Abstract:
A patient monitoring system detects physiological signals from a patient during an MRI examination. The patient monitoring system wirelessly transmits data associated with the physiological signals to a remote base unit. The wireless transmission of data is carried out in a manner to not be disruptive to the MRI examination. Data can be uploaded to or downloaded from the patient monitoring system and remote base unit using a magnet-friendly electronic storage device, such as a flash memory drive.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application 60/799,884, filed May 12, 2006, the disclosure of which is incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates generally to electronic patient monitors and, in particular, to downloading data from or uploading data to a wireless patient monitor or a base unit in a magnet-friendly manner. 
         [0003]    Magnetic resonance imaging (MRI) allows images to be created of soft tissue from faint electrical resonance (NMR) signals emitted by nuclei of the tissue. The resonance signals are generated when the tissue is subjected to a strong magnetic field and excited by a radiofrequency pulse. 
         [0004]    The quality of the MRI image is in part dependent on the quality of the magnetic field, which must be strong and extremely homogenous. Ferromagnetic materials are normally excluded from the MRI environment to prevent unwanted magnetic forces on these materials and distortion of the homogenous field by these materials. 
         [0005]    A patient undergoing an MRI “scan” may be received into a relatively narrow bore, or cavity, in the MRI magnet. During this time, the patient may be remotely monitored to determine, for example, heartbeat, respiration, temperature, and blood oxygen. A typical remote monitoring system provides “in-bore” sensors on the patient connected by electrical or optical cables to a monitoring unit outside of the bore. 
         [0006]    At times, it may be desirable to take physiological data collected during the MRI procedure and provide it to other points within the hospital or to enroll it in the hospital&#39;s data system. Large amounts of data are often transmitted wirelessly or through a dedicated local area network; however, the shielded room which holds the MRI system blocks standard radiofrequency transmission outside of that room. It is undesirable to introduce high-speed data cables into the shielded MRI room because the cables can serve as antennas introducing or allowing the escape of unwanted radio frequency signals. The high magnetic field of the MRI magnet makes use of standard magnetic media, such as tapes or magnetic disks, impractical or unreliable. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    The present inventors have recognized that standard “memory sticks” using flash memory can be made to be highly immune to strong magnetic fields and RF fields to provide a reliable method for transferring data in an MRI environment. In this regard, in embodiment, the present invention provides a memory interface on a monitor or base unit intended for use in the MRI environment to provide a high capacity data transfer device that is largely immune to high magnetic fields and RF fields. The data transfer device is designed to portable and may be used for the transference of physiological information acquired during an MRI scan. In addition, the data transfer device may be used to upload software to the monitor or base unit. A data interlock procedure ensures proper identification of the source of the data. 
         [0008]    Therefore, in accordance with one aspect, the present disclosure is directed to a base unit and memory device. The base unit wirelessly receives physiological data from a patient monitor that acquires physiological signals from a patient during an MRI examination. The base unit has an internal memory and an externally accessible data port that is linked to the internal memory. The memory device is magnet-resistant and portable. Further, the memory device is connectable to the data port for data transference to and from the internal memory of the base unit. Also, the memory device is capable of maintaining data storage when positioned proximate an MRI machine. 
         [0009]    According to another aspect, the present invention includes a method for providing data to or receiving data from a base unit operable with an MRI machine that wirelessly receives physiological information associated with physiological signals of a patient during an MRI examination from a wireless patient monitor. The base station is contained within a shielded MRI suite also containing the MRI machine that performs the MRI examination. A portable, magnet-friendly memory device may be connected to a data port of the base unit and data transferred between the internal memory and the memory device in a data transmission path formed between the base unit and the memory device. 
         [0010]    In accordance with yet another aspect, the present disclosure includes a method for providing data to or receiving data from a patient monitor operable with an MRI machine. The patient monitor wirelessly transmits physiological information associated with physiological signals acquired from a patient during an MRI examination to a remote base unit. The patient monitor is contained within a shielded MRI suite also containing the MRI machine that performs the MRI examination. The method includes connecting the memory device, which is portable and magnet-friendly, to a data port of the patient monitor and transferring data between the internal memory and the memory device in a data transmission path formed between the patient monitor and the memory device. 
         [0011]    Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention. 
           [0013]    In the drawings: 
           [0014]      FIG. 1  is a block diagram showing a wireless patient monitor, such as may be used in an MRI machine, adjacent to the patient to communicate with a base station positioned in the MRI suite outside of the magnet bore; 
           [0015]      FIG. 2  is a fragmentary detail of a side panel of the base station showing two USB ports allowing the connection of a flash memory for uploading or downloading data and or software, the flash memory including an LCD display; 
           [0016]      FIG. 3  is a schematic diagram of the principal components of the base station showing memory-holding patient information and firmware; and 
           [0017]      FIG. 4  is a flow chart showing the principal steps of preparing the flash memory for downloading of data. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    Referring now to  FIG. 1 , the present invention may be used with a wireless patient monitor  10  that may collect physiological signals from a patient (not shown) undergoing an MRI scan. The physiological signals, which may include, for example, heartbeat, respiration, temperature, and blood oxygen, is collected through transducers  12  and transmitted by means of an antenna  14  to a remote base station  16 . 
