Healthcare Across Borders - September 2003 Current And Emerging Technologies In Insulin Pumps And...

Healthcare Across Borders - September 2003

Current And Emerging Technologies In Current And Emerging Technologies In Insulin Pumps And Continuous MonitorsInsulin Pumps And Continuous Monitors

John Walsh, P.A., C.D.E. John Walsh, P.A., C.D.E.

North County EndocrineNorth County Endocrine

700 West El Norte Pkwy700 West El Norte Pkwy

Escondido, CA 92126Escondido, CA 92126

(760) 743-1431 (760) 743-1431

The Diabetes Mall

www diabetesnet.com

(619) 497-0900 (619) 497-0900 [email protected]@diabetesnet.com

Children With Diabetes Children With Diabetes Toronto August 18, 2007Toronto August 18, 2007

http://www.diabetesnet.com/





Highlights

Smart Pump Capabilities

Duration Of Insulin Action

Bolus On Board (BOB)

Continuous Monitors

Continuous Monitor Tips

Future Devices/Pumps

Wrap Up


Winning With Technology

8 Type 1s set a new speed record in the 2007 RAAM team race, riding from Oceanside, CA, to Atlantic City in just over 5.5 days.

They attribute their win to perseverance, reduced bonking using Navigator continuous monitors, and reliance on the ultimate energy hormone – insulin – delivered from Omnipod pumps.


Smart Pump Capabilities


Unique Pump Features

Accu-Chek Spirit

• Boluses determined by BG not by BOB

• Accu-Chek meter software has Low BG Index that may help predict hypo unawareness

• Strong motor and delivery

Animas 2020

• High contrast color screen for easy viewing

• Smallest mainstream pump

• Smallest basal rate increment – 0.025 u


Unique Pump Features

Insulet Omnipod

• No tubing for easy weari

• Automatic cannula insertion and priming

• Remote bolusing

Medtronic Paradigm

• Built-in CGM eliminates one device

• Simple to operate

• Carelink online software


Carb Counter

Pumps offer user-selected food lists to improve carb counting• Easy carb calculation • Improves bolus accuracy• Available in• Accu-Chek Spirit (#1000 on PDA)• Animas 1250 (#500) • Deltec Cozmo (#250)• Insulet Omnipod (#1000 on PDM)

Current Feature


Problem: Exposure And Variability

40

60

80

100

120

140

160

180

200

220

240

260

280

300

320

340

360

380

400

2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00

PM

11:00 PM 12:00

AM

1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00

AM

11:00

AM

12:00

PM

1:00 PM 2:00 PM

glucose (mg/dl)

One day’s BG results with usual meals and insulin. The DCCT proved that exposure to high blood glucose was

damaging. New emphasis is on glucose variability.

Exposure or Average =

Variability or Swing =

A1c or avg. BG from meter

SD from PC or meter


Therapy Effectiveness Scorecard

Screen 1 :

Average BG

BG tests per day

BG standard deviation

Screen 2:

Carbs per day

TDD • % of TDD as correction boluses • % of TDD as carb boluses• of TDD as basal rates


Therapy Scorecard Screen 1

14 Day Average:

BG 146 mg/dl Tests 3.5/day Std Dev 53 mg/dl

Overall controlAdequate testingBG variability – aim for less than half of avg BG

Monitor control, testing frequency, and glucose variablility


Therapy Scorecard Screen 2

14 Day Average:

Carbs 206 g TDD 48.58 u Meal 38.07% Corr 4.95% Basal 56.98%

Boluses taken? Low carb?Guides therapy – A1c, lows, etcCarb bolus %Corrections less than 8% of TDD?Is basal at least 40-45% of TDD?

Monitor carb intake, TDD, basal/carb bolus balance, and correction bolus %


Check Your Correction Boluses

If correction boluses are NOT less than 8% of TDD:

Raise basal rates,

Raise carb boluses, or

Stop skipping carb boluses

Move half of the excess units above 8% into basal rates or carb boluses, whichever is smaller, or into both if basals and carb boluses are balanced

Note: Paradigm pumps give correction bolus % as a % of total bolus dose, not the TDD. Do not use this percentage here!


