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Current And Emerging Technologies In Insulin Pumps


but offers no long-term protection. Also, an A1c of 7.9% does not stop ... Keep The Usual Suspects In Mind. I ate too much. Bad infusion set or site ... – PowerPoint PPT presentation

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Title: Current And Emerging Technologies In Insulin Pumps

Current And Emerging Technologies In Insulin
Pumps Continuous Monitors
  • May 8, 2008
  • John Walsh, PA, CDE
  • (619) 497-0900
  • Advanced Metabolic Care Research
  • 700 West El Norte Pkwy
  • Escondido, CA 92126
  • (760) 743-1431

  • Background
  • Smart Pumps and Features
  • Pump Control Tips
  • DIA and BOB
  • Super Bolus
  • Continuous Monitors and Tips
  • Wrap Up

EDIC Study FindingsLower Glucose Prevents Heart
Attacks Early Death
  • After the DCCT ended in 1993, the EDIC Study has
    followed these participants.
  • Over 11 years, A1c levels in intensive and
    conventional control groups have been identical
    at 7.9 (was 7.4 and 9.1).
  • However, heart attacks and strokes have been
    twice as high (98 vs 46) in the original
    conventional versus intensive group, even though
    A1c levels have been identical since the DCCT
    trial ended.

1. EDIC Study Group presentation at 2005 ADA,
K.M. Venkat Narayan Clinical Diabetes 2488-89,
EDIC Study FindingsLower Glucose Temporarily
Reduces Nerve Damage
  • The tight control group also

    experienced half as much neuropathy
  • BUT, as shown in figure, improvedcontrol in the
    past delays progression but offers no long-term
  • Also, an A1c of 7.9 does not stopprogression of
    nerve damage (or CVD)
  • Take Home Improve control and KEEP it there!

Avg A1c 7.9
Diabetes Care, Vol 29, No. 2, pp. 340-344
Goal A Healthy, Saner Life With Less Glucose
Exposure And Variability
The DCCT proved that exposure to high blood
glucose was damaging. New emphasis is on glucose
Glucose Variability (Swing)
SD from PC or meter
Glucose Exposure
A1c or average BG from meter
Current Pump Reality
  • Pumps provide only modest improvements in A1c
    levels over MDI
  • About 0.6 lower (mid to upper 8 range)
  • Avg. A1c of 8.5 is well above goal of less than
    7 or 6.5
  • But glucose levels ARE more stable with less
    insulin needed per day

Smart Pump Features
Smart Pump Features Overview
  • Automatic carb and correction calculations based
  • Carb and correction factors
  • Glucose targets
  • DIA avoids insulin stacking
  • Carb and correction boluses adjusted for BOB for
    accuracy and safety
  • Personal carb database
  • Correction bolus shown as of TDD
  • Direct glucose entry and detailed glucose history
  • Reminders, alerts, weekly schedule, temp basal
    rates, etc.

Deltec Cozmo
  • Features Pumps
  • HypoManager 1
  • Weekly Schedule 1
  • Missed Meal Bolus 1
  • Bolus Not Completed 1
  • Disconnect Bolus 1
  • Basal Test 1
  • Meal Maker with CozFoods 4
  • Therapy Effectiveness 2
  • BG Variability (SD) 1

Meter/CGM Improve BG History
  • Pump Meter direct BG entry
  • Deltec Cozmo Freestyle CoZmonitor
  • Omnipod Freestyle
  • Paradigm Lifescan (US)/Bayer (Eur)
  • Pump Cont Mon no direct BG entry
  • Medtronic x22 Paradigm RT
  • Future Pump Meter/Monitor Combos
  • Animas pump Lifescan meter
  • Cozmo Abbott Navigator
  • Animas Omnipod Dexcom
  • AccuChek pump meter

Disconnect Bolus
  • Disconnect up to 2 hrs forsports, sauna, sex,
  • Useful for Mini-vacations
  • User estimates time off andpump gives up to 50
    of missed basal as bolus
  • Alarm reminds user to re-connect
  • On reconnecting, pump shows missed basal and
    offers to supply the missing amount

Weekly Schedule
  • Users profile changes automatically for specific
    days of the week
  • Allows different basal patterns and missed meal
    bolus alerts for each day of the week
  • No need to remember to change basal patterns or
  • Great for college, shift work, weekends,
    exercise, or other regular variation in schedule

Pump As Carb Counter
  • Pump or external controller contains
    user-selected food list for accurate carb
    counting for
  • Easy carb calculations
  • More accurate boluses
  • Available in Animas 2020, Deltec Cozmo, Omnipod
    PDM, and Spirit PDA

