Smart Pumps And Tomorrow’s Intelligent Devices July 21, 2005 John Walsh, P.A., C.D.E. Diabetes Clinical Specialist North County Endocrine President Diabetes Services, Inc. San Diego, California (619) 497-0900 www.diabetesnet.com Healthcare Across Borders - September 2003
Download ReportTranscript Smart Pumps And Tomorrow’s Intelligent Devices July 21, 2005 John Walsh, P.A., C.D.E. Diabetes Clinical Specialist North County Endocrine President Diabetes Services, Inc. San Diego, California (619) 497-0900 www.diabetesnet.com Healthcare Across Borders - September 2003
Smart Pumps And Tomorrow’s Intelligent Devices
July 21, 2005
John Walsh, P.A., C.D.E.
Diabetes Clinical Specialist North County Endocrine President Diabetes Services, Inc.
San Diego, California (619) 497-0900 www.diabetesnet.com
Highlights
• A1c levels remain high despite DCCT • What lowers the A1c • Classic meters • Glucose exposure and variability • Classic pumps • Smart pumps • Future intelligent devices Healthcare Across Borders - September 2003
Where We Are
The Graduate: “Plastics” The Post-Graduate: “Medical Devices” Healthcare Across Borders - September 2003
Where It Started
Patent issued September 14, 1971 to Anton Herbert “Tom” Clemens for the Ames Reflectance Meter Healthcare Across Borders - September 2003
Why We Do It
Better Control Reduces Complications
60 50 40 30 20 10 0
76% Risk Reduction
•
55.0
13.0
Retinopathy Progression 59% Risk Reduction 39% Risk Reduction 29.8
•
23.9
16.4
7.9
Laser Rx 1 Micro albuminuria
2
54% Risk Reduction
•
5.1
2.5
64% Risk Reduction Conventional Intensive
•
13.4
5.0
Clinical Neuropathy
3 1.
2.
3.
DCCT Research Group,
Ophthalmology.
1995;102:647-661 DCCT Research Group,
Kidney Int.
1995;47:1703-1720 DCCT Research Group.
Ann Intern Med.
1995;122:561-568.
Any Rise In A1c Causes More Damage Any Fall Helps
Better
Healthcare Across Borders - September 2003
Short-term Costs In Diabetes Versus A1c
Total average yearly cost of care over 3 years (1994 to 1998) for 2,394 diabetes patients relative to their A1c level. Patients were followed at the Fallon Clinic in Worchester, MA. There were a total of 447 hospital admissions plus various clinic visits, infections, etc.
New DCCT/EDIC Data
Starting in 1993, the EDIC study has followed DCCT participants for 12 years.
For 11 years, A1c levels between the intensive and conventional control groups have been identical at 8.4% despite different treatments and education during the DCCT study.
After 12 years, only 46 heart attacks and strokes occurred in the original intensive control group compared to 98 in the conventional control group. This 53% reduction occurred even though the A1c levels were identical
for the last 11 years
.
CVD is 10 times higher in Type 1 diabetes, so start good control now.
Healthcare Across Borders - September 2003
A1c Levels Remain High Despite DCCT
Healthcare Across Borders - September 2003
A1cs Since The DCCT
8.6% in 396 Canadian Type 1s in 1992 1 9.7% in 1,120 German children in 1996 2 9.7% in in U.S. in NHANES III, 1988 to 1994 8.6% in 2,873 European kids and adolescents in 1997 3 9.2% in 62 Canadian Type 1s in 2004 8.4% in EDIC trial (followup to DCCT study)
A1c GOAL < 6.5% to 7%
1.
2.
3.
Diabetes Care. 1997 May;20(5):714-20 Horm Res 1998;50:107 –140 HB Mortensen et al: Diabetes Care. 1997 May;20(5):714-20 Healthcare Across Borders - September 2003
Current Diabetes Therapy Falls Short
Noncompliance is not a patient problem. It is a system failure.
When a system fails, trying harder will not work.
Only changing the diabetes care system will work.
Healthcare Across Borders - September 2003
Therapy Fails Between Office Visits
In most chronic diseases, treatment intervals with a doctor visit every 3 to 4 months works well.
