Audio Systems for MRI

Abstract

The present invention describes an audio system, and components and / or units thereof, configured for use during operation of a Magnetic Resonance Imaging (MRI) device. Further, a set of headphones 4 is configured for use with the MRI audio system and for use by a patient 8 who is to undergo an MRI examination, the headphones 4 comprising an array 22 of MEMS speaker elements arranged in parallel and positioned within a cup 26 of the headphones 4.

Description

[Technical field]

[0001] The present invention relates to an audio system and components and / or units thereof for use during operation of a magnetic resonance imaging (MRI) device. [Background technology]

[0002] In the medical field, magnetic resonance imaging (MRI) is a commonly used non-invasive technique to diagnose medical conditions in patients. Also, in functional MRI (fMRI), an MRI scanner is used to measure brain activity, thus providing a map of important functional areas of the brain. Functional MRI (fMRI) is used clinically to plan brain surgery, and researchers and / or scientists use fMRI to study brain physiology, evaluate drug efficacy, and understand the brain and brain disorders, including psychiatric disorders, with the hope of moving to future clinical use. Typically, an MRI system operator places a patient in the MRI magnet bore of a large homogenous magnetic field, and the MRI system exposes the patient to a set of gradient magnetic fields and radiofrequency (RF) pulses. The MRI system measures the very small RF signals emitted by the patient's nuclei and processes the information to recreate an image of the patient's body part inside the MRI system. MRI generates high-energy pulses in the frequency range of 50MHz to 300MHz. The frequency is determined by the strong fixed magnetic field and the gradient magnetic field.

[0003] MRI magnet bores are small, especially in the head coil, and can induce a cramped feeling in many patients. MRI systems produce noisy noises as they change the gradient fields. Noise levels during an MRI examination can reach levels above 110-130 dB due to fluctuations in the currents in the gradient coils. These noisy noises can lead to significant challenges in patient-operator communication, as well as increased anxiety and discomfort for patients. These noise levels can even be harmful to patients undergoing MRI scans. In these conditions, up to 20% of patients do not remain sufficiently still during the 20-60 minute process for a successful MRI image. Because many patients are generally distressed by the noise, patients often have to be sedated or anesthetized. Nevertheless, sedation is not appropriate if interactive brain functions are to be studied. As is known in the art, the MRI system operator can reduce or eliminate the patient's discomfort and anxiety by providing the patient with sufficient guidance and communication, and possibly some type of entertainment.

[0004] MRI scanners are very strong magnets that are always on: ferromagnetic and / or metallic objects will be attracted to the MRI magnet bore, and if the object's mass is significant this can lead to serious or possibly fatal accidents.

[0005] MRI scanners are also very strong radio transmitters that can damage or destroy unshielded electronic equipment and can generate standing waves, which can lead to heat buildup and powerful electrical discharges in people who come into contact with them.

[0006] Furthermore, MRI scanners are extremely sensitive receivers of radio frequency (RF) signals. All digital electronic devices emit RF, which can degrade or even destroy MR (magnetic resonance) images.

[0007] MRI scanners use signals from the nuclei of hydrogen atoms to generate images. Any material near the patient that contains hydrogen may be interpreted as part of the patient. Some materials may also block the RF signals needed to build MR images, degrading image quality. Furthermore, many conventional materials create magnetic field distortions and artifacts. Therefore, materials must be carefully selected and tested to ensure they do not affect the quality of the MR images.

[0008] Materials used in contact with the patient must be certified according to biocompatibility standards. Additionally, the materials must withstand cleaning and disinfecting agents and / or have the option of replaceable hygienic covers. Materials must also be comfortable against the patient's head and ears and must not introduce pressure points that could potentially increase pain and anxiety. The combination of all these material requirements makes designing products for the MRI environment particularly challenging.

[0009] As an illustration, noise cancellation has been used initially in vehicles and / or airplanes to attenuate unwanted noise, as well as in travelers' headphones. Yet all of these devices require a microphone or accelerometer to capture sound waves locally and convert them into an electrical signal that can be processed to produce a noise canceling signal. Furthermore, electrodynamic loudspeakers (the traditional speakers used everywhere) have internal magnets that pose a risk to MRI scanners. Also, they will not function as intended when subjected to the strong external magnetic field in the MRI magnet bore. Thus, such devices are not suitable for such MRI scanners / devices / machines due to their metal or semiconductor content that would be at risk of overheating or degrading as a result of the fluctuating high magnetic fields encountered in the MRI scanners / devices / machines.