Example: Correction Boluses Over 8%

10 Day Average:

Carbs 175 g TDD 54.1 u Meal 36% Corr 21% Basal 43%

Move 1/3 to 1/2 of the overage to basals or carb boluses:

21% of 54.1 = 11.3 units, 8% of 54.1 = 4.3 units

11.3 u - 4.3 u = 7 units excess

1/3 to 1/2 of 7 u = 2.3 to 3.5 u to be added to basal rates or carb boluses

Over 8%


Weekly Schedule

The user’s basal profile changes automatically for specific days of the week

Different basal patterns and missed meal bolus alerts for each day of the week

No need to remember to change basal patterns or alerts

Great for regular exercise, college classes, shift work, and other routine variations in schedule

Current Feature


Disconnect Bolus

Disconnect for up to 2 hours for sports, sauna, etc.

User estimates time off pump

Pump offers to give up to 50% of missed basal as disconnect bolus

Alarm reminds user to re-connect at set time

On reconnecting, pump determines basal missed and offers to supply the missing basal amount

Current Feature


Duration Of Insulin Action (DIA) How long a bolus lowers the blood sugar

and

Bolus On Board (BOB) Bolus insulin still active from previous boluses


Duration Of Insulin Action (DIA)

4 hrs 6 hrs2 hrs0

Accurate boluses require an accurate DIA.G

luco

se-lo

werin

g Ac

tivity

Current Feature


A Short DIA Time May SEEM OK

Pumpers and clinicians often set the DIA too short because:

• Recommended boluses do not bring high BGs down (ie, basal rates or carb bolus are too low)

• Shortening the DIA seems easier or safer than raising basal rates or lowering the carb factor.

• The default DIA is too short and never gets reset

• A low basal rate hides the true bolus activity


A short DIA hides the true BOB and its glucose-lowering activity.

Hiding bolus activity makes boluses excessive and may cause basal rates to be lowered inappropriately

Set your DIA to your insulin’s action time.

Do not modify the DIA based on control problems.

A Short DIA Can Cause Problems


0

2

4

6

8

10

0 1 2 3 4 5

Curvilinear 5 hr Linear 4.5 hr

A Comparison Of Linear And Curvilinear DIAs

Set the DIA for a linear pump 30 minutes shorter to get results close to that of a curvilinear pump. A Deltec or Omnipod pump set at 4.5 hrs is equivalent to a Medtronic or Animas pump set at 5 hrs.

Hrs

Units of insulin activity left

Curvilinear DIA = 5 hrs

Linear DIA = 4.5 hrs


Recommended DIA Times

From Pumping Insulin, 4th ed., adapted fom Mudaliar et al: Diabetes Care, 22: 1501, 1999

Set DIA to 4 hrs or more to calculate BOB and bolus doses accurately

Linear

Curvilinear


Blind Boluses Also Hide BOB

89.8

57.7

32.5

14.2

0

10

20

30

40

50

60

70

80

90

100

With BG orcarb

With carb With BG With BG andcarb

% of Boluses with BG or Carb Inputs Only 32.5% of 204,005 boluses from over 500 Cozmo pumps used across the US were accompanied by a BG value.

2/3 of boluses are given without a BG test

Only 1 of every 7 boluses had both carbs and a BG

Data in preparation for publication

67.5

% b

lind

bolu

ses


Bolus On Board (BOB) The glucose-lowering activity that remains

from recent boluses

An accurate BOB calculation

• Prevents insulin stacking

• Improves bolus accuracy

• Reveals current carb or insulin deficit

Your BOB can be determined only after a BG has been entered into pump!

aka: insulin on board, active insulin, unused insulin** Introduced as Unused Insulin in 1st ed of Pumping Insulin (1989)


BOB Prevents Insulin StackingWith a bedtime BG of 173,

is there an insulin deficit or a carb deficit?

6 pm 8 pm 10 pm 12 am

DinnerDinner

DessertDessertCorrectionCorrection Bedtime BG

= 173 mg/dl

Insulin stacking is common for anyone who gives

frequent boluses!


Hypo Manager Do you eat carbs or take insulin?

1BG = 173 mg/dl (9.6 mmol)

Bolus on board = 0.4 u

Correction bolus: 1.2 u

Insulin deficit = - 0.8 u

Give 0.8 u now? Y or N

2BG = 173 mg/dl (9.6 mmol)

Bolus on board = 4.6 u

Correction bolus: 1.2 u

Insulin excess = 3.4 u

You may need: 37 grams of carb later to prevent a low BG

Only after a BG has been entered can a pump determine whether carbs or insulin are needed

Helps prevent & treat hypoglycemia and avoid over-treatment

Current Feature


Recommended Boluses Differ Between Pumps Does Your Pump Subtract BOB From Carb Boluses?

