SIGNALIFE’s New ECG Technology: Advances Patient and Consumer Heart Care
[It Expands Clinical And Medical Cardiac Research Opportunity] Summary: A truly disturbing fact is the vast majority of ECG recording doctors are using to make diagnosis lack accuracy. If ones raw data isn’t sound, then it is irresponsible to make decisions based on that data. Inaccurate data becomes even more dangerous when it is plugged into systems that magnify it, and quickly provide it to physicians as a basis for diagnosis and treatment. Unfortunately, this is what has occurred during the evolution of most existing ECG systems.
Introduction
Since introduction in clinical settings, the long-term goals of electrocardiography has been the noninvasive detection of the presence of heart disease, the classification and characterization of disease, and the monitoring of cardiac function to assess change in cardiac state or effect of therapy [1]. Somewhere along the way most existing manufacturers loss site of the long term goal, and became sidetracked by the development of non-core technologies. Over time, this lack of focus has led to a sacrifice in the quality of data collected and then used by doctors. The ironic return for sacrificing the integrity of the data has been faster and more powerful tools to interpret and display said inaccurate data; such as auto-interpretation, data filters, computer averaging, electrical axis determination and interval measurement.
The disastrous result is that currently more emphasis is being put on less accurate data in the world of ECGs. The vast majority of healthcare intuitions have inaccurate data being fed into inpatient telemetry systems. Systems used for Heart trend reporting e,g. ST segments and other waveform data that are connected to ST and other alarms parameters, and often integrated with hemodynamic and other monitoring equipment.
We are all aware that if your raw data isn’t sound, then there isn’t any use in developing systems to interpret it. Unfortunately, as technology advanced providing filters and computer averaging, it hid the fact that the raw data was potentially distorted. This point; however, was not lost in the Signalife’s patented technology. A technology that uses a unique approach to acquire accurate data first and foremost, ensuring the most accurate information is available for making a diagnosis.
Signalife’s patented technology provides a unique platform for biomedical signal acquisition, classification, and evaluation of treatment for cardiovascular diseases. This platforms allows for a more accurate and precise identification of changes in cardiac function than any other ECG system in existence. The Fidelity ECG system(s) is based on patented technology that covers the full spectrum of cardiac frequencies. This system [2] allows for better-quality data by avoiding problems that exist in all other systems. The
Fidelity technology controls baseline wandering that distorts the heart's signal. The system does not involve filters, computer averaging, or any reconstruction of any portion of the ECG waveform. Being the only technology on the market not to use filters and techniques to mask the data is pertinent today. Kligfield and Okin [3] recently concluded there is a highly prevalent and likely widespread problem of improper filter settings being used in routine electrocardiography. This particular issue should be of tremendous concern to any risk management department.
History of technology
Signalife’s current patented technology was developed over a number of years. The original signal processing technology was developed in the early 1990s for the U.S. Air Force and NASA to enable recording of pilots’ brainwaves in the harsh environment of the jet airplane cockpits. The technology was further improved and used in sleep recorder devices that would enable home-based sleep studies. Signalife’s research and development team adjusted certain parameters of this technology to provide what is currently considered clinical-quality electrocardiographic recordings in ambulatory, exercise stress testing, and ultimately continuous 24/7 monitoring. Although many feel Signalife’s technology could set new standards of what is considered clinical-quality electrocardiographic recordings, but that shall remain speculation for now. What is clear is that the technology has been shown to produce a more accurate recording than other systems on the market [7], [8], [9].
Superior performance
Signalife technology has demonstrated superior performance over other systems on the market time and time again. Most ECG manufacturers have taken the classic, fundamentally flawed, approach to capturing an ECG. First they get a complete acquisition of the biomedical signal, and then on the back end they use digital filters to remove noise and provide a “clean” signal, that appears accurate but isn’t, i.e. “to improve cosmetic appearance of ECG tracing” [3]. The major problem with this approach is that it allows an unacceptable amount of baseline wander and a significant amount of distortion of the ECG data [12]. Signalife has a better approach to signal acquisition that does not rely on digital filters and keeps base line wander under control. Note, the use of digital filters not only reduces the noise but it removes a piece of the real information in the ECG. In addition, different digital filters can mimic heart disease not present in original ECG signal [12]. Signalife’s system provides more accurate data by relying on a front-end amplification system. Signalife prides itself on capturing correct data upfront, so it doesn’t need to be “cleaned” later. Signalife’s technology is optimized for different requirements of each step during signal acquisition, providing a much better tool for diagnoses. [3]
Signalife is a company which chose the correct approach to noninvasive detection of the presence of heart disease, the classification and characterization of disease, and the monitoring of cardiac function to assess change in cardiac state or effect of therapy.
In April of 2004, a group of authors from the FDA presented a position paper at 29th Annual Conference of the International Society for Computerized Electrocardiology (ISCE) describing a “new ambulatory recording system;” i.e. the Signalife system, that can become another source for diagnostic-quality 12-lead ECG records[2].
