Watson_lecture - Biomechanical Design Model Heart Failure...

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Unformatted text preview: Biomechanical Design Model: Heart Failure Treatment June 2009 John T. Watson, Ph.D. Biomechanical Design Key Points Paramount: Patient's Quality of Life Public Health Need: Heart Failure Bioengineering a Biomechanical Therapeutic Systems Paramount: Patient's Quality of Life "Important Things Stay the Same..." 1978 "Need to Base Our Ultimate Objectives on the Search for a Long, Productive Life for Humankind Based on Love of People." Ted Cooper Medical Implant Design Patient Needs Design Theory Concepts Prototypes Manufacture Test Safety Reliability Clinical Trials Retrieval Magnitude of the Problem Prevalence Sex and Race Bioengineering a Treatment Coronary Heart Disease Age-Adjusted Death Rates: Actual and Expected United States, 1950-2000 500 Deaths per 100,000 400 ~ 1,329,000 Projected Deaths in 2000 300 200 815,000 Deaths Prevented in 2000 ~ 514,000 Actual Deaths in 2000 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 100 0 1950 Year Causes of Heart Failure Coronary artery disease High blood pressure Diabetes Cardiomyopathy Heart valve disease Thyroid disease Congenital malformations Conduction arrhythmias Heart Failure Symptoms Shortness of breath Swollen ankles and legs Fatigue Angina Loss of appetite Weight gain or loss Heart Failure Treatments Diuretics Beta blockers Digoxin ACE inhibitors Implantable defibrillators Spironalactone Congestive Heart Failure in the United States 550 thousand new cases each year 4.8 million persons living with CHF CHF listed on 1 in 9 death certificates in 1999 (262,000) $21 billion spent in 2002 for CHF patient care Alternate Heart Failure Therapies Allotransplantation Surgical Procedures Xenotransplantation United States Cardiac Transplantation Volumes Historical Trend and Forecast 2,400 2,300 2,200 2,300 2,100 2,000 1,900 1994 1996 1998 2000 2002 2004 2006 2008 Congressional Mandate Federal and National Leaders National Institutes of Health National Institutes of Health Bioengineering Solutions for Heart Failure Assist and Replace the Heart Bioengineering a Solution for Heart Failure 20 Mechanical Circulatory Support First LVAD Patient: 1966 Patient needs guide design and therapy Highest Quality Control Bioengineering a Solution to Treat Heart Failure Use First Principles and design for the Specific Disease or Condition Heart Failure Characteristics La Place Equation: T = r x p T = wall tension (Kg/s2), r = cylinder radius (mm) p = pressure across the wall (kPa) LaPlace Law First Generation VADs 1977 Vision: Designing highly reliable two year VAD systems that provide a good quality of life and function, which society can afford. Timeline: 15 years Heart Failure Treatment "2Year Reliability" 1977 Blood Pumps Converters Percutaneous Transcutaneous Fabrication Batteries 1980 Integration: Implantable LVAD Systems 1984 Readiness: TwoYear Reliability InVitro Animal 1990 Clinical: REMATCH Novacor THI/Boston VAD Specifications Natural History of Cardiac Output for Women and Men? Experts Recommendation (1970s): 10L/min. Pulsatile or nonPulsatile Pumping Action?? VAD Specifications Cardiac Output = Stroke Volume x Heart Rate 10 L/min = Stroke Volume x 100 SV = 100 ml VAD Specifications Cardiac Output = Stroke Volume x Heart Rate 10 L/min = Stroke Volume x 250 BPM SV = 40 ml Limit = Continuous Flow MCS Specifications LV Power = P x Flow x 2.2 x 10 P = 100 mm Hg x 10 L/min x 2.2 x 10 = 2.2 watts Efficiency = 2.2/14 ~ 16 % TAH Specifications P LV = 2.2 Watts PRV = 40 mm Hg x 10 L/min x 2.2 x 10 PRV = 0.88 Watts Total P = 3.08 W Eff. = 3.08/25 ~ 12 % Biomaterials Design Lifetime Function Load/Strain Performance Quality/ISO Biology Apoptosis Quality of Life Limitations Heart Failure Treatment Heart Failure Treatment TwoYear Reliability Study Heart Failure Treatment "Set Your Own Limits" Heart Failure Treatment Patient Quality of Life: 2000 Intention to Treat Analysis as of January 2003 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0 VE LVAS (n=68) OMM (n=61) Percent Survival 1yr = 51% 2yr = 29% P=0.0043 1yr = 28% 2yr = 13% 6 12 18 24 30 36 42 Months Post Enrollment Heart Failure Treatment Second Generation VAD Vision: Designing highly reliable five year VAD systems that provide a good quality of life and function, which society can afford. Timeline: 10 Years Heart Failure Treatment Continuous Flow Pumps Heart Failure Treatment Rotary Blood Pumps 2000 TAH DEVICE FEATURES Flow - 4 to 8 L/min AbioCorTM Quiet No Skin Penetration Battery-Operated - internal, up to 30 min. - external, 4 hrs. Heart Failure Treatment TAH Patient at One Year Combination Therapy Mechanical circulatory support combined with adjuctive therapies to restore cardiac function over a period of 9 18 months. Adjuctive therapies, such as, proteins, genes, pharmaceutics, biologics and controlled biomechanics. Heart Failure Treatment Summing Up Patient's Quality of Life is Paramount MCS can Restore Cardiac Function Unique Mechanism to Understand and Treat Heart Failure just want to see my baby grow up and be a mom for all three of my kids" 2004 "I Heart Failure Rising in USA Public Health Burden 60 550,000 new mortality Thousands of patients Heart Failure cases per year 5 yr = 50% 50 40 30 20 10 0 80 85 90 95 2000 Health Care Budget year Nat. Center for Heath Statistics Heart Failure Treatment Self-Contained TAH Vision: Designing highly reliable five year TAH systems that provide a good quality of life and function, which society can afford. Timeline: 15 Years Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure REMATCH Combination Therapy Clinically Beneficial Functional Properties That Improve Patient Quality of Life Engineer physical properties Systems Bioengineering Delivery Systems ...
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