Picture of a diseased heart, what actually happens when the heart no longer functions. Why the things that go wrong cause heart failure Causes of heart failure: Coronary artery disease Heart attack High blood pressure Heart valve conditions Unhealthy lifestyle
Progression of artificial hearts over the past 50 years Pump experimentations – research started Bridges for transplantation Have been under development for 50 years Show improvement over time in: Weight/Size Length of patient sustainment Battery source efficiency/implementation Portability Safety
Second artificial heart to ever be implanted in humans (in 1981 by Dr. Denton A. Cooley) 3 parts: air-driven pumps, external monitoring/control system, external power system (AC/DC power) Replaces left and right ventricles (as opposed to Saxton and Andrews who simply connected ventricles to aorta with a tube/pump system) Used to sustain a man for 55 hours until a donor heart became available Continuous-flow pumps builds on Saxton and Andrew’s ideas of using continuous-flow pumps in humans Less than 3 day support (usually takes about a year to get a donor heart) Control system is the size of a large washing machine Complex external control system (required consistent monitoring) with switches and dials
Similar to AKUTSU III: Two air-powered pumps (artificial ventricles), external control system, external power system Air line connects Jarvik-7 to external consol for power/compressed air Tubing connects Jarvik-7 to aorta Supported a patient (William Schroeder) for 620 days Improved consol allows doctor to easily control/monitor pump rate, pumping pressure, and other essential functions Backup battery in case of power failure, also allows patient to be more easily transported External consol = size of refrigerator Doesn’t use air from lungs Doesn’t permanently replace heart Patient still must be hooked up to consol system for support Piercing connecting tubes increase risk of infections
Designed to address problems in akutsu II and jarvik 7. Advantages very quickly Too much stuff SPELL CHECK Shorten to: here’s what designers wanted: more portable, etc. still limited because: Compare more in part two of oral presentation Since it’s been implanted in 2001, it has been used in x cases, approved by gov. etc. Consists of internal and portable external components (to be described in detail) No connecting tubes that pierce skin (reduced risk of infection) Weighs only two pounds Portable external power source Internal control system and backup battery pack allows patient to be active Backup battery can sustain patient in case of external battery failure Heart replacement is permanent
The PCE and external TET are the two only exterior components of the AbioCor system
The PCE is designed to allow a patient mobility. It carries 2 pairs of batteries, PCE control module, and the external TET.
TET - Transcutaneous Energy Transmission - Is essentially a silicone ring containing a coil of wire. Power is transferred via electromagnetic induction to the implanted TET. a. Held in place by a DuoDERM® patch with Velcro® fasteners It is wireless so wires won’t have to be wired through the skin, this helps prevent infections.
Internal battery – placed in the abdomen. Sealed in a titanium case and is connected to the Implanted controller. It lasts for about a year and is easily replaced. External battery pack – 4 lbs
The AbioCor Console is a specialized computer with a keypad and screen. It is plugged into a regular household electrical wall outlet to provide power to the AbioCor System through the Implanted TET and External TETs. The Console also contains a backup Battery that can supply power for 35 to 40 minutes if normal electrical power is interrupted. The Console uses radio waves (like a cell phone) to send commands through the RF Antenna to the AbioCor Implanted Controller and to receive information from the Implanted Controller about how the Replacement Heart is functioning. The Console also notifies the patient and caregiver with alarm lights and sounds if a problem occurs with the AbioCor System. (KSA)
The control module, like the console, also monitors the status of all of the AbioCor System’s internal components by communicating with the implanted controller through wireless technology. If a problem occurs within one of the internal devices, the control module immediately notifies the patient. **Doctors cannot send commands using the PCE control unit. PCE control unit is a limited version of the console
• monitoring of the Thoracic Unit and the other implanted components • control of the Thoracic Unit • communication with the external components and alarms (the AbioCor Console or Patient-Carried Electronics) The Implanted Controller manages the cardiac output rate of the Replacement Heart to provide the needed blood flow. Most of the time, the Implanted Controller works automatically, but it can be operated manually by the clinician. The Implanted Controller is sealed in a titanium case, connected to the Replacement Heart by cables. It is implanted in the abdomen at the same time as the Replacement Heart. The Implanted Controller monitors the AbioCor system to make sure it is working correctly. It also exchanges information with the Console to trigger an alarm if a problem occurs. PCE – Only communication, PCE cannot give commands. Only console can give commands **cardiac output rate: the amount of blood that flows through your heart, expressed in liters per minute (L/min); a liter is about 34 ounces, a little more than a quart SEE KSU pg. 4
Clear Epoxy – Easily cast into irregular shapes and allows for visual inspections for proper blood flow. AngioFlex (Polyetherurethane) – Prevents backflow Hydraulic fluid - Interal
Anticoagulation – Drugs that prevent coagulation FDA instructions list over 20 do NOTS Including cleaners that contain: iodine, hydrogen peroxide, hypochlorite, permanganate, or chromate. (Will damage outer coverings)
Although the AbioCor System is an effective treatment for end stage heart failure, doctors use other biomedical systems as well to combat this disease. Depending on each individual patient’s condition, doctors may use Left Ventricle Assist Systems (LVAS) or a different artificial heart. Similar to artificial hearts, LVAS are also designed to provide cardiac support to the patient. Both LVAS and total artificial hearts are fully implanted in the body. However, unlike artifical hearts, LVAS do not replace the heart. Furthermore, LVAS supplement the native heart by optimizing blood flow output from the heart while total artifical hearts pump all of the patient’s blood (Hoenicke). Both devices are treatments of heart failure and end stage heart failure. Doctors select the appropriate biomedical system depending on the patient’s condition. Two of the most advanced LVAS are the Jarvik 2000 and the Penn State LionHeart™. The two most advanced and implanted artificial hearts are the AbioCor System and the CardioWest Heart.