Diabetes is unlike any other chronic disease. A complex disease with unclear accountability, it has a required treatment interval of 2 to 5 hours. Only intelligent pumps or devices can make the frequent treatment decisions necessary to ease the care burden on patients and health providers.
Healthcare Across Borders - September 2003
What Lowers The A1c
Frequent testing * Frequent boluses * Rapid insulin * Accurate carb counting * Easy bolus calculations * Easy history * Basal can be adjusted to precise need * Bolus based on carbs and BG * Properly set doses --> Walsh Pump Formulas
* Where a pump helps
Healthcare Across Borders - September 2003
Benefit Of Frequent Testing
400 (22) 300 (17) 200 (11) 100 (5.6)
1 test versus 7 tests a day
Breakfast Lunch Healthcare Across Borders - September 2003 Dinner Bed
12
Actual A1c Versus Testing Frequency
Data From 378 People On Pumps
11 10 Atlanta Diabetes Associates study: 378 patients sorted from a database of 591 Pumps=MM 511 or earlier BG Target=100 C peptide <0.1
9 HbA1c=5.99+5.32 / (BGpd+1.39) 8
ADA: < 7%% AACE: < 6.5%
7 6 5 4 0 2 4 6 8 10
SMBG Frequency (BG per day)
12 14
Glucose Exposure and Glucose Variability
Healthcare Across Borders - September 2003
Glucose Exposure and Glucose Variability
Glucose exposure is measured by • A1c • 14/30 day average on a meter Glucose variability is measured by • Standard deviation, currently via meter download Healthcare Across Borders - September 2003
Exposure And Variability
A Day’s Blood Sugars
Monitoring every 30-60 min with usual meals and insulin doses 400 380 360 340 320 300 280 260 240 220 200 180 160 140 120 100 80 60 40 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM
Variability or Swing Exposure or Average
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 Healthcare Across Borders - September 2003
Exposure And Variability Are Different
Glucose variability (SD) and A1cs in two individuals: Top: A1c = 6.6% SD = 20 mg/dl (1.1 mmol) Bottom: A1c = 6.7% SD = 61 mg/dl (3.4 mmol)
Exposure And Variability Are Unrelated
This study of 256 consecutive meter downloads demonstrated no relation between glucose exposure (A1c) and glucose variability (SD) SD varied from very stable at 8.1 mg/dl (0.4 mmol) to very unstable at 152.5 mg/dl (8.4 mmol)
Comparison of A1c and meter downloads from 256 subjects at Johns Hopkins
Average SD was 63.3 mg/dl (3.5 mmol)
Take home: Keep SD below 63
Glucose Variability
Like weight cycling, variable blood sugars may be more damaging than consistently high blood sugars Healthcare Across Borders - September 2003
Pumps Or MDI Are Better Despite A1c
The DCCT conventional group (top) was 22 times more likely to get retinopathy at an A1c of 9%.
The intensive group
at the same A1c
was only 8 times as likely to get retinopathy.
The reduced risk may result from less glucose variability seen with pumps and MDI.
Impact Of Glucose Variability
from Irl Hirsch, MD
Cell death is about 2.5 times as likely in human umbilical vein endothelial cell cultures after 14 days when glucose varies between 90 and 360 mg/dl compared to cells kept at 360 mg/dl. 1 Activation of PKC-beta after 14 days is about 80% higher when glucose varies between 90 and 360 mg/dl compared to cells kept at 360 mg/dl. 2 1. Amer J Physiol Endocrinol Metab 281: E924-E930, 2001 2. Diabetes 52: 2795, 2003 Healthcare Across Borders - September 2003
Pumps Reduce Glucose Variability
In the Kumamoto trial of Type 2 diabetes, those on pumps had significantly lower glucose variability (SD): MDI: A1c = 6.7%
SD = 61 mg/dl (3.4 mmol)
Pump: A1c = 6.6%
SD = 20 mg/dl (1.1 mmol)
Healthcare Across Borders - September 2003
Pumps Versus MDI (Aspart/Glargine)
200 180 160 140 CSII (n=93) MDI (n=91) 120 100 BB Mean ± 2 SEM AB BL AL BD AD Midnight 3 AM
Bode, et al.
Diabetes
52,(Suppl 1), 2003 Abstract 438.
CVD And Mortality In Relation To BG
In this study, heart attacks and death were more closely linked to postmeal blood sugars, suggesting that glucose variability may play a role.
Myocardial Infarction Mortality Rate Postmeal Premeal
1139 diet-controlled subjects, 30-55 yo at diagnosis. During 11 yr followup, 112 (15.2%) suffered from myocardial infarction, 197 (19.82%) of 994 had died. Odds ratio for all-cause mortality for males at the age of 36-45 years was 5.1 and for females 7.0
Reality: Postmeal Peaks In Children
>300 46% <180 10% 180-240 18% 241-300 26%
Continuous Monitors Reduce Glucose Variability
15 users with implanted Dexcom continuous monitors were blinded to glucose during the first 50 days, followed by open readout for the next 44 days.
Blinded Open 8.91
hrs/day 9 8 7 6 5 4 3 2 1 0 - 65 min 2.62
1.53
+ 250 min + 32 min 1.52
2.06
4.75
-13 min 6.38
6.16
-160 min 7.23
4.57
40-55 56-80 81-140 blood sugar 141-240
Healthcare Across Borders - September 2003
241-400
Glucose Exposure: Pumps vs MDI (Aspart/Glargine) During CGMS Less area under the glucose curve (AUC) shows that pumps reduced glucose exposure and variability better than MDI P = 0.0027 3000 2500 2000 1500 1000 N = 63 in each treatment 500 0 Pumps MDI Measurement of AUC (glu) ≥ 80 mg/dL during 48-hour continuous glucose monitoring period
Bode, et al.
Diabetes
52,(Suppl 1), 2003 Abstract 438.
Glucose Exposure and Glucose Variability
Both damage health Both need to be lowered Frequent testing and devices help
Healthcare Across Borders - September 2003
Classic Meters
Healthcare Across Borders - September 2003
Testing Frequency
In a Kaiser study of actual prescription fulfillment among 44,181 patients with diabetes: • 60% of Type 1s were not testing 3-4 times a day as recommended by the ADA • 67% of Type 2s were not testing once a day as recommended by the ADA
Why Aren’t People Testing?
Lack of understanding No direct benefit No mechanism for long-term benefit No link to cause of BG problems Finger-pricking required No guidance for lowering highs No reward for good readings No easy way to record other things Healthcare Across Borders - September 2003
Current Meters
• In use 35 years • Still dumb to very dumb • Do not measure true hypoglycemia – missed lows and lows treated without testing • No direct benefit for outcomes • $2,000 a year for 7 x a day testing • Not fun Healthcare Across Borders - September 2003
Logbook And Meter Inaccuracies
In a study 1 that compared logbook entries to meter downloads: • One of every seven entries was not recorded because it was high • One of every seven entries was made up • No difference was found between adolescents and adults in the entry of fictitious and missing data Time and date settings in meters are often incorrectly set. This causes patterns of high or low readings to be associated with the wrong time of day. Insulin adjustments made on faulty timing can worsen control raher than improve it.
Current Tools Have Had Little Effect DCCT Pre
1992
Post
2003 On 4 inj. (or pump) 27.8% (0.4%) 72.6% (6.4%) Median A1c 8.3% 8.3% 18,403 German children followed over 10 years of “improving diabetes care”.
1
State-of-Art Meter Technology- 2005
Healthcare Across Borders - September 2003
Today’s Most Common Analysis Tool
Healthcare Across Borders - September 2003
Better Analysis Tools
Standard Deviation
Graphs courtesy of BD InterActiv™ Diabetes Software
Glucose Goals
• A1c less than 7.5% in children and less than 6.5% in adults • Lows • Never below 50 mg/dl (3 mmol) • Never frequent Meters can suggest interventions based on • Not at night goals and patterns • Highs • Never above 250 mg/dl (14 mmol) • Never frequent • Mealtime Age Pre Post Variation <5 yo 5-11 yo 70-160 70-140 < 250 mg/dl < 225 mg/dl with < 120 rise with < 100 rise 12+ yo 70-140 < 200 mg/dl with < 80 rise • Write down a reason for all readings below 50 or above 250 Poor control? Change your lifestyle, basals or boluses.
