CN1138974A - Method and circuit of eliminating radio intereference in electrocardiac channel - Google Patents
Method and circuit of eliminating radio intereference in electrocardiac channel Download PDFInfo
- Publication number
- CN1138974A CN1138974A CN95106877.6A CN95106877A CN1138974A CN 1138974 A CN1138974 A CN 1138974A CN 95106877 A CN95106877 A CN 95106877A CN 1138974 A CN1138974 A CN 1138974A
- Authority
- CN
- China
- Prior art keywords
- circuit
- input
- radio
- signal
- pulse
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims description 12
- 238000002595 magnetic resonance imaging Methods 0.000 claims abstract description 31
- 230000000694 effects Effects 0.000 claims abstract description 8
- 230000001360 synchronised effect Effects 0.000 claims abstract description 4
- 239000003990 capacitor Substances 0.000 claims description 4
- 238000001914 filtration Methods 0.000 description 8
- 238000005516 engineering process Methods 0.000 description 7
- 210000000056 organ Anatomy 0.000 description 5
- 210000000115 thoracic cavity Anatomy 0.000 description 5
- 238000005481 NMR spectroscopy Methods 0.000 description 2
- 210000000481 breast Anatomy 0.000 description 2
- 239000008358 core component Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000007704 transition Effects 0.000 description 2
- 238000010009 beating Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000003759 clinical diagnosis Methods 0.000 description 1
- 239000000306 component Substances 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000006378 damage Effects 0.000 description 1
- 238000003745 diagnosis Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- 230000035800 maturation Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000033772 system development Effects 0.000 description 1
Images
Landscapes
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
The present invention is used for the electrocardiogram channel in magnetic resonance imaging (MRI) system. The key part is an electronic analog switch IC and its analog switch is controlled by the blank signal, which is produced while the scanning MRI system provides radio pulse. During radio pulse, the analog switch is turned off to cut off the radio interference and thus to eliminate the effect of radio pulse interference on electrocardio gated synchronous pulse generating circuit completely. The said circuit has clear logic and simple structure.
Description
The invention discloses circuit and the method for eliminating the electrocardiac channel Radio Frequency Interfere in a kind of magnetic resonance imaging system.
In the sweep object of nuclear magnetic resonance (MRI) system, diagnosis to organ in the thoracic cavity occupies suitable ratio, owing to beating of human heart, and the direct scanning imagery if do not take special measure, the thoracic organs picture quality that is obtained is very poor, is difficult to satisfy the clinical diagnosis demand.Thereby when thoracic organs is scanned, utilize each cycle internal fixation phase place of heart ECG (electrocardiogram) signal to trigger the MRI scanning sequence constantly and become technological means first-selected and indispensable in the MRI application, technology that Here it is so-called " ECG gate ".After adopting this " ECG gate " technology, the motion artifacts that heartbeat causes is suppressed to greatest extent, makes at the MRI image that also can obtain clinical value when scanning such as thoracic organs such as hearts.
ECG (electrocardiogram) signal that obtains patient under general situation has been a kind of maturation and quotidian technology, will bother manyly and in the MRI system, will seek out the desirable ECG signal waveform that is scanned patient, reason is that when utilizing the ECG gating technology that the thoracic organs that is scanned patient is scanned patient lies in the magnet and ECG breast conductive electrode just in time is positioned at this strongest position of MRI systems radiate radio-frequency power of magnet center.Like this, the energy of the radio-frequency pulse (being called driving pulse) that is given off during the MRI system scan is led ECG (electrocardiogram) electrode by breast unavoidablely and is coupled in the ECG passage, and this coupling even the amplitude that arrives RF pulse envelope by force surpass the amplitude of normal ECG signal wave crest.Although the ECG passage is a low pass filter for the radio frequency of MRI system, the radio-frequency (RF) energy of radio-frequency pulse has been suppressed substantially, but its envelope drops within the passband of ECG passage, thereby can comparatively waltz through the ECG passage, thereby decide the uniqueness in the MRI system scan initial moment of sequence in an ecg cycle to suffer destruction based on identification QRS waveform (QRS waveform and radio-frequency pulse can not occur simultaneously in this method) in " ECG gate " technology of making.
Angle from signal spectrum, MRI system RF pulse envelope and ECG signal difference are little, basically all drop on same frequency band range (in 0.5 ~ 100Hz), if adopt the method for filtering (no matter being active or passive) to come the filtering radio-frequency pulse to disturb merely like unlikely.
It is the problem that numerous MRI system development manufacturer unit faces jointly that radio-frequency pulse when adopting " ECG gate " technology in the MRI system in the filtering ECG passage disturbs.U.S. Pat P-4887609 has delivered the Method and circuits of Radio frequency interference in a kind of filtering ECG passage, it utilizes an active filter with two kinds of filter pass bands (3DB) characteristic, make that when between the ECG signal apparition passband of this active filter is 0 ~ 50Hz, it is passed through smoothly; And when the ECG signal does not occur, make that the passband of active filter is 0 ~ 5Hz, like this, have only near the low-frequency signal components of direct current and can pass through, thereby reach filtering interfering in the ECG passage and obtain the purpose of clean complete ECG signal waveform, but the method depends on the identification to the initial moment of QRS waveform in the ECG signal, if this identification has error will reduce filtration result to interference noise.
The object of the present invention is to provide a kind of Blank signal that utilizes in the magnetic resonance imaging system to eliminate the interferential Method and circuits of radio-frequency pulse in ECG (electrocardiogram) passage.
Technical solution of the present invention realizes in the following manner: one tunnel positive pulse signal that is called the Blank signal is arranged in the MRI system, it is synchronous with the radio-frequency pulse of emission that the positive pulse of this Blank signal goes out now, for the invention provides the interferential approach of a kind of effective inhibition radio-frequency pulse.
In ECG passage radio-frequency pulse interference cancellation circuit, it is by signal input circuit I, waveform processing circuit II, electronic analog swtich integrated circuit III and signal holding circuit IV constitute, core component is an electronic analog swtich integrated circuit, the ECG signal that is superimposed with radio-frequency pulse in the magnetic resonance imaging system is input to the input of signal input circuit, and be input to the input of waveform processing circuit by the Blank signal that magnetic resonance imaging system provides, the input of electronic analog swtich is connected with the outfan of signal input circuit, its control end is connected with the outfan of waveform processing circuit, and its outfan is connected with the input of waveform holding circuit.
Method of the present invention is exactly the break-make that the Blank signal that occurs synchronously with radio-frequency pulse that utilizes that magnetic resonance imaging system the time provides in scanning is controlled electronic analog swtich, when radio-frequency pulse appears at the input of analog switch, make analog switch disconnect through the Blank signal after the waveform processing, stop passing through of radio-frequency pulse, this moment, circuit output end was owing to the effect of waveform holding circuit is keeping the Blank pulse preceding flashy level to occur; And when not having radio-frequency pulse to occur, the Blank pulse does not also occur, and analog switch is held open, and the level of circuit output end is consistent with the level of circuit input end.Like this, radio-frequency pulse has obtained effectively suppressing, and can obtain not having the interferential ECG signal waveform of radio-frequency pulse at the outfan of circuit.
It is clear that Method and circuits of the present invention has logical relation, simple in structure, the fine and characteristics that need not debug substantially of effect.When real work, has good effect, even the radio-frequency pulse interference magnitude in the MRI system surpasses under the situation of ECG signal amplitude peak, also this radio-frequency pulse interference filtering can be fallen, and what influence ECG signal itself is not almost had, thereby " ECG gate " technology based on the QRS waveform recognition of ECG signal is realized well.
Figure 1 shows that theory diagram of the present invention.
Figure 2 shows that the oscillogram of ABCDEF each point of the present invention.
Fig. 3 is a circuit diagram of the present invention.
Below in conjunction with drawings and Examples the present invention is explained in detail.
In Fig. 1, a kind of circuit arrangement that is used for eliminating ECG (electrocardiogram) passage Radio frequency interference, it is by signal input circuit I, waveform processing circuit II, electronic analog swtich integrated circuit III and signal holding circuit IV constitute, its core component is analog switch III, the ECG signal that is superimposed with radio-frequency pulse in the magnetic resonance imaging system is input to the input of signal input circuit I, and be input to the input of waveform processing circuit II by the Blank signal that nuclear magnetic resonance provides, the input of electronic analog swtich III is connected with the outfan of signal input circuit I, its control end is connected with the outfan of waveform processing circuit II, and its outfan is connected with the input of waveform holding circuit IV.
Utilize the fixed phase relationship that Blank signal and radio-frequency pulse occur substantially simultaneously in the magnetic resonance imaging system, when radio-frequency pulse appears at the input of analog switch, make analog switch disconnect through the Blank signal after the waveform processing, stop passing through of radio-frequency pulse, this moment, circuit output end was owing to the effect of waveform holding circuit is keeping the Blank signal preceding flashy level to occur; And when not having radio-frequency pulse to occur, the Blank signal does not also occur, and analog switch is held open, and the level of circuit output end is consistent with the level of circuit input end.Like this, radio-frequency pulse has obtained effectively suppressing, and can obtain not having the interferential ECG signal waveform of radio-frequency pulse at the outfan of circuit.
Among Fig. 2, disturb the disturbed ECG signal (shown in Fig. 2-A) that is superimposed to be sent to the input A of analog switch with radio-frequency pulse in the ECG of the MRI system passage, the Blank pulse signal (shown in Fig. 2-B) that is provided by the MRI system is sent to the input B of waveform processing circuit, through the trailing-edge broadening in the waveform processing circuit, processing such as polarity and logic level transition back obtains the switch controlling signal (shown in Fig. 2-E) of analog switch at the control input end of analog switch E, why to be in order to compensate with the trailing-edge broadening of Blank signal since the radio-frequency pulse tailing edge that the delay effect of power switch causes in the MRI system with respect to time lag of Blank pulse back edge, the purpose of carrying out polarity and logic level transition is to satisfy polarity that the analog switch control end requires and logic level (logical zero of TTL and " 1 " correspond respectively to level " 0.5V " and " 3.5V " for the pulse signal that will have the TTL logic level is converted to; The logical zero of analog switch control end and " 1 " correspond respectively to " 0.5V " and " 11.5V ").The operating characteristic of analog switch is conducting when control end is input as level"1", and disconnects for level "0" the time, like this at the outfan F of the entire circuit interferential normal ECG signal of radio-frequency pulse (shown in Fig. 2-F) that can obtain complete filtering.In waveform holding circuit of the outfan of analog switch serial connection is in order to make when analog switch disconnects, the wave distortion of the normal ECG signal that flashy level may be caused by the analog switch disconnection with elimination before outfan F keeps analog switch to disconnect.
In Fig. 3, by resistance R
3, R
4And R
5, Zener diode D
1, diode D
2And D
3With formation signal input circuit I, wherein resistance R
3An end be the input of this signal input circuit, the other end and resistance R
4, diode D
2Anode and diode D
3Negative electrode connect D
2Negative electrode and power supply V
C2Connect D
3Anode and resistance R
5An end and Zener diode D
1Anode connect D
1Negative electrode and power supply V
C1Connect R
5The other end be connected with ground.Zener diode D
1Both end voltage be 3.6V, its anode voltage is clamped at about 1.4V, D
2Be connected to+12V power supply V
C2, D
3Be connected to D
1Anode, D
2And D
3The amplitude limit effect make input and radio-frequency pulse disturb the excursion of the ECG signal that is superimposed to be limited between 0.8V ~ 11.2V, to guarantee the operate as normal of analog switch;
By U
1, U
2, U
3, R
1, C
1And R
2The waveform processing circuit II of the Blank signal that constitutes, U
1(74LS122) be a monostable flipflop, it works in trailing edge and triggers duty, U
1Negative pulse trigger input A
1 (1)With U
2An input (2) (74LS32) links together and constitutes the input of Blank waveform processing circuit, capacitor C
1Be connected across U
1CEXT end (11) and REXT/CEXT hold between (13) resistance R
1An end and U
1REXT/CEXT end (13) connect the other end and power supply V
C1Connect U
1Positive pulse outfan (8) and U
2Another input (1) connect U
2Outfan (3) and U
3Input (74LS26) (1) is connected U simultaneously with (2)
3Outfan (3) and resistance R
2An end connect R
2The other end and power supply V
C2Connect.
The Blank signal pulse inputs to U
1Trailing edge trigger end (2), at U
2Positive pulse outfan Q (8) obtain a positive pulse that triggers by Blank signal pulse trailing edge, its pulse width is 0.7R
1C
1, this positive pulse is connected to or door U
2An input (1), the Blank signal pulse itself be connected to or the door U
2Another input (2), like this at U
2Outfan obtain pulse signal than former Blank signal pulse trailing edge delay, why need this trailing edge delay to be because the tailing edge of radio-frequency pulse has the hysteresis of certain hour (Millisecond), U with respect to the tailing edge of Blank signal
2Outfan (3) be connected to U
3Input (1,2), U
3Be an open collector high pressure output NAND gate, its outfan connects analog switch U
4Control end (6), R
2Be its pull-up resistor, U
3Effect be the U that satisfies that the Transistor-Transistor Logic level pulse signal of its input is converted to its outfan
4The pulse signal that requires of control end logic level (" 1 " and " 0 " logic level corresponds respectively to+11.5V with+0.5V);
Analog switching ic III is a core devices of the present invention, in the present invention analog switch U
4(MC14066) working power is+5V ~+15V, now be chosen to be+12V, " 1 " of its control end and " 0 " logic level correspond respectively to+11.5V and+0.5V, input of electronic analog swtich (9) and resistance R
4Link to each other, at U
4Input (9) be the change in voltage scope for+0.8V ~+11.2V be superimposed with the interferential ECG signal of radio-frequency pulse because the operating characteristic of analog switch itself, when radio-frequency pulse occurs, U
4Control end (6) and resistance R
2And U
3Outfan link to each other U
4Control end (6) be level "0", analog switch disconnects, and because waveform processing circuit U
1The hysteresis of Blank signal pulse tailing edge is made U
4Certainly disturb between the apparition at radio-frequency pulse to disconnect fully always, after radio-frequency pulse, U
4Control end (6) be level"1", the analog switch conducting, the ECG signal is smoothly by analog switch U
4, at U
4Outfan (8) be connected in series a capacitor C
2, like this at U
4Outfan just filtered out the interferential ECG signal of radio-frequency pulse fully.The present invention has adopted a capacitor C that is serially connected in analoging switch output end
2As signal holding circuit IV, purpose is in order to make that when analog switch disconnects flashy level before outfan F keeps analog switch to disconnect is to eliminate the wave distortion that may be disconnected the normal ECG signal that causes by analog switch.
Method of the present invention and physical circuit both can be used as some and have been integrated in ECG (electrocardiogram) passage of MRI system and go when implementing, also can be used as independent parts and be serially connected between the ECG signal acquisition circuit unit and ECG gate synchronous pulse-generating circuit unit of MRI system.
Claims (4)
1, a kind of circuit arrangement of eliminating Radio Frequency Interfere in the electrocardiac channel, comprise signal input circuit (I), waveform processing circuit (II) and signal holding circuit (IV), it is characterized in that: also have an electronic analog swtich integrated circuit (III), the electrocardiosignal that is superimposed with radio-frequency pulse in the magnetic resonance imaging system is input to the input of signal input circuit (I), and be input to the input of waveform processing circuit (II) by the Blank signal that magnetic resonance imaging system provides, the input of electronic analog swtich (III) is connected with the outfan of signal input circuit (I), the control end of electronic analog swtich (III) is connected with the outfan of waveform processing circuit (II), and its outfan is connected with the input of waveform holding circuit (IV).