Jarvik 2000 The Jarvik 2000 is a LVAS designed to sustain patients with heart failure for short-term periods or permanently. The device consists of three main parts: the internal axial flow pump, the external controller, and the battery. The internal axial flow pump is implanted inside the left ventricle of heart, where it uses a spinning rotor to propel blood from the left ventricle to the aorta (Jarvik 2000 FlowMaker). Meanwhile, the heart continues to pump naturally, pushing the extra volume of blood sent by the Jarvik 2000 to the rest of the body. Generating an average pump flow rate of 5 liters per minute, the internal axial pump of the Jarvik 2000 magnifies the blood output of the heart (Jarvik 2000 Heart). As seen in figure ??, the internal pump speed is connected to the external controller through a skin-piercing wire. The external controller is small and allows the patient to manually adjust blood flow rate of the internal pump depending on the patient’s activity level. This control unit also alerts the patient of any device malfunctions (Jarvik 2000 FlowMaker). Finally, the internal pump and external controller are both powered by the Jarvik 2000’s battery. A power cable connects the implanted pump to its wearable battery and controls through the abdominal wall (Jarvik 2000 FlowMaker). This external battery can power the Jarvik 2000 for 8 to 10 hours. The external components, including the external controller and the battery, weigh less than three pounds. Advantages and Disadvantages of the Jarvik 2000 In comparison to the AbioCor System, the Jarvik 2000 has three main advantages: a smaller and lighter internal component, a smaller and lighter external controller, and longer battery life. Because the Jarvik 2000 does not replace the heart, the device’s internal component is extrememly light, weighing only 85 grams, and small (Jarvik 2000 Heart). A smaller internal component allows doctors to use the Jarvik 2000 in more pateints, while the AbioCor System’s size limits its candidate patients. Furthermore, the Jarvik 2000’s smaller and lighter external controller and longer battery life makes patients more mobile and less restrained by their medical condition. On the other hand, the Jarvik 2000 does not replace the heart. In the event of an entirely failed heart, the Jarvik 2000 cannot be used as a treatment. The use of skin-piercing wires in the Jarvik 2000 is also a disadvantage because pierced skin increases the risk of infection. The AbioCor System, however, is completely self-contained and eliminates this risk.
Advantages: Smaller (1.5” by 2.5”) fits in small adults and children Ligheter (12 ounces, compared to the AbioCor which weights 2 lbs) Battery Life: Uses a 1lb external 14volt Lithium ion battery), lasts up to 10 hours (AbioCor lasts 2-3 hours) Disad: Not a TAH (helps ventricles pump blood optimally but does not pump blood for body, heart is not removed and replaced) Skin-piercing wires to connect internal components to external controller
Penn State LionHeart™ The Penn State LionHeart™ is the first fully self-contained LVAS, designed to sustain patients suffering from severe heart failure for both short-term and long-term periods. The LionHeart™ consists of internal components and external components. There are three internal components: the blood pump, motor controller, and internal coil. There are two external components: the battery pack and system monitor (Hoenicke). The LionHeart™ uses the same TET system as the AbioCor System to transfer power non-invasively through the intact skin to power the internal components. In fact, the LionHeart™ is essentially the LVAS equivalent of the AbioCor System. As seen in figure ??, the internal pump is implanted in the abdomen near the ribs. Advantages and Disadvantages of the Penn State LionHeart™ Because the Penn State LionHeart™ resembles the AbioCor System so much, the two biomedical devices share the same advantages and disadvantages. Both devices are relatively large in size and weigh nearly triple the size of a human heart, making both devices unsuitable for smaller patients. On the other hand, both devices are completely self-contained, eliminating the risk of life-threatening infections from skin-piercing wires in previous devices.
Two ventricles implanted separately that can move as needed to facilitate its implantation (vs. single-body large AbioCor) Limited by drive console size (smaller unite recently approved) Full FDA approval for bridge to transplant (vs. AbioCor implantation limited to two centers) CardioWest Heart The CardioWest Heart is an artificial heart that consists of two ventricles and an external driver and console system. These ventricles are implanted separately to replace diseased ventricles. The ventricles connect to the external driver through two skin-piercing tubes (one from each ventricle). The driver is pneumatic, providing pulses of air and vacuum to the ventricles that make the artifical heart pump (The CardioWest Total Artificial Heart). When a patient exercises and blood vessels contract, increased blood enters the artificial ventricles which in turn pumps more blood to meet the patient’s circulatory demand. The external driver system also serves as a console system, allowing the patient to adjust blood flow rate. Advantages and Disadvantages of the CardioWest Heart The CardioWest is smaller in size than the AbioCor System, allowing the CardioWest Heart to fit in more patients. Furthermore, the CardioWest heart uses two separate ventricles, making implantation surgery safer and easier (Singer, E.). However, unlike the AbioCor System, the CardioWest Heart is not desgiend to permanently replace the heart. The CardioWest also relies on skin-piercing tubes, which risks infection in the patient
The development of the AbioCor System and alternative biomedical systems simmilar to the AbioCor System is considered a huge accomplishment in biotechnology development and heart failure treatment. However, research on heart failure treatments and further development of artificial hearts continues. Doctors and engineers continue this research in hopes of further improving current systems and generating new treatments for heart failure. Two main areas of current research and devopment are the AbioCor II Replacement Heart System and tissue engineering.
Abiomed is currently developing a predecesor to the Abiocor System – the AbioCor II Replacement Heart System, designed to address many of the AbioCor System’s limitations. Although the AbioCor II is still in clinical testing, Abiomed plans to address the following problems of the AbioCor System in the AbioCor II System: the size and weight of the thoracic unit, blood clotting, and length of patient sustainment. The grapefruit-sized AbioCor System weighs about two pounds, making it too large to be implanted in the majority of patients. In fact, the AbioCor System is suitable to fit in only 50% of men and 20% of women (Singer, E.). In response to this problem, the AbioCor II System will be 30% smaller than its predecesor, fitting in the majority of men and at least 50% of women (Smith, A.), . The AbioCor System also has caused incidents of blood clot formation in several patients. As a result, Abiomed is investigating new polymers and biosynthetic materials for the AbioCor II to decrease the likelihood of clot formation in patients (Singer, E.). Finally, the AbioCor System is designed to sustain patients for up to 18 months. The AbioCor II is designed to last 5 years.
Along with further artificial heart development, doctors are experimenting with tissue engineering as an alternative solution to heart failure with the ultimate goal of regrowing a failed heart. One popular idea is the use of nanotechnology to create hundreds of microsized electromagnetic motors to replace a failing heart. This unit would be powered by a TET system simmilar to that of the AbioCor (Singer, E.). Furthermore, a team of doctors at MIT is experimenting with a biodegradable scaffold that can be used to guide the orientation of culture heart cells; ideally, the heart cells will be orientated into a new heart (Thomson). Although tissue engineerign research is still in preliminary phases, the ability to regrow failed hearts would be an effective and long-term solution to heart failure if plausible.
The AbioCor is about the size of a grapefruit or softball. The natural heart is about the size of a clenched fist. As such, only 50 percent of men and 20 percent of women have chest cavities large to hold the AbioCor (http://www.chfpatients.com/implants/artificial_hearts.htm). We recommend that the AbioCor is trimmed down to accommodate smaller patients. Titanium has a density around 4.5 g per cubic centimeter. The densities of polymers and organic tissue are significantly lower at around 1-2 g per cubic centimeter. We suggest that titanium be replaced with biomaterials. For example, The Polymer Technology Group, Inc., a specialized biomaterial research and development company, has created several synthetic polymers, including BioSpan Segmented Polyurethane and Bionate Thermoplastic Polycarbonate Urethane. Other companies are hard at work engineering tissue for use in a biomedical application. If AbioMed were to replace titanium with biomaterials, not only would the thoracic unit weigh less and take up less space, but it would have the added bonus of increased biocompatibility (titanium is not perfectly biocompatible).
The batteries, as previously mentioned, only last for about 4 hours on a charge. The internal battery can only sustain the System for 45 minutes before it runs out of charge. The battery system, as it stands, hinders the freedom of the patient tremendously. We recommend that the AbioCor takes advantage of cutting edge battery technology in order to give patients more freedom.
The AbioCor is an extremely complicated system and obviously an extremely important one. It is imperative that the System is carefully monitored at all times. Although this is the PCE’s job, we recommend that an additional monitoring system be put in place. No matter how advanced the PCE’s software is, there will be glitches. In the case of the AbioCor, glitches could very well result in death. We are envisioning a situation where data are constantly collected on the System and sent to expert technicians who make sure the system is operating correctly.
The AbioCor System: Overview
AbiCor® Replacement Heart System Team Baits Adam Naylor, Philip Kaule, Samantha Luber, Andrew Foo, Scott Richards November 5 th , 2009
Brief Introduction <ul><li>Each year 700,000 people die from heart disease </li></ul><ul><li>Only 2,000 donor hearts are available each year </li></ul><ul><li>Potential AbioCor client-base of 100,000 people </li></ul>
Overview of Today’s Presentation <ul><li>Anatomy and physiology of the heart </li></ul><ul><li>Explanation of heart failure and its causes </li></ul><ul><li>Brief history of attempts at heart replacement </li></ul><ul><li>Physical description of AbioCor Heart </li></ul><ul><li>Explanation of the function of the AbioCor Heart </li></ul>
Anatomy of the Heart http://www.starsandseas.com/SAS_Images/SAS_Physiol_Images/SAS%20cardiopics/heart_flow.jpg
Blood Flow Through the Heart Inferior Vena Cava Right Ventricle Right Atrium Superior Vena Cava Aorta Artery Pulmonary Artery Left Atrium Pulmonary Vein Left Ventricle http://www.starsandseas.com/SAS_Images/SAS_Physiol_Images/SAS%20cardiopics/heart_flow.jpg
Timeline of Artificial Heart Development 1960 1970 1980 1990 2000 Pump Experimentation Liotta Total Artificial Heart Jarvik-7 Total Artificial Heart Jarvik 2000 Heart Akutsu III Total Artificial Heart AbioCor Replacement Heart System AbiorCor 2
Akutsu III Total Heart Replacement <ul><li>Accomplishments: </li></ul><ul><ul><li>Complete artificial heart </li></ul></ul><ul><ul><li>Continuous-flow pumps in humans </li></ul></ul><ul><li>Limitations: </li></ul><ul><ul><li>Short-term support </li></ul></ul><ul><ul><li>Not portable </li></ul></ul><ul><ul><li>Complex control system </li></ul></ul>http://www.texasheart.org/Research/ Devices/akutsu.cfm Pumps Akutsu III TAH
Jarvik-7 Total Artificial Heart <ul><li>Design Accomplishments: </li></ul><ul><ul><li>Longer support time </li></ul></ul><ul><ul><li>Safety features </li></ul></ul><ul><ul><li>Patient is transportable </li></ul></ul><ul><li>Limitations: </li></ul><ul><ul><li>Large external console </li></ul></ul><ul><ul><li>Not permanent </li></ul></ul><ul><ul><li>Health risks </li></ul></ul>Jarvik-7 TAH http://www.texasheart.org/Research/images/jarvik7.jpg Air line Tubing Artificial Ventricle
AbioCor Replacement Heart System <ul><li>Design Accomplishments: </li></ul><ul><ul><li>Completely self-contained </li></ul></ul><ul><ul><li>Compact </li></ul></ul><ul><ul><li>Portable </li></ul></ul><ul><ul><li>Permanent </li></ul></ul>AbioCor External Battery Internal Control System Heart Replacement http://www.texasheart.org/Research/Devices/abiocor.cfm
The AbioCor System http://www.heartreplacement.com/how.html
External and internal tet Internal TET External TET http://faculty.ksu.edu.sa/MFALREZ/EBooks%20Library/Biomedical%20Technologies/AbioCor%20System-Impl.%20Art.%20Heart.pdf TET – Transcutaneous Energy Transmission
Battery System Internal battery - Used as a back-up system (45 minutes) PCE battery - Lasts for two hours (per battery pair) http://faculty.ksu.edu.sa/MFALREZ/EBooks%20Library/Biomedical%20Technologies/AbioCor%20System-Impl.%20Art.%20Heart.pdf
