Patent Application
20080097231
Like reference symbols in the various drawings indicate like elements.
Cardiac event monitoring is used to evaluate a patient who experiences transient, infrequent symptoms of various forms of heart disease. Symptoms such as shortness of breath, dizziness, and palpitations are some of the common patient complaints. These symptoms may be caused by disturbances in the electrical signals that control the heart muscle contractions. The disturbances can be random, spontaneous, or emotion- or stress-induced.
Referring to
The wearable electrode system 110 includes a cable 125, at least two electrodes 130 at one end of the cable 125, and a cable connector 135 at the other end of the cable 125. The cable connector 135 is configured to plug into the base connector 120. Each electrode 130 is designed with a conducting member on a flat patch that contacts the patient's skin. In some cases, the flat patch of each electrode 130 is coated with a gel that improves electrical conduction between the patient's skin and the electrode surface. The patch can include an adhesive that sticks to the patient's skin. The electrodes 130 are usually placed along the patient's chest, at appropriate locations for producing the best ECG signal.
Referring also to
The controller 150 includes a processor 151, memory 152, a clock 153, and a counter 154 to process signals from the wearable electrode system 110 and/or the plug-in adapter 115, receive input from a patient or a service technician using the system 100, and transmit recorded data to a monitoring center, as provided by a health professional, a clinic, or a hospital. The input devices on the base unit 105 include a symptom record button 160, a yes/transmit button 165, and a no button 170. The yes/transmit button 165 can be used in one of two ways: it can be used as a response button to answer “yes” when queried by the controller 150, or it can be used to indicate to the controller 150 to transmit the ECG. The no button 170 can be used in one of two ways: it can be used as a response button to answer “no” when queried by the controller 150, it can be used to indicate to the controller 150 to cancel a transmission of an ECG.
The output devices on the base unit 105 include a display 175 such as a liquid crystal display (LCD) that provides an interface with the patient and/or a technician, and a speaker 180 for transmitting data regarding the recording.
The system 100 is designed to record, store, and transmit ambulatory ECG signals received from the wearable electrode system 110 or the plug-in adapter 115. The system 100 can be worn for days or weeks, as it is intended for use by patients who are experiencing symptoms that are transient and infrequent in nature. The base unit 105 can be worn outside the patient's clothing if there is any chance that moisture (for example, sweat) might come in contact with the base unit 105. The base unit 105 can be worn under outer wear, such as raincoats or jackets, for protection during wet or cold conditions.
A patient would normally operate the base unit 105 and the wearable electrode system 110 as a single unit to capture ECG data. However, some patients who want the features of the base unit 105 and the wearable electrode system 110 may also want the option of finger electrode capture, which is less irritating to the patient than using the wearable electrodes 130, which have to be placed on the patient's skin to obtain data. Thus, the plug-in adapter 115 is designed to couple with the base unit 105 when the wearable electrode system 110 is disconnected or detached from the base unit 105.
Referring to
Referring also to
Referring also to
During the auto capture mode (step 415), the patient carries the small, battery-powered system 100 on their person for the duration of the testing period. The electrodes 130 are attached to the patient's body, such as, for example, the patient's chest, using the associated adhesive patches, and the electrodes 130 detect the electrical signals from the patient's heart. The controller 150 continuously analyzes the signals from the electrodes 130 to detect an abnormality in the electrical signal of the heart. If the controller 150 detects an abnormality, the controller 150 records and stores the event data according to pre-defined protocols. Moreover, any memory 152 that is devoted to the auto capture mode can be dynamically managed and overwritten, as needed, for new activity. Moreover, the controller 150 can send a signal to the speaker 180 indicating to the patient that data has been recorded and that the patient should transmit that data to a monitoring center. The controller 150 operates in auto capture mode (step 415) until it receives an indication that the wearable electrode system 110 is disconnected from the base unit 105 (step 405) or unless the patient had set up the base unit 105 to operate in manual mode (step 410).
