Patent Publication Number: US-2012035435-A1

Title: Electrocardiogram monitor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent Application Ser. No. 61/148,364, filed on Jan. 29, 2009, and titled “COMBINED ELECTROCARDIOGRAM AND RESPIRATORY MONITOR,” the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Electrocardiogram (ECG) gating is used in a wide variety of medical imaging procedures, including but not limited to computed tomography (CT), positron emission tomography (PET), ultrasound, and magnetic resonance imaging (MRI). ECG gating is used in MRI primarily for cardiac MRI and also for magnetic resonance angiography (MRA) and other magnetic resonance techniques where it is necessary to synchronize data acquisition with cardiac contraction. ECG and respiratory monitoring may also be used when a patient is having general anesthesia, sedation, or a contrast agent injection during MRI to monitor vital signs. 
     When cardiac MRI is performed, it is necessary for the magnetic resonance (MR) scanner to detect the ECG signal from the patient so that imaging can be synchronized to the heartbeat. Without an effective mechanism to detect an ECG signal, these techniques are degraded by heart motion and may not be diagnostic. Some alternatives to cardiac imaging without ECG gating involve very fast scanning, which is fast enough to freeze the motion of the heart. Another alternative is termed “self-gating” where the heart motion or tissue/artery pulsation is extracted from the image data. These alternative methods place limitations on the scanning, but are still used because currently the use of ECG gating is cumbersome, unreliable, and time consuming adding expense and inconvenience to the patient due to the time to properly position the electrodes/leads on the patient. 
     Currently, ECG gating is performed by placing three or four leads on the patient&#39;s chest. These leads (sometimes called electrodes) preferably are made out of non-ferrous conducting material to avoid metal artifact. The leads should be sufficiently large in diameter to avoid causing a burn from excessive conduction of current through too small an area of the skin. Typically, at least 2 centimeters (cm) in diameter is sufficient to avoid burns from excessive electrical resistance at the lead-skin interface. 
     Because the MRI scanner environment is electrically noisy with noise from gradient activity, RF activity, and muscle enervation related to patient movements, it can be very difficult to place the electrodes in the optimum position for receiving a sufficiently strong signal that can be detected distinctly from the superimposed electrical noise. As a result, after placing all four leads, it may be necessary to adjust the position to find positions that provide a stronger signal. Also, it is important that the electrodes have a very strong stick mechanism, typically a sticky glue, to keep the electrode attached to the skin on the chest. If the electrode becomes unattached, it will not function properly. Additionally, because electrical wires can heat up in the MRI scanner due to a developed oscillating current, the wires need to be carefully positioned so that they do not touch the skin, but are as straight as possible to avoid loops that can pick up current from the oscillating magnetic fields of the MRI scanner. 
     After placing the leads on the chest, the leads are joined to a cable that exits the bore of the scanner and is plugged into a port on the scanner. The process of connecting the leads can be somewhat confusing because the labeling of the leads (right arm, left arm, right leg, left leg) often does not match up well to the position of the four electrodes. Confusion in connecting the electrodes to the ECG cable may slow down the process of connecting the wires, delaying the scan, and reducing the number of patients per day that can be scanned using an imaging machine. This adds cost to the examinations which require ECG gating. 
     Whenever ECG gating is necessary, it is frequently also necessary to monitor the patient&#39;s breathing with a respiratory monitoring device such as a respiratory bellows. This helps with properly instructing the patient in breath holding during scanning by allowing the operator to observe whether the patient is following (or not following) breathing instructions. Respiratory monitoring also may be used for respiratory gating the MRI scan to reduce respiratory motion artifact. 
     Thus, after the ECG leads are connected, a device for monitoring respiration may be wrapped around the chest or abdomen. The device is usually a hollow tube that can stretch like an accordion. As its length changes with inspiration and expiration, the hollow tube drives air through a tube which can then be detected to monitor the breathing. However the standard bellows used with MRI scanners, typically a one cm circular tube, frequently does not have sufficient airflow to be sensitive enough to detect breathing in all patients. Accordingly, it is often necessary to readjust the respiratory bellows position or its strap in order to improve the signal. The respiratory bellows on the front of the chest can also interfere and knock loose the ECG leads which are placed on the front of the chest. Although the respiratory bellows are reusable from one patient to the next, the ECG electrodes are disposable, which adds cost. 
     SUMMARY 
     In an example embodiment, a device is provided for sensing an electrocardiogram signal of a patient. The device includes, but is not limited to, a substrate and a plurality of electrodes mounted to the substrate. The plurality of electrodes are configured to sense an electrocardiogram signal of a patient when the plurality of electrodes are placed in contact with the patient. The device may include a strap configured to wrap around a portion of the patient wherein the substrate mounts to the strap. The device further may include a respiration sensor mounted to the strap. 
     In another example embodiment, a diagnostic system is provided. The diagnostic system includes, but is not limited to, an ECG sensor device, a scanner configured to generate data related to a physiological characteristic of a patient, and a computing device. The ECG sensor device includes, but is not limited to, a substrate and a plurality of electrodes mounted to the substrate. The plurality of electrodes are configured to sense an electrocardiogram signal of the patient when the plurality of electrodes are placed in contact with the patient. The computing device includes a communication interface, a processor operably coupled to the communication interface, and a computer readable medium operably coupled to the processor. The communication interface is configured to receive the sensed electrocardiogram signal from the ECG sensor device. The computer-readable medium has computer-readable instructions stored thereon that, when executed by the processor, cause the system to control operation of the scanner based on the received electrocardiogram signal. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. Other principal features and advantages of the invention will become apparent to those skilled in the art upon review of the following drawings, the detailed description, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments will hereafter be described with reference to the accompanying drawings, wherein like numerals denote like elements. The drawings depict example embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope. 
         FIG. 1  depicts a block diagram of an example embodiment of a patient diagnostic system. 
         FIG. 2  depicts an ECG sensor device of the patient diagnostic system of  FIG. 1  in accordance with a first example embodiment. 
         FIG. 3  depicts an ECG sensor device of the patient diagnostic system of  FIG. 1  in accordance with a second example embodiment. 
         FIG. 4  depicts an ECG sensor device of the patient diagnostic system of  FIG. 1  in accordance with a third example embodiment. 
         FIG. 5  depicts an ECG sensor device of the patient diagnostic system of  FIG. 1  in accordance with a fourth example embodiment. 
         FIG. 6  depicts an ECG sensor device of the patient diagnostic system of  FIG. 1  in accordance with a fifth example embodiment. 
         FIG. 7  depicts a combined ECG and respiration sensor device of the patient diagnostic system of  FIG. 1  in accordance with an example embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , a block diagram of a patient diagnostic system  100  is shown in accordance with an example embodiment. Patient diagnostic system  100  may include a computing system  102 , a scanner  104 , and an ECG/respiration sensor device  106 . Different and additional components may be incorporated into patient diagnostic system  100 . Computing system  102  may include an input interface  108 , a communication interface  109 , a computer-readable medium  110 , an output interface  112 , a processor  114 , a data processing application  116 , a display  118 , a speaker  120 , and a printer  122 . Different and additional components may be incorporated into computing system  102 . 
     Input interface  108  provides an interface for receiving information from the user for entry into computing system  102  as known to those skilled in the art. Input interface  108  may use various input technologies including, but not limited to, a keyboard, a pen and touch screen, a mouse, a track ball, a touch screen, a keypad, one or more buttons, etc. to allow the user to enter information into computing system  102  or to make selections presented in a user interface displayed on display  118 . The same interface may support both input interface  108  and output interface  112 . For example, a touch screen both allows user input and presents output to the user. Computing system  102  may have one or more input interfaces that use the same or a different input interface technology. 
     Communication interface  109  provides an interface for receiving and transmitting data between devices using various protocols, transmission technologies, and media as known to those skilled in the art. Communication interface  109  may support communication using various transmission media that may be wired or wireless. Computing system  102  may have one or more communication interfaces that use the same or a different communication interface technology. Data and messages may be transferred between computing system  102 , scanner  104 , and/or ECG/respiration sensor device  106  using communication interface  109 . 
     Computer-readable medium  110  is an electronic holding place or storage for information so that the information can be accessed by processor  114  as known to those skilled in the art. Computer-readable medium  110  can include, but is not limited to, any type of random access memory (RAM), any type of read only memory (ROM), any type of flash memory, etc. such as magnetic storage devices (e.g., hard disk, floppy disk, magnetic strips, . . . ), optical disks (e.g., CD, DVD, . . . ), smart cards, flash memory devices, etc. Computing system  102  may have one or more computer-readable media that use the same or a different memory media technology. Computing system  102  also may have one or more drives that support the loading of a memory media such as a CD or DVD. Computer-readable medium  110  may provide the electronic storage medium for scanner  104  and/or ECG/respiration sensor device  106 . Computer-readable medium  110  further may be accessible to computing system  102  through communication interface  109 . 
     Output interface  112  provides an interface for outputting information for review by a user of computing system  102 . For example, output interface  112  may include an interface to display  118 , speaker  120 , printer  122 , etc. Display  118  may be a thin film transistor display, a light emitting diode display, a liquid crystal display, or any of a variety of different displays known to those skilled in the art. Speaker  120  may be any of a variety of speakers as known to those skilled in the art. Printer  122  may be any of a variety of printers as known to those skilled in the art. Computing system  102  may have one or more output interfaces that use the same or a different interface technology. Display  118 , speaker  120 , and/or printer  122  further may be accessible to computing system  102  through communication interface  109 . 
     Processor  114  executes instructions as known to those skilled in the art. The instructions may be carried out by a special purpose computer, logic circuits, or hardware circuits. Thus, processor  114  may be implemented in hardware, firmware, or any combination of these methods and/or in combination with software. The term “execution” is the process of running an application or the carrying out of the operation called for by an instruction. The instructions may be written using one or more programming language, scripting language, assembly language, etc. Processor  114  executes an instruction, meaning that it performs/controls the operations called for by that instruction. Processor  114  operably couples with input interface  108 , with communication interface  109 , with computer-readable medium  110 , and with output interface  112 , to receive, to send, and to process information. Processor  114  may retrieve a set of instructions from a permanent memory device and copy the instructions in an executable form to a temporary memory device that is generally some form of RAM. Computing system  102  may include a plurality of processors that use the same or a different processing technology. 
     Data processing application  116  performs operations associated with processing data for a patient gathered using one or more electronic devices that continuously, periodically, and/or upon request monitor, sense, measure, etc. the physiological characteristics of a patient. In an example embodiment, the data is obtained from a medical imaging system such as an MRI device, a CT scanner, a PET scanner, an ultrasound machine, an X-ray machine, etc., from a sensor associated with measuring a physiological characteristic of a patient such as a temperature, a blood pressure, a heart rate, blood chemistry, a respiratory rate, a heart state or condition, an intra-abdominal pressure, etc., from medical personnel evaluating and treating the patient, etc. The operations may be implemented using hardware, firmware, software, or any combination of these methods. With reference to the example embodiment of  FIG. 1 , data processing application  116  is implemented in software (comprised of computer-readable and/or computer-executable instructions) stored in computer-readable medium  110  and accessible by processor  114  for execution of the instructions that embody the operations of data processing application  116 . Data processing application  116  may be written using one or more programming languages, assembly languages, scripting languages, etc. 
     Scanner  104  may include a medical imaging system such as an MRI device, a CT scanner, a PET machine, an X-ray machine, an ultrasound device, etc. Scanner  104  generates data related to a patient in two-dimensions, three-dimensions, four-dimensions, etc. The source of and the dimensionality of the data is not intended to be limiting. Computing system  102  may be separate from or integrated with scanner  104  to control the operation of scanner  104 . 
     ECG/respiration sensor device  106  may include an ECG sensor device  124  and a respiration sensor device  126 . Different and additional components may be incorporated into ECG/respiration sensor device  106 . ECG sensor device  124  detects/senses an ECG signal generated by the heartbeat of the patient. Respiration sensor device  126  detects/senses an inspiration/respiration of the patient. 
     With reference to  FIG. 2 , an ECG sensor device  200  is shown in accordance with a first example embodiment. ECG sensor device  200  may include a substrate  201 , a first electrode/lead  202 , a second electrode/lead  204 , a third electrode/lead  206 , a fourth electrode/lead  208 , a first wire  210 , a second wire  212 , a third wire  214 , a fourth wire  216 , and a cable  218 . ECG sensor device  200  combines the ECG electrodes/leads on a single device for rapid application to the patient. ECG sensor device  200  may include a fewer or a greater number of electrodes and corresponding wires. 
     Substrate  201  may comprise a non-conductive material such as non-conductive silicone, silicon rubber, plastic, or other electrically insulating material. Substrate  201  further may comprise a biocompatible flexible material, which is deformable, such as a foam. In an example embodiment, a viscoelastic foam may be used. Substrate  201  may be encased in a film which prevents fluids from contacting, for example, the foam, and makes ECG sensor device  200  easy to clean between patients. In an example embodiment, a covering made of plastic film such as Dacron or CRYPTON fabric such as that manufactured by Crypton, Inc. is used. A heat shrink covering may also be applied to form substrate  201 . Substrate  201  may be formed in a variety of shapes including circles, ellipses, polygons, etc. having a variety of sizes sufficient to accommodate the desired number and arrangement of electrodes/leads and corresponding wires. 
     First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are mounted on a surface of substrate  201 . As used herein, the term “mount” includes join, unite, connect, associate, insert, hang, hold, affix, attach, fasten, bind, paste, secure, bolt, screw, rivet, solder, weld, press against, formed with, glue, clip, layer, etch, and other like terms. For example, the material forming first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  may be incorporated into substrate  201  where it is desired to have an electrode with a conductive path inside substrate  201  similar to the manner in which conductive tracts are incorporated into silicon electronic chips or electrical circuit boards. 
     First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  may be formed of a conductive, non-metallic material. In example embodiments, first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are formed of conductive silicon rubber, conductive epoxy, carbon black, carbon rubber, etc. 
     First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are sufficiently separated from one another to prevent short circuits between them. Typically, at least one cm is a sufficient spacing between each of first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208 . First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  may be formed in a variety of shapes including circles, ellipses, polygons, etc. 
     First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  may be formed having a variety of sizes. Normally, ECG electrodes/leads have a small cross-sectional area to precisely define the point source of the signal. However, because MRI and other scanning devices do not require knowledge of the source of the ECG signal with high precision, large cross-sectional area electrodes/leads can be used to provide a better electrical contact with the skin possibly eliminating the need for use of conducting gel or for precise placement of the electrode/lead. Additionally, skin preparation is not necessary using a large cross-sectional area for the electrodes/leads, and the risk of burns is decreased. In the example embodiment of  FIG. 2 , first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are generally circular and have a diameter of approximately two centimeters and preferably three or four centimeters though larger diameters may be used. 
     First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  may be arranged to form an array having a variety of shapes. In the example embodiment of  FIG. 2 , first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are arranged to form a generally T-shaped array though such an arrangement is not intended to be limiting. First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are arranged to provide a sufficient signal related to the heartbeat of the patient. 
     A deformable material may be positioned between each electrode  202 ,  204 ,  206 ,  208  and substrate  201  to ensure a good contact with the skin of the patient. In an example embodiment, the deformable material is a foam, which is one to ten cm thick. A viscoelastic foam may be particularly comfortable. A deeper foam, for example, five to ten cm thick or more may be used to allow first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  to make good contact with the skin. 
     The patient may lay on ECG sensor device  200  so that the skin contacts first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  to sense/measure an ECG signal of the heartbeat of the patient, for example, for ECG gating. Conductivity between the skin and first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  may be enhanced using a conductive gel. Use of a conductive gel may allow conduction through a gown such that removal of the gown may not be necessary. If the gown is removed, the bare skin can be prevented from directly touching ECG sensor device  200  by placing a thin paper or other material between the patient and ECG sensor device  200 . The paper may be porous to the conductive gel placed on electrodes  202 ,  204 ,  206 ,  208  such that the conductive gel assists in the conduction of the electrical signal through the paper at the sites of electrodes  202 ,  204 ,  206 ,  208 . ECG sensor device  200  is easily cleaned for reuse by removing and replacing the paper between patients. No adhesive and no shaving is required to make adequate contact between the electrode/lead and the skin of the patient. 
     First electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  are connected or mount to first wire  210 , second wire  212 , third wire  214 , and fourth wire  216 , respectively, so that first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  conduct a signal detected by first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208 , respectively. The material forming first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  may be incorporated into substrate  201  where it is desired to define a conductive path inside substrate  201  similar to the manner in which conductive paths are incorporated into silicon electronic chips or electrical circuit boards. First electrode/lead  202  and first wire  210 , second electrode/lead  204  and second wire  212 , third electrode/lead  206  and third wire  214 , and fourth electrode/lead  208  and fourth wire  216  may be formed of a continuous line of conductive material. An electro-optical converter on the skin or close to electrodes/leads  202 ,  204 ,  206 ,  208  may allow use of optical fibers as wires instead of electrically conducting material. 
     First wire  210 , second wire  212 , third wire  214 , and fourth wire  216  may comprise conducting fibers mounted within substrate  201 , or mounted on substrate  201 , such that there is no possibility that wires  210 ,  212 ,  214 ,  216  can contact the skin of the patient inadvertently. In an example embodiment, first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  are formed of carbon fiber or carbon rubber. In the example embodiment of  FIG. 2 , first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  are generally straight without curves or loops which may generate a current from the oscillating magnetic fields possibly generated by scanner  104 . The carbon fiber or other conducting element forming first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  also can be wrapped in a tight spiral of the order of one millimeter (mm) to provide a sufficient inductance to prevent conduction of high frequency signals, e.g. greater than approximately 50 Hertz (Hz), that are substantially greater than the frequency of the heart beat which is typically one to two Hz. This also helps to avoid picking up induced currents which might cause a skin burn. 
     First wire  210 , second wire  212 , third wire  214 , and fourth wire  216  may pass through substrate  201  without mounting to substrate  201 . Wires  210 ,  212 ,  214 ,  216  may be formed of conductive strips or filaments insulated within substrate  201  and which lead to an edge of substrate  201  where they can be joined together to form cable  218 . Wires  210 ,  212 ,  214 ,  216  may be formed of non-ferrous conducting material. Carbon rubber is an optimum material because it has good conductivity and is pliable, readily conforming to the variable shape of the chest or back. Wires  210 ,  212 ,  214 ,  216  may be formed of pliable material having elements that are configured to undergo plastic deformation to allow for adjustment to different sizes of patients and or different desired spacing between electrodes/leads  202 ,  204 ,  206 ,  208 . 
     Cable  218  may be formed of carbon fibers which transport a signal from the patient through first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  to computing system  102 . Cable  218  may be made of several conductive fibers and encased in a radio frequency (RF) shield to provide stiffness that minimizes curves or loops and electrical interference with the ECG gating signal. In an example embodiment, the signal is an analog signal. 
