. An impedance measuring device is adapted to be electrically connected to a first electrode, a second electrode and a third electrode, and includes: an amplifier having an inverting input electrically connected to the third electrode, and a non-inverting a phase input terminal, and an output terminal electrically connected to the first electrode; a signal generator electrically connected to the non-inverting input terminal of the amplifier for outputting the one-step voltage signal to the non-inverting input terminal of the amplifier The step voltage signal transitions from a first voltage to a second voltage; a current detector electrically coupled between the second electrode and the signal generator for detecting flow through the second electrode a current to generate a current detection signal; and a processor electrically coupled to the current detector to receive the current detection signal, and based on the current detection signal and the first voltage and the second voltage The difference is that a capacitance value is obtained as follows: Wherein, C is the capacitance value, T is a preset integral time, I (t) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage. The impedance measuring device according to claim 3, wherein the processor further obtains a conductance value according to a peak value of the current detecting signal and a difference between the first voltage and the second voltage, as follows: G = I _P / V ₀ , where G is the conductance value and I _P is the peak value of the current detection signal. An impedance measuring system comprising: a first electrode; a second electrode; a third electrode; an amplifier having an inverting input electrically connected to the third electrode, a non-inverting input, and a Electrically coupled to the output of the first electrode; a signal generator electrically coupled to the non-inverting input of the amplifier for outputting a one-step voltage signal to the non-inverting input of the amplifier, the step voltage signal Converting from a first voltage to a second voltage; a current detector electrically connected between the second electrode and the signal generator for detecting a magnitude of a current flowing through the second electrode to generate a current detecting signal; and a processor electrically connected to the current detector to receive the current detecting signal, and obtaining a capacitor according to the current detecting signal and the difference between the first voltage and the second voltage The value is as follows: Wherein, C is the capacitance value, T is a preset integral time, I (t) is the current detection signal, V ₀ is the difference between the first voltage and the second voltage. The impedance measuring system of claim 5, wherein the third electrode is formed with a through hole for the second electrode to pass through . The impedance measuring system of claim 5, wherein the second electrode is disposed coaxially with the third electrode, and the third electrode surrounds the second electrode. The impedance measuring system according to any one of claims 5 to 6, which is used for body surface measurement. An impedance measuring system according to any one of claims 5 and 7 for use in in vivo measurement.