If the controller 150 determines that the wearable electrode system 110 is connected to the base unit 105 (step 405) and the patient set up the base unit 105 to operate in manual mode (step 410), then the controller 150 operates in a manual mode (step 420). As with the auto capture mode, the patient carries the battery-powered system 100 on their person for the duration of the testing period in the manual mode. The electrodes 130 are attached to the patient's body and the electrodes 130 detect the electrical signals from the patient's heart. When a symptom occurs, the patient triggers the controller 150 in the base unit 105 to record the ECG by pressing the symptom record button 160. The display 175 shows a countdown message while the recording takes place. The controller 150 operates in manual mode (step 420) until it receives an indication that the wearable electrode system 110 is disconnected from the base unit 105 (step 405) or unless the patient sets up the base unit 105 to operate in auto capture mode (step 410).
If the controller 150 determines that the wearable electrode system 110 is not connected to the base unit 105 (step 405), then the controller 150 determines whether the plug-in adapter 115 is connected to the base unit 105 (step 425). For example, the plug-in adapter 115 could be equipped with the resistors 365, 370 having a resistance that is unique to the plug-in adapter, and the base unit 105 could detect the resistance when the plug-in adapter 115 is connected to the base unit 105. If the plug-in adapter 115 is connected to the base unit 105, as shown in
When the patient experiences a symptom, he presses the symptom record button 160 and watches the display 175, as shown in
After the recording is complete, the patient disconnects either the wearable electrode system 110 or the plug-in adapter 115 from the base unit 105. Therefore, the controller 150 determines that the wearable electrode system 110 is not connected to the base unit 105 (step 405) and the plug-in adapter 115 is not connected to the base unit 105 (step 425). The controller 150 then determines if the yes/transmit button 165 has been pressed (step 435). In this implementation, the base unit 105 is configured to only transmit if both the wearable electrode system 110 and the plug-in adapter 115 are disconnected from the base unit 105. If the yes/transmit button 165 has not been pressed (step 435), then the controller 150 causes the base unit 105 to enter into standby mode to conserve energy (step 440).
If the controller 150 determines that the yes/transmit button 165 has been pressed (step 435), then the controller 150 operates in transmit mode (step 445). During transmit mode, the patient transmits the ECG data to a monitoring center using a telephone or some other suitable device. To transmit the ECG data, the patient calls the monitoring center, and follows the directions given by the monitoring center. Next, the patient places the base unit 105 on a flat surface near the telephone and places the mouthpiece of the phone behind the base unit 105. The patient presses the yes/transmit button 165, which indicates to the controller 150 to send a signal to the speaker 180 to start transmission of the ECG data. During transmission, the speaker 180 emits a series of tones that indicate the ECG data. If needed, in some circumstances, the patient can re-transmit ECG data.
The monitoring center staff reviews the tracings and, when necessary, notifies the patient's physician immediately. A report is generated and forwarded to the physician. In the implementation shown in
Other implementations are within the scope of the following claims. For example, in other implementations, the base unit 105 could be configured to be able to transmit when either the wearable electrode system 110 or the plug-in adapter 115 is connected from the base unit 105. Thus, in this implementation, the patient is not required to remove the wearable electrode system 110 or the plug-in adapter 115 from the base unit 105 prior to transmitting the data. The patient may merely be required to press the transmit button 165 in order to initiate the transmit mode.
The base unit 105 can be any size suitable for permitting a patient to carry the base unit 105 on the patient's body without undue hardship.
Alternatively, the patient can wait to transmit the ECG data, which can be stored within the memory 152 of the controller 150, for a period of time after the data is recorded.
The plug-in adapter 115 can be formed from other suitable shapes, or can be ergonomically designed. For example, the adapter 115 can have a flat base that faces the base unit 105 when plugged into the base unit 105 and have a triangularly-shaped outer surface with two angled surfaces such that the electrodes 305, 310 are formed along the angled surfaces. As another example, the adapter 115 can have a flat base that faces the base unit 105 when plugged into the base unit 105 and have a concave or convex outer surface on which the electrodes 305, 310 are formed. The outer surface can be polygonal, with each side including an electrode. Although the plug-in adapter 115 is suitable for making contact between the patient's fingers and the electrodes 305, 310, the plug-in adapter 115, and, in particular, the electrodes 305, 310, can be contacted to any body part of the patient. For example, the electrodes 305, 310 can be contacted to the chest, the legs, or the arms of the patient. Moreover, the electrodes 305, 310 may be designed with different shapes or sizes.
The power source 155 may be turned off and on by a switch 205 (