Whenever BOB is greater than correction need, recommended boluses may be excessive for Paradigm and Omnipod pumps, or Animas pump when BG is above target

3.0U 45 gr 160 3.0U 1.0U 3.0U

Excess BOB is subtracted from correction bolus, but NOT carb bolus

3 u + 1 u– 3 u

- = 1 u bolus


Recommended Boluses Differ Between Pumps

Carb factor = 1u / 10 gr

Corr. Factor = 1 u / 40 mg/dl (2.2 mmol) over 100 mg/dl (5.6 mmol)

Target BG = 100 mg/dl

TDD = ~50 u

0

1

2

3

4

60 90 120 150 180 210 240

Deltec Cozmo Animas 1250 Medtronic 522

units

BG inmg/dl

Bolus recommendations from different pump for various BGs when BOB = 3.0 u and 30 grams of carb will be eaten


Helpful Features Often Go Unused

• Reminders, alerts

• Entry of BG results

• Carb counting aids

• Temporary basal rates

• Alternate and temporary basal patterns

• Tracking and use of BOB

• Review of glucose history and insulin use

Use features that can improve your control!


Helpful Reminders And Alerts

• Chech BG after a bolus after a low after a high

• Bolus at certain times

• Warn if bolus was not given for a particular meal *

• Warn if bolus was not completed *

• When to change infusion set

• Low reservoir (ie, 20, 10, 5 and 0 units, with extra 10 “hidden” units for basal delivery)*

Current Feature

* in Cozmo pump


Looking At History Helps

Pump & Meter for direct BG entry

• Deltec Cozmo + Freestyle CoZmonitor

• Omnipod + Freestyle

• Paradigm + BD Logic

Pump & Cont Mon, no direct BG entry

•Medtronic 5/722 + Paradigm RT

Future Pumps & Cont Mons

• Abbott Navigator + Deltec Cozmo, or Insulet Omnipod

• Animas + Lifescan

• AccuChek

Current Feature


Continuous Monitors


Old Tools


The Value of Frequent Testing

Breakfast

100 (5.6)

200 (11)

400 (22)

300 (17)

DinnerLunch Bed

4 opportunities

1 opportunity to intervene

288 opportunities


Continuous Monitors Reduce Exposure & Variability15 users with implanted Dexcom continuous monitors blind to glucose readout for 50 days, then open readout for the next 44 days.

2.62

1.53 1.522.06

4.75

8.91

6.386.16

7.23

4.57

0

1

2

3

4

5

6

7

8

9

40-55 56-80 81-140 141-240 241-400

Blinded Open

hrs/day

More normal BGs

- 65 min+ 32 min

+ 250 min -13 min

-160 min

Fewer lows Fewer highs


Continuous Monitoring

Benefits• Lots more info• Alarms to

prevent lows & highs

• Security in knowing where the BG is and where it is going

• Trends shown by graph, arrows, or predictors

Limitations• Less accuracy• Data gaps• Minimal insurance

coverage in U.S.• Occ. cell phone,

microwave, other interference


Continuus Monitor Components

1. Sensor through the skin

2. Radio transmitter on sensor

3. Receiver display

• BG readings every 1-5 min

• Trend graphs for 1, 3, 9, 24 hrs showing where BG has been and is going

• Trend arrows

• High and low alarms

4. Software to download & analyze data


Dexcom STS

• FDA approved 3/27/06 for 18 and older

• 7 day sensor

• Readings every 5 min.

• 3-14 days of readings per sensor

• One high, two low alerts

• $475 + $60 for each 7 day sensor

• Transmitter: ~$250 every 6 mos

• Good analysis software

Transmitter ~0.8 x 1.5”


Medtronic Paradigm RT

No closed loop

• FDA approved: 4/13/06, now for 7 and older

• One high and one low alert, trend arrow

• Readings every 5 min.

• $1340 + $35 for each 3 day sensor

• Transmitter: ~$900 every 6 mos

Transmitter ~1.1 x 1.4”


Freestyle Navigator

• FDA approval expected soon

• Good accuracy below 100 mg/dl

• Calibration requires 10 hrs, then 1-2 times per day for 1st two days

• Readings every 1-2 minutes with trend arrow (4 clicks to trend graphic)

• 5 day use

• High and low glucose alarms

• Rate of change alarm

• Likely to be used in Deltec Cozmo and Insulet Omnipod pumps

Investigational Device.Limited by U.S. Law to Investigational Use


TRU Directional Trend Arrows

Glucose going down-1 to -2 (mg/dL)/min

Glucose going up1 to 2 (mg/dL)/min

Glucose falling quickly< -2 (mg/dL)/min

Fairly stable glucose -1 to 1 (mg/dL)/min (3.3 mmol/hr)

Glucose rising quickly> 2 (mg/dL)/min


Trend Arrows Have Limits

No trend arrow = BG change up to 60 mg/dl (3.3 mmol) / hr

An hour later159 mg/dl (8.8 mmol)

Now100 mg/dl (5.6 mmol)

41 mg/dl (2.3 mmol)

With a bedtime BG of 300 (16.7 mmol) and a level trend arrow, the breakfast reading could be 0 or 750 mg/dl (0 to 41.7 mmol)!

Large BG changes

with no trend arrow

Trend arrows lack accuracy!


200150

050

100

2 4p 6 8p 10 12a

250300

Line Graphs Provide Better Trend Info

Shortest Trend1 Hr – Dexcom2 Hr – Navigator3 Hr – Paradigm

Longest Trend9 Hr – Dexcom24 Hr – Navigator & Paradigm

Target Zone – all

Event Icons – Navigator


Easy Basal Testing

10 pm 2 am 8 am

120 mg/dl

© Pumping Insulin, 2006© Pumping Insulin, 2006

Overnight basal test

Goal: green line


Easy Bolus Testing

6 pm 8 pm 10 pm

300

200

100

60

Carb bolus Correction bolus

© Pumping Insulin, 2006© Pumping Insulin, 2006

6 pm 8 pm 10 pm

Goal: green line


Continuous Monitor Study


A Comparison Of Continuous Monitors

The Dexcom STS 3 Day & Paradigm RT continuous monitors were available for this studyA head to head comparison of monitors while worn by one person with Type 1 diabetes.Each monitor’s accuracy tested against Ultra readings

Monitor screens above show glucoses over the same 3 hour time span (range of 0 to 400 mg/dl). Ultra reading at the time was 73 mg/dl compared to 93 and 122 mg/dl.


GlycensitTM Analysis

Blue dotted lines = ISO standardsYellow area = where 95% of data points will fallRed lines = minimum and maximum deviation by star pointsIdeally, all readings would fall between the blue dotted lines -- this

is the standard for today’s glucose meters

A B

http://tomcatbackup.esat.kuleuven.be/GLYCENSIT/


Difference From Ultra Meter Readings For Each SensorSensor A Sensor B

0-9 mg/dl off 116 5210-19 mg/dl off 83 6220-29 mg/dl off 32 4630-39 mg/dl off 11 3640-49 mg/dl off 9 2750-59 mg/dl off 4 1460-69 mg/dl off 2 7over 70 mg/dl off 5 18

Monitor Accuracy

Table shows how much each monitor’s glucose values differed from a simultaneous reading on the Ultra meter.

44.3%31.7%12.2%

4.2%3.4%1.5%0.8%1.9%

19.8%23.7%17.6%13.7%10.3%

5.3%2.7%6.9%

76.0%

19.8%

4.2%

43.5%

41.6%

14.9%


Which Monitor Alerted First?

Accurate warning of low and high readings is desired. This table shows which monitor alerted at least 5 min earlier for true lows and highs.

Monitor A was first to alert for readings below 80 mg/dl 76% of the time, B was first 3% of the time, with 21% ties.

For detection of highs above 160, Monitor A was first 68% of the time, B was first 5% of the time, with 27% ties.

Monitor A Monitor B Tie

For BGs less than 80 28 1 8

For BGs over 160 25 2 10

Which Monitor Alerted First?


More On Accuracy

1 R L Weinstein et al: Diabetes Care, 30, 1125-1130, 2007

Navigator 5 day (shown in graph)1

Median ARD = 9.3%

Clark error grid

A: 81.7%

B: 16.7%

C and D: 1.7%

Dexcom 7-day (to FDA - not shown):

Median ARD = 17%

Clark error grid

A: 70%

B: 28%

C and D: 3%


Continuous Monitors Today

• Readings have to be validated with a meter

• Not used by pump for dose calculations

• No warning when a reading is inaccurate

• Need daily calibration with fingerstick BGs

• Accuracy varies between devices and over time

• Otherwise wonderful


Future Devices And Pumps


Animas Debiotech Micropump

Animas is one of several companies developing very small insulin pumps from Micro-Electro-Mechanical Systems or MEMS technology. Made from silicon, can be mass-produced at low cost


Valeritas H-Patch Pump

Good introduction for Type 2s to basal/bolus therapy

• Automatic needle insertion

• Single basal available as 20, 30, or 40 units per day

• Button on pump delivers 2U per push


Pressure Pumps

Pressure from small solenoid drives precise insulin delivery

Eliminates need for motor and solid reservoir

Insulin can be stored in a bladder to reduce size

Two bladders with independent controls allow dual delivery

Dual pumping for:• Insulin + symlin

• Insulin + glucagon

• Or a micro pull/push interstitial glucose monitor


ExFactors For Activity

Enter into pump:

1. Exercise intensity (1-7 scale)

2. Exercise duration (15-480 min)

3. Current level of fitness for that activity (1-5 scale)

Pump then shows carb intake or insulin reduction needed for the activity

Future Pump Feature


Temporary Basal Reduction For Excess BOB

A temporary basal reduction offsets excess BOB so it is not necessary to eat at bedtime.

