Method for the detection and handling of hypoglycemia
A method is described herein to detect and treat hypoglycemia. An example of this method involves the detection of hypoglycemia in a patient with a computing device, computation of a recommended carbohydrate amount to ingest by the patient with the computing device in response to said detecting the hypoglycemia, output of the recommended carbohydrate amount with the computing device, and the performance of a hypoglycemia surveillance with the computing device to determine whether the recommended carbohydrate amount remedied the hypoglycemia.
1 . A method, comprising:
detecting whether a patient is currently experiencing hypoglycemia with a computing device when a first blood glucose measurement of the patient is below a hypoglycemia threshold;
computing a recommended carbohydrate amount to ingest by the patient with the computing device in response to said detecting the hypoglycemia;
outputting the recommended carbohydrate amount with the computing device;
causing the patient to ingest the recommended carbohydrate amount;
performing hypoglycemia surveillance with the computing device to determine whether the recommended carbohydrate amount remedied the hypoglycemia;
receiving with the computing device a supplemental blood glucose measurement of the patient after said computing the recommended carbohydrate amount and after a predetermined delay period;
computing a supplemental recommended carbohydrate amount to ingest by the patient with the computing device in response to the supplemental blood glucose measurement being equal or less than a surveillance end threshold that is a larger than the hypoglycemia threshold;
causing the patient to ingest the supplemental recommended carbohydrate amount;
determining with the computing device that the hypoglycemia has been remedied based at least on the supplemental blood glucose measurement exceeding the surveillance end threshold; and
ending said performing the hypoglycemia surveillance when the supplemental blood glucose measurement exceeds the surveillance end threshold.
2 . The method according to claim 1 , further comprising:
receiving with the computing device data indicating that the patient lacks hypoglycemia symptoms after said computing the recommended carbohydrate amount; and
determining with the computing device that the hypoglycemia has been remedied based at least on the lack of the hypoglycemia symptoms.
3 . The method according to claim 1 , further comprising:
delaying said performing the hypoglycemia surveillance for a delay period.
4 . The method according to claim 3 , wherein the delay period is at least 15 minutes.
5 . The method according to claim 1 , further comprising:
ending said performing the hypoglycemia surveillance when the supplemental blood glucose measurement exceeds the surveillance end threshold comprising a relative threshold that varies based on amount of carbohydrates previously consumed.
6 . The method according to claim 5 , wherein the relative threshold is based on a time dependent carbohydrate absorption function that increases with time.
7 . The method according to claim 5 , further comprising:
calculating with the computing device the relative threshold using the following formula
BG end,relative =γ( t−t 1 )·BG hypo,end +(1−γ( t−t 1 ))·BG 0
where:
BG end,relative =Relative threshold for ending the surveillance phase;
BG hypo,end =Threshold where hypoglycemia is considered ended;
γ(x)=Carbohydrate absorption function for time interval x;
t=Current time when relative threshold is being calculated;
t 1 =Time when first carbohydrate recommended or consumed; and
BG 0 =Original blood glucose measurement.
8 . The method according to claim 5 , further comprising:
receiving a third blood glucose measurement;
calculating with the computing device the relative threshold using the following formula
BG
end
,
relative
=
γ
(
t
-
t
2
)
·
BG
hypo
,
end
+
(
1
-
γ
(
t
-
t
2
)
)
·
BG
2
+
γ
(
t
-
t
2
)
γ
(
t
2
-
t
1
)
(
γ
(
t
-
t
1
)
-
1
)
(
BG
2
-
BG
1
)
where:
BG end,relative =Relative threshold for ending the surveillance phase;
BG hypo,end =Threshold where hypoglycemia is considered ended;
γ(x)=Carbohydrate absorption function for time interval x;
t=Current time when relative threshold is being calculated;
t n =Time of n th measurement since hypoglycemia; and
BG n =n th blood glucose measurement since hypoglycemia.
9 . The method according to claim 1 , wherein the recommended carbohydrate amount is selected from a group consisting of a small carbohydrate amount, a medium carbohydrate amount, and a large carbohydrate amount.
10 . The method according to claim 1 , further comprising:
normalizing the recommended carbohydrate amount based on patient weight.
11 . The method according to claim 1 , further comprising:
adjusting the recommended carbohydrate amount based on patient weight risk of fainting during hypoglycemia.
12 . The method according to claim 1 , further comprising:
adjusting the recommended carbohydrate amount based on a total daily dose of insulin by the patient.
13 . The method according to claim 1 , further comprising:
calculating with the computing device the recommended carbohydrate amount using the following formula
{
n
BU
,
small
=
f
n
(
n
BU
,
TDD
+
n
BU
,
fainting
)
n
BU
,
medium
=
f
n
(
n
BU
,
TDD
+
n
BU
,
fainting
+
1
)
n
BU
,
large
=
f
n
(
n
BU
,
TDD
+
n
BU
,
fainting
+
2
)
where:
n BU,small =Small amount of carbohydrate;
n BU,medium =Medium amount of carbohydrate;
n BU,large =Large amount of carbohydrate;
f n =Normalization factor based on patient weight;
n BU,fainting =Risk of fainting additional bread unit; and
n BU,TDD =Additional bread unit recommended for patients with a total daily dose (TDD) of insulin≤30 UI.
14 . The method according to claim 9 , wherein said computing the recommended carbohydrate amount includes selecting the small carbohydrate amount, the medium carbohydrate amount, and the large carbohydrate amount based on a very low blood glucose limit, a low blood glucose limit, and a medium-low blood glucose limit.
15 . The method according to claim 14 , wherein the very low blood glucose limit, the low blood glucose limit, and the medium-low blood glucose limit are respectively 60 mg/dl, 100 mg/dl, and 140 mg/dl.
16 . The method according to claim 14 , further comprising:
calculating with the computing device the recommended carbohydrate amount using the following formula
n
BU
=
{
0
if
BG
ml
<
BG
n
BU
,
small
if
BG
l
<
BG
≤
BG
ml
n
BU
,
medium
if
BG
vl
<
BG
≤
BG
l
n
BU
,
large
if
BG
≤
BG
vl
Equation
21
where:
n BU =Amount of carbohydrate;
n BU,small =Small amount of carbohydrate;
n BU,medium =Medium amount of carbohydrate;
n BU,large =Large amount of carbohydrate;
BG 1 =Blood glucose measurement at hypoglycemia detection;
BG ml =Medium-low blood glucose range limit;
BG l =Low blood glucose range limit; and
BG vl =Very low blood glucose range limit.
17 . The method according to claim 1 , wherein said computing the recommended carbohydrate amount includes adjusting the recommended carbohydrate amount based on prior blood glucose measurements made after detecting the hypoglycemia, prior amounts of carbohydrates ingested, and a carbohydrate absorption function.
18 . The method according to claim 1 , further comprising:
receiving a second blood glucose measurement after the patient ingested the second recommended amount of carbohydrate;
calculating with the computing device a second recommended carbohydrate amount using the following formula
{
BG
vl
,
2
=
γ
(
t
-
t
1
)
·
BG
vl
,
1
+
(
1
-
γ
(
t
-
t
1
)
)
·
BG
1
BG
l
,
2
=
γ
(
t
-
t
1
)
·
BG
l
,
1
+
(
1
-
γ
(
t
-
t
1
)
)
·
BG
1
BG
ml
,
2
=
γ
(
t
-
t
1
)
·
BG
ml
,
1
+
(
1
-
γ
(
t
-
t
1
)
)
·
BG
1
where:
BG vl,2 =Very low blood glucose range limit or threshold for a second amount of carbohydrate;
BG l,2 =Low blood glucose range limit or threshold for a second amount of carbohydrate;
BG ml,2 =Medium-low blood glucose range limit or threshold for a second amount of carbohydrate;
γ(x)=Carbohydrate absorption function for time interval x;
t=Current time when relative threshold is being calculated;
t 1 =Time when first carbohydrate was consumed; and
BG 1 =First blood glucose measurement.
19 . The method according to claim 18 , further comprising:
receiving a third blood glucose measurement after the patient ingested the second recommended amount of carbohydrate;
calculating with the computing device a third recommended carbohydrate amount using the following formula
{
BG
vl
,
3
=
γ
(
t
-
t
2
)
·
BG
vl
,
3
+
(
1
-
γ
(
t
-
t
2
)
)
·
BG
2
+
γ
(
t
-
t
2
)
γ
(
t
2
-
t
1
)
(
γ
(
t
-
t
1
)
-
1
)
(
BG
2
-
BG
1
)
BG
l
,
3
=
γ
(
t
-
t
2
)
·
BG
l
,
3
+
(
1
-
γ
(
t
-
t
2
)
)
·
BG
2
+
γ
(
t
-
t
2
)
γ
(
t
2
-
t
1
)
(
γ
(
t
-
t
1
)
-
1
)
(
BG
2
-
BG
1
)
BG
ml
,
3
=
γ
(
t
-
t
2
)
·
BG
ml
,
3
+
(
1
-
γ
(
t
-
t
2
)
)
·
BG
2
+
γ
(
t
-
t
2
)
γ
(
t
2
-
t
1
)
(
γ
(
t
-
t
1
)
-
1
)
(
BG
2
-
BG
1
)
where:
BG vl,3 =Very low blood glucose range limit or threshold for a third amount of carbohydrate (i.e., at time t 3 );
BG l,3 =Low blood glucose range limit or threshold for a third amount of carbohydrate (i.e., at time t 3 );
BG ml,3 =Medium-low blood glucose range limit or threshold for a third amount of carbohydrate (i.e., at time t 3 );
γ(x)=Carbohydrate absorption function for time interval x;
t=Current time when relative threshold is being calculated;
t n =Time of n th measurement since hypoglycemia; and
BG n =n th blood glucose measurement since hypoglycemia.
20 . The method according to claim 1 , further comprising:
calculating subsequent amounts of carbohydrates by superimposing the effects of previous carbohydrate amounts.
21 . The method according to claim 14 , further comprising:
calculating the very low blood glucose limit, the low blood glucose limit, and the medium-low blood glucose limit based on no more than the last three blood glucose measurements.
22 . The method according to claim 6 , further comprising:
calculating with the computing device the carbohydrate absorption function using the following formula
{
γ
(
x
)
=
0
if
x
=
0
γ
(
x
)
=
-
0.000125
·
x
2
+
0.022525
·
x
+
0.0019
if
0
<
x
<
78
γ
(
x
)
=
1
if
x
≥
78
where:
γ(x)=Carbohydrate absorption function; and
x=Time frame of interest (in minutes).
23 . The method according to claim 6 , further comprising:
calculating with the computing device the carbohydrate absorption function using the following formula
{
γ
(
x
)
=
-
1
t
a
2
x
2
+
2
t
a
x
if
0
≤
x
≤
t
a
γ
(
x
)
=
1
if
x
>
t
a
where:
γ(x)=Carbohydrate absorption function;
x=Time frame of interest (in minutes); and
t a =Total carbohydrate absorption time.
24 . The method according to claim 6 , further comprising:
calculating with the computing device the carbohydrate absorption function using the following formula
{
γ
(
x
)
=
1
t
a
x
if
0
≤
x
≤
t
a
γ
(
x
)
=
1
if
x
>
t
a
where:
γ(x)=Carbohydrate absorption function;
x=Time frame of interest (in minutes); and
t a =Total carbohydrate absorption time.
25 . The method according to claim 6 , further comprising:
calculating with the computing device the carbohydrate absorption function using the following formula
γ( x )=1− e −α·x
where:
γ(x)=Carbohydrate absorption function;
X=Time frame of interest (in minutes); and
a=0.03.
26 . The method according to claim 6 , further comprising:
calculating with the computing device the carbohydrate absorption function using the following formula
γ( x )=1− e −α·x 2 −bx
where:
γ(x)=Carbohydrate absorption function;
x=Time frame of interest (in minutes);
a=0.0004; and
b=0.015.
27 . The method according to claim 6 , wherein the carbohydrate absorption function is a linear function.
28 . The method according to claim 6 , wherein the carbohydrate absorption function is a parabolic function.
29 . The method according to claim 6 , wherein the carbohydrate absorption function is an exponential function.
30 . The method according to claim 1 , further comprising:
receiving with the computing device a manual input that the patient has the symptom of hypoglycemia.
31 . The method according to claim 1 , further comprising:
determining automatically with the computing device that the patient has the symptom of hypoglycemia.
32 . The method according to claim 31 , wherein said determining automatically includes analyzing results from a questionnaire to detect hypoglycemic symptoms with the computing device.
33 . The method according to claim 31 , wherein said determining automatically includes analyzing a video of the patient for the hypoglycemic symptoms with the computing device.
34 . The method according to claim 31 , wherein said determining automatically includes analyzing speech of the patient for the hypoglycemic symptoms with the computing device.