Artificial Heart Program (AHP) is a flagship bio-engineering initiative by SHARE INDIA that brings together engineering institutes, medical institutions, and industry partners to advance the indigenous development of life-saving cardiac assist devices in India through collaborative, innovation-driven research.

SHARE INDIA jump started its activities toward the development of a blood pump suitable for bench testing and pre-clinical readiness. The LVAD has two critical parts, Motor and Pump Head. The commercially available, CentriMag pump is used as a control standard for the development of the blood pump.

The disposable pump head was developed by CBIT, KITS and SNIST. The 3D printed prototype underwent in-vitro hemolysis testing in AIG Hospital using a mock loop testing system developed by our team. It showed minimal hemolysis comparable to similar devices in extensive use. After the successful trials on the prototypes, the pump parