CN113080928A

CN113080928A - Active noise reduction system and medical equipment with same

Info

Publication number: CN113080928A
Application number: CN202110342696.6A
Authority: CN
Inventors: 胡凌志; 张双悦; 张馨月
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2021-07-09

Abstract

The application relates to an active noise reduction system and a medical device with the same. The active noise reduction system wears the error microphone on the head of a detected person through the first fixing component, the secondary sound source surrounds the accommodating area of the medical equipment, when the head of the detected person is located in the accommodating area, the transfer function of a secondary path between the secondary sound source and the error microphone is identified on line, a noise elimination audio signal is generated according to the transfer function and a noise signal acquired by the error microphone in real time, and noise elimination sound is emitted to the accommodating area through the secondary sound source according to the noise elimination audio signal. Through the application, the problem that the noise of the medical equipment in the related art is too large in the using process is solved, and noise reduction is realized.

Description

Active noise reduction system and medical equipment with same

Technical Field

The application relates to the technical field of medical equipment, in particular to an active noise reduction system and medical equipment with the same.

Background

Medical devices generate noise during operation. Taking a medical device as an example of a Magnetic Resonance Imaging (MRI) system, alternating current of a gradient coil of the MRI system receives a lorentz force in a strong Magnetic field, and the gradient coil receiving the lorentz force drives an epoxy resin in the epoxy resin to generate overall vibration, thereby generating mechanical noise related to a Magnetic Resonance sequence.

Noise generated by medical equipment during use can cause anxiety in patients, and high decibel noise can also risk hearing damage. Therefore, it is necessary to reduce the influence of noise.

Disclosure of Invention

The embodiment provides an active noise reduction system and a medical device with the same, so as to solve the problem that the medical device in the related art is too noisy in the using process.

In a first aspect, the present embodiment provides an active noise reduction system for use in a medical device, the medical device including a receiving area capable of receiving a subject, the active noise reduction system including a secondary sound source, an error microphone, a first stationary component, and an active noise reduction controller;

the secondary sound source and the error microphone are respectively electrically connected with the active noise reduction controller;

the first fixing component can be worn by a subject, and the error microphone is fixed on the head of the subject when the first fixing component is worn by the subject;

the active noise reduction controller is used for identifying a transfer function of a secondary path between the secondary sound source and the error microphone on line when the head of the examinee is in the accommodating area, and generating a noise reduction audio signal according to the transfer function and a noise signal acquired by the error microphone in real time;

the secondary sound source comprises a plurality of secondary speakers which are annularly arranged in the accommodating area; and the secondary sound source is used for emitting silencing sound to the accommodating area according to the silencing audio signal.

In some embodiments, the number of the error microphones is at least two, and the first fixing component is configured to fix the two error microphones to the left ear and the right ear of the subject, respectively, and to direct the sound pickup directions of the two error microphones toward the head of the subject when the subject wears the first fixing component.

In some of these embodiments, the first securing component is an earplug; the error microphone is disposed in the ear plug, and when the ear plug is worn by the subject, a pickup direction of the error microphone is directed toward the head of the subject.

In some of these embodiments, the first securing assembly comprises an ear cup; the error microphone is disposed inside the ear cup, and when the ear cup is worn by the subject, the pickup direction of the error microphone is toward the head of the subject.

In some of these embodiments, the medical device is a magnetic resonance imaging system and the error microphone is a magnetic resonance compatible microphone; the secondary sound source is a magnetic resonance compatible loudspeaker.

In some of these embodiments, the magnetic resonance imaging system includes a magnetic resonance scanner, and the plurality of secondary speakers are disposed on the magnetic resonance scanner and housed by a housing of the magnetic resonance scanner.

In some of these embodiments, the magnetic resonance imaging system comprises a scanning bed comprising a second stationary assembly comprising a plurality of fixtures disposed on a left side and a right side of the scanning bed, respectively; each of the fixing pieces is used for fixing the secondary speaker.

In some of these embodiments, the active noise reduction system further comprises: the reference sensor is arranged on the medical equipment and is electrically connected with the active noise reduction controller;

the reference sensor is used for generating a reference signal in real time according to noise generated by the medical equipment;

and the active noise reduction controller is used for generating the noise elimination audio signal according to the transfer function, the noise signal acquired by the error microphone in real time and the reference signal generated by the reference sensor in real time.

In some of these embodiments, the reference sensor is an acoustic sensor or a non-acoustic sensor.