Future Pump Feature


Super Bolus For A High GI MealShift Basal To Bolus

A Super Bolus shifts part of the next 2-4 hours of basal insulin into an immediate bolus. Gives a faster insulin effect for high GI and large carb meals with less risk of a low.

Activated whenever user eats more than a selected quantity of carbs, such as 30 or 40 grams

Future Pump Feature


Super Bolus For A Postmeal High Shift Basal To Bolus

Enables a faster correction of highs with less risk of a low.

Future Pump Feature


Automatic Basal/Bolus Testing

A pump could automatically test:

The TDD from• Average blood sugar, stand. dev., frequency of lows

• % TDD used for corrections

• Basal/bolus balance

Basal rates from• Daytime when a meal is skipped (accounting for BOB)

• Overnight (accounting for BOB at bedtime)

The carb factor from• Premeal, 2 hr postmeal peak, normal in 4-5 hrs?

The correction factor from• High-to-normal in 4-5 hours?

Current And Future Pump Feature


Pattern Analysis

Pattern shows

• Inadequate or missed breakfast boluses or inadequate day basal rate

• Correction or carb boluses appear to be excessive at lunch

• Tests only when low in evenings

Devices • make sense of patterns in real time• analyze history accurately• much faster than MDs and RNs!

Future Pump Feature


Insulin Lookback

To find out if a low or high reading was caused by basals or boluses, a pump can compare:

• how much basal and

• how much bolus

• was active in the previous 5 hours

Lows – usually caused by the larger insulin amount

Highs – usually caused by the smaller insulin amount

Future Pump Feature


Lookbacks

# 1

BG = 47 at 1:00 am

5 hr. lookback:

Boluses = 9.2 u

Basal = 4.6 u


Lookbacks

# 2

BG = 228 at 4:30 pm

5 hr. lookback:

Boluses = 6.5 u

Basal = 2.4 u


Delay Eating Alert Delay eating when BG is OK for high GI meal

or a large # of carbs

Future Pump Feature

Allows insulin to start working before carbs begin to raise the blood sugar.

Result: less glucose exposure

Don’t forget to eat when pump alerts it is time!


Delay Eating AlertDelay eating when BG is high

A lower glucose at the start of a meal reduces glucose exposure.

Remember:

Test early

Don’t forget to eat on time

Don’t forget the bolus was given

Future Pump Feature


Continuous Monitor Tips


No Two Points Are Created Equal! Level of Risk Depends on Trend

20

30

40

50

60

70

80

90

100

0 50 100 150 200Minutes

Glucose (mg/dl)

Going UpLower Risk

Going DownHigher Risk


Going Up: Consider Action!

187

8:43 AM

1 hr

Bolus too small or too late


Watch For Peaking Out!

187

8:43 AM

1 hr

Peak

Wait!!


Wait and Watch!

1 hour

And check BOB


Turnaround Time An Object in Motion Stays in Motion


Don’t Stack The Insulin


Look And Learn

Breakfast bolus too small or too late

Lunch bolus too small or afternoon basal too low

Excess night basal or bedtime bolus


Stay Between The Lines

As readings improve, lower the glucose for the upper alert


Continuous Monitoring Tips

• Be patient, have realistic expectations

• Don’t panic when your meter and sensor differ

• Expect some lag time

• Don’t react too quickly and stack your insulin

• Look at trends, not just individual values

• Rapid rises usually mean more insulin is needed

• Validate your readings with a meter


Wrap Up

Pumps and continuous monitors offer technology improves control

More flexibility and confidence, lesshypoglycemia, less glucose exposure, less variability, and a healthier life

Data easily analyzed with suggested improvements that guide user toward improved control through success

Requires commitment, responsibility and training, but less work for everyone overall


Questions & Discussion

http://www.diabetesnet.com/ishop/product_info.php?cPath=58&products_id=691

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Healthcare Across Borders - September 2003 Current And Emerging Technologies In Insulin Pumps And...

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