Cardiac performance monitoring system for use with mobile communications devices
Described herein are apparatuses (e.g., devices, systems, software), and methods for monitoring the cardiac health of a patient. The apparatuses and methods may include a smartphone or hand held computing device having an accelerometer. The apparatus may also include a device with a plurality of electrodes integral with or attached to the smartphone. The devices can be placed on a patient's chest to measure electrical signals and vibrations on the chest caused by the heartbeat. The measurements can generate a seismocardiogram (SCG) and in some variations an electrocardiogram (ECG). The apparatuses and methods can analyze the data in the SCG to produce a measure of the cardiac function. Changes in such measures can provide an early warning for potential cardiac problems and signal the need for the patient to seek treatment prior to a fatal cardiac event.
1. A non-transitory computer-readable storage medium storing a set of instructions capable of being executed by a smartphone having an accelerometer, that, when executed by the smartphone, causes the smartphone to record a seismocardiogram (SCG) from the smartphone's accelerometer by detecting vibrations on a patient's chest corresponding to heart motion for a first time period, further wherein the set of instructions, when executed by the smartphone, cause the smartphone to do at least one of: analyze the SCG to determine an index of cardiac function, display the SCG, transmit the SCG, or store the SCG, wherein the set of instructions, when executed by the smartphone, causes the smartphone to analyze the SCG to determine the index of cardiac function by taking a ratio of the sum of isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) divided by the left ventricle ejection time (ET).
2. The non-transitory computer-readable storage medium of claim 1 , further wherein the set of instructions, when executed by the smartphone, causes the smartphone to receive an electrocardiogram (ECG) from the patient, wherein the ECG is taken over the first time period.
3. The non-transitory computer-readable storage medium of claim 1 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to identify two or more characteristic regions of the SCG from the regions consisting of: mitral valve closure, isovolumetric contraction, aortic valve opening, rapid ejection, aortic valve closure, mitral valve opening, and rapid filling.
4. The non-transitory computer-readable storage medium of claim 3 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to identify two or more characteristic regions of the SCG using an electrocardiogram (ECG) that is taken over the first time period.
5. The non-transitory computer-readable storage medium of claim 1 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to instruct the patient to position the smartphone against the patient's chest prior to recording the SCG.
6. The non-transitory computer-readable storage medium of claim 1 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to verify the orientation of the smartphone and notify the user if the orientation of the smartphone during the first time period was incorrect.
7. The non-transitory computer-readable storage medium of claim 1 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to identify multiple SCG cycles taken during first time period and to average the multiple SCG cycles.
8. The non-transitory computer-readable storage medium of claim 1 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to identify multiple SCG cycles using an electrocardiogram (ECG) that was taken over the first time period.
9. A non-transitory computer-readable storage medium storing a set of instructions capable of being executed by a smartphone having an accelerometer, that, when executed by the smartphone, causes the smartphone to: record a seismocardiogram (SCG) from the smartphone's accelerometer by detecting vibrations on a patient's chest corresponding to heart motion for a first time period; and receive an electrocardiogram (ECG) from the patient over the first time period; analyze the SCG to determine an index of cardiac function for the patient; and do at least one of: display, transmit and store the index of cardiac function, wherein the set of instructions, when executed by the smartphone, causes the smartphone to analyze the SCG to determine an index of cardiac function for the patient by taking a ratio of the sum of isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) divided by the left ventricle ejection time (ET).
10. The non-transitory computer-readable storage medium of claim 9 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to analyze the SCG to determine an index of cardiac function for the patient by identifying characteristic regions of the SCG using the ECG.
11. The non-transitory computer-readable storage medium of claim 9 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to analyze the SCG to determine an index of cardiac function for the patient by identifying two or more of mitral valve closure, isovolumetric contraction, aortic valve opening, rapid ejection, aortic valve closure, mitral valve opening, and rapid filling.
12. The non-transitory computer-readable storage medium of claim 9 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to identify multiple SCG cycles using an ECG that was taken over the first time period and to average the multiple SCG cycles.
13. The non-transitory computer-readable storage medium of claim 9 , wherein the set of instructions, when executed by the smartphone, causes the smartphone to verify the orientation of the smartphone and notify the user if the orientation of the smartphone during the first time period was incorrect.
14. A method of determining an index of cardiac function for a patient using a smartphone having an accelerometer, the method comprising: placing the smartphone on the patient's chest; recording a seismocardiogram (SCG) for a first time period using the smartphone's accelerometer; and analyzing the SCG to determine an index of cardiac function, wherein analyzing the SCG to determine an index of cardiac function comprises analyzing the SCG using the smartphone to determine the index of cardiac function by taking a ratio of the sum of isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) divided by the left ventricle ejection time (ET).
15. The method of claim 14 , further comprising receiving an electrocardiogram (ECG) in the smartphone, wherein the ECG is recorded from the patient over the first time period.
16. The method of claim 14 , wherein placing the smartphone on the patient's chest comprises the patient placing the smartphone on the patient's own chest.
17. The method of claim 14 , further comprising using the smartphone to verify the orientation of the smartphone on the patient's chest before or during the first time period.
18. The method of claim 14 , wherein analyzing the SCG to determine an index of cardiac function comprises identifying multiple SCG cycles taken during first time period and averaging the multiple SCG cycles.
19. The method of claim 14 , wherein analyzing the SCG to determine an index of cardiac function comprises identifying multiple SCG cycles taken during the first time period using an electrocardiogram (ECG) that was recorded from the patient over the first time period.
20. The method of claim 14 , wherein analyzing the SCG to determine an index of cardiac function comprises identifying two or more characteristic regions of the SCG from the regions consisting of: mitral valve closure, isovolumetric contraction, aortic valve opening, rapid ejection, aortic valve closure, mitral valve opening, and rapid filling.
21. The method of claim 14 , further comprising displaying the SCG on the smartphone.
22. The method of claim 14 , further comprising transmitting the SCG to a remote server using the smartphone.
23. A method of determining an index of cardiac function for a patient using a smartphone having an accelerometer, the method comprising: placing the smartphone on the patient's chest; recording a seismocardiogram (SCG) for a first time period using the smartphone's accelerometer; receiving an electrocardiogram (ECG) in the smartphone, wherein the ECG is recorded from the patient over the first time period; and analyzing the SCG to determine an index of cardiac function, wherein analyzing the SCG to determine an index of cardiac function comprises analyzing the SCG using the smartphone to determine the index of cardiac function by taking a ratio of the sum of isovolumetric contraction time (ICT) and isovolumetric relaxation time (IRT) divided by the left ventricle ejection time (ET).
24. The method of claim 23 , further comprising using the smartphone to verify the orientation of the smartphone on the patient's chest before or during the first time period.
25. The method of claim 23 , wherein analyzing the SCG to determine an index of cardiac function comprises identifying multiple SCG cycles taken during the first time period using the ECG.
26. The method of claim 23 , further comprising transmitting the SCG to a remote server using the smartphone.