2, a kind of circuit of eliminating Radio Frequency Interfere in the electrocardiac channel according to claim 1 is characterized in that: by resistance R
3, R
4And R
5, Zener diode D
1, diode D
2And D
3Constitute signal input circuit (I), wherein resistance R
3An end be the input of this signal input circuit, the other end and resistance R
4, diode D
2Anode and diode D
3Negative electrode connect D
2Negative electrode and power supply V
C2Connect D
3Anode and resistance R
5An end and Zener diode D
1Anode connect D
1Negative electrode and power supply V
C1Connect R
5The other end be connected with ground.
3, a kind of circuit of eliminating Radio Frequency Interfere in the electrocardiac channel according to claim 1 is characterized in that: by U
1, U
2, U
3, R
1, C
1And R
2The waveform processing circuit (II) of the Blank signal that constitutes, U
1Be a monostable flipflop, it works in trailing edge and triggers duty, U
1Negative pulse trigger input A
1 (1)With disjunction gate U
2An input (2) link together and constitute the input of this waveform processing circuit, capacitor C
1Be connected across U
1CEXT end (11) and REXT/CEXT hold between (13) resistance R
1An end and U
1REXT/CEXT end (13) connect the other end and power supply V
C1Connect U
1Positive pulse outfan (8) and U
2Another input (1) connect U
2Outfan (3) and non-conjunction U
3Input (1) be connected U simultaneously with (2)
3Outfan (3) and resistance R
2An end connect R
2The other end and power supply V
C2Connect.
4, a kind of method of eliminating the electrocardiac channel Radio Frequency Interfere, it is characterized in that: the Blank signal with the synchronous appearance of radio-frequency pulse that utilizes magnetic resonance imaging system to provide when scanning is controlled the break-make of electronic analog swtich, when radio-frequency pulse appears at the input of analog switch, make analog switch disconnect through the Blank signal after the waveform processing, stop radio-frequency pulse to pass through, this moment, circuit output end was owing to the effect of waveform holding circuit is keeping the Blank pulse preceding flashy level to occur; And when not having radio-frequency pulse to occur, the Blank pulse does not also occur, and analog switch is held open, and the level of circuit output end is consistent with the level of circuit input end.Like this, radio-frequency pulse has obtained effectively suppressing, and can obtain not having the interferential ECG signal waveform of radio-frequency pulse at the outfan of circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95106877.6A CN1070043C (en) | 1995-06-27 | 1995-06-27 | Method and circuit of eliminating radio intereference in electrocardiac channel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN95106877.6A CN1070043C (en) | 1995-06-27 | 1995-06-27 | Method and circuit of eliminating radio intereference in electrocardiac channel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1138974A true CN1138974A (en) | 1997-01-01 |
| CN1070043C CN1070043C (en) | 2001-08-29 |
Family
ID=5076104
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN95106877.6A Expired - Lifetime CN1070043C (en) | 1995-06-27 | 1995-06-27 | Method and circuit of eliminating radio intereference in electrocardiac channel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1070043C (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100423693C (en) * | 2005-06-29 | 2008-10-08 | 深圳迈瑞生物医疗电子股份有限公司 | Method and device for resisting electrical fast burst interference suitable for respiratory waveform acquisition |
| CN101297754B (en) * | 2007-05-02 | 2012-08-08 | 韦伯斯特生物官能公司 | Coherent signal rejection in ECG |
| US9238141B2 (en) | 2013-08-15 | 2016-01-19 | Medtronic, Inc. | Devices and methods to provide stimulation therapy in the presence of external conditions that induce undesirable perturbations |
-
1995