Carb Bolus Varieties
  • Regular
  • Taken immediately for most meals
  • Extended / square wave
  • Extended over time gastroparesis
  • Combo / dual wave
  • Some now, some later bean burrito, some pastas
    and pizzas, Symlin

Helpful Aids And Alerts
  • Carb or insulin recommendation for each BG
  • Bolus-not-completed alert
  • Missed meal bolus alert
  • Check after high or low BG
  • 10 extra units for basal when reservoir reads
  • Easier analysis with TDD and basal/bolus balance
  • Overview of basal/bolus balance and correction

Not available in all pumps
Getting The Big PictureTherapy Effectiveness
A summaryof glucose and insulin history
Therapy Effectiveness Scorecard
  • Screen 1
  • Average BG (over 2 to 30 days)
  • BG tests per day
  • BG standard deviation (SD)
  • Screen 2
  • Carbs per day
  • TDD
  • correction boluses
  • carb boluses
  • basal rates

Largely available in Paradigm pumps as well
Therapy Scorecard Screen 1
Monitor control, testing frequency, glucose
14 Day Average BG 146 mg/dl Tests
3.5/day Std Dev 53 mg/dl
Overall controlAdequacy of testingBG
variability aim forless than 65 mg/dl or less
than half of average BG
Therapy Scorecard Screen 2
Monitors carb intake, TDD, basal/carb bolus
balance, correction bolus
14 Day Average Carbs 206 g TDD
48.58 u Meal 38.07 Corr
4.95 Basal 56.98
Boluses taken? Low carb diet?Guides therapy
A1c, lows, etcCarb bolus Correction less than
8 of TDD?Basal at least 40 to 45 of TDD?
Check Correction Bolus
  • If correction boluses make up more than 8 of the
    TDD (and lows are NOT a problem)
  • Move half of the excess units above 8 into basal
    rates or carb boluses
  • Raise the basal rates
  • Lower the carb factor
  • Or stop skipping carb boluses

Example Correction Boluses Over 8
10 Day Average Carbs 175 g TDD
54.1 u Meal 36 Corr 21
Basal 43
Over 8
  • Move 1/3 to 1/2 of the overage to basals or carb
  • 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 add to basals
    or carb boluses

Therapy Effectiveness Guides
  • TDD Raise for frequent highs or high A1c
  • Lower for frequent lows or for frequent lows
    and highs
  • Basal/Bolus Balance about 50 of TDD
  • Correction Factor carb factor X 4.4 (mg/dl),
    carb factor / 4 (mmol)
  • Correction Bolus if over 8 of TDD, move
    excess into basals or carb boluses
  • Average BG lt 160 when checking before after
    meals, lt 140 when checking mainly before meals
  • Standard Deviation
  • Keep less than 1/2 of avg BG or below 65 mg/dl

Pump Control Tips
High BGs? Keep The Usual Suspects In Mind
  • I ate too much
  • Bad infusion set or site
  • Inaccurate carb counts
  • Missed or late boluses
  • Bad insulin
  • Stress hormone rebound
  • Empty refrigerator syndrome
  • Stress, pain, steroid meds

Bad Infusion Set Or Site
  • If you have unexplained highs
  • How often do they happen?
  • Do they correct only when you replace your
    infusion set?
  • If you answer yes
  • Always use tape to anchor the infusion line
  • Consider changing to a different infusion set

The right infusion set and good site technique
prevents headaches and improves your A1c
Tape The Tubing!!!
  • Put 1 tape on the infusion line to stop Teflon
  • Tape the tubing down to stop movement of Teflon
    catheter under the skin
  • Stops unexplained highs caused when insulin
    leaks back to surface
  • Less skin irritation
  • Prevents pull outs
  • Lose tape not insulin!

No anchor!
Tape The Tubing!!!
  • Lose tape not insulin!