Healthcare Across Borders - September 2003
Classic Pumps
Healthcare Across Borders - September 2003
Basal And Bolus In Pumps
Breakfast Lunch Dinner Bolus Bolus Bolus Basal 2:00 7:00 12:00 16:00 Time 20:00
Healthcare Across Borders - September 2003
24:00 7:00
Classic Pump Features
• More physiologic insulin delivery to mimic the pancreas • Basal: steady background insulin delivery to keep BG from rising while fasting • Bolus: spurts of insulin to cover carbs or lower high BGs Healthcare Across Borders - September 2003
Pumps Offer More Normal Lifestyle
Liberalization of diet — timing & amount (by user) Increased control with exercise (by user) Able to work shifts & through lunch (by user) Less hassle with travel and time zones (by user) Aid to weight control (by user) Less anxiety in trying to keep on schedule (by user)
Pumps vs MDI in Type 2 DM
People with Type 2 diabetes who have tried both a pump and MDI strongly prefer the pump.
CSII MDI Less Pain Less Social Limitations Preference Advocacy Less Hassle Less Life Interference General Satisfaction Flexibility Convenience Less Burden -5 * ** * * *** *** *** *** *** 0 5 10 15 20 25 30 Change in Scores (Raw Units) From Baseline to Endpoint 35
Classic Pumps vs MDI
Meta-analysis of 12 controlled trials (600 people) found classic pumps lower A1c by 0.56%, lessen BG variability and require 7.58 fewer u/day 1 Another meta analysis of 20 studies found a “modest but worthwhile improvement” of 0.61% in A1c with pumps using 11.9 fewer units a day 2 In glargine vs pump (#24 each), no difference in A1c, but glycemic variability (MAGE) and doses were lower 3 1.
2.
3.
BMJ. 2002 Mar 23;324(7339):7052 Health Technol Assess. 2004 Oct;8(43):1-186 Diabetes Nutr Metab. 2004 Apr;17(2):84-9 Healthcare Across Borders - September 2003
Classic Pump Issues
• Carb and correction boluses calculated by user • Underestimating carbs in meals with inaccurate boluses 1 • 34% low before training • 17% low after training • No carb entry or database • Boluses easy to forget • No accounting of BOB leads to insulin stacking • No direct BG entry • No exercise component
Today’s Smart Pumps
Healthcare Across Borders - September 2003
Walsh Pump Formulas To Improve Dose Accuracy
Total Daily Dose = weight in lbs / 4 (kg / 1.8) Basal Dose = 50% (35% to 65%) of TDD Carb Factor = 500 / TDD Correction Factor = 2000 / TDD (110 / TDD in mmol) BG target = 90-120 mg/dl (5-6.7 mmol) before meals Carb rise = Less than 80 mg/dl rise after meals Basal target = +/- 30 mg/dl (1.7 mmol) BOB = 20-25% used per hour (auto in smart pump) Correction boluses = < 8% of TDD J Walsh and R Roberts:
Pumping Insulin
, 2005
Smart Pump – Boluses
Carb boluses Accuracy improved with personal carb factor adjusted for different times of day Personal carb database Correction boluses Personalized correction factors for different times of day Safer correction of high BGs Reports amount of correction bolus used (ie, over 8% of TDD)
An accurate TDD --> accurate basals & boluses
Healthcare Across Borders - September 2003
Carb Bolus Assistance
Each manufacturer provides bolus dose recommendations differently.
Healthcare Across Borders - September 2003
Smart Pump – Correction Boluses
Average Summary screen from Cozmo history
6 day average: Meal Corr Basal Total Carb 19.41 u 11.34 u 23.34 u 54.09u
175 g
Here,
correction boluses
make up 21% of TDD When correction boluses make up more than 8 to 10% of the TDD, 1/3 of this amount is moved to basal rates or carb boluses (as long as hypoglycemia is not the primary problem).
Healthcare Across Borders - September 2003
Overlapping Boluses
When several boluses are given in the evening, how much total bolus insulin remains at bedtime?
Dinner Dessert Correction
Bedtime BG 163
6 pm 8 pm 10 pm Healthcare Across Borders - September 2003 12 am
Smart Pump – Bolus On Board
Bolus On Board (BOB) Discounts bolus for residual BOB Improves accuracy Avoids stacking of bolus insulin Acts as guide to whether carbs or insulin are needed, ie, BG is 130 mg/dl but BOB = 5 u Requires a blood sugar test, an accurate duration of insulin action, and BG targets
Prevents hypoglycemia!
Healthcare Across Borders - September 2003
Dose Size Affects Duration
As bolus size increases, so too does duration of action.
For 154 lb (70 kg) person: 0.05 = 3.5 u 0.1 = 7 u 0.2 = 14 u 0.3 = 21 u
Smart Pump – Reminders
Reminders (alarms) to • test glucose following a bolus • test glucose after a low reading • test glucose after a high reading • give a bolus at certain time of day • warn when bolus delivery was not completed, etc.
• change infusion site Healthcare Across Borders - September 2003
Pump Is Carb Counter
Pump or external controller contains user-selected food list for accurate carb counting Healthcare Across Borders - September 2003
Meter Talks to Pump
108 Healthcare Across Borders - September 2003
Pump is Meter
Healthcare Across Borders - September 2003
Blood Sugar History
11 day average: BG Tests 167 mg/dl 2.1/day
From Cozmo: Average blood sugar history This person tests infrequently and only before meals, so correction boluses are underestimated Correction bolus totals cannot be accurate until more testing is done Healthcare Across Borders - September 2003
Ways To Reduce Glucose Exposure
A lower glucose at the start of a meal reduces glucose exposure.
Rules:
Test early Bolus early Don’t forget to eat on time Don’t forget you’ve already bolused Healthcare Across Borders - September 2003
Intelligent Timer For High Premeal BG
An intelligent pump would alert the user when the BG is likely to cross a selected threshold value, such as 120 mg/dl (6.7 mmol). This safe meal delay reduces glucose exposure, especially when combined with a Super Bolus Max. drop ~4-5 mg/dl per min Healthcare Across Borders - September 2003
Super Bolus For High GI Meal
In future pumps, a Super Bolus could be given when the user wants to eat more than a pre selected quantity of carbs, such as 40 or 50 grams A Super Bolus shifts future basal insulin into an immediate bolus. Part of the next 2 to 4 hours of basal insulin is shifted into a bolus for faster effect without causing a low. Helps cover high GI and large carb meals. Healthcare Across Borders - September 2003
Pump And Meter Combos
Direct glucose entry into database eliminates data errors and offers optimum use of glucose/insulin data • AccuChek Spirit + meter • CozMore System + Therasense CoZmonitor • Soill Diabecare III pump + meter • Medtronic 515/715 + BD Paradigm Link • Soon: Animas + ? Lifescan or Glucowatch Healthcare Across Borders - September 2003
Smart Pump – Data Collection
Current pumps track basals, boluses, blood sugars, carb intake, and timing (exercise/activity soon) Better analysis and many intelligent features, such as automatic testing of basals and boluses, can be done now with current pumps and meters Graphs courtesy of BD InterActiv™ Diabetes Software
Future Intelligent Pumps And Devices
Healthcare Across Borders - September 2003
M o n i t r i o n g l i n I n s u D e r i l v e y Convergence Toward Automation 1922 Insulin & syringes We are here 1979 Pumps 1983 Pens Open Loop Connectivity Data Management 1971 Home Monitors Advice/Feedback Continuous Monitors Closed Loop There is 1926 Clinic Monitoring
HCP Self Management Automation Healthcare Across Borders - September 2003
Adapted courtesy Roche/Disetronic
Intelligence (Improved Control) Can Be Added To:
Pumps Pens Meters PDAs Smart phones Any combination of above
Goal: Better management of complex situations
Requires a central reporting station to identify problems and notify user, guardian, or MD/RN Healthcare Across Borders - September 2003
Device IQ History Classic Smart Intelligent Automatic Meters 1971 ?
?
?
Pumps 1979 2003 ? 2006 ?