- 1995-06-27 CN CN95106877.6A patent/CN1070043C/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100423693C (en) * | 2005-06-29 | 2008-10-08 | 深圳迈瑞生物医疗电子股份有限公司 | Method and device for resisting electrical fast burst interference suitable for respiratory waveform acquisition |
| CN101297754B (en) * | 2007-05-02 | 2012-08-08 | 韦伯斯特生物官能公司 | Coherent signal rejection in ECG |
| US9238141B2 (en) | 2013-08-15 | 2016-01-19 | Medtronic, Inc. | Devices and methods to provide stimulation therapy in the presence of external conditions that induce undesirable perturbations |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1070043C (en) | 2001-08-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| DE3886142T2 (en) | High speed digital telemetry system for implantable devices. | |
| DE3934139C2 (en) | Electronic control circuit for a brushless DC motor | |
| DE19601866B4 (en) | Transcutaneous energy and information transfer facility | |
| EP2587275A1 (en) | Catheter for MRI-guided cardiac pacing | |
| CN1070043C (en) | Method and circuit of eliminating radio intereference in electrocardiac channel | |
| CN105232027A (en) | Portable electrocardiosignal processing method and device | |
| US6028476A (en) | Power switched amplifer | |
| EP1056039A2 (en) | Transmitter and receiver | |
| WO2013110389A1 (en) | Environment detection device and related method for determining the position and/or motion of an object | |
| CN87108294A (en) | The digital receiver that two benchmark are arranged | |
| DE4438868A1 (en) | Carbon brush for mechanically commutated DC motor | |
| DE102022127935A1 (en) | Electrosurgical device, system and method for controlling an electrosurgical device | |
| US3968430A (en) | Installation for the detection and processing of electrical signals | |
| DE2932819C2 (en) | Generation of a supply voltage for pulsating loads | |
| CN209913740U (en) | Drive control circuit and electric equipment | |
| DE2827572C2 (en) | Procedure for eliminating interference in a mobile radio receiving system | |
| DE2523431A1 (en) | FREQUENCY / VOLTAGE CONVERTER AND FUEL SUPPLY SYSTEM | |
| DE102018211033A1 (en) | Method for operating a circuit for generating an electromagnetic field and circuit | |
| CN210669883U (en) | Filter for filtering noise and interference signal | |
| DE102006015060B4 (en) | Load control device and load control system | |
| DE102012200020B4 (en) | Method and device for transmitting at least one predetermined signal form to a spatially remote transmitting device | |
| DE4437560A1 (en) | Circuit for compensating AC voltage ripple in DC voltage supply | |
| DE2658278A1 (en) | Buffer amplifier system for electric signals - has second amplifier part which is switched on only when output switch is operated | |
| DE69714207T2 (en) | CIRCUIT | |
| US4918263A (en) | Co-ordinate measuring system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C56 | Change in the name or address of the patentee |
Owner name: SHENZHEN ANKE HI-TECH CO., LTD. Free format text: FORMER NAME OR ADDRESS: SHENZHEN ANKE HIGH TECH. CO., LTD. |
|
| CP03 | Change of name, title or address |
Address after: 518067, No. 26, Mount Shun Road, Shekou, Guangdong, Shenzhen, Nanshan District Patentee after: Anke High-Tech Co., Ltd., Shenzhen City Address before: 518067, No. 3, Mount Shun Road, Shekou, Guangdong, Shenzhen Patentee before: Anke High Technology Co., Ltd., Shenzhen |
|
| PP01 | Preservation of patent right |
Effective date of registration: 20070927 Pledge (preservation): Preservation |
|
| PD01 | Discharge of preservation of patent |
Date of registration: 20071019 Pledge (preservation): Preservation |
|
| CX01 | Expiry of patent term |
Expiration termination date: 20150627 Granted publication date: 20010829 |
|
| EXPY | Termination of patent right or utility model | ||
| DD01 | Delivery of document by public notice |
Addressee: Yang Hong Document name: Notification of Expiration of Patent Right Duration |