Solid state heart assist device

Disclosed is a control system having a processor configured to control a plurality of electromagnets to assist heart contractions and expansions based on input received from an electrocardiogram electrode and blow flow sensors.

BACKGROUND

Example embodiments relate to an electromagnetic pumping system and control system and more particularly to a pump and control system that moves fluid through cavities and valves using electromagnets controlled by a control processor unit. The pump and control system may be embodied in many useful forms such as, but not limited to, a heart assist device.

2. Description of the Related Art

In the United States alone, more than 735,000 heart attacks occur annually, with 5.7 million adults suffering from heart failure. Every year, $110 billion dollars are spent treating heart attacks, and the total direct medical costs of cardiovascular disease are projected to increase from $396 billion in 2012 to $918 billion in 2030. There is a substantial need for a solution to more effectively treat and resolve the problem, as heart failure remains one of the greatest costs and challenges facing our country's health.

The current, state-of-the-art ventricular assist devices (VADs) are implantable turbine pumping systems that require invasive surgeries and external electrical leads, which are prone to infection. Currently, other companies are attempting to improve these devices by reducing their size. However, there are limitations to this approach. For example, the current pumps are limited by the minimum tube size needed to move 5 L/min of blood at an appropriate pressure. Thrombosis is the most significant problem, and regardless of how small the turbine is, the turbine will still shear blood cells and create an immune response. The issues discussed above are only some of the inherent constraints of the current VADs available.

SUMMARY

The inventor is transforming the traditional thinking regarding VADs to create the next generation of devices, which addresses the problems with current technologies while adding other innovative features. Inventor's novel electromagnetic pumping system (EMPS) addresses the issue of thrombosis through its lack of moving parts, which greatly reduces biocompatibility risks. The EMPS may be composed of small flexible components that may be anchored nondestructively to the heart through a minimally invasive surgical approach.

Example embodiments provide a pump and control system. In one nonlimiting example embodiment, the EMPS and control system is configured as a device to gently handle fluid for use in assisting the natural heart in contraction or to contract an artificial heart. The device may assist a failing heart by using a number of electromagnets (EM) on the surface of the heart which interact with permanent magnets (PM) implanted in the heart. If the heart is too damaged for this, the ventricles of the heart may be replaced with artificial ventricles and the electromagnets and permanent magnets may power the artificial heart in the same way it assists the natural heart.

In example embodiments, a control unit may control the device with little to no input from a user or caregiver through advance adaptive control algorithms and or neural network pattern recognition programs.

In example embodiments, an implanted power storage system may allow for wireless changing for the device by providing a backup that will run the devices when wireless charging is not occurring. This will allow the devices it to be fully implanted reducing risks of infection and physical trauma while increasing patient quality of life.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings, in which example embodiments of the invention are shown. The invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the sizes of components may be exaggerated for clarity.

Embodiments described herein will refer to plan views and/or cross-sectional views by way of ideal schematic views. Accordingly, the views may be modified depending on manufacturing technologies and/or tolerances. Therefore, example embodiments are not limited to those shown in the views, but include modifications in configurations formed on the basis of manufacturing process. Therefore, regions exemplified in the figures have schematic properties and shapes of regions shown in the figures exemplify specific shapes or regions of elements, and do not limit example embodiments.

The subject matter of example embodiments, as disclosed herein, is described with specificity to meet statutory requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter might also be embodied in other ways, to include different features or combinations of features similar to the ones described in this document, in conjunction with other technologies. Generally, example embodiments relate to a pump and control system and more particularly to a pump and control system that moves fluid through cavities and valves using electromagnets controlled by a control processor unit. The pump and control system may be embodied in many useful forms such as, but not limited to, a heart assist device.

FIGS. 1 and 2illustrate an example of a device100configured to operate as a left ventricular assist device. As shown inFIGS. 1 and 2, the device100may include a first plurality of electromagnets5which may be placed on an exterior surface of a left ventricle. The first plurality of electromagnets5may include a first electromagnet10, a second electromagnet11, and a third electromagnet12, however, the first plurality of electromagnets5may include more than three electromagnets or less than three electromagnets. In other words, the number of electromagnets is not critical.