     In an example embodiment, cable  218  may further comprise a 50 inch plain copper cable with a five-prong connector, which eliminates the task of clipping alligator clips to ECG sensor device  200 . Four six foot, two mm diameter, carbon fiber threads may be used to connect first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208  to the copper wires in the plain cable portion of cable  218 . Each individual carbon fiber thread may be insulated using six feet of 3/64 inch ID polyolefin tubing. All four insulated carbon fiber threads further may be insulated with six feet of RF-shielded polyolefin tubing. Each carbon fiber thread may be tied or looped onto the corresponding copper wire of the 50 inch plain cable. All bare wires may be shielded with polyolefin tubing. The 5-prong connector attached to a terminal end of the copper wire may plug into communication interface  109  of computing system  102 . 
     In an alternative embodiment, the signal may be transmitted wirelessly to communication interface  109  of computing system  102 , for example, using a Bluetooth protocol or other method of wireless data transmission at a frequency different from a frequency of scanner  104 . When conducting signals wirelessly, the signal may be transmitted as an analog signal, or the signal may be first converted into a digital signal before transmission to computing system  102 . 
     With reference to  FIG. 3 , an ECG sensor device  300  is shown in accordance with a second example embodiment. ECG sensor device  300  may include a substrate  301 , a first electrode/lead  302 , a second electrode/lead  304 , a third electrode/lead  306 , a fourth electrode/lead  308 , a first wire  310 , a second wire  312 , a third wire  314 , and a fourth wire  316 . ECG sensor device  300  combines the ECG electrodes on a single device for rapid application to the patient. ECG sensor device  300  may include a fewer or a greater number of electrodes and corresponding wires. Substrate  301  is similar to substrate  201 . For example, substrate  301  may comprise a sheet of non-conductive silicone or a viscoelastic foam block. 
     First electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308  are similar to first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208 . First electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308  are arranged to form a generally T-shaped array though oriented in a direction rotated approximately 90 degrees relative to the T-shaped array formed with reference to  FIG. 2 , though such an arrangement is not intended to be limiting. First electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308  may be positioned with a spacing of approximately two inches or more from one another. 
     First electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308  are connected or mount to first wire  310 , second wire  312 , third wire  314 , and fourth wire  316 , respectively, so that first wire  310 , second wire  312 , third wire  314 , and fourth wire  316  conduct a signal detected by first electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308 , respectively. First wire  310 , second wire  312 , third wire  314 , and fourth wire  316  may be formed in a manner and of a material similar to that described with reference to first wire  210 , second wire  212 , third wire  214 , and fourth wire  216 . In the example embodiment of  FIG. 3 , however, first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  comprise tabs which protrude from substrate  301  to interface with alligator clips which can be connected to a cable that connects to computing system  102  through communication interface  109 . 
     In the example embodiment of  FIG. 3 , first electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308  are generally circular spots having a diameter of approximately one inch and are formed of carbon-filled epoxy injected into substrate  301 , which is comprised of a four inch by six inch sheet of uncured silicone gel. The conductive carbon-filled epoxy/gel may be created by mixing carbon black, graphite, and a binding agent. First wire  210 , second wire  212 , third wire  214 , and fourth wire  216  comprise carbon fiber threads placed within substrate  301  such that one end is integrated into first electrode/lead  302 , second electrode/lead  304 , third electrode/lead  306 , and fourth electrode/lead  308 , respectively, and the remainder of the thread tunnels through the non-conductive silicone of substrate  301  out to a common region where the threads protrude approximately one inch from substrate  301  to interface with the alligator clips connected to the cable that connects to computing system  102  through communication interface  109 . Alternatively, first wire  210 , second wire  212 , third wire  214 , and fourth wire  216  may exit the edge of substrate  301  in a manner similar to that described with reference to  FIG. 2 . 
     With reference to  FIG. 4 , an ECG sensor device  400  is shown in accordance with a third example embodiment. ECG sensor device  400  may include a substrate  401 , a first electrode/lead  402 , a second electrode/lead  404 , a third electrode/lead  406 , a fourth electrode/lead  408 , a first wire  410 , a second wire  412 , a third wire  414 , and a fourth wire  416 . ECG sensor device  400  combines the ECG electrodes on a single device for rapid application to the patient. ECG sensor device  400  may include a fewer or a greater number of electrodes and corresponding wires. Substrate  401  is similar to substrate  201 . For example, substrate  401  may comprise a sheet of non-conductive silicone or a viscoelastic foam block. 
     First electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408  are similar to first electrode/lead  202 , second electrode/lead  204 , third electrode/lead  206 , and fourth electrode/lead  208 . First electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408  are connected or mount to first wire  410 , second wire  412 , third wire  414 , and fourth wire  416 , respectively, so that first wire  410 , second wire  412 , third wire  414 , and fourth wire  416  conduct a signal detected by first electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408 , respectively. First wire  410 , second wire  412 , third wire  414 , and fourth wire  416  may be formed in a manner and of a material similar to that described with reference to first wire  210 , second wire  212 , third wire  214 , and fourth wire  216 . In the example embodiment of  FIG. 4 , however, first wire  410 , second wire  412 , third wire  414 , and fourth wire  416  comprise tabs which protrude from substrate  401  to interface with alligator clips which can be connected to the cable that connects to computing system  102  through communication interface  109 . 
     In the example embodiment of  FIG. 4 , first electrode/lead  402  and first wire  410 , second electrode/lead  404  and second wire  412 , third electrode/lead  406  and third wire  414 , and fourth electrode/lead  408  and fourth wire  416  together each form an L-shape. First electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408  each comprise a 2.5 inch by 0.5 inch conductive carbon rubber strip embedded in substrate  401  which comprises a four inch by six inch by 3/16 inch silicone sheet. First electrode/lead  402  is placed approximately 0.5 inch from a left edge of substrate  401 , and fourth electrode/lead  408  is placed approximately 0.5 inch from a right edge of substrate  401  across the six inch length of substrate  401 . First electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408  are spaced approximately one inch from one another. First wire  410 , second wire  412 , third wire  414 , and fourth wire  416  comprise a carbon fiber thread or approximately ⅛ inch wide strip of carbon rubber used to conduct the electrical signal from each electrode/lead  402 ,  404 ,  406 ,  408  out to a common region where first wire  410 , second wire  412 , third wire  414 , and fourth wire  416  protrude approximately one inch from substrate  401  to interface with alligator clips. In an example embodiment, first electrode/lead  402  and first wire  410 , second electrode/lead  404  and second wire  412 , third electrode/lead  406  and third wire  414 , and fourth electrode/lead  408  and fourth wire  416  are set into a sheet of uncured silicone gel to integrate and secure the materials. 
     With reference to  FIG. 5 , an ECG sensor device  500  is shown in accordance with a fourth example embodiment. ECG sensor device  500  may include a substrate  501 , a first electrode/lead  502 , a second electrode/lead  504 , a third electrode/lead  506 , and a fourth electrode/lead  508 . ECG sensor device  500  combines the ECG electrodes on a single device for rapid application to the patient. ECG sensor device  500  may include a fewer or a greater number of electrodes. Substrate  501  is similar to substrate  201 . For example, substrate  501  may comprise a sheet of non-conductive silicone or a viscoelastic foam block. 
     First electrode/lead  502 , second electrode/lead  504 , third electrode/lead  406 , and fourth electrode/lead  508  are similar to first electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408  except that first electrode/lead  502 , second electrode/lead  504 , third electrode/lead  406 , and fourth electrode/lead  508  protrude approximately one inch from an edge of substrate  501  to interface with alligator clips which can be connected to the cable that connects to computing system  102  through communication interface  109 . 
     With reference to  FIG. 6 , an ECG sensor device  600  is shown in accordance with a fourth example embodiment. ECG sensor device  600  may include a substrate  601 , a first electrode/lead  602 , a second electrode/lead  604 , a third electrode/lead  606 , and a fourth electrode/lead  608 . ECG sensor device  600  combines the ECG electrodes on a single device for rapid application to the patient. ECG sensor device  600  may include a fewer or a greater number of electrodes. Substrate  601  is similar to substrate  201 . For example, substrate  601  may comprise a sheet of non-conductive silicone or a viscoelastic foam block. 
     First electrode/lead  602 , second electrode/lead  604 , third electrode/lead  606 , and fourth electrode/lead  608  are similar to first electrode/lead  402 , second electrode/lead  404 , third electrode/lead  406 , and fourth electrode/lead  408  except first electrode/lead  602 , second electrode/lead  604 , third electrode/lead  606 , and fourth electrode/lead  608  extend to an edge of substrate  501  without protruding therefrom though interfacing with alligator clips which can be connected to the cable that connects to computing system  102  through communication interface  109 . 
     With reference to  FIG. 7 , an ECG/respiration sensor device  700  is shown in accordance with an example embodiment. ECG/respiration sensor device  700  may include a strap  702 , an ECG sensor device  704 , and a respiration sensor device  705 . ECG sensor device  704  and respiration sensor device  705  mount to strap  702 . Strap  702  is sized and shaped to wrap around the chest or abdomen of the patient. The fastening of strap  702  can be accomplished using hook-and-loop fasteners or other non-magnetic materials. Strap  702  may be non-elastic and depend on the elasticity of respiration sensor device  705  for a tight fit to the patient. ECG/respiration sensor device  700  is an example embodiment of ECG/respiration sensor device  106  which combines ECG sensor device  124  and respiration sensor device  126  in a single device for rapid application to the patient. 
     ECG sensor device  704  comprises at least one ECG electrode and may include one or more of ECG sensor device  200 , ECG sensor device  300 , ECG sensor device  400 , ECG sensor device  500 , and ECG sensor device  600 . Additionally, without limitation and with reference to the example embodiment of  FIG. 7 , ECG sensor device  704  may include a substrate  706 , a first electrode/lead  707 , a second electrode/lead  708 , a third electrode/lead  710 , a fourth electrode/lead  712 , a first wire  714 , a second wire  716 , a third wire  718 , and a fourth wire  720 . ECG sensor device  704  may include a fewer or a greater number of electrodes. Substrate  706  is similar to substrate  201 . For example, substrate  706  may comprise a sheet of non-conductive silicone or a viscoelastic foam block. 
