Data from an actual clinical trial for the closed-loop artificial pancreas is summarized in the following cumulative

Question:

Data from an actual clinical trial for the closed-loop artificial pancreas is summarized in the following cumulative histograms, where the percentage of blood glucose measurements below a particular value is plotted against the blood glucose value. The three curves denote:

(i) actual blood glucose BG measurements collected from finger stick measurements (solid),

(ii) one continuous glucose measurement sensor CGM2 (dashed), and

(iii) a (redundant) second glucose measurement sensor CGM2 (dotted).

100 90 80 70 60 50 40 Mean: BG .. Mean: CGM1 Mean: CGM2 20 10 250 350 50 100 150 200 300 400 Blood Glucose [mg / dL] Fig

From a medical safety perspective, one would like to keep the blood glucose measurements in the range of 70€“180 mg/dL.

(a) For each of the three measurements (two CGMs and actual BG), compute the fraction of the data that lies in the range 70€“180 mg/dL. Comment on the absolute and relative safety of an algorithm that uses these measurements.
(b) Repeat the calculations for the more stringent performance range of 80€“140 mg/dL.

(c) Using the concepts introduce in Chapter 9, comment on the error characteristics of the two sensors, using the nomenclature introduced in Section 9.4.3.