In example embodiments, the first plurality of electromagnets5may be flexible and may bend and move with the natural motion of the heart beating. The first plurality of electromagnets5may be housed in a flexible material with cavities and valves that will allow for the movement of a cooling fluid through the housing to discharge heat generated be the electromagnets5. The first plurality of electromagnets5may be connected by a lead7to a control system40. A first permanent magnet20, may be on the interior of the left ventricle and may be anchored to the median septum of the natural heart or implanted within the median septum of the natural heart. The permanent magnet20(and the permanent magnets22-23, to be explained shortly) may be made from rare earth metals such as neodymium or from other highly magnet materials which may be in the form of powder or small pieces to allow them to be flexible. That is, permanent magnet20may be comprised of smaller magnets. Other materials that could be used are super magnetic nanoparticles, alloyed metals that may increase magnetic properties. Magnetic liquids may also be used to make the permanent magnet20(and the permanent magnets21-23) very flexible and to allow it to be easily implanted endoscopically. The permanent magnet20may be coated in a soft flexible material like silicon which may be infused with chemicals to encourage cells to grow over the material to help the permanent magnet20anchor to the heart wall. The permanent magnet may also be anchored with stitches and or barred anchors to reduce the risk of detachment. The risk of detachment may be addressed by implanting the permanent magnet20inside the median septum of the natural heart. When the permanent magnet20is implanted in the median septum of the natural heart it may be done through a catheter that will insert a balloon which will the be filled with magnet materials suspended in a binder. After the catheter has implanted the balloon filled magnet materials suspended in a binder the electromagnets5can be energized to align the magnet materials polarity to be opposite that if the electromagnets5. This alignment process can be used to customize the permanent magnet20to match up with the electromagnets5for and given heart ventricle both artificial or natural. The permanent magnets in the total assist model200(to be explained later) may be on opposite side of the median septum and may be aligned so they pull towards one another to help them stay anchored. As one skilled in the art will readily recognize, more than one permanent magnet may be used on each chamber of the heart if needed. The device100may further include an electrocardiogram electrode30, placed on the exterior of the heart and connected to the control system40. The electrocardiogram (ECG) electrode30may provide input about the state of the heart such as, but not limited to, the heart rate. The ECG electrode may feed the control system40with a relatively full picture of the heart as it is beating, however, in some embodiments, more than one ECG electrode may be used depending on the model and need based on the patient. The data from the ECG electrodes may be used with a neural network type program in the control system40to allow for the control system40to recognize patterns in the heart and make the changes. The ECG may help the control system40determine the timing that is needed when assisting the heart.

FIGS. 3 and 4illustrate an example of a device200configured to operate as a total heart assist device. InFIGS. 3 and 4a first plurality of electromagnets5is placed on the exterior surface of the left ventricle and a second plurality of electromagnets6is placed on the exterior surface of the right ventricle. InFIGS. 3 and 4the first plurality of electromagnets5includes a first electromagnet10, a second electromagnet11, and a third electromagnet12and the second plurality of electromagnets6includes a fourth electromagnet13, a fifth electromagnet14, and a sixth electromagnet15. ThoughFIGS. 3 and 4illustrate the first and second pluralities of electromagnets5and6as comprising three electromagnets the number is relatively unimportant. For example, each of the first and second pluralities of electromagnets5and6may include more than three or less than three electromagnets.

In the nonlimiting example embodiment ofFIGS. 3 and 4, the device200may include one or more electromagnets17on the exterior surface of the right atrium, and one or more electromagnets16on the exterior surface of the left atrium. These electromagnets16and17may be flexible and may bend and move with the natural motion of the heart beating. The electromagnets16and17may be connected by a lead to the control system40.

In the nonlimiting example ofFIGS. 3 and 4, the device200may further include a first permanent magnet20that may be attached on the interior of the left ventricle. In this nonlimiting example embodiment the first permanent magnet20may be anchored to the median septum of the natural heart. The device200may also include second permanent magnet21arranged on the interior of the right ventricle and attached to an opposing side of the median septum. The device200may also include a third permanent magnet23on the interior of the left atrium and a fourth permanent magnet22that may be on the interior of the right atrium. These permanent magnets20,21,22, and23may be flexible and may be endoscopy implanted. In this nonlimiting example embodiment, the device200may further include an electrocardiogram electrode30, placed on the exterior of the heart and connected to the control system40, to provide input about the state of the heart.

FIG. 5illustrates an example of an artificial heart hybrid with an assist device300incorporated therein. The ventricles of this artificial hybrid heart may be artificial50, but may also have properties that mimic the natural ventricles. The artificial ventricles may be attached to the patient's natural atria and may use the patient's natural valves when possible. The artificial ventricles may be made of a soft bio-compatible material like silicon, or some other polymer or potentially a combination of materials. The artificial ventricle may also be made from synthetic and biological material. This may be done using some tissue from the patient and then reinforcing it with synthetic material. When synthetic and biological materials are used, the synthetic materials may bio-degrade and leave behind a purely biological ventricle. The use of a bio-degradable synthetic ventricle could allow for the regrowth of a biological ventricle from the patient's tissues. This may also come in the form of a extracellular matrix that has been seeded with stem cells. The pumping system would act as a prosthesis as the cells grow and mature. The end result could be the removal of the pumping system and or it could be shut down to be used in future if need be. The artificial ventricles may be powered be the same electromagnetic drive system that is used in devices100and200. For example, a first plurality of electromagnets5may be placed on an exterior surface of the artificial left ventricle and a second plurality of electromagnets6may be placed on a surface of the artificial right ventricle. The first and second pluralities of electromagnets5and6may be flexible and may bend and move the artificial ventricles in the natural motion of a heart beating. The pluralities of electromagnets5and6may be connected by a lead to a control system40. The device300may further include a first permanent magnet20on the interior of the left ventricle and may be anchored to the median septum of the artificial ventricles and a second permanent magnet21anchored in on the interior of the right ventricle. These permanent magnets20and21may be flexible to allow for the artificial ventricles to move like that of a natural heart. There may be an electrocardiogram electrode30, placed on the exterior of the natural part of heart and connected to the control system40, to provide input about the state of the heart.

In example embodiments, the leads that connect the first and second pluralities of magnets electromagnets5and6and/or the electromagnets16and17as well as the leads that connect and the ECG electrode30to the control system40, may be removable to allow for easy replacement in the case of component failure.

In example embodiments, the heart assist devices100,200, and300may include a plurality of sensors as shown inFIG. 6. As one example, strain gauges60,61,62may be placed either within or on the natural veins and arteries of the heart. These strain gauges60,61,62may be used to determine the blood pressure at the inlets and outlets. As another example, optic/sonic sensor63,64,65may be a optical, sonic hybrid sensor or just an optical and/or sonic sensor and may be incorporated into the device to detect oxygen within the blood and other biometrics such as velocity of the blood. The strain gauges60,61,62in combination with the optic/sonic sensor63,64create a unique sensor which allows for real and continuous blood pressure and flow sensing. This is a very advantageous capability to have for controlling heart assist devices and helps to makes these devices safer and more reliable. This sensor configuration could also be very useful in monitoring the patient prior to implantation of a heart assist devices or heart transplant. This means that a sensor array made up of strain gauges and optic/sonic sensors could be implanted independent of the heart assist device to monitor a patient who is at high risk of heart failure. The same power system110and control system80that will run the heart assist could be used to run the sensor array allowing for rapid installation of the heart assist components when the need arises. The electromagnet driver90and back up battery100could then be implanted with the heart assist components and control system would then be wirelessly updated to run the electromagnets. This modular approach may allow for the heart assist device to change with the needs of the patient. For example, allowing the patient to go from the left assist version to the full assist version may be accomplished by simply implanting more electromagnets and permanent magnets, connecting them to the driver90, and updating the control system40. By the same token if the patient's condition worsens and they start to require more power an additional power system110can be implanted to provide this. Because of this all the electrical components may be designed to handle at least twice the load required. Other sensors70may be placed within the control system enclosure40to detect operational parameters including, but not limited to temperature, movement, and altitude to sense the environment within the body and activity levels.