     In the example embodiment of  FIG. 7 , first electrode/lead  707 , second electrode/lead  708 , and third electrode/lead  710  are mounted on a surface of strap  702  such that, when strap  702  is wrapped and secured around the patient, first electrode/lead  707 , second electrode/lead  708 , and third electrode/lead  710  contact the back of the patient. Fourth electrode/lead  712  is mounted on a surface of strap  702  such that, when strap  702  is wrapped and secured around the patient, fourth electrode/lead  712  contacts the left side of the patient. First electrode/lead  707 , second electrode/lead  708 , third electrode/lead  710 , and fourth electrode/lead  712  are generally distributed in a horizontal direction and sufficiently separated from one another to prevent short circuits between them. Typically, at least one cm spacing is sufficient to prevent short circuits. In the example embodiment of  FIG. 7 , first electrode/lead  707 , second electrode/lead  708 , third electrode/lead  710 , and fourth electrode/lead  712  have a generally circular shape though other shapes may be used. Deformable material, such as viscoelastic foam, may be interposed between strap  702  and each electrode/lead  707 ,  708 ,  710 ,  712  to ensure contact with the skin. In an example embodiment, approximately one inch of viscoelastic foam may be used. 
     In the example embodiment of  FIG. 7 , first wire  714 , a second wire  716 , a third wire  718 , and a fourth wire  720  have a high inductance to reduce the transmission of electrical signals greater than approximately 50 Hz and together form a cable  722  which extends to an edge of strap  702 . Cable  722  is mounted to a second cable  724  which protrudes from strap  702 . 
     Respiration sensor device  705  may comprise an accordion like tube  726  which expands and contracts with respiration of the patient to detect a respiratory motion of the patient. Accordion like tube  726  may include an elastic hollow portion that changes in size with patient respirations and may be mounted between a first end  732  of strap  702  and a second end  734  of strap  702 . When strap  702  is wrapped and secured around the patient, accordion like tube  726  is positioned to the front of the patient generally across the chest or abdomen area. Respiration sensor device  705  may comprise a respiratory bellows, which may have a large cross-section, for example, greater than approximately one cm, to provide a greater airflow with each respiration making the respirations easier to detect. 
     In another example embodiment, respiration sensor device  705  may comprise two respiratory bellows integrated into strap  702 . The two respiratory bellows may have a large cross-section, for example, greater than approximately one cm. One end of each bellows-strap can have hook-and-loop fasteners or other attachment mechanisms that enable attachment to the other bellows-strap or onto first end  732  of strap  702  or second end  734  of strap  702 . As the patient breathes, only the respiratory bellows expand/contract because it is the only elastic component of strap  702 . The length of the bellows-strap can be adjustable in order to accommodate the anatomical variability of patients. 
     Alternatively, respiration sensor device  705  may measure chest movement by sensing the stretching of at least one region of elastic within strap  702 . Chest movement may also be detected by analysis of the variations in the electrical signals corresponding to chest wall motion such as the electrical activity of the intercostal or other muscles or variations in chest wall impedance. 
     In the example embodiment of  FIG. 7 , the pneumatic signal from respiration sensor device  705  is conducted through a third cable  728  which joins together with second cable  724  into a fourth cable  730  which is large enough to avoid getting caught in the various crevices of scanner  104  as the table on which the patient rests slides in and out of scanner  104 . Combining the ECG gating and respiratory bellows into a single device allows fourth cable  730  carrying the first signal from respiration sensor device  705  and the second signal from ECG sensor device  704  to be combined into a single cable. This has the advantage of having just one cable to manage for transmitting a signal about respiration and about ECG from the patient to computing system  102  which interfaces with scanner  104 . Fourth cable  730  may be relatively stiff with a slippery surface so that fourth cable  730  glides easily along a surface of scanner  104  as the patient is advanced in and out of scanner  104 . The larger diameter of fourth cable  730  assists in keeping fourth cable  730  from getting caught in crevices between the sliding table and the fixed bed, which further minimizes the tension which second cable  724  places on ECG sensor device  704  and which third cable  728  places on respiration sensor device  705  thereby minimizing the risk of either device becoming disconnected. Because the crevices are typically about five mm or less in diameter, fourth cable  730  may have a diameter greater than approximately 5 mm, and preferably about one cm. 
     ECG/respiration sensor device  700  may include a marker to indicate a proper alignment of ECG/respiration sensor device  700  with the sternum of the patient so that the signals from electrodes/leads  707 ,  708 ,  710 ,  712  are optimally detected. ECG/respiration sensor device  700  can be removed and discarded or cleaned by swabbing with alcohol for reuse by the next patient in the same way that other reusable devices are cleaned for the next patient. 