[0010] Conventional headphones with good passive noise attenuation are simply too thick (30-50mm) to fit into the head coils used for neuro / brain imaging. To fit into commonly used head coils, such as the Siemens 64 and 32 channel, for example, the compressed structure width (i.e. the thickness of each earmuff of the headphones) should not exceed 15mm.

[0011] There are several critical areas that must be addressed when exposing patients to an MRI scan. First, the strong fields generated by the MRI device must not interfere with the proper operation of the MRI Audio System. Second, the large RF pulses from the MRI system must not harm or heat the MRI Audio System. Third, the MRI Audio System must not emit enough RF energy to degrade the MRI image quality. Fourth, the Faraday shield used to contain the MRI Audio System's RF signals must not produce anomalies in the MRI image. Fifth, some components of the MRI Audio System, such as headphones, must fit within the MRI system and comfortably accommodate a wide range of patients. Sixth, the MRI Audio System must be affordable, reliable, and easy to use.

[0012] Thus, an improved MRI audio system is desirable.The present invention seeks to solve these problems and others by providing a new and improved MRI audio system. Summary of the Invention

[0013] It is an object of the present invention to provide an improved MRI audio system and an improved set of headphones for use during a Magnetic Resonance Imaging (MRI) examination, in which materials and components, illustratively based on non-magnetic MEMS (Microelectromechanical system) technology, are used that do not contribute in any manner or fashion to the degradation or possibly destruction of any MR (Magnetic Resonance) images.

[0014] It is another object of the present invention to provide an improved MRI audio system for use during an MRI scan, which is regulatory approved for clinical and research MRI use. The improved MRI audio system is also intended to provide ease and peace of mind of use, head coil compatibility, sufficient noise attenuation and sound quality, system stability and reliability, as well as attractive initial price and low maintenance costs.

[0015] It is yet another object of the present invention to provide improved headphones for MRI audio systems, thus providing the required noise attenuation, avoiding the use of additional ear plugs, and having a compact design allowing them to fit into common head coils used for neuro / brain MRI scans.

[0016] It is yet another object of the present invention to provide an audio system that allows integration with MRI scanner OEM (original equipment manufacturer) systems to enable the use of automatic voice functions and patient alarms.

[0017] BRIEF DESCRIPTION OF THE DRAWINGS The main features of the invention are set out in the independent claims. Further features of the invention are set out in the dependent claims.

[0018] The present invention relates to an audio system configured for magnetic resonance imaging (MRI). The MRI audio system comprises at least one audio source located in a control room, a control room interface unit located in the control room and configured for wireless and / or cabled interconnection and communication with said at least one audio source, a magnetic room interface unit located in a magnetic room, the entire magnetic room being shielded by a metal shielding located inside the magnetic room, an optical cable comprising at least one optical fiber and arranged in a waveguide having a relatively small diameter compared to its length and thus providing high attenuation to electromagnetic waves, the waveguide connecting the magnetic room and the control room, the optical cable comprising said at least one optical fiber of the optical cable, the optical cable connecting the control room interface unit and the magnetic room interface unit in such a manner that the metal shielding of the magnetic room is not penetrated, a shielding box, and a set of headphones configured for use by a patient who is to undergo an MRI examination. The shielding box is connected to the headphones via a shielding cable configured for transport of signaling between the shielding box and the headphones. The shielding box comprises at least one battery for providing energy to the headphones via the shielding cable. The magnetic room interface unit is interconnected with the shielding box for mutual communication by at least one of wireless communication via an RF antenna of the magnetic room interface unit and an RF antenna of the shielding box, and / or an optical cable connecting the magnetic room interface unit and the shielding box. The headphones comprise an array of non-magnetic MEMS speaker elements arranged in parallel and positioned within a headphone cup.

[0019] The headphones may further comprise at least one MEMS microphone positioned inside the cup near the patient's mouth.

[0020] The MRI audio system headphones may further include a feedforward (FF) microphone / mic and a feedback (FB) microphone / mic. The FF microphone may be located outside the headphones and not blocked by the head coil, and may be configured to record ambient noise in the MR room. The FB microphone may be located inside the earmuffs of the headphones and near the patient's ears, and may be configured to record sounds presented to and / or heard by the patient.