In example embodiments, an advanced control system80may be located in a control system enclosure40(seeFIG. 7). The advanced control system80may be connected to the sensors60-65and the electromagnets (for example, any one of, or all of, the first and second pluralities of electromagnets5and6and/or the electromagnets16and17). The control system80may have a processor82with memory81, a receiver83, a transmitter84, a gyroscope85to detect a patient's physical state (i.e., lying down, standing), an accelerometer86, an altimeter87and a thermometer88. Also, driver90for the electromagnets may be in the control system enclosure40. There may also be a backup battery100in the enclosure40that may be charged from a primary battery pack111.

FIG. 8illustrates an example of a power system enclosure110that will house various power elements. For example, the power system enclosure110may house the primary battery111and the components of the wireless charging system these components may be built in a way that makes them flexible which would allow for the power system enclosure110to also be flexible allowing for less damaging implantation surgery options and made from some flexible bio-compatible material such as silicon. The power system enclosure110may be filled will a non-conductive fluid and may be run through a heat exchanger of some sort to help prevent the receiver coil121and primary battery111from heating up to a point that they may damage the surrounding tissue. This fluid may also be circulated through the flexible housing around the electromagnets5to prevent them from overheating and damaging the heart tissue. The wireless charging system120, for example, may be made up of a receiver coil121, a receiver122that can be used to alert the RX controller127that a transmission coil112is in place and to start the charging, a transmitter123to allow the RX controller127to communicate with the external battery pack113which can be used to alert the external battery pack113that the primary battery is fully charged, to prevent over charging, or the receiving coil121or primary battery111has reached a dangerous temperature. Also, the wireless charging system120may include a rectifier124which may convert the current if needed, a signal filter125to clean the current when is it received, thermometer126to ensure the coil121and the RX controller127does not get too hot. The RX controller127will control the charging process to ensure effectiveness and safety. This wireless charging circuit may be like those used in charging mobile phones and other small electronics. The induction receiver coil121may be charged by induction transmission coil112which may be powered by the external battery pack113. The external battery pack113may be something that is like a belt of can hang on the waistline of the patient or over their shoulders. This power system110may be designed to allow for another power system to be connected in parallel with it in the case more power is needed. It may also be designed in a way to power more than just the heart assist, for example, it could be designed to power other artificial organs or organ support devices. For example, a fully implanted insulin pump could use the same power system110as the heart assist reducing the need for an additional surgery. The power system110may also be used to power implantable sensors. For example, neural sensors placed on or near the spinal cord to provide neural impulse signals to a prosthetic may be powered be the same power system110. These examples are meant to show that the power and control system may be designed to allow for other devices to be integrated into them to reduce the surgeries needed.

In example embodiments, a wearable system130may be wirelessly connected to the control system40using near field communication technology. The wearable system130may include a wearable device131, such as a necklace, wrist band, or the like that has a housing and a fastening member. The wearable device131may have a display132which may be touch screen to allow for easy user interaction connected to a processor135which may allow the wearable to decrypt and analyze the data sent from the control system80. The wearable system130may further include a memory140which may allow the wearable system130to store data sent from the control system80, a receiver133to allow the wearable system130to receive data from the control system's transmitter84, and a transmitter134that may allow the wearable device131to communicate with the control system80and send data from the sensors on the wearable device131, such as the accelerometer137or the GPS138. Each of the above elements may be powered by a wearable battery139which may be interchangeable to prevent the user from having to remove the wearable device131for long periods with charging. Also, the wearable system130may further include sensors such as, but not limited to, a heart rate sensor136, accelerometer137, GPS138and altimeter139which may use a substantial amount of power making it better to have outside the body. These sensors may aid in providing data to the processor82in the control system80.

The wearable device131may be synched to a mobile phone for storage and transmission of information using Bluetooth141. This data can be used by a doctor or caregiver to monitor the patient. In the event the patient has complications, the doctors can see the condition of the patient and the device remotely. If the patient is not feeling well they can call the doctor and the doctor can see their condition through the connection of the phone to the wearable system130. If the patient is in danger the caregiver can call emergency services to the location given by the GPS on the wearable system130. The wearable device131may also be synched to a patient monitor system at a health care facility or through other secure internet connected devices depending on the patient's location and needs.

In operation, once the drive system made up of electromagnets (for example, the pluralities of magnets5and6and the electromagnets16-17) and permanent magnets20-23, the control system enclosure40and the power system enclosure120are implanted, blood may be pumped through the atria and the ventricles of a natural and/or artificial hearts. The sensors60-65may monitor operational parameters preferably every half second or more often. Based on operational parameters detected and transmitted from the sensors60-65and the ECG electrode30, the processor82of the control system80calculates a timing and force which the electromagnetic driver90will translate into power to be sent to the electromagnets10-17in the appropriate order. For example, in one embodiment, the optic/sonic sensors60,61,62detect and transmit information to processor82about the blood oxygen level and the stain gauges63,64,65sense a change in blood pressure. When the blood oxygen level or pressure is high as compared to the normal blood oxygen level or blood pressure that has been set and or determined by the neural network program and or predictive control loops, and or feedback control loops or some combination of control loops algorithms, programs and models, as health operation limits for the patient, the power to the electromagnets10-17is decreased. When the blood oxygen level, flow and/or pressure is low, as compared to the preset blood oxygen level or blood pressure, the power is increased. In essence, the power sent to the electromagnets determines how much assistance is given or how hard the ventricles and/or atria contract. The force required to assist the heart depends primarily on the patient and their condition. The force needed can also change if the patient's condition worsens or gets better, which is why a control system that can adapt to the patient in real time is essential. The timing is determined from data collected from the ECG electrode and other sensors which senses when the heart beats and transmits to the processor82which then activates the electromagnetic drive90at the appropriate time.

Once the timing and needed force is calculated by the processor82, the processor82sends a signal to the electromagnetic driver90to activate the electromagnets in the contraction order which depends on the version of the device. For example, the electromagnetic driver90may fire the electromagnets10-17of the second or third device200and300by switching polarity to first attract permanent magnets20-23and reversing polarity to push the permanent magnets20-23away. The electromagnet firing order will depend on the version of device. The left assist device100, for example, may start by activating electromagnet12and then activating to electromagnet11and then activating electromagnet10and the total heart assist device200may start by activating electromagnet17and then activating electromagnet15and then activating electromagnet14and then activating electromagnet13.

The electromagnet firing order will depend on the version of device, the left assist device may start with electromagnet12and the full assist device may start with17. Based on a predetermined or preset delay, the electromagnetic driver90activates the next electromagnet in the array in the same manner as previously described to complete a pump cycle. The processor80, using the sensor inputs from any one of, or all of, the sensors60-65, may then calculate the force and timing before repeating the process for the next pump cycle. The processor80will do this by using control algorithms that will be stored in the memory81. The processor80could also use a neural network program and the data log on the of previous control loops to recognize patterns and make predictions and changes to the control parameters as need be.

If the transmitted blood oxygen level and blood flow and/or blood pressure falls outside of the safe or healthy preset or predetermined range, then the processor80defaults to a safe baseline default timing and force. Also, when a disturbance is detected, such as detecting with the accelerometer86that an individual has started to run, the processor80may calculate the timing and force based on predetermined and/or preset parameters and from the history of the last time such a disturbance occurred.

