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NANS I 3 Steve Adler December 6, 2012. Indications for Use. U.S. Infumorph Europe Morphine and Baclofen. Accuracy. Definition: Accuracy refers to the correctness of a single measurement. Accuracy is determined by comparing the measurement against the true or accepted value.
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NANS I3 Steve Adler December 6, 2012
Indications for Use • U.S. • Infumorph • Europe • Morphine and Baclofen
Accuracy Definition: Accuracy refers to the correctness of a single measurement. Accuracy is determined by comparing the measurement against the true or accepted value. For our purposes, the true or accepted value is the programmed dose
Introduction • Product development process for accurate pump • Requirements • Solutions – valve gated technology • Bench or verification tests • Clinical study results • Clinical significance, next steps
Design Considerations for Accurate (Precise, Durable) Pump • Prior pumps had shortcomings • Important design considerations • Accuracy of drug delivery • Accuracy of reported volume in reservoir • Consistency of amount received by the patient over time • Limit any variation in flow rate due to programmed dose, battery age, reservoir volume, temperature or pressure • Ability to accurately deliver micro-doses • No variation in device performance over a wide range of concentrations and compounds
Product Development • New technology was required to design a pump with a an accurate dosing mechanism • The challenges were to design • A completely different flow regulating mechanism • Electronics that would allow precise timing and provide redundant safety checks • A power supply with exceptional longevity • Communication capabilities that were insusceptible to interference and able to prevent programming errors
Prometra Pump • Dose Accuracy 98% • No temp, pressure, reservoir volumeeffects • Longevity >10 years • Designed to deliver any compound • Can deliver micro-doses
Bench Testing • Extensive bench testing was performed to confirm overall accuracy, as well as accuracy under a variety of conditions. • Pressure extremes • Temperature extremes • Various programmable rates • Various reservoir fill levels • Various environmental exposures • Temperature cycling • Electric shock exposure • Vibration testing • Multiple sterilization cycles • Drug flow accuracy was within specification in each testing scenario.
PUMP Clinical Study: Accuracy Results Accuracy Results (%) Number of Refills = 2,073 Number of Patients = 148 • Accuracy was calculated as the delivered (volumetrically determined) to programmed (DP) drug volume ratio • Numerator: sum of delivered drug volumes over all (scheduled and unscheduled) valid fill/refill sessions per patient • Denominator: sum of programmed drug volumes over all (scheduled and unscheduled) valid fill/refill sessions per patient • Overall accuracy is calculated by averaging the per patient DP ratios
Accuracy by Flow Rate • Flow rate range: 0-1.5 mL/day • No statistically significant differences between flow rate categories
Accuracy by Months Post-Implantation • No statistically significant differences between any of the time-points
Accuracy by Residual Volume • (12.0-16.0] was lower than [0.0-4.0] (p=0.0119) • (16.0-20.0] was lower than all other categories (p<0.0001) • Mean accuracy was 100% in the lowest residual volume category (0.0, 4.0].
Accuracy by Concentration • Morphine concentration range: 1-50 mg/mL • No significant differences between concentration categories • No pump failures or other complications occurred related to drug concentration
Durability and Longevity • The only moving parts are the valves • Fewer moving parts and a simpler design mean less opportunity for complications • The valves require very little energy • Promotes longer battery life, requiring fewer replacement surgeries over the course of a patient’s IT therapy.
Accuracy With Other Drugs? • Proper function of pumps can be affected by the drug being delivered. • Concentration, molecular size, and corrosion of pump materials can have serious effects • Clinical trial results indicate that the Prometra Pump is very accurate when delivering morphine sulfate • Experience with both Infumorph® and compounded morphine at a wide range of concentrations • What about other drugs? • Accuracy should be unaffected by the type of drug in the pump.1 • The titanium dosing chamber of the Prometra Pump simply measures the exact volume of the fluid to be delivered. • This measurement is unaffected by type of fluid in the chamber 1Yearwood, T. Results of Secondary Pain Medications to Improve Pain Outcomes in The Prometra Programmable Infusion Pump. Poster Presentation at the 11th Annual ASRA Pain Medicine Meeting, November 2012
Clinical Significance? • Scheduling of refill visits • Possibly avoiding overdose/underdose, withdrawal symptoms • Drug dependent • Micro-dosing • Future applications
Intracranial Drug Administration ICV Intraparenchymal (IPa) Intracerebroventricular (ICV) IT
Clinical Need for Accuracy in Drug Delivery to the Brain • limit exposure to other organs • deliver complex dosing pattern • greatly reduce effective drug dosage
Conclusions • Achieved design goals • 98% accurate, independent of external factors • Confirmed in bench tests • Validated in clinical trials • Clinical significance depends on disease/drugs