In a second aspect, the present embodiments also provide a medical apparatus comprising a receiving region capable of receiving a subject, and the active noise reduction system of the first aspect.

Compared with the related art, according to the active noise reduction system and the medical equipment with the same provided by the embodiment, the error microphone is worn on the head of the examinee through the first fixing component, the secondary sound source surrounds the accommodating area of the medical equipment, when the head of the examinee is in the accommodating area, the transfer function of the secondary path between the secondary sound source and the error microphone is identified on line, the noise elimination audio signal is generated according to the transfer function and the noise signal acquired by the error microphone in real time, and the noise elimination sound is emitted to the accommodating area through the secondary sound source according to the noise elimination audio signal, so that the problem that the noise of the medical equipment in the related art is overlarge in the using process is solved, and the noise reduction is realized.

The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the application.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic structural diagram of an active noise reduction system according to an embodiment of the present application;

fig. 2 is a first schematic structural diagram of a magnetic resonance imaging system according to an embodiment of the present application;

fig. 3 is a schematic structural diagram ii of a magnetic resonance imaging system according to an embodiment of the present application;

FIG. 4 is a flowchart of a feedback-type active noise reduction method of a magnetic resonance imaging system according to an embodiment of the present application;

FIG. 5 is a control schematic diagram of a feedback-type active noise reduction method according to an embodiment of the present application;

FIG. 6 is a flow chart of a feedforward type active noise reduction method of a magnetic resonance imaging system according to an embodiment of the present application;

fig. 7 is a control schematic diagram of a feedforward active noise reduction method according to an embodiment of the present application.

Detailed Description

For a clearer understanding of the objects, aspects and advantages of the present application, reference is made to the following description and accompanying drawings.

Unless defined otherwise, technical or scientific terms used herein shall have the same general meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The use of the terms "a" and "an" and "the" and similar referents in the context of this application do not denote a limitation of quantity, either in the singular or the plural. The terms "comprises," "comprising," "has," "having," and any variations thereof, as referred to in this application, are intended to cover non-exclusive inclusions; for example, a process, method, and system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to the listed steps or modules, but may include other steps or modules (elements) not listed or inherent to such process, method, article, or apparatus. Reference throughout this application to "connected," "coupled," and the like is not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Reference to "a plurality" in this application means two or more. "and/or" describes an association relationship of associated objects, meaning that three relationships may exist, for example, "A and/or B" may mean: a exists alone, A and B exist simultaneously, and B exists alone. In general, the character "/" indicates a relationship in which the objects associated before and after are an "or". The terms "first," "second," "third," and the like in this application are used for distinguishing between similar items and not necessarily for describing a particular sequential or chronological order.

The medical device provided by the present embodiment includes, but is not limited to, a magnetic resonance imaging system, or other medical devices that can generate noise during operation. In the present embodiment, the active noise reduction system and the active noise reduction method will be described and explained by taking a magnetic resonance imaging system as an example.

Noise reduction techniques are generally classified into passive noise reduction, active noise reduction, and sequential noise reduction. The passive noise reduction is realized by adding damping materials, vacuum and other vibration barrier materials to achieve the purpose of blocking sound wave transmission or reducing the vibration of a sound generating source. Active noise reduction is mainly used for earphones at present, and the principle is that the characteristics of external noise are measured, and sound waves with opposite phases are generated by a built-in loudspeaker to completely counteract the influence of the external noise. Sequence noise reduction avoids the rapid change of gradient current waveform as much as possible by optimizing a magnetic resonance imaging sequence, thereby achieving the purpose of reducing the stress vibration of the gradient coil.

The three noise reduction modes in the magnetic resonance imaging system can be applied, wherein passive noise reduction is taken as a main noise reduction mode. For example, the magnetic resonance gradient coils are placed in a vacuum to achieve a reduction in patient aperture noise. However, this method requires an additional vacuum chamber, is complicated in process, and occupies a space of the patient, which is inherently tight, affecting patient comfort. In addition, due to the multiple propagation paths of the sound waves, the noise reduction effect of the method is limited, and is usually only in the order of 10 dB. Sequence noise reduction is also a common method in magnetic resonance, however, the sequence noise reduction has a great limitation on the application of magnetic resonance, can be used in only a few sequences (such as ZTE and SPIRAL sequences), and cannot be popularized to all clinically common sequences.