[0021] The control room interface unit may be interconnected with the at least one audio source for mutual communication by at least one of wireless communication via an RF antenna of the control room interface unit and / or a wired connection by a cable connecting the control room interface unit and the at least one audio source.

[0022] The wireless communication between the control room interface unit and the at least one audio source may be wireless communication via at least one wireless transceiver.

[0023] The magnetic room interface unit may further comprise a charging unit configured to charge the at least one battery in the shielding box for supplying energy to the headphones. The at least one battery may be rechargeable.

[0024] The metal shield placed inside the magnetic room can be a Faraday cage.

[0025] The present invention also relates to a set of headphones configured for use in a Magnetic Resonance Imaging (MRI) audio system and for use by a patient scheduled to undergo a Magnetic Resonance Imaging (MRI) examination, the headphones comprising an array of MEMS speaker elements arranged in parallel and positioned within a headphone cup.

[0026] The set of headphones may further include at least one MEMS microphone for the patient's voice, located inside the cup near the patient's mouth. The headphones may include a feedforward microphone located so that it is not obstructed by the head coil and can record noise in the MR room. The headphones may further include a feedback microphone located inside the earmuffs, which records sounds presented to the patient.

[0027] The headphones can be over-ear or circumaural headphones.

[0028] These and other aspects of the invention will be apparent from and further explained by way of example with reference to the drawings in which: [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a diagram of an audio system for an MRI according to the present invention. [Diagram 2] Diagram of the Control Room Interface Unit of the MRI Audio System. [Diagram 3] Diagram of the Magnetic Room Interface Unit of the MRI Audio System. [Figure 4] A diagram of how the MRI Audio System's shielded battery box and MRI headphones work. [Figure 5A] Diagram of the MRI headphones within the MRI audio system based on MEMS elements. [Figure 5B]FIG. 5B is a blown up / enlarged view of a portion from FIG. 5A showing one MEMS element positioned with a sealing on a holder or speaker plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Microelectromechanical systems (MEMS) is a manufacturing technology where modified semiconductor fabrication techniques are used to create micromechanical components. MEMS technology has been around for several years, and MEMS microphones are widely used today. MEMS loudspeakers, on the other hand, are a newer technology that became available only a few years ago. The underlying technology is based on the inverse piezoelectric effect. Unlike piezoelectric loudspeakers, MEMS loudspeakers have rich loud audio and a wide frequency response from 20Hz to 20kHz. The resonant frequency of these loudspeakers is close to or higher than 20kHz. This is an improvement over traditional loudspeakers that have a resonance below 20kHz. MEMS loudspeakers are believed to be able to replace electrodynamic loudspeakers in many markets. The MEMS elements are mounted using an automated process. The MEMS elements do not require tuning / matching. The MEMS elements are small, robust, and use very little power.

[0031] The present invention relates to an MRI audio system and components and / or units thereof, the MRI system being based on non-magnetic MEMS components such as MEMS microphones, MEMS loudspeakers and MEMS headphones.

[0032] Figure 1 shows an MRI audio system according to the invention. The MRI audio system comprises a Control Room Interface Unit (CRI) 1. The Control Room Interface Unit 1 is an interface between an end user's audio source 11, illustratively a computer, a cell / mobile phone, a tablet and / or an iPad®®, and / or the like, and the optical signals passing to and from the magnetic room 5. The Control Room Interface Unit 1 is located in a control room 10.

[0033] The control room interface unit 1 may comprise an RF antenna 14. The RF antenna 14 may be configured to connect (via the control room interface unit 1) at least one audio source 11 (e.g., but not limited to, a computer, a mobile phone, a tablet, an iPad®®, etc.) to the MRI audio system. Additionally or alternatively, the at least one audio source 11 may be connected to the control room interface unit 1 of the MRI audio system by a wired connection, e.g., a suitable cable 32. During the MRI examination, a radiologist will be in the control room 10 and will be able to communicate with the patient 8 to be examined via the MRI audio system.

[0034] The control room interface unit 1 will be connected to a physical control interface 20, illustratively using a USB or other suitable cable 19. The physical control interface consists of buttons, knobs and / or similar controls for adjusting volume, press to talk, mute, etc. The control room interface unit 1 will also be connectable, either as part of the physical control interface 20 or separately, to an external speaker and microphone interface 21, which may be based on MEMS elements (illustratively microphones and / or (loud) speakers) as required. These interfaces will facilitate two-way communication between the patient 8 and the operator, including operator control of audio input and / or sound levels.

