Report preclinical trials Oct 10, 2015
In mid-September, we conducted preclinical animal tests over two days with cardiac pump model 8. During the past six months we have been working to improve the pump’s physiological function and optimize the drive system (with a new engine). Both pump drive system has for several months been tested in a simulator. We have gradually been able to improve and optimize the function. The purpose of the test was now testing the function in physiological pre-conditions. Trial precipitated as follows:
The pump function
Model 8 is designed as two pumps connected in series and controlled by a computerized control system. The heart pump is controlled in a physiological manner and provides the correct number of heartbeat with a natural rhythm for each pulse. The design with two pumps enables the heart, if necessary, to handle different amounts of blood from the two body halves (a low pressure side and a high pressure side). This system at the test functioned largely as intended, although there is room for some further improvement. These changes do not require redesign of the mechanism, but may be made in the computer program that controls the pump and which can then be further tested in a simulator.
The driving system
The new model has a more efficient driving system than previous models. Each pump half is driven by a small electric motor with an efficiency of about 90%. Each pump only consumed 200 mA during the test. Theoretically, this means that a battery with a weight of about 800 grams would be enough to power heart pumps for a whole day. The pump even gave larger stroke volume than necessary which caused a certain under-pressure on the right side. There is therefore reason to slightly reduce stroke volume and possibly try an even smaller engine. Due to the high efficiency, there is no increased temperature in the motor and driving system. The driving system delivered good blood pressure and pulse rate. The outcome of the test in terms regarding the driving system was thus very encouraging. It is obvious that here we have found a good solution in principle.
Implantation of the pump
In connection with the test we first put the animal in the heart-lung machine and the biological heart was taken out. We then implanted our heart pump. We had constructed new connections to simplify the procedure. It went this time much easier than in the previous test but it still was not good enough. Our biggest problem so far has been to de-air the system. We now had a new solution, which admittedly was somewhat better than before, but not perfect. The pump was not leaking but we had slightly disturbing leaks in the connections between the pump and the animal’s vessel. These connections must be improved.
After completion of the test can conclude that the driving system is conceptually fully developed and that the amount of blood pumped from each chamber is more than enough. We also estimate the pump principle and its basic design as fully developed. Further optimization will primarily take place through changes in the computerized control system with an extended sensor. We have a challenge in standardizing the surgical technical solution regarding implantation, connections and de-airing Additional tests are therefore already planned and will take place within a few months for the improvement and adjustment of these parameters.
With this report, we can now conclude, in line with what we previously communicated in the company’s memorandum, that heart pump model No. 8 is equipped with an effective and energy-efficient driving system and has an electric motor with higher efficiency than model 7 had. Model No. 8 is also controlled by a computerized control system which was developed during the spring / summer 2015 by a leading company in motor control. The previously announced tests that was planned during the spring 2015 of will be replaced with longer simulator testing of the new control system. The next clinical test will instead be in the middle of September, and additional animal tests are planned in the coming months in preparation of the prolonged trial in late 2016.
The outcome of the completed test gave us in terms of energy sufficient evidence to bring forward the work on battery selection. We will in the coming months launch cooperation with companies in the development of battery and battery customization. We will also start work on the introduction of sensor control and self-regulation (autoregulation) of the heart pump earlier than we had planned. Auto regulation means that the pump itself senses when the heart rate must be increased – for example when the individual does heavy physical work. We believe we have come further than planned in terms of reducing consumption of the pump. As we swapped the simulator test earlier in 2015, the long-term clinical tests that we previously intended to carry out during the autumn of 2016 will be conducted during the spring of 2017.
Board of Directors
Results animal test Nov. 2015
Published 15 11 17
The first week of November was conducted additional preclinical animal tests with cardiac pump model 8. During the previous trial in mid-September the pump basically worked flawlessly with high efficiency and low energy consumption. We however had some problems with the surgical technique for implantation. Since September, the we have now improved the technique of implantation and optimization of the driving system. The purpose of the test was now to once again test these functions under physiological conditions. The trial functioned as follows.
The function of the pump
The pump is designed as two pumps connected in series and controlled by a computerized control system. We had now added a further control function that simplified implantation of the pump. The new control system proved to work according to plan and we achieved natural pulse and normal pressure conditions. We could control both stroke volume and heart rate. The animal’s oxygenation was also good. The steering system was shown to function completely as intended, which is an important principle step forward.
The driving system
It was once again confirmed that the driving system is efficient and draws a small amount of energy and has high efficiency. Even at higher load only a small part of the engine capacity was utilized. This means that the size of the motor can be reduced without affecting the operation of the pump. This is very positive. The vacuum that was created in the right atrium at the previous trials could this time be completely avoided through improved computer control of the pump. The computer program can balance the power demand between the two halves of the heart, thus providing a fully coordinated overall function. The driving system delivered good blood pressure and pulse rate. The outcome of the test in terms of the driving system was thus very encouraging.
Implantation of the pump
In connection with the trial the animal was first put on the heart-lung machine and the biological heart was then taken out. Our heart pump is thereafter sewn in. In previous tests, we had some problems with the implantation. In previous tests there was some leakage in the connections and we had problems with bleeding. The connections were now newly designed and we had new ports for de-airing. These new solutions were found to work as intended. There was absolutely no leakage. De-airing was also easier and faster, and all but complete.
After additional animal test we can now see that model cardiac pump 8 works well in a biological system. It delivers good pressure and heart rate and can be easily and effectively controlled. The connections were tight. Only a small part of the engine capacity was utilized, which means that the next cardiac pump model can have a smaller engine. As for the overall development, we are presently little ahead of schedule.
With this report, we can now state, in accordance with what we have previously communicated in the company’s memorandum, that the heart pump model No. 8 with its function, driving system, connections, and the de-airing ports is a principle fully developed. This does not mean in any way that we have reached the finishing line. We now have to optimize engine operation and technology and to further develop the computerized control function. We also need to start the development of the energy supply. We aim to eventually develop an implantable battery system – something that other (simpler) models of the artificial heart are completely lacking. We will be based on the experience we have gained in this test also in the coming months to develop a new, slightly smaller engine version designed for subsequent long-term preclinical animal tests.
In the coming months we will conduct further animal tests with the new, smaller version. These will be the preparation for preclinical long-term tests that we intend to implement early 2017. As we said earlier, we are working toward the goal of conducting clinical tests on humans sometime late 2017 / early 2018.
Göran Hellers, Chairman of the Board