         [0019]    Typically, the wireless patient monitor  10  will be in or near the bore of the magnet of the MRI machine (not shown) and subject to extremely high magnetic fields, switching magnetic gradients, and radio frequency signals. The base station  16  will normally be positioned outside the bore in a lower strength magnetic field. Both the wireless patient monitor  10  and the base station  16  are contained within a shielded MRI suite  20 , the latter essentially blocking the transmission of radio signals or high-speed data into or out of the room by conventional means. 
         [0020]    Referring now to  FIG. 2 , the present invention provides an electronic memory device, such as a flash memory drive  22 , having a self-contained interface circuitry and an electrical connector  26  that may connect to a compatible port  24  in the base station  16  to receive data from the remote base station  16  related to the data collected from the wireless patient monitor  10 . The electrical connector  26  fits within the port  24  to provide a radio frequency shield around the data transmission path between the base station  16  and the flash memory drive  22 . The flash memory drive  22  may optionally be connected to patient monitor  10  via connector  26  for the purpose of uploading and downloading of data, software, and firmware. In one embodiment, the connection of the flash memory drive with the base unit is via a USB interface. In one embodiment, the data port  24  is a USB port and connector  26  is a USB connector. It is recognized that other types of connections may be used, including, for example, IEEE 1394 connections, such as Firewire®. Firewire is a registered trademark of Apple Computer, Inc. of Cupertino, Calif. 
         [0021]    The flash memory drive  22  may optionally include on its upper surface an LCD display  28 . Flash memory drives with LCD displays of this type are commercially available from Memorex Products, Inc. of Cerritos, Calif. under the trade name Travel Drive ID and include a USB 2.0 flash drive with a built-in LCD and one gigabyte of memory storage. 
         [0022]    Referring now to  FIG. 3 , the remote base station  16  may include a processor  36  communicating with internal memory  38  holding, for example, an operating firmware  40  and one or more patient record data sets  42 . During a commissioning process of the wireless patient monitor  10 , the wireless patient monitor  10  may be associated with a particular patient record data set  42  each identified by a unique identification item patient identification information  41  linked to the record and held within the remote base station  16 . A commissioning process suitable for this purpose is described in pending U.S. application Ser. No. 10/066,549 filed Feb. 5, 2002. After commissioning, physiological data is collected from the wireless patient monitor  10 , as moderated by the processor  36 , through a receiver/transmitter  44  connected to an antenna  46 . In addition, the physiological data collected by wireless patient monitor  10 , can be directly uploaded to the flash memory connected via a port connected to the wireless patient monitor  10 . 
         [0023]    Referring now to  FIG. 4 , upon receiving a request to download patient data of records  42  collected by the wireless patient monitor  10 , the remote base station  16  executes a stored program using the internal processor  36  communicating with the ports  24  to identify a particular physiological data set associated with the record  42  being downloaded. The correct patient record is confirmed by displaying the patient identification information  41  associated with that patient record  42  per process block  30 . 
         [0024]    Per process block  32 , a download instruction may then be received from a user providing for downloading of the data of the record  42  and the patient identification information  41 , the latter which is displayed on the LCD display  28 . Upon completion of this downloading, as indicated by process block  34 , instructions may be received allowing the removal of the memory drive  22 . The patient identification information  41  ensures that each memory drive  22  and its data are clearly and uniquely identified to the particular physiological data set. Confusion of patient records on data is thus minimized. The record identification information  41  is also stored in a header file within the memory drive  22  that must be aligned with the records to which the data will be merged when it is loaded into the hospital record system. 
         [0025]    The memory drive  22 , when connected to a port  24 , may download physiological data  42  as indicated, but may also include updated operating firmware  40  that may be used to patch or replace operating firmware/software  40  to allow upgrading of the remote base station  16  without the connection of the remote base station  16 , to the Internet or to magnetic media, which might be destroyed by the strong polarizing field of the MRI machine. The memory drive provides for the storage of data as trapped electrostatic charges that are immune from strong magnetic fields and incorporate only small amounts of ferromagnetic material that, outside of immediate proximity to the MRI machine, are immune from strong force generation. 
         [0026]    Additionally, the base unit may also communicate with another device that produces the physiological data, such as a remote monitor or display unit, similar to that described in U.S. Ser. No. ______, filed on ______, the disclosure of which is incorporated herein. The wireless patient sensor  10  may also include a magnet-friendly audio system, similar to that described in U.S. Ser. No. ______, filed on ______, the disclosure of which is incorporated herein. The wireless patient sensor may also be powered by a magnet-friendly battery, similar to that described in U.S. Ser. No. ______, filed on ______, the disclosure of which is incorporated herein. 
         [0027]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims.