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+====== Introduction to Electrocardiography ======
+Since I don't have any completed research yet in this field, I'll use this page to explain the problem I will be researching and highlight the ups and downs involved. Most people are probably familiar with the ECG because many medical procedures are done under the supervision of heart activity, so we will start with what Wikipedia has to say about this. Then we'll move onto a description of how this area of research relates to this.
+====== History ======
+{{http://www.ecglibrary.com/pics/mac5000.jpg }}
+I think it's important to mention that people have been toiling directly with this problem since the 1800's. One way to interpret this is to say that everything one can do probably has already been done. Yet another way to interpret this is to say that the problem must already be solved since you see ECG in use everywhere.
+For a detailed explanation of the history of electrocardiography, see the [[http://www.ecglibrary.com/ecghist.html|ECG Library]]'s excellent time line of events leading up to the first electrocardiographs and then the progress towards modern electrocardiography.
+My interpretation of this history is that even every seemingly minor step forward has raised the bar for researchers who, in kind, have made even more progress. And every one of these steps has had an important impact on the quality of healthcare.
+===== Electrocardiogram =====
+Below is [[http://en.wikipedia.org/wiki/Electrocardiogram|Wikipedia]]'s brief introduction to what is used by most modern, clinical medical staff to monitor the electrical activity of a patient's heart.
+An electrocardiogram (ECG or EKG, abbreviated from the German Elektrokardiogramm) is a graphic produced by an electrocardiograph, which records the electrical activity of the heart over time. Its name is made of different parts: electro, because it is related to electrical activity, cardio, Greek for heart, gram, a Greek root meaning "to write". The abbreviation "EKG" is preferred over the more straightforward "ECG" in oral communication, because the latter may be misheard as EEG.
+{{ EKGI.png?300 |An example of an ECG signal from a single lead}}
+{{ http://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/ECG_principle_slow.gif/300px-ECG_principle_slow.gif}}
+Electrical waves cause the heart muscle to pump. These waves pass through the body and can be measured at electrodes (electrical contacts) attached to the skin. Electrodes on different sides of the heart measure the activity of different parts of the heart muscle. An ECG displays the voltage between pairs of these electrodes, and the muscle activity that they measure, from different directions. This display indicates the overall rhythm of the heart, and weaknesses in different parts of the heart muscle. It is the best way to measure and diagnose abnormal rhythms of the heart((Braunwald E. (Editor), Heart Disease: A Textbook of Cardiovascular Medicine, Fifth Edition, p. 108, Philadelphia, W.B. Saunders Co., 1997. ISBN 0-7216-5666-8.)), particularly abnormal rhythms caused by damage to the conductive tissue that carries electrical signals, or abnormal rhythms caused by levels of salts, such as potassium, that are too high or low (("The clinical value of the ECG in noncardiac conditions." Chest 2004; 125(4): 1561-76. PMID 15078775)). In myocardial infarction (MI), the ECG can identify damaged heart muscle. But it can only identify damage to muscle in certain areas, so it can't rule out damage in other areas(("2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care - Part 8: Stabilization of the Patient With Acute Coronary Syndromes." Circulation 2005; 112: IV-89 - IV-110.)). The ECG cannot reliably measure the pumping ability of the heart; ultrasound is used for that.
+You can find more information about how to interpret the currently used ECG machines at [[http://en.ecgpedia.org|ECGpedia]].
+===== Inverse Problem of Electrocardiography =====
+One way to look at electrocardiography is to express it in terms of the direction of the problem:
+{{ forwardinverse.png|Forward vs Inverse Problem}}
+  * **Forward:** This means collecting data from the heart itself and being able to predict what the effect will be on the surface of the skin.
+  * **Inverse:** This means collecting data on the surface of the skin and being able to predict what the cause was from the heart itself.
+In the figure, the base of the arrows indicate from what values a prediction is made about the values pointed at by the tips of the arrows.
+The challenge involved with the inverse problem is that the ideal result would be to obtain a highly-detailed electrical image of the heart from only a few, minimally invasive leads on the surface of the body. The nature of this problem is daunting because you need to acquire a lot of information (an image) from a little bit of information (a few leads).
+Therefore, when strictly considered in terms of input and output at any given instant (what input at the heart causes what output on the skin's surface), there will be several inputs that could have caused the specific output you measured. This is frustrating because we know for a fact that the heart is behaving one way at a time and not several different ways and therefore we should have a single, unique solution.
+An excellent illustration of this problem can be seen below courtesy of one of the former PhD students working on this with [[http://www.sci.utah.edu/cibc/personnel/brooks.html|Professor Dana Brooks]], [[http://www.ece.neu.edu/students/aghodrat|Alireza Ghodrati]]:
+{{ http://www.ece.neu.edu/students/aghodrat/research1.jpg?600 }}