24 years
Judge devices not by their features, but by whether they reduce glucose exposure and variability.
Healthcare Across Borders - September 2003
An Intelligent Insulin Pen
300 personal carb selections with accurate carb counts Carb factor (1:1 TO 1: 100) Correction factor (1:4 to 1: 400) 5 sec microdraw BG meter 0.1 unit precision motor Non-volatile memory 3,000 events Bluetooth data transfer
Wearable Pumps
Relatively large Lower upfront cost Best suited for Type 2?
Omnipod Animas 200 u 200 u 2.4 x 1.6 x 0.7
2.9 x 2.0 x 0.75
Healthcare Across Borders - September 2003 1.1 oz 3.1 oz
Animas-Debiotech Micropump
Debiotech has been developing small pumps from Micro-Electro Mechanical Systems or MEMS technology. These devices are made from silicon (not silicone!) and easily mass-produced to keep cost low.
Silicon is harmless, but it is not clear how insulin may interact with silicon surfaces.
Healthcare Across Borders - September 2003
Smart Phones And PDAs
Convenient bolusing from a remote device Easy messaging Better graphics Larger carb database and memory Improved data analysis Direct fax to physician Bidirectional communication Able to combine data from all devices (pen, pump, meter, carb database, exercise component, communication) Healthcare Across Borders - September 2003
Today Meter size Sample size Alternate site testing Test speed Accuracy Calibration Memory Battery Ketone testing Built-in lancet
Meters
Tomorrow Measure glucose variability Pattern recognition/correction Intelligent timers Recommends test timing/frequency Tied to insulin delivery Gameboy attitude Improved accuracy to calibrate continuous monitors Smart phone enabled Healthcare Across Borders - September 2003
NIR-Based Noninvasive Glucose Monitor
Healthcare Across Borders - September 2003
Sensys Medical Systems
Measures glucose non-invasively with NIR spectroscopy Device weighs less than 1.5 pounds Fiber-optic head secured to the forearm Needs HGM for calibration Various components such as sweat, fat, etc. can interfere with efficacy Can use either volar or dorsal aspects of the forearm Rechargeable battery Studies underway
Spectra of Water, Hemoglobin, Blood & Glucose
Absorbance 0.042
0.040
0.038
0.036
0.034
0.032
0.030
0.028
0.026
0.024
0.022
0.020
0.018
0.016
0.014
0.012
0.010
0.008
0.006
0.004
1.2
Hemoglobin
1.3 1.4 1.5 1.6 1.7 1.8 Wavelength (microns) Absorbance 0.062
0.060
0.058
0.056
0.054
0.052
0.050
0.048
0.046
0.044
0.042
0.040
0.038
1.2 1.3 1.4
Glucose
1.5 1.6 1.7 1.8 Wavelength (microns) 1.9 2.0 2.1 2.2 2.3 1.9 2.0 2.1 2.2 2.3 2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.2 1.3
Water
1.4 1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.2 1.3 1.4
Blood
1.5 1.6 1.7 1.8 1.9 2.0 2.1 2.2 2.3 Healthcare Across Borders - September 2003
Medtronic Guardian RT
Real time readings Add-on to routine BG monitoring Radio communication from sensor to monitor High and low glucose alarms FDA pending
Guardian RT System
Healthcare Across Borders - September 2003
Sample CGMS Reports
Daily Report of Blood Glucoses Healthcare Across Borders - September 2003
Sample CGMS Reports
Modal time reports for breakfast, lunch, dinner, etc.
Healthcare Across Borders - September 2003
Sample CGMS Reports
Composite 3 day report Healthcare Across Borders - September 2003
GlucoWatch
®
Biographer
First To Receive FDA Approval
Healthcare Across Borders - September 2003
Animas-Debiotech Microneedles
Silicon microneedles can be used to infuse insulin or allow glucose measurements in interstitial fluid. This needle array could replace the AutoSensor in a GlucoWatch for effective continuous monitoring.
Healthcare Across Borders - September 2003
FreeStyle Navigator
TheraSense Continuous Glucose Monitor
Meter replacement
DexCom Monitors
Implanted And Transdermal
DexCom Subcutaneous Sensor
Special bioprotective layer prevents foreign body reaction with sensor Can measure glucoses ranging from 40 mg/dl to 700 mg/dl (2.2-38.9 mmol/L) Recalibration every 20 days 160 – 180 day lifespan for sensor Still need to do HGM 2-3 times/day to initiate glucose algorithm Easily implanted in subcutaneous tissue Can be accomplished as outpatient procedure
Diabetes Care 27:734, 2004
Healthcare Across Borders - September 2003
Endocrinology Clinics NA 33:175, 2004
Therasense Navigator System
Interstitial transdermal system Wireless Calibrated 1-2 times per day Readings every 1-2 minutes High and low glucose alarms Most accurate meter below 100 mg/dl
SpectRx Glucose Sensing System
Laser device on the skin surface Patch with sensor system embedded Healthcare Across Borders - September 2003 www.spectrx.com
Preliminary data with SpectRx ISF System
Healthcare Across Borders - September 2003
ADICOL Project –Disetronic / Roche
Advanced Insulin Infusion with a Control Loop
Open-flow Microperfusion System Inserted into the subcutaneous adipose tissue Double lumen catheter Acquires glucose readings every 30 minutes Goal – subcutaneous glucose sensing/insulin delivery system Healthcare Across Borders - September 2003
Future Intelligent Device Features
• Intelligent timers • Super bolus for better carb coverage and faster corrections • Accounting for exercise • Meaningful advice • Pattern spotting and analysis • Direct communication capabilities Healthcare Across Borders - September 2003
Intelligent Device Pattern Alert
Smart devices should reduce glucose exposure and glucose variability Healthcare Across Borders - September 2003
Intelligent Pump Features
Automatic TDD adjustment • • • Average blood sugar and standard deviation % TDD used for corrections Basal/bolus balance Automatic basal testing • • Overnight Daytime, when meal is skipped Automatic carb factor testing • Premeal, 2 hr postmeal peak, normal in 4-5 hrs?
Automatic correction factor testing • High-to-normal in 4-5 hours?
Healthcare Across Borders - September 2003
Smart Versus Intelligent Devices Feature
Carb list Basal/bolus testing Exercise adjustment Timer % of corr. bolus Super Bolus # of hypos Communication
Smart
Alphabetic By user By user By user Ignored By user By user Verbal/fax
Intelligent
By recent use Automatic Automatic Automatic Automatic Automatic Automatic Bidirectional Healthcare Across Borders - September 2003
Non-Invasive Status
No system is close to being used for a closed loop No current system can replace the “finger stick” monitor for “real time” glucose values and treatment decisions Current “finger stick’ systems continue to be poorly leveraged Well over 40 companies are attempting to develop continuous glucose monitoring systems Healthcare Across Borders - September 2003
User Interface – The Critical Component
Despite 30 years of pump and meter development, device communication to users is still in it’s infancy.
Healthcare Across Borders - September 2003
Future Intelligent Devices
Carb database for accurate carb counts.
Healthcare Across Borders - September 2003
Future Intelligent Devices
Suggestions for carb intake Healthcare Across Borders - September 2003
Future Intelligent Devices
A high glucose can be analyzed to determine the magnitude of the error Healthcare Across Borders - September 2003
Future Intelligent Devices
Recommended carb intake or insulin reduction to balance activity.
Healthcare Across Borders - September 2003
Future Intelligent Devices
New dose recommendations based on A1c, % of TDD given as correction boluses, and frequency of hypoglycemia Healthcare Across Borders - September 2003
A Few Needs
A faster “rapid” insulin with consistent action Define duration of insulin action so it can be associated with an intelligent device delivering different bolus amounts in the same individual Effective control algorithms for automated basal and bolus testing and for internet advice centers Healthcare Across Borders - September 2003
Take Home
Frequent testing reduces glucose exposure and variability Pumpers test more often, but few people with diabetes test enough Diabetes devices have barely begun to tap their capabilities More can be done now with pumps and classic meters Many opportunities to combine and enhance devices Healthcare Across Borders - September 2003
Pumps Have Come A Long Way
Healthcare Across Borders - September 2003
Questions
Healthcare Across Borders - September 2003