[0035] A patient 8 is in the magnetic room 5 and is laid on a patient bed 6 which is moved into the MRI magnet bore 7 during the MRI examination. Inside the MRI magnet bore 7 the magnetic field strength can be of several Tesla. The entire magnetic room 5 is shielded by a metal shield 15 located inside the magnetic room 5. The metal shield 15 can be, by way of example and not limitation, a Faraday cage.

[0036] The control room interface unit 1, located or arranged in the control room 10, is connected to the components of the MRI audio system, particularly its magnetic room interface unit 3, located or arranged in the magnetic room 5, via a fiber optic cable 16. The fiber optic cable 16 is arranged in a waveguide 2. The waveguide 2 is used to feed the fiber optic cable 16 from the control room 10 to the magnetic room 5. The waveguide 2 can illustratively be a metal tube having a relatively small diameter compared to its length, thus providing high attenuation for electromagnetic waves. Said waveguide 2, being a small diameter metal tube, can have a typical attenuation of illustratively about 100 dBm for electromagnetic waves in the frequency range used by MR. All signaling from the control room interface unit 1 in the control room 10 to the magnetic room interface unit 3 in the magnetic room 5 and vice versa passes over the fiber optic cable 16 through the waveguide 2, so as not to penetrate the Faraday cage shielding 15 of the magnetic room 5. Fiber optic cable 16 will carry control and audio signals.

[0037] The magnetic room interface unit 3 may include an RF antenna 13. The RF antenna 13 may be configured for connection to a headphone set 4 of the MRI audio system via an antenna 18 of the headphone set 4. The headphone 4 may be over-ear headphones. The headphone 4 may be wireless. Using at least one integrated microphone 25, the headphone 4 enables two-way communication between the patient 8 and an operator (not shown) during the MRI scan. The at least one integrated microphone 25 may be a MEMS microphone. Thus, the MRI audio system will enable auditory signals from an audio source 11 in the control room 10 (i.e., from the operator or the OEM system) to enter the scanner or magnetic room 5 and be presented to the patient 8.

[0038] The magnetic room interface unit 3 is responsible for the wireless communication inside the shielded room 5. The magnetic room interface unit 3 may also be responsible for battery charging of the headphones 4.

[0039] Inside the magnetic room 5, the MRI audio system further comprises a shielding box 9. The shielding box 9 can be configured to store one or more batteries (not shown) therein, which will supply energy to the headphones 4. The one or more batteries can be rechargeable. The shielding box 9 can further be configured to serve as an interface for optical and / or wireless audio signals. The shielding box 9 must be fully shielded. One or more cables 17 can interconnect the shielding box 9 and the headphones 4. The cables 17 should be as short as possible. The cables 17 from the shielding box 9 to the headphones 4 must also be fully shielded.

[0040] The headphones 4 have earmuffs connected to a shielding box 9 via a cable 17. The earmuffs include a circuit board 30 with a speaker driver and a circuit for active noise cancellation (ANC). An antenna 18, illustratively at least one RF antenna, can be found inside the earmuffs for wirelessly transmitting and receiving audio to and from the magnetic room interface unit 3. Audio RF transmission to the left and right earmuffs of the headphones 4 occurs isochronously from the magnetic room interface unit 3. Optionally, cable signaling can be implemented via a fiber optic cable 12.

[0041] The optional fiber optic cable 12 can be used when wireless communication is not desired by the end user (not shown) or when wireless communication via the RF antennas 13, 18 suddenly, unexpectedly or intentionally becomes unavailable or turned off. The fiber optic cable also provides the option of transporting uncompressed audio and / or audio with a higher sampling rate end, thus higher fidelity and reduced latency.

[0042] Figure 2 shows in detail the Control Room Interface Unit 1 of the MRI Audio System. The Control Room Interface Unit (CRI) 1 is used to interface the different audio sources 11. The purpose of this unit is to convert the signaling from the different audio sources 11 into an optical format that will be transmitted via a fiber cable 16 to the magnetic room 5. In the other direction, the audio from the patient 8 will be sent back to the control room 10 via the fiber cable 16 and then made available to the operator via the speaker loudspeaker and microphone interface 21.

[0043] The control room interface unit 1 may include a wireless transceiver for easy connection to wireless devices (e.g., mobile phones, tablets, laptops, PCs, etc.) via RF antenna 14. Via USB interface 19, a connected PC may see the control room interface unit 1 as an external speaker. Digital input and analog line-in audio interfaces may be required to connect to an OEM (original equipment manufacturer) device for routing automated voice commands to the MRI audio system or to connect to other audio sources. Digital output and analog line-out audio interfaces may be used to route the patient 8 voice to an OEM device / equipment and / or to connect to other audio sinks. The audio codec may have a digital audio output interface to the microcontroller unit (MCU) that can select between both analog and digital audio input interfaces. The audio codec may have a digital audio input interface that can output audio signals from the MCU to both analog and digital audio output interfaces. The optical transceiver can be connected to a serial interface on a microcontroller unit (MCU) to transport control and audio data via a fiber optic cable 16 through the waveguide 2 to a magnetic room interface unit 3. This device 1 also supports digital (I2S / I3S) audio inputs that can be selected from any of several audio input streams, both analog and digital. 2 S = Inter-IC audio / Inter-integrated circuit audio) audio output.

[0044] Automated Voice is an automated voice command used by the OEM to illustratively command the patient 8 to lie quietly. The MRI audio system must be able to store the automated voice command and present the automated voice command to the patient 8 via the new headphones 4.

[0045] FIG. 3 shows the magnetic room interface unit 3 of the MRI audio system in detail. The magnetic room interface unit (MIU) 3 serves a wireless access point inside the magnetic room 5. The wireless access point can serve several two-way audio channels. A patient channel is used for patient communication and a personal channel is used to communicate with personnel. The different audio channels can be broadcast to all channels or unicast to a single channel. The operator inside the operator room 10 has the option to select the receivers of the different channels. The signals are transmitted to and from the control room 10 via optical fiber 16. The magnetic room interface unit (MIU) 3 can also serve as a charging unit (with a battery charger) for the headphones 4 (i.e., one or more rechargeable batteries in a shielded box 9 for the headphones 4). When the battery or batteries for the headphones 4 need to be recharged, a box 9 with charging terminals (not shown) is placed into this MIU unit 3 with charging terminals 33 (see + / - in Figure 3) and the MIU 3 is placed outside the 20mT safety line of the MRI scanner, i.e. at a safe distance from the MRI magnet bore 7.

[0046] The audio signal from the operator room 10 is transported to the MIU 3 via an optical fiber 16. At least one optical transceiver in FIG. 3 converts between optical and electrical signals. The audio signal is then transported inside the MR room 5 to the headphones 4 via a wireless interface (wireless transceiver) with an RF antenna 13 or optionally via a second fiber 12 interface. The magnetic room interface unit 3 further comprises a microcontroller unit (MCU) configured for controlling the magnetic room interface unit 3 and for audio and / or data control. Each of the at least one optical transceiver can be connected to a serial interface on the microcontroller unit (MCU) for transporting control and audio data.

[0047] FIG. 4 shows in detail how the headphones 4 function together with the shielding box 9. The shielding battery box 9, which also serves as an interface for the optional optical fiber 12, is connected to the left and right earmuffs of the headphones 4 via a relatively short cable 17. The cable 17 may be connected to one or both earmuffs. The battery box 9 will convert the battery voltage with the help of at least one voltage regulator to the voltage required by the MCU in the battery box 9 and by the electronics in the earmuffs of the headphones 4 (such as the MCU, ANC, and MEMS driver as examples).

[0048] Audio is transmitted (received and / or transmitted) via the wireless interface 18, 13 or optionally via the fiber interface 12. In the other direction, the signal from the microphone 25 of the patient 8 will be processed by a microcontroller unit (MCU) and sent to the wireless or optical transceiver of the Magnetic Room Interface Unit 3.

[0049] The strong magnetic field inside the MRI magnet bore 7 precludes the use of ferromagnetic materials. Traditional electrodynamic loudspeakers contain magnets and cannot be used inside the MRI magnet bore 7.

[0050] This design will use an array of non-magnetic MEMS speakers 22 to generate sound waves. MEMS (Micro-Electro-Mechanical Systems) is a technology in which mechanical elements and electronics are implemented at the silicon substrate level. While MEMS microphones have been around for some time, MEMS loudspeakers are a new technology that have only become commercially available in the past few years. A single MEMS speaker element has limited ability to move air and therefore can only be used for in-ear applications. To compensate for the limited sound pressure level (SPL) from a single element, multiple MEMS elements 22 can be placed in parallel.

[0051] The MRI audio system will implement circumaural (over-ear) headphones 4. In the forward direction, the audio signal will be received via a fiber optic cable 12 or a wireless interface 18, 13. The microcontroller unit will decode the protocol, extract the audio data, and send it to an active noise canceling (ANC) unit. This ANC device will reshape the audio signal using inputs from a feedforward microphone (FF microphone) 24 and a feedback microphone (FB microphone) 23. The FF microphone 24 will record the environmental noise signal. The FB microphone 23 will record the passively attenuated environmental noise signal together with the audio signal (from the array of parallel non-magnetic MEMS speakers 22). The environmental noise signal can be combined in anti-phase with the audio signal to reduce the environmental noise. The passively attenuated environmental noise together with the audio signal can be combined alone with the audio signal to reduce the environmental noise signal.

[0052] FIG. 5A shows an MRI headphone 4 of an MRI audio system based on non-magnetic MEMS elements. The headphone 4 will fit commonly used head coils from major OEMs (original equipment manufacturers) and will show at least 30 dB SNR (single rating) noise attenuation during common MRI sequences. The product will be used for both research and clinical fMRI and MRI applications. The headphone 4 consists of two earmuffs connected with a headband. Each earmuff provides passive attenuation and consists of a rigid cup 26 that serves as a holder for the MEMS array 22, the circuit board 30 for the speaker driver, and the active noise canceling circuitry as well as a fixation for the headband. On top of each rigid cup 26 of each earmuff of the headphone 4, an ear pad 29 can be placed, thus providing some space for the ears of the patient 8. Inside the cup 26 there is a liner 27, which can be made of an acoustically absorbing material, to provide further passive noise attenuation. The MEMS holder plate 28 in combination with the sealing 31 in front of each individual MEMS speaker element 22 provides pressure tight separation between the front and rear volumes of the MEMS speaker 22, which is required for the MEMS speaker 22 to generate sufficient sound pressure levels. The front volume of each individual MEMS speaker element 22 is the total volume of air provided to the ear of the patient 8, which is the space within the cup 26 located between the driver with the speaker 22 and the ear of the patient 8, and this space / front volume is closed (i.e. sealed to the patient and ear pads 29 so as to be substantially / practically airtight). The rear volume of each individual MEMS speaker element 22 is the volume of air behind the driver with the MEMS speaker element 22, which faces towards the liner 27 located on the cup 26.

[0053] Figure 5B is a blown up / enlarged view of a particular portion from Figure 5A showing one of the MEMS elements 22 positioned on a holder or speaker plate 28 by a sealing 31. The front and rear volumes are also shown in Figure 5B.

[0054] The headphones 4 are battery powered from a shielded box 9. The battery can be rechargeable and must operate inside the strong magnetic field of the MRI magnet bore 7. The battery and parts of the electronics will be placed in a complete shielded box 9 to ensure that there is no generation of RF noise that would affect the MR images or that the components are not affected by RF, static or gradient fields. A DC voltage bias must be available for the MEMS elements. This DC voltage can be achieved by connecting multiple battery cells in series and / or by using one or more DC / DC converters to increase the voltage from one or more batteries.

[0055] Hearing protection designs must utilize materials and geometries that provide passive noise cancellation. When headphone designs utilize slim form factors, active noise cancellation becomes essential to attenuate sounds with frequencies below 1 kHz.

[0056] During an MRI examination, the MRI machine / scanner may produce sound pressure levels of over approximately 120 dB. The MRI audio system aims to provide at least approximately 30 dB SNR (single number rating) attenuation. This will be achieved by a combination of passive and active noise cancellation. Active noise cancellation uses two microphones 23, 24. One microphone 23 inside the earmuff is close to the patient's ear to record the same sound heard by the patient 8. The second microphone 24 will be placed on the outside of the headphones 4 and will record the ambient noise. The two microphones 23, 24 used in the ANC can be MEMS microphones. The ANC chip on the circuit board 30 will use these two signals and the applied sound to construct an acoustic signal that will reduce the noise portion of the signal heard by the patient 8. The patient microphone 25 should be placed inside the cup 26 and close to the patient's 8 mouth.

[0057] Additional modifications, variations, and adaptations of this invention will suggest themselves to those skilled in the art without departing from the scope of the invention as defined in the following claims.

Claims

1. 1. An audio system configured for magnetic resonance imaging (MRI), comprising: At least one audio source (11) located in a control room (10); a control room interface unit (1) located in the control room (10) and configured for at least one of wireless and cable interconnection and communication with the at least one audio source (11); a magnetic room interface unit (3) placed in a magnetic room (5), the entire magnetic room (5) being shielded by a metal shield (15) arranged inside the magnetic room (5); an optical cable (16) arranged in the waveguide (2) comprising at least one optical fiber and having a relatively small diameter compared to its length and therefore providing high attenuation to electromagnetic waves, the waveguide (2) connecting the magnetic room (5) and the control room (10), the optical cable (16) comprising the at least one optical fiber, the optical cable (16) connecting the control room interface unit (1) and the magnetic room interface unit (3) in such a manner that the metal shield (15) of the magnetic room (5) is not penetrated; a shielding box (9); a set of headphones (4) configured for use by a patient (8) who is to undergo an MRI examination; Equipped with The shielding box (9) is connected to the headphones (4) via a shielded cable (17) configured for transporting signaling between the shielding box (9) and the headphones (4), and the shielding box (9) comprises at least one battery for supplying energy to the headphones (4) via the shielded cable (17); the magnetic room interface unit (3) is interconnected with the shielding box (9) for mutual communication by at least one of: i) wireless communication with the shielding box (9) via an RF antenna (13) of the magnetic room interface unit (3) and an RF antenna (18) for the headphones (4); and ii) an optical cable (12) connecting the magnetic room interface unit (3) and the shielding box (9); The headphones (4) comprise an array (22) of non-magnetic MEMS speaker elements arranged in parallel and positioned within a cup (26) of the headphones (4), MRI audio system.

2. 2. The MRI audio system of claim 1, wherein the headphones further comprise at least one MEMS microphone positioned inside the cup near the patient's mouth.

3. 3. The MRI audio system of claim 1, wherein the control room interface unit (1) is interconnected with the at least one audio source (11) for mutual communication by at least one of: i) wireless communication via an RF antenna (14) of the control room interface unit (1); and ii) wired connection by a cable (32) connecting the control room interface unit (1) and the at least one audio source (11).

4. 4. The MRI audio system of claim 3, wherein the wireless communication between the control room interface unit (1) and the at least one audio source (11) is wireless communication via at least one wireless transceiver.

5. 3. The MRI audio system of claim 1, wherein the magnetic room interface unit (3) further comprises a charging unit configured to charge the at least one battery of the shielding box (9) for supplying energy to the headphones (4), the at least one battery being rechargeable.

6. 3. The MRI audio system according to claim 1, wherein the metal shield (15) placed inside the magnetic room (5) is a Faraday cage.

7. 3. The MRI audio system of claim 1, wherein the headphones further comprise a feedforward microphone positioned outside the headphones, positioned so as not to be blocked by a head coil, and configured to record ambient noise in the MR room, and a feedback microphone positioned inside earmuffs of the headphones, near the ears of the patient, and configured to record at least one of i) sounds presented to the patient, and ii) sounds heard by the patient.

8. A set of headphones (4) configured for use in a magnetic resonance imaging (MRI) audio system and for use by a patient (8) scheduled to undergo a magnetic resonance imaging (MRI) examination, comprising: left and right earmuffs each comprising a rigid cup (26) providing passive damping; a headband connecting the two earmuffs; a shielded box (9) connected to one or both of the two earmuffs by a shielded cable (17) and configured to house therein at least one battery for supplying energy to the headphones via the shielded cable (17); At least one RF antenna (18) disposed inside the earmuffs and configured to wirelessly transmit and receive audio to and from a magnetic room interface unit (3); An array (22) of MEMS speaker elements arranged in parallel and positioned within the cup (26) of the headphones (4). Equipped with Each cup (26) is configured to serve as a holder for the array of MEMS speaker elements (22), a circuit board (30) for a speaker driver, and an active noise cancelling circuit, as well as a fixation for the headband. A set of headphones (4).

9. 9. A set of headphones (4) according to claim 8, further comprising at least one MEMS microphone (25) for the patient's voice placed inside the cup (26) near the patient's mouth, wherein the headphones (4) comprise a feedforward microphone (24) placed so as not to be obstructed by a head coil and configured to record noise in the MR room (5), and a feedback microphone (23) placed inside earmuffs and configured to record sounds presented to the patient (8).

10. A set of headphones (4) according to claim 8 or 9, wherein the headphones (4) are over-ear headphones.

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