The active noise reduction technology is applied to a magnetic resonance imaging system, and generally adopts an active noise reduction earphone mode. The active noise reduction earphone can be worn in the magnetic resonance scanning process, and the noise level felt by a patient is greatly reduced through active noise reduction. However, a plurality of electronic components such as a noise collection and a loudspeaker need to be integrated in the active noise reduction earphone, and the space occupied by the earphone can be further crowded in the narrow scanning space of the magnetic resonance, so that the comfort of the patient is affected, certain inconvenience is brought to the scanning process of the patient, and the earphone is difficult to be used as a general noise reduction means.

Another active noise reduction method is to perform regional noise reduction, and a "quiet zone" is formed in a certain region by the active noise reduction loudspeaker array, so that the regional noise reduction purpose is achieved without wearing any external earphone by the patient. However, with this method, the error microphone is far from the ear, and the relative position relationship between the ear and the error microphone is not fixed, so the noise reduction effect is generally weaker than that of the headphone.

To this end, the present embodiment provides an active noise reduction system. The active noise reduction system is applied to the medical apparatus described above, which includes a receiving region 50 capable of receiving a subject. For example, in the case of the medical device being a magnetic resonance system, the receiving region 50 is a scanning bore formed by a magnetic resonance scanner of the magnetic resonance system.

Fig. 1 is a schematic structural diagram of an active noise reduction system according to an embodiment of the present application, and as shown in fig. 1, the active noise reduction system includes: a secondary sound source 301, an error microphone 302 and an active noise reduction controller 303, and a first stationary component 40. The secondary sound source 301 and the error microphone 302 are electrically connected to the active noise reduction controller 303, respectively. The electrical connection in this embodiment includes a cable connection and also includes a wireless connection. In the case of a wireless connection, the error microphone 302 also includes a power supply and a communication device for the wireless connection.

A first fixing assembly 40 to be worn by the subject, and an error microphone 302 to be fixed to the head of the subject when the first fixing assembly 40 is worn by the subject. Preferably, the error microphones 302 may be fixed near the auricle or in the ear canal of the subject when the subject wears the first fixing member 20, and the number of the error microphones 302 may be two or more and fixed near the left and right ears of the subject by the first fixing member, respectively. The pickup directions of the error microphones 302 are all directed to the head of the examinee; these error microphones 302 are distributed around the subject's head to form a quiet zone that can at least encompass the region between the subject's ears.

An active noise reduction controller 303 for identifying a transfer function of a secondary path between the secondary sound source 301 and the error microphone 302 on-line (in real time) when the head of the subject is within the accommodation region 50, and generating a muffled audio signal from the transfer function and a noise signal acquired by the error microphone 302 in real time.

The secondary sound source 301 comprises a loudspeaker array consisting of a plurality of secondary loudspeakers surrounding the receiving area 50. When the head of the subject is located in the accommodation region 50, the aforementioned quiet zone can be completely surrounded by the accommodation region 50. The secondary sound source 301 is for emitting a muffled sound to the containing area 50 according to the muffled audio signal.

Through the active noise reduction system provided by the embodiment, the influence of noise on the examinee can be reduced, and the examinee is prevented from feeling anxiety or causing hearing damage of the examinee.

In addition, although the conventional active noise reduction earphone can be used to reduce noise in the ear region of the subject, the volume and weight of the active noise reduction earphone are large because the conventional active noise reduction earphone has numerous electronic components such as the secondary sound source 301 and the error microphone 302 disposed on the earphone, and the space of the accommodating region 50 provided by the medical device is limited; further, the subject is required to wear the active noise reduction earphone all the time when the subject receives the examination of the medical equipment in the accommodation area 50, and the comfort is low due to the large volume and heavy weight.

In particular, in a magnetic resonance imaging system, magnetic resonance compatibility of electronic components used in the magnetic resonance imaging system needs to be considered, a plurality of electronic components are integrated in an active noise reduction earphone, and the requirement on the type selection of the electronic components is high, so that the design and manufacturing cost of the active noise reduction earphone is increased.

In the magnetic resonance imaging system provided by the above embodiment, the error microphone 302 is worn on the head of the subject by the first fixing component 40, and the secondary sound source 301 is disposed on the magnetic resonance scanner 10 or the scanning bed 20, so that the problem of large volume and weight of the active noise reduction earphone is avoided, the requirement for the type selection of the electronic components can be relaxed, and the design and manufacturing cost is reduced.

In order to reduce the volume and weight of the portion of the subject to be worn, the first fixing member 40 may be an earplug, a lightweight earmuff, or the like.

Taking the first fixing component 40 as an example, the ear plug may be made of a material such as sponge that is compatible with magnetic resonance and can insulate sound, and the error microphone 302 is embedded in the ear plug. When the earplug is worn by a subject, the earplug is inserted into the ear canal to realize physical sound insulation on one hand, and on the other hand, the earplug can fix the error microphone 302 in the ear canal of the subject and enable the sound pickup direction of the error microphone 302 to face the head of the subject, such as the ear canal or eardrum of the subject. The earplug is used as the first fixing component 40, so that the size is small, the physical noise reduction capability is realized, the error microphone 302 can be fixed in the ear canal by the earplug, and the error microphone 302 is prevented from falling off.

Taking the first fixing member 40 as an earmuff, the error microphone 302 can be disposed inside the earmuff, i.e. on the side of the earmuff contacting the ear. When the subject wears the ear muff, the ear muff fixes the error microphone 302 near the auricle and makes the sound pickup direction of the error microphone 302 toward the head of the subject, for example, toward the ear canal or eardrum of the subject. Compare in the earphone of making an uproar falls in the initiative with secondary sound source and error microphone all integrated in the ear muff, only need set up error microphone 302 in the ear muff in this embodiment, avoided the big problem of earphone volume and weight of making an uproar falls in the initiative, can also relax the requirement to the electronic component lectotype, reduce design and manufacturing cost.

In the case where the medical device is a magnetic resonance imaging System, the error microphone 302 is a magnetic resonance compatible microphone, such as an optical microphone made of a non-ferromagnetic material, or a Micro-Electro-Mechanical System (MEMS) microphone made of a non-ferromagnetic or weakly ferromagnetic material. The secondary sound source 302 described above is a magnetic resonance compatible speaker, such as a speaker made of a non-ferromagnetic or weakly ferromagnetic material. It should be noted that the magnetic resonance compatible microphone and the magnetic resonance compatible speaker described above may be any one of the related art.

By adopting the active noise reduction system consisting of the secondary sound source 301, the error microphone 302, the active noise reduction controller 303 and the first fixing component 40, noise reduction of noise in the working process of the magnetic resonance imaging system can be realized according to a feedback type active noise reduction method.

In some of these embodiments, an active noise reduction system is also provided having a reference sensor that may be disposed within the medical device and electrically connected to the active noise reduction controller 303. The reference sensor is used for generating a reference signal in real time according to noise generated by the medical equipment. The active noise reduction controller 303 may also be configured to generate a noise reduction audio signal according to the transfer function, the noise signal acquired by the error microphone in real time, and the reference signal generated by the reference sensor in real time.

By adopting the active noise reduction system consisting of the secondary sound source 301, the error microphone 302, the reference sensor, the active noise reduction controller 303 and the first fixing component 40, noise reduction of noise in the working process of the magnetic resonance imaging system can be realized according to a feedforward active noise reduction method.

Fig. 2 is a schematic structural diagram of a magnetic resonance imaging system according to an embodiment of the present application, as shown in fig. 2, the magnetic resonance imaging system includes a scan bed 20 and a magnetic resonance scanner 10 formed with a scan cavity 100, and the magnetic resonance imaging system may further include various devices required for magnetic resonance imaging, such as an imaging controller and the like.

The magnetic resonance imaging system provided by the present embodiment further comprises an active noise reduction system consisting of at least a secondary sound source 301, an error microphone 302 and an active noise reduction controller 303, and the first stationary component 40. The secondary sound source 301 and the error microphone 302 are electrically connected to the active noise reduction controller 303, respectively.

The electrical connection in this embodiment includes a cable connection and also includes a wireless connection. In the case of a wireless connection, the error microphone 302 also includes a power supply and a communication device for the wireless connection.

An active noise reduction controller 303 for identifying a transfer function of a secondary path between the secondary sound source 301 and the error microphone 302 on line when the head of the subject is in the accommodation region 50, and generating a noise reduction audio signal from the transfer function and a noise signal collected by the error microphone 302 in real time.

The error microphone 302 is a magnetic resonance compatible microphone, such as an optical microphone made of a non-ferromagnetic material, or a Micro-Electro-Mechanical System (MEMS) microphone made of a non-ferromagnetic or weakly ferromagnetic material. The secondary sound source 302 described above is a magnetic resonance compatible speaker, such as a speaker made of a non-ferromagnetic or weakly ferromagnetic material. It should be noted that the magnetic resonance compatible microphone and the magnetic resonance compatible speaker described above may be any one of the related art.

In some of these embodiments, a plurality of secondary speakers are provided on the scanning bed 20. The scanning bed 20 further comprises a second fixing assembly (not shown), which comprises a plurality of fixing members (not shown), which are respectively disposed at the left side and the right side of the scanning bed 20; each fixture is for securing one or more secondary speakers. With the present embodiment, a method of arranging secondary speakers is provided, which can facilitate maintenance of the secondary speakers by arranging them on the left and right sides of the scanning bed 20.

In other embodiments, a plurality of secondary speakers are disposed in the magnetic resonance scanner 10, for example, the secondary speakers are disposed on the housing of the magnetic resonance scanner 10, can be exposed to the scan chamber, or can be received by the housing of the magnetic resonance scanner 10. Preferably, these secondary speakers may be housed by the housing of the magnetic resonance scanner 10, thereby avoiding crowding of the scanning chamber 100.

By adopting the active noise reduction system consisting of the secondary sound source 301, the error microphone 302, the active noise reduction controller 303 and the first fixed component 40, noise reduction of noise in the working process of the magnetic resonance imaging system can be realized according to a feedback type active noise reduction method.

Fig. 3 is a schematic structural diagram of a magnetic resonance imaging system according to an embodiment of the present application. With respect to the magnetic resonance imaging system shown in fig. 2, the magnetic resonance imaging system shown in fig. 3 further comprises a reference sensor 304 for acquiring a reference signal of the noise source, the reference sensor 304 being arranged in the vicinity of the noise source. For example, the reference sensor 304 of fig. 3 is disposed inside the magnetic resonance scanner 10 and electrically connected to the active noise reduction controller 303. In the magnetic resonance imaging system with the reference sensor 304, the active noise reduction controller 303 may reduce noise during operation of the magnetic resonance imaging system according to a feed-forward active noise reduction method, for example, the active noise reduction controller 303 is configured to generate a noise reduction audio signal according to a transfer function, a noise signal collected by the error microphone in real time, and a reference signal generated by the reference sensor in real time.

It should be noted that the reference sensor 304 may be an acoustic sensor (i.e., an acoustic microphone), and may be a non-acoustic sensor, such as a six-axis sensor.

Fig. 4 is a flowchart of a feedback-type active noise reduction method of a magnetic resonance imaging system according to an embodiment of the present application, and fig. 5 is a control schematic diagram of the feedback-type active noise reduction method according to the embodiment of the present application.

Referring to fig. 4 and 5, the feedback type active noise reduction method includes the steps of:

in step S401, the active noise reduction controller identifies a transfer function of a secondary path between the secondary sound source and the error microphone on line when the head of the subject is within the accommodation area.

Step S402, the error microphone collects noise signals in real time.

In step S403, the active noise reduction controller generates a noise reduction audio signal according to the transfer function and the noise signal.

In step S404, the secondary sound source emits a muffled sound to the accommodation area according to the muffled audio signal.

As shown in fig. 5, in the feedback active noise reduction technology, a reference sensor is not used to measure a reference signal, and only the error microphone is used to obtain the residual noise after destructive interference and send the residual noise to the active noise reduction controller, so as to achieve the purpose of adjusting the secondary sound source and make it emit a secondary noise with the same amplitude and opposite phase as the primary noise.

Fig. 6 is a flowchart of a feedforward active noise reduction method of a magnetic resonance imaging system according to an embodiment of the present application, and fig. 7 is a control schematic diagram of the feedforward active noise reduction method according to the embodiment of the present application.

Referring to fig. 6 and 7, the feedforward type active noise reduction method includes the steps of:

in step S601, the active noise reduction controller identifies a transfer function of a secondary path between the secondary sound source and the error microphone on line when the head of the subject is within the accommodation area.

Step S602, the error microphone collects noise signals in real time, and the reference sensor generates reference signals in real time according to the noise generated by the medical equipment.

Step S603, the active noise reduction controller generates a noise elimination audio signal according to the transfer function, the noise signal, and the reference signal.

In step S603, the secondary sound source emits a muffled sound to the accommodation area according to the muffled audio signal.

As shown in fig. 7, the feedforward active noise reduction technique directly obtains a reference signal by placing a reference sensor at a target noise source, and both a residual noise signal measured by an error microphone and the reference signal obtained by the reference sensor are used as input of an active noise reduction controller, so as to generate and adjust a secondary sound source signal, drive the secondary sound source to emit a secondary noise, and destructively interfere with a noise generated by a primary sound source, so as to finally minimize a sound pressure value at the error microphone.

The active noise reduction algorithm used in the above embodiments includes, but is not limited to, the LMS algorithm and the FXLMS algorithm. In the above embodiments, the secondary path refers to the combination of all physical channels between the secondary sound source and the error microphone, including but not limited to analog-to-digital converter, signal transmission circuit, digital-to-analog converter, filter circuit, and the actual physical channel between the secondary sound source and the error microphone. The on-line identification refers to estimating the secondary path while the active noise reduction system is running, and in the embodiment, auxiliary random noise is added to the secondary sound source to serve as excitation of on-line identification, so that the estimation of the secondary path is realized.

The magnetic resonance imaging system may further comprise an error microphone fixed to the magnetic resonance scanner or the table to enhance or assist the noise reduction effect.

With the above-described embodiments and preferred embodiments of the present application, active noise reduction is achieved by generating a "quiet zone" in the ear region of the patient with a secondary sound source, without the need for a speaker in the headset. Above-mentioned embodiment is integrated the entering light earplug or the ear muff of falling noise passively with the error microphone, has reduced the influence to patient's comfort level to the error microphone can be along with examinee's ear synchronous motion, real-time online identification secondary circuit's transfer function with detect the in-the-ear noise condition, promote the performance of making an uproar of falling by a wide margin. In the above preferred embodiment, the electronic components such as the secondary sound source and the reference sensor are integrated with the magnetic resonance scanner or the scanning bed, so that the scanning space of the examinee is not occupied, and the examinee cannot perceive the physical presence of the examinee, so that the comfort of the patient is not affected by the electronic components such as the secondary sound source.

It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to be limiting. All other embodiments, which can be derived by a person skilled in the art from the examples provided herein without any inventive step, shall fall within the scope of protection of the present application.

It is obvious that the drawings are only examples or embodiments of the present application, and it is obvious to those skilled in the art that the present application can be applied to other similar cases according to the drawings without creative efforts. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

The term "embodiment" is used herein to mean that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly or implicitly understood by one of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the patent protection. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. An active noise reduction system for use with a medical device comprising a receiving area capable of receiving a subject, wherein the active noise reduction system comprises a secondary sound source, an error microphone, a first stationary component, and an active noise reduction controller;

2. The active noise reduction system of claim 1, wherein the number of the error microphones is at least two, and the first fixing assembly is configured to fix the two error microphones to the left ear and the right ear of the subject, respectively, and to orient sound pickup directions of the two error microphones toward the head of the subject when the first fixing assembly is worn by the subject.

3. The active noise reduction system of claim 1, wherein the first stationary component is an earplug; the error microphone is disposed in the ear plug, and when the ear plug is worn by the subject, a pickup direction of the error microphone is directed toward the head of the subject.

4. The active noise reduction system of claim 1, wherein the first securing assembly includes an ear cup; the error microphone is disposed inside the ear cup, and when the ear cup is worn by the subject, the pickup direction of the error microphone is toward the head of the subject.

5. The active noise reduction system of claim 1, wherein the medical device is a magnetic resonance imaging system and the error microphone is a magnetic resonance compatible microphone; the secondary sound source is a magnetic resonance compatible loudspeaker.

6. The active noise reduction system of claim 5, wherein the magnetic resonance imaging system includes a magnetic resonance scanner, and wherein the plurality of secondary speakers are disposed on the magnetic resonance scanner and housed by a housing of the magnetic resonance scanner.

7. The active noise reduction system of claim 5, wherein the magnetic resonance imaging system comprises a scanning bed, the scanning bed comprising a second stationary assembly, the second stationary assembly comprising a plurality of stationary members, the plurality of stationary members being disposed on a left side and a right side of the scanning bed, respectively; each of the fixing pieces is used for fixing the secondary speaker.

8. The active noise reduction system of any of claims 1-7, further comprising: the reference sensor is arranged on the medical equipment and is electrically connected with the active noise reduction controller;

9. The active noise reduction system of claim 8, wherein the reference sensor is an acoustic sensor or a non-acoustic sensor.

10. A medical device comprising a receiving area capable of receiving a subject, and the active noise reduction system of any one of claims 1-9.