The Console Console http://faculty.ksu.edu.sa/MFALREZ/EBooks%20Library/Biomedical%20Technologies/AbioCor%20System-Impl.%20Art.%20Heart.pdf
PCE Control Module http://faculty.ksu.edu.sa/MFALREZ/EBooks%20Library/Biomedical%20Technologies/AbioCor%20System-Impl.%20Art.%20Heart.pdf
Materials used in the AbioCor System <ul><li>Titanium and AngioFlex® are the two predominant materials used in the AbioCor system. </li></ul>
Materials used in the electrical and control system <ul><li>Implantable Battery and controller </li></ul><ul><ul><li>Enclosed in a medical grade titanium case. </li></ul></ul><ul><li>External TET </li></ul><ul><ul><li>External covering is covered in silicone. </li></ul></ul><ul><li>Internal TET </li></ul><ul><ul><li>Outer covering – AngioFlex </li></ul></ul><ul><ul><li>Cable out insulation – Carbothane </li></ul></ul><ul><ul><li>Connector – Titanium </li></ul></ul>Internal Battery External TET Internal TET Connector Cable out Internal Controller
Materials used in the Thoracic Unit Look at FDA pdf for sources <ul><li>Grafts (circled in green in Fig 1.) are made out of Dacron </li></ul>
Materials used in the Thoracic Unit Velour Polyester cuffs are sutured onto the atria. Clear epoxy on the exterior blood pump area. Tri-leaflet valves are made of AngioFlex ®(Polyetherurethane) Exterior is covered in titanium
Limitations of the AbioCor <ul><li>The AbioCor is very large – Only fits 50% of U.S Males </li></ul><ul><li>Limited lifespan – 1-2 years </li></ul><ul><li>Limited battery life – 4 hours </li></ul><ul><li>CPR is not allowed </li></ul><ul><li>Anticoagulation management is painful </li></ul>
Alternative Systems to the AbioCor <ul><li>Leading alternative treatments for end stage heart failure: </li></ul><ul><ul><li>Left Ventricle Assist Systems </li></ul></ul><ul><ul><ul><li>Jarvik 2000 FlowMaker® </li></ul></ul></ul><ul><ul><ul><li>Penn State LionHeart </li></ul></ul></ul><ul><ul><li>Total Artificial Hearts </li></ul></ul><ul><ul><ul><li>Cardiowest </li></ul></ul></ul>
Thoratec HeartMate II <ul><li>Advantages: </li></ul><ul><ul><li>Smaller </li></ul></ul><ul><ul><li>Lighter </li></ul></ul><ul><ul><li>Longer battery life </li></ul></ul><ul><ul><li>Continuous-flow pumps </li></ul></ul><ul><ul><li>Axial pumps </li></ul></ul><ul><li>Disadvantages: </li></ul><ul><ul><li>Not at total artificial heart </li></ul></ul><ul><ul><li>Skin-piercing wires </li></ul></ul>HeartMate II http://surgery.med.umich.edu/cardiac/images/content/HeartMate2_LVAD.jpg
Penn State LionHeart <ul><li>Advantages </li></ul><ul><ul><li>Completely self-contained </li></ul></ul><ul><li>Disadvantages </li></ul><ul><ul><li>Large internal component </li></ul></ul>Penn State LionHeart http://www.biomed.metu.edu.tr/courses/term_papers/artificial-hearts_gokduman_files/image013.jpg
Current Research and Development <ul><li>AbioCor II </li></ul><ul><li>Tissue Engineering </li></ul>
AbioCor II Replacement Heart System <ul><li>Addresses the limitations of the AbioCor System </li></ul><ul><ul><li>30% smaller thoracic unit </li></ul></ul><ul><ul><li>Use of new polymers and biosynthetic materials </li></ul></ul><ul><ul><li>5-year reliability </li></ul></ul>AbioCor II Heart http://medicineandman.com/blog/wp-content/uploads/2006/09/_images_89703063.jpg
Tissue Engineering <ul><li>Nanotechnology </li></ul><ul><ul><li>Microsized electromagnetic motors </li></ul></ul><ul><li>Biodegradable scaffold </li></ul><ul><ul><li>Shape a culture of heart cells </li></ul></ul>
Design Recommendation <ul><li>Lighter Thoracic Unit </li></ul><ul><li>Longer Battery Life </li></ul><ul><li>Increased Medical Surveillance </li></ul>
Summary <ul><li>Each year 100,000 people will die from lack of donor heart availability </li></ul><ul><li>AbioCor designed to permanently replace patient’s heart </li></ul><ul><li>AbioCor is most advanced heart replacement system to date </li></ul>