Differences

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--- heartbeats [2010/05/28 03:10] – Some small additions jochen
+++ heartbeats [2010/05/28 03:14] – typo jochen
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 ===== Motivation =====
-For many tasks, it is often helpful to collect secondary physiological measurements, such as heart-rate over time. The data processing can be rather complicated.
+For many experimental tasks (e.g. subjects follwing a set of specific but differing instructions), it is often helpful to collect secondary physiological measurements, such as heart-rate over time (both as a manipulation check but also as potential candidates for mediation analysis). The data processing can be rather complicated, and a function to automatize the actual detection of heart beats in the ECG data is helpful.
 ===== Requirements =====
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   * segment-wise beat detection (maximum value position within each sub-segment where value > mean + 0.5 * skew)
-Next, the detected (or provided) beats will analyzed, and any irregularities (that is to say, places where either the distance between beats is too small or too large or the shape of the detected beat does not match the mean signature) will be displayed, one by one, in a small dialog:
+Next, the detected (or provided) beats will be analyzed, and any irregularities (that is to say, places where either the distance between beats is too small or too large or the shape of the detected beat does not match the mean signature) will be displayed, one by one, in a small dialog:
 {{:heartbeats_cleanup.png|heartbeats cleanup dialog}}
@@ Line 72: / Line 72: @@
 {{:ecg_and_hr_overview.png|heartbeats plot figure 2}}
-The second figure shows the entire signal over time in a 20Hz sampling (in blue) with the detected heart-rate super-imposed to control for flaws in the detection. This can be done by zooming in on a smaller piece of the signal:
+The second figure shows the entire signal over time in a 20Hz sampling (in blue) with the detected heart-rate (which is rescaled to 2.5 + BPM/60) super-imposed to control for flaws in the (initial auto-) detection. This can be done by zooming in on a smaller piece of the signal:
 {{:ecg_and_hr_zoomed.png|heartbeats plot figure 2 - zoomed}}.