Signalife’s approach, its “new system,” is exactly what makes it better than anything else on the market. The Fidelity system differentiates it from all other ECG systems. In fact, not one company in the world does or even claims to match the ECG signals of Signalife's Fidelity 100. This is why no existing system or company represents competition for Signalife's Fidelity 100. This includes Phillips, Siemens, GE, and all other 12 lead ECG monitoring systems in the marketplace today. When it comes to ECG, Signalife’s new system is simply better at getting the intended job done. To highlight this point, I would note that all low-end frequencies between .05 and .5 Hz and high-end frequencies above 40 Hz to 150 Hz are basically excluded by existing ECG equipment. Further, most systems do not comply with the ECG guidelines issued by the American Heart Association [3], [4].
The Fidelity 100 can account for minimal ECG voltage changes i.e. 5 μV changes while others requiring changes of over 20 to 40 μV. This is pivotal for detecting myocardial ischemia in heart muscle. The cardiac ischemia is reflected by ST segment elevations and/or other distortions of the ST segment as well as other segments of the ECG waveform. It is Fidelity 100's specificity and sensitivity that allows the acquisition of a clean and undistorted heart signal. This is why the Fidelity 100 out performs all other ECG monitors. These facts become extremely important when monitoring high-risk cardiac patients not only in a pre-hospital setting, but during their hospital stay as well as in post discharge monitoring.
In regards to Signalife, one can say that no system approaches this quality and provides the physician with an accurate 12 lead ambulatory diagnostic recording. The Fidelity 100 provides the data that you need while the heart is under stress to properly characterize the signals coming from the heart to allow the development of a proper treatment plan for the patient. This is what cardiac care is all about i.e. reducing errors in providing the basic information needed for more accurate diagnosis and treatment. This translates into better care and a higher quality of life for the patient.
The Fidelity 100
During initial clinical evaluation, Fidelity 100 was used to provide a continuous ECG monitoring of ischemic episodes for Signalife’s Device Implementation, Validation, and Application (DIVA) program at Duke Clinical Research Institute at Duke University. In laboratory testing, using database of simulated ECG signals, the Fidelity 100 has outperformed competitors’ electrocardiographs in ability to faithfully reproduce original ECG signal. The results from DIVA study and field use of the Fidelity 100, demonstrate that Signalife Fidelity 100 outperformed well-known ECG recorders made by GE, Philips, Mortara, Siemens and NorthEast Monitoring [7], [8], [9].
Modified Fidelity 100 using the same patented technology was used to record surface ECG and intracardiac signals during electrophysiological studies at Cleveland Clinic. A group of authors from Cleveland Clinic and Signalife presented their work during 2006 Heart and Rhythm Society (HRS) meeting in Boston, Massachusetts [10]. The recordings obtained using Signalife technology demonstrated higher fidelity signals compared to the recordings from GE Prucka system, a widely used system. Following the Cleveland Clinic/Signalife presentation at the 2006 (HRS), a scientist from Medtronic approached Signalife R&D team inquiring about the Signalife technology and Fidelity 100. After demonstrating the Fidelity 100 at the Beth Israel Deaconess Medical
Center in Boston, Massachusetts, the Principal Investigator from the Center and the scientist from Medtronic selected Fidelity 100 over GE MAC 5000 for ECG recorder that will be used in a Medtronic study.
Later that same year, the Signalife technology was put through the arduous test when Olympic Gold medalist and a Super Bowl winner, Willie Gault, ran on a treadmill while wearing the Fidelity 100 [11]. This demonstration drew attention and awe of many attendees of the 2006 American Heart Association Scientific Sessions, including a large number of Signalife competitors.
Fidelity 200
Signalife has continued down the path toward noninvasive detection of the presence of heart disease, the classification and characterization of disease, and the monitoring of cardiac function to assess change in cardiac state or effect of therapy by applying its technology to an event monitor. Signalife has now received FDA 510(k) clearance to market and sell, without prescription, its ambulatory event recorder throughout the United States. This device is a direct-to-consumer non-prescription flexible credit cardsized heart monitoring device which will be used as an early-detection device by patients who desire to independently monitor their condition. The HeartLife Tempo Card uses the award-winning technology contained in Signalife's Fidelity 100 Heart Monitor. In operation, at the onset of an event that will be recorded, the patient will hold the event recorder to his/her chest, press the "record" button, and record up to a 45-second event.
The event recorder will be capable of storing up to six, 45-second recordings. The patient will then either take the recorder to his or her physician for review, or transmit the data to a subscription-based 24-hour monitoring center where it can be immediately evaluated by a qualified ECG technician, cardiac nurse or cardiologist.
This card will allow patients to effectively monitor their hearts anytime, anyplace, without the necessity of a prescription or other physician intervention. This, in turn, will lead to additional care and may lead to earlier intervention and other preventative measures for cardiovascular disease - the most costly of all diseases nationwide with annual expenditures approaching $400,000,000 spent across the country.
Fidelity 300
Signalife believes that ambulatory electrocardiography can be advanced through the application of its patented technology. Fidelity 300, under development, is a portable Holter recorder that provides superior data quality and capabilities for up to 30 days of recording. The American College of Cardiology and American Heart Association recognize the importance of Ambulatory Electrocardiography (AECG) and provides Guidelines on the use of AECG to aid clinical decision making. Accurate electrocardiographic interpretation assumes that technical standards are adhered to during the acquisition and recording of ECG signal in the field. It is well known that artifacts may result in an incorrect diagnosis of arrhythmias and may lead to unnecessary interventions and treatment [13].
Signalife’s patented technology provides a unique platform that allows for high-fidelity recording in harsh environments. Signalife is striving to become the gold standard for collecting ECG data in ambulatory environment.
Fidelity 400
The Signalife Fidelity 400 Intra-Cardiac Monitor, under development, applies Signalife's award-winning proprietary physiological signal acquisition and amplification technology to record intracardiac signals procured from intracardiac catheter. An intracardiac catheter is a flexible tube that is inserted through a vein in the leg and fed into the heart. The catheter is equipped with electrodes which allow recording of signals from within the heart. These signals are transmitted to a monitor allowing physicians to evaluate various cardiac functions, including arrhythmias. These readings are beneficial in that they measure signals directly from the heart, as opposed to signals read from the surface of the body. The main objective and benefit of the novel system is to offer a technology that overcomes problems presently associated with recordings of surface ECGs and intracardiac signals during electrophysiological studies.
The Future
As Signalife continue to take the correct approach in noninvasive detection of the presence of heart disease it continues to improve its system. While focusing first and for most on collecting accurate data that gives you the most accurate starting point. Only then can you make the proper diagnosis and treatment plan. Signalife is continuing to properly develop lifesaving systems and integrate systems such as auto-interpretation, electrical axis determination and interval measurement. Inpatient telemetry systems include; trending reporting for heart rate, ST segments, etc, ST and HR alarms, and integration with hemodynamic monitoring equipment. All of which can be extremely beneficial if used with accurate data.
Conclusion
One of the basic doctrines of healthcare states that if a tool exists that can improve the level of care provided it must be used, so one would expect mandates which require this type of system will eventually come along. Those that wish to uphold the highest standards of care should begin using this system as soon as they hear of it, not because they have to but because it’s the right thing to do.
Based on laboratory, clinical, and field evaluations, Signalife technology can be used to properly diagnose more precise changes in the electrical signal of the heart which lead to the detection of known cardiovascular abnormalities. Signalife’s technology is the only choice for recording a consistently accurate ECG. Never sacrifice fidelity when it comes to the heart.
References:
1. Robert L. Lux, Journal of Electrocardiology, Vol. 33 Supplement, 2000.
2. David Buckles et al, Advances in Ambulatory Monitoring: Regulatory Considerations,
International Society for Computerized Electrocardiology ’04 Abstract Book, Pg. 15,
April 2004.
3. Paul Kligfield and Peter M. Okin, Prevalence and Clinical Implications of Improper
Filter Settings in Routine Electrocardiography, Journal of Cardiology, Vol. 99, 2007,
711-713.
4. American Hearth Association, http://circ.ahajournals.org/cgi/reprint/115/10/1306.
5. Budimir S. Drakulic et al, Electrocardiograph High Pass Frequency Response Revisited,
presented at the ISCE 30th Annual Conference poster session, Lihue Kauai, HI, April 12-
17, 2005.
6. ACC/AHA, Journal of American College of Cardiology, Vol. 34, No. 3, September
1999:912-48.
7. Marko N. Kostic et al, Evaluation of Novel ECG Signal Processing on Quantification of
Transient Ischemia and Baseline Wander Suppression, presented at the 29th International
Conference of the IEEE Engineering in Medicine and Biology Society in Lyon, France,
August 2007.
8. Signalife, Inc., Appendix A – DIVA Recordings, Signalife Technology, November 2007.
9. Signalife, Inc., Appendix B – Cathlab Recordings, Signalife Technology, November
2007.
10. Mauricio Arruda et al, A Novel Portable Wireless Multi-channel ECG and Intracardiac
Recording System, presented at the 2006 Heart and Rhythm Society Conference in
Boston, Massachusetts.
11. Signalife, Inc., Appendix C – AHA Demonstration, Signalife Technology, November
2007.
12. Haran Burri, et al, Simulation of Anteroseptal Myocardial Infarction by
Electrocardiographic Filters, Journal of Cardiology, Vol 39, 2006, 253-258.
13. ACC/AHA, Guidelines for Ambulatory Electrocardiography, Journal of American
College of Cardiology, Vol.34, No.3, 1999, 912-48
http://www.executivehm.com/currentissue/article.asp?art=272831&issue=241
a link to this article was posted on the SGN website 4/11/08
http://www.signalife.com/Pages/News2008.asp
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