The processor80may also transmit information to the wearable device131. In one example, the processor80transmits information about heart rate, blood oxygen level, and battery level that is received by the wearable device131and shown on display132. The wearable device131may also be synched with the mobile phone and/or a patient monitor where information may be transmitted and stored. The receiver83in the control system80may be used to update the control system80wirelessly allowing doctors and care givers to make changes to the system's parameters and download the memory log, when the appropriate access codes are presented. This will also allow the engineers to update the control system programs and algorithms without removing the device from the patient using the same transmitter84and receiver84the wearable uses to communicate with the control system. The control system80may be made on a platform that allows the whole circuit to be flexible. The flexible circuit design for the control system may or may not have solid components like memory that will be connected to a flexible chip which will allow the circuit to bend, this would allow the control system enclosure40to also be flexible allowing for less damaging implantation surgery options. The control system enclosure could be a silicon pouch or some other flexible bio-compatible material in which the flexible control system circuit could be, entrapped in the silicon or suspended in a non-conduction fluid. This non-conductive fluid in the control system enclosure could also be used to assist in cooling the processor by moving the fluid though a heat exchanger to disperse heat to the surrounding body.

Example embodiments of the invention have been described in an illustrative manner. It is to be understood that the terminology that has been used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations of example embodiments are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described.

In example embodiments the control system40may use data for the ECG30but this may not be the primary control variable. The ECG30may only be controlling the timing of the energization or contraction of the electromagnets5. The primary input that the control system40muse to determine the intensity and duration of the contractions may be based on the output flow from the heart. A normal health human heart outputs between 5-10 L/min. The heart output may be the primary input that the control system40may use to control the electromagnets5. For example, in one embodiment, the optic/sonic sensors60,61,62detect and transmit information to processor82about the blood flow rate out of the heart and the stain gauges63,64,65sense a change in blood pressure and other activity related feedback. The blood flow rate and disturbances in the form of activity changes will be used to calculate the intensity and duration of the next pulse send to the electromagnets5during the next contraction of the heart. A flow chart of what this logic may look like is seen inFIG. 12. From the flow chartFIG. 12the control system40will not need to know when the ventricle is full because the timing of the pulse to the electromagnets5is determined by the heart natural contraction timing which is sensed by the ECG30. The delay between the a+ pulse and the a− pulse may be determined by the flow rate out of the heart. Meaning as the flow rate out stops this indicates the hearts natural contraction is complete and the ventricle is preparing to refill.

Using the data for the optic/sonic sensors60,61,62and the stain gauges63,64,65the processor82may provide the current state of the heart to the control system40. The control system40may then calculate how much assistance the heart will need from the electromagnets5to bring the heart output back a set point. The set point that the control system40may be controlling to, may be determined by historical sensor data on the patient and other changes in the condition of the patient. An example of a change in the condition of the patient would be moving from a sitting to a standing position. In this example the control system40may receive a signal from the gyroscope85and accelerometer86that the patient's position has changed, and the control system may increase the set point for heart output to a higher level to prevent the patient from getting light headed after standing quickly. Predictive controls have never been used to control a heart assist device of any kind.

The electromagnets5may assist in contraction of the natural or artificial heart by applying force to the outside wall of the ventricle. This force may be created by the magnetic field interactions that pull magnetized components of opposite polarity towards one another. When the electromagnets5are energized they may create a magnetic field with the opposite polarity of the permanent magnet20and they may be pulled towards one another. The electromagnets5may be anchored on the outside of the ventricle and may therefore apply force to the ventricle wall and assist the heart in forcing the blood out of the ventricle, thereby increasing the heart's output. The polarity of the electromagnets5can then be reversed and they will push away from the permanent magnet20assisting the ventricle in filling. This electromagnetic pumping system is novel in the way that multiple free-standing magnetic components generate magnetic fields that interact with one another to create mechanical force on diaphragms that can be used to assist both artificial and nature hearts. An electromagnetic pumping system has never been used to assist a heart through the linear interaction of magnetic field through the heart ventricle.

The use of wireless charging will allow for the devices to be charged from and external source. This source may be the battery belt113or some other power source. One alternative power source may be a bed charging system which will pull power from a conventional wall outlet and use a larger version of the wireless charging transmitter112to create a charging field around the whole bed. This will allow the patient to sleep without the need for any wires connected to them.