Photo courtesy of
Use Sterile Technique For Site Prep
  • 30 of people are constant staph carriers and 25
    are intermittent. MRSA is now common. Prevent
  • Wash hands
  • Sterilize skin with IV Prep
  • Place bio-occlusive IV3000 over site
  • Insert infusion set through IV 3000
  • Steps for staph carriers
  • Use antiseptic soap all over body once every 1-2
  • Occasionally, apply bacitracin ointment to inside
    of nose

  • Pump Settings That Affect Control

Important Pump Settings
  • TDD adjust when having frequent lows or highs
  • Basal basal/bolus balance, secure sleep
  • Basal rate variation large variation not
  • Carb factor postmeal control
  • Carb factor variation may indicate basal
  • Correction factor lower high BGs safely
  • DIA bolus accuracy, HypoManager

CDA1 StudyCarb Factors From Cozmo CDA Study
  • Note how actual carb factors are distributed in
  • They are NOT bell-shaped!!!
  • People prefer magic numbers 7, 10, 15, and 20
    (grs/unit) for their carb factors
  • A normal, bell-shaped, physiologic distribution
    is shown in green
  • MANY magic carb factors are inaccurate

Carb Factors From CDA1 Sudy
  • Graph shows carb factor versus TDD for 200 pumps
    with better control (avg BG lt 209 mg/dl)
  • Note a break in relationship (red line) near a
    TDD of 40 u/day or carb factor of 10
  • Suggests that people are hesitant to lower carb
    factors below 10

CDA1 Carb Rule s Compared To PI
Carb Rule s
  • The average carb factors in the blue boxes are
    those used in pumps with better control where the
    avg BG was 209 mg/dl or less. TDDs are shown in
    the tan box on the left.

CDA1 Basal/Bolus Balance
  • As TDD rises, basal percentage falls slightly
    from 51.7 at a TDD of 20 u to 49.4 at 40 u and
    48.3 at 80 u
  • Basals vary widely 27 to 83 of TDD
  • Many basal rates do not appear to be accurate
  • If correction bolus excess is distributed evenly
    into basals and carb boluses, real basal rates
    would average over 50 of TDD

Walsh-Roberts Rules For Optimum Readings
  • Starting TDD (TDD X 0.9) (wt lbs/4 X 0.9)
  • Keep Basal/Bolus Balance near 50/50
  • Basal test rise/fall less than 30 mg/dl (1.7
    mmol) over 8 hrs
  • 500 Rule for Carb Factor
  • 2000 Rule for Correction Factor (110 Rule for
  • Set DIA at 4 to 6 hrs
  • Keep correction boluses less than 8 of TDD
  • or kg/1.8 If current TDD less than wt/4
    with good control, TDD current TDD X 0.90

J Walsh and R Roberts Pumping Insulin, 2006
Delay Eating When BG Is High
Glucose exposure is reduced when high readings
are allowed to fall before eating. Remember
Test early Dont forget to eat on time Dont
forget you bolused
Duration Of Insulin Action (DIA)How long a bolus
lowers your glucoseBolus On Board (BOB)Bolus
insulin still active from previous boluses
ProblemMost Carbs Are Faster Than Rapid Insulin
An hour later, half of most meals glucose rise
has occurred, but 80 of rapid insulin activity
Time over which most meals affect the BG
bolus activity remaining
Take Home Bolus 15 to 30 minutes before meals
Use extended and combo boluses sparingly
From Pumping Insulin
Typical Carb Digestion Times
  • Food Digestion Time
  • water 0 m
  • fruit/veg juice 5-20 m
  • fruit/veg salad 20-40 m
  • melons/oranges 30 m
  • apples/pears 40 m
  • broccoli/caulif 45 m
  • raw carots/beets 50 m
  • potatoes/yams 60 m
  • cornmeal/oats 90 m

Food Digestion Time fish 30-60
m milk/cot cheese 90 m legumes/beans 120
m egg 45 m chicken 1.5-2 hr seeds/nuts
2.5-3 hr beef/lamb 3-4 hr cheese 4-5 hr
Take Home Choose combo foods to lengthen carb
digestion time
Best Bolus Timing For Carbs
  • Figure shows rapid insulin injected 0, 30, or 60
    min before a meal
  • Normal glucose and insulin profiles shown in the
    shaded areas
  • DO NOT bolus an hour ahead of your meals!!!

Accurate DIA Prevents Lows
  • Accurate DIA Time
  • Accurate BOB
  • Accurate Boluses Accurate HypoManager
  • Prevents Lows

Short DIAs Hide Bolus Insulin Activity
  • A short DIA hides true BOB level and its
    glucose-lowering activity
  • Causes unexplained lows
  • Leads to incorrect adjustments in basal rates,
    carb factors, and correction factors
  • Or user starts to ignore smart pumps advice
  • Set DIA based on real insulin action time.
  • Do not modify DIA time to fix a control problem.

Duration Of Insulin Action (DIA)
Accurate boluses require an accurate DIA
DIA times shorter than 4 to 7 hrs will hide BOB
and its glucose lowering activity
Glucose-lowering Activity
6 hrs
2 hrs
4 hrs
Large Doses, Longer Duration
  • Large doses (0.3 u/kg or 30 u for 220 lb. person)
    of rapid insulin in 18 non-diabetic, obese
    people show significant activity beyond 4 hours.
  • Medium doses (0.2 u/kg or 10 u for 110 lb.
    person) show similar results.
  • Large doses may lengthen DIA

Apidra product handout, Rev. April 2004a
Dose Size May Affect Duration Of Action
  • For a 154 lb or 70 kg person
  • 0.05 u/kg 3.5 u
  • 0.1 u/kg 7 u
  • 0.2 u/kg 14 u
  • 0.3 u/kg 21 u

Woodworth et al. Diabetes. 199342(Suppl. 1)54A
But Studies Routinely Underestimate DIA
  • To measure pharmacodynamics, glucose clamp
    studies are done in healthy individuals
  • SQ doses from 0.05 to 0.3 u/kg
  • But injected insulin ALSO SUPPRESSES normal basal
    release from the pancreas (grey area in figure)
  • Unmeasured basal suppression makes smaller
    boluses appear to have a shorter DIA
  • When basal suppression is accounted for, true DIA
    times become longer

Recommended DIA Times
  • A DIA of 4 to 6 hrs gives best estimate for
    residual bolus activity
  • A longer DIA is a safer DIA

4 hr Linear
4 hr Curvilinear
From Pumping Insulin, 4th ed., adapted fom
Mudaliar et al Diabetes Care, 22 1501, 1999
DIA Time Selection
  • Current limited research suggests that DIA times
    are NOT different between children and adults
  • Immediate factors can change insulin action time
  • Shorter with activity and exercise
  • Shorter in hot weather
  • Longer with fat in diet
  • Do not change DIA time for temporary factors

DIA Tips
  • If pump often suggests boluses that are too
    small, do not shorten the DIA it is rarely NOT
  • Instead, ask what is causing the highs and where
    more insulin is needed in basal rates, in carb
    boluses, or both
  • DO NOT shorten the DIA for occasional activity.
  • lower boluses or basals ahead of time for planned
  • or eat more carbs or lower basals for unplanned
  • Basal rates that are too low make the DIA appear

How Different Pumps Handle DIA
Differences In DIA Calculations Differences In DIA Calculations Differences In DIA Calculations Differences In DIA Calculations Differences In DIA Calculations Differences In DIA Calculations
DIA Type Of DIA Measured Default DIA My Preferred DIA Time Increment For DIA
Animas 2020 Curvilinear 100 4 hrs 4.5 to 6 hrs 30 min
Deltec Cozmo Linear 100 3 hrs 4 to 5.25 hrs 15 min
Insulet Omnipod Linear 100 4 hrs 4 to 5.5 hrs 30 min
Paradigm 522/722 Curvilinear 95 6 hrs 5 to 6 hrs 60 min
Bolus On Board (BOB)Glucose-lowering activity
that remains from recent boluses
  • An accurate BOB
  • Prevents insulin stacking
  • Improves bolus accuracy
  • Reveals current carb or insulin deficit
  • Basal insulin is NOT measured by BOB!

aka insulin on board, active insulin, unused
insulin Introduced as Unused Insulin in 1st ed
of Pumping Insulin (1989)
BOB Prevents Insulin Stacking
  • Bedtime BG 173
  • Is there an insulin or a carb deficit?

Bedtime BG 173 mg/dl
6 pm
8 pm
10 pm
12 am
BOB Is Present In 65 Of Boluses
  • CDA1 Study Results
  • Of 201,538 boluses, 64.8 were given within 4.5
    hrs of a previous bolus
  • An accurate DIA shows that BOB is present for
    MOST boluses

4.5 hrs
Take Home insulin stacking is a common threat
Blind Boluses Hide BOB
  • In 2005, only 28,969 of 117,711 carb boluses
    given by 541 pumps across the US were accompanied
    by a BG value.
  • 6 of 7 carb boluses are blind given with no BG
  • With no BG, BOB cannot be accounted for by the
    pump in most carb boluses

85.8 blind boluses
Before giving a bolus, check your BOB (via
BG).Do not give blind boluses.
  • If BOB is present, it doesnt matter how it got
  • Safety requires that BOB be subtracted from BOTH
    carb and correction boluses to avoid
  • BOB is measured only when a BG is entered
    into pump!

How Different Pumps Handle BOB
Whats In BOB And What Is It Applied Against? Whats In BOB And What Is It Applied Against? Whats In BOB And What Is It Applied Against? Whats In BOB And What Is It Applied Against? Whats In BOB And What Is It Applied Against?
BOB Includes This Type Of Bolus BOB Includes This Type Of Bolus BOB Is Subtracted From This Type Of Bolus BOB Is Subtracted From This Type Of Bolus
Carb Correction Carb Correction
Animas 2020 Yes Yes No Yes
Deltec Cozmo Yes Yes Yes Yes
Insulet Omnipod No Yes No Yes
Medtronic Paradigm Yes Yes No Yes
Except when BG is below target BG
Different Pump Bolus Recommendations
  • BOB 3.0 u and 30 gr. of carb will be
    eaten at these glucose levels
  • Carb factor 1u / 10 gr
  • Corr. Factor 1 u / 40 mg/dl over
  • Target BG 100
  • TDD 50 u

Bolus recommended by each pump when
Omnipod cannot be determined here - it counts
only correction bolus insulin as BOB
Recommended Bolus Errors Can Be Corrected
  • A Paradigm user can scroll down 3 times to see
    active insulin, then adjust dose
  • 3
  • 1.5
  • - 4.5
  • 0 u bolus

3.0U 30 gr 160 3U 1.5U 4.5U
HypoManagerShows current insulin OR carb deficit
  • Compares BOB to correction bolus need
  • When BOB is smaller gt all pumps recommend a
    correction bolus
  • When BOB is larger gt Cozmo recommends eating
  • A very helpful feature
  • Shows current carb OR insulin deficit
  • Reduces overeating when BG is low
  • Warns when carbs may be needed later even though
    current BG is OK or high.

  • Helps TREAT lows
  • Encourage users to test when low
  • The BG reading triggers what should be an
    accurate recommendation for carb intake to treat
    that low
  • Prevents ETRS Empty The Refrigerator Syndrome
  • Dont use with Symlin, ?gastroparesis

Continuous Monitors
CGM Benefits
  • Increased sense of security
  • Immediate feedback look and learn
  • Control with safety
  • Worth out of pocket cost for many
  • Reimbursement gradually catching on

Continuous Monitor
  • A continuous monitor (OR frequent meter checks)
    can assist optimum energy flow

Optimum BG range for energy flow
Plus Insulin Pump
  • With full BG record, basals and boluses can be
    adjusted to provide optimum fuel flow

Optimum BG range
Continuous Monitoring
  • Benefits
  • Lots more info
  • Alarms to prevent lows
  • Security in knowing where the BG
    is and where it is going
  • Trends shown by graph, arrows, or predictors
  • Limitations
  • Accuracy
  • Data gaps
  • Insurance coverage
  • Occ cell phone and other interference

Continuous Monitor Tips
CGM Look And Learn
  • Excess night basal or bedtime bolus
  • Breakfast bolus too small or too late
  • Lunch bolus too small or afternoon basal too low

No Two Points Are Created Equal!
Lower Risk Going Up
Higher Risk Going Down
Level of a BGs risk depends on its trend
Turnaround Time A Glucose in Motion Stays in
Dont Stack Insulin
Stay Between The Lines
As readings improve, bring the upper glucose
target alert line down
Continuous Monitoring Tips
  • Be patient, have realistic expectations
  • Dont panic when meter and sensor differ
  • Expect some lag time
  • Dont 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

Comparison Of Two Continuous Monitors
  • The Dexcom STS 3 Day Paradigm RT continuous
    monitors were worn at the same time by one person
    with Type 1 diabetes. With low alert at 80 mg/dl
    and high alert at 160 mg/dl, 262 readings from
    Ultra meter performed over 33 days. Ultra tests
  • As soon as either monitors low or high alert
  • When values between the monitors disagreed
  • And at routine intervals, including calibrations
  • Screens show same 3 hr time period (0 to 400
    mg/dl), Ultra reading was 73 mg/dl.

GlycensitTM Analysis
  • Simultaneous comparison vs 262 Ultra readings
    over 33 days
  • Blue dotted lines ISO meter standard
  • Yellow area 95 of all data points
  • Red lines min and max deviation by star points
  • Ideally, all readings would fall between the blue
    dotted lines

Which Monitor Alerted First?
  • 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 as ties.
  • Monitor A was first to arlert for readings above
    160 mg/dl 68 of the time, B was first 5 of the
    time, with 27 as ties.

More On Monitor Accuracy
  • 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 (not shown)
  • Median ARD 17
  • Clark error grid
  • A 70
  • B 28
  • C and D 3

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