     Sometimes, it is desirable to have electrodes/leads oriented vertically instead of horizontally as shown with reference to  FIG. 7 . In this case, a wide section of strap may allow the electrodes/leads to be oriented vertically. The distance between the electrodes/leads may be adapted for obese or pediatric patients or patients with large breasts. ECG sensor device  704  may include electrodes/leads on both the front and back and/or side of the chest of the patient to maximize the ECG signal. ECG sensor device  704  may include more electrodes/leads than are necessary with a mechanism to select which electrodes/leads are used after placement on the patient. In this way, if the ECG signal is not adequate, different electrodes/leads can be selected without having to move the patient out of the bore of scanner  104 . When there are more electrodes/leads than are necessary, an algorithm included as part of data processing application  116  can evaluate the signal received from all of the electrodes/leads and automatically select the optimum combination for ECG gating. For example, the optimum combination of electrodes/leads may be the pairs which provide the maximum signal, maximum signal to noise ratio, the most stable signal, the signal least affected by RF and gradient switching electrical noise, etc. In another example embodiment, computing system  102  can display a signal corresponding to different combinations of electrodes/leads using display  118  and allow the operator to select the best combination, for example, using input interface  108  under control of data processing application  116  executed by processor  114 . For example, the operator may select the combination which allows gating off the P wave instead of using the QRS wave to trigger the ECG signal earlier in the cardiac cycle. 
     In an example embodiment, strap  702  comprises a 37 inch by two inch non-elastic belt. The side of strap  702  facing away from the patient comprises a loop fastener. The side of strap  702  pressed against the patient includes four vertically oriented three inch by 0.5 inch conductive carbon electrodes integrated into a strip of silicone, or other non-conductive material, starting 1.5 inches from the right and spaced three inches from one another. The shape of strap  702  may be slightly conical to conform to the anatomy of the human abdomen. A 1.5 inch by 5.5 inch strip of hook fastener is mounted to first end  732  of strap  702  and used to fasten strap  702  to the patient. 
     In an example embodiment, the three inch by 0.5 inch conductive carbon electrodes are 2.5 mm thick though the thickness can vary from one mm to four mm depending on the mouth of the alligator clips that interfaces with the electrodes. A one inch tab of each carbon electrode protrudes from strap  702  and serves to interface with alligator clips to communicate with computing system  102  through communication interface  109 . In an example embodiment, the electrodes have a hardness of approximately 60±5 as measured on a JISA hardness meter, a tensile strength of approximately 50 kilograms/cm 2 , a tensile elongation of approximately 200%, a volume resistivity of approximately 5-10 ohms/cm, and a flammability of approximately UL94. 
     In an example embodiment, respiration sensor device  705  is embedded in first end  732  of strap  702 , and respiration sensor device  705  has an approximately two cm 2  cross sectional area and is bent into a U-shape to double the cross-sectional area and to cover more chest/abdomen in the superior/inferior direction. Second end  734  of strap  702  may mount to respiration sensor device  705  by wrapping around the curve of the U and attaching onto itself. Within respiration sensor device  705 , two rubber bands return the bellows back to their resting state after being stretched by inhalation. The bellows of respiration sensor device  705  may be composed of a corrugated (accordion-like) airtight shell made of a non-magnetic material that can expand and contract as the patient breathes. A ten foot long rubber tube may connect to the bottom of respiration sensor device  705  and attach to an air-pressure sensor via an appropriate press-fit air-tight connector. 
     In another example embodiment, one or two four inch by four inch foam/air filled elastic bladders are used in place of the bellows for respiratory monitoring. An elastic rubber mold can be used as well. The foam within the bladder may be a material with rapid shape recovery such as polyurethane, a viscoelastic material, etc. A valve that allows air into the bladder upon recovery may be used to further accelerate the bladder recovery time. When two bladders are used, a plastic “Y” connector may be used to connect both bladders to a ten foot rubber tube that attaches to the air-pressure sensor via an appropriate connector. One side of each bladder may be covered with a sheet of hook fasteners to attach to strap  702  and allow adjustment, when necessary. The bladders may be positioned such that they are atop the conductive electrodes/leads on the underside of strap  702  and press against the patient. Two bladders may be placed approximately two inches from first end  732  of strap  702  and approximately one inch from each other. As the chest expands, it compresses the bladder and forces air out into the sensor; as the chest contracts, the bladder draws air back into the bladder as it recovers. The bladder encasing the foam may be replaced by covering the foam with a flexible vinyl coating. 
     With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 
     The word “example” is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as “example” is not necessarily to be construed as preferred or advantageous over other aspects or designs. Further, for the purposes of this disclosure and unless otherwise specified, “a” or “an” means “one or more”. Still further, the use of “and” or “or” is intended to include “and/or” unless specifically indicated otherwise. 
     The foregoing description of example embodiments has been presented for purposes of illustration and of description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. The embodiments were chosen and described in order to explain the principles of the invention and as practical applications of the invention to enable one skilled in the art to utilize the invention in various embodiments and with various modifications as suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents