1. Field of Invention
This invention relates to a electrocardiogram (ECG) diagnostic device, and more specifically, to a disposable ECG diagnostic chest pad having pre-positioned lead electrodes and internal wiring which may be placed quickly as a single unit upon a patient and may be separated into two sections by way of perforated sections in the underling pad material, thus allowing greater flexibility in monitoring and diagnosing a patient's electrocardiogram waves.
2. Description of Prior Art
It has been long known in the medical community that the current condition, and possibly future state, of a subject patient's heart muscle can be ascertained by measuring the cardiac electrical activity. The electrical system of the heart not only initiates and controls the rate of heartbeat, but also coordinate to transmission in the most efficient mechanical manner. When such electric signals are irregular, it is a sign of cardiac problems, particularly cardiac arrest, better known as a “heart attack.”
Like all electrical signals, the electrical signals generated by the heart can be expressed as a wave or a series of waves having a frequency and amplitude. Again, like all electrical signals, these waves can be detected and measured—in this case by an electrocardiograph. Electrodes, generally pads containing conductive material, such as silver chloride and an adhesive are attached to the trunk and limbs of a patient's body. The electrodes are in turn attached to “leads” or cables which are connected to the electrocardiograph. Generally, in modem medical practice a ten-lead electrocardiograph is used to produce twelve lead measurements through the use of bipolar electrodes. The electrocardiograph receives the signals from the leads, processes them and outputs the resulting waveform patterns, usually on a strip of moving paper. These resulting patterns are known as an electrocardiogram (ECG). By viewing the resulting ECG output, the physician or other healthcare professional can determine the current condition of the patient's heart muscle and can compare such pattern against healthy and known abnormal patterns. As such, an initial diagnosis of the patient's condition can be made.
The majority of electrocardiological testing is performed in hospital emergency rooms where time of patient treatment of the essence in order to obtain a positive outcome. Trained personnel are required to properly position the electrodes onto the chest wall and limbs of the patient and connect the corresponding wires. In an emergency room situation, this procedure must be performed with speed and accuracy. The work of attaching the ten or twelve electrodes and the corresponding leads can be time consuming. In addition, the leads tend to clutter up the chest area, making additional emergency medical procedures more difficult to perform. Such problems associated with this process are increased when the patient is a small child or an infant.
Traditional prior art electrocardiograph systems typically utilize electrodes comprising elastic cloth or other material having moderate flexibility together with rigidity and strength, such as rubber, synthetic rubber or porous synthetic resins having air permeability. Lead cables are attached either externally or internally and are connected to a control box mounted on the pad. The pad is fastened with belt- or strap-like means, which must wrap around the subject's waist, chest, and arms. These pads are generally used for long term monitoring, and are not typically disposable. For the short-term use in the emergency room, single disposable electrodes are individually applied, with an adhesive backing, to the patient's body at the designated optimal locations. The corresponding leads from the electrocardiograph are then attached to the electrodes by any number of means known in the art, such as alligator clips or plugs. As previously mentioned this process is cumbersome and time consuming, particularly within an emergency situation. Under such circumstances, the electrodes may be incorrectly placed or fall off the patient, thus requiring additional time for replacement upon the patient.
Several solutions are presented in the prior art which attempt to solve some of the aforementioned problems by pre-positioning the leads. The first general solution seen in the art is a vest that contains the leads built into the material. Two such examples are an “Apparatus for Transmitting ECG Data,” to Mills, U.S. Pat. No. 4,608,987 and an “ECG Diagnostic Pad,” to Sekine, U.S. Pat. No. 5,224,479. By having the leads prepositioned within the vest, the entire apparatus can be placed upon the patient and immediately used, thus saving valuable time. However, such vests, including those seen in Mills and Sekine, have several drawbacks. First, these vests must be made in multiple sizes in order to fit the vast multitude of patient sizes and shapes from infant to adult and from thin to overweight. Production and acquisition costs are increased as well as the storage space needed to stock a supply of multiple, different-sized vests. The amount of materials used for an entire vest also adds to cost concerns. Most prior art vests are not disposable and reuse and refurbishment costs may be prohibitive.
A second solution presented in the prior art is the use of “electrode strips.” In these devices, the electrodes placed within a strip of material, usually containing an adhesive backing layer. The leads are generally wired into the strip. When need, the adhesive backing is exposed or adhesive otherwise applied and the strip is positioned and affixed to the patient's torso. Representative examples can be see in U.S. Pat. No. 4,233,987 to Feingold, U.S. Pat. No. 5,184,620 to Cudahy et al. and U.S. Pat. No. 5,868,671 to Mahoney. While cheaper to produce, store and use than vests, these and other prior art strips do have their drawbacks. First, may of the prior art electrode strips, such as the device illustrated and claimed in the Cudahy et al. patent, utilize leads which are positioned only across the torso of the patient. Readings from the upper and lower extremities cannot be taken or optimal positioning cannot be obtained. The Feingold strip allows individual placement, but having only three leads, it is likely that the medical professional would not utilize placement at the extremities. Another drawback to prior art electrode strips is their inability to be used to monitor a patent. Often, after the initial diagnosis, a physician or other medical professional may wish merely to monitor the patient's cardiac activity. As such, only certain leads of the ECG need to be used. It is, again, preferable, to eliminate as leads and other materials from the patient's chest in order to allow room for other procedures. Using the conventional technique of placement of individual leads, the unnecessary leads can be removed. However, in prior art electrode strips, one cannot remove the unnecessary electrodes without also removing the electrodes needed for the monitoring function.
It is therefore an object of the present invention to provide a means for quickly and accurately positioning electrodes and leads for electrocardiographic analysis.
It is a further object of the present invention to provide an electrocardiographic electrode pad that provides signals from the torso and extremities of a patient.
It is yet another object of the present invention to provide an electrocardiographic electrode pad that can be used for patient monitoring.
It is an additional object of the present invention is to provide inexpensive and disposable ECG diagnostic pad which can be attached and removed quickly so as to not interfere with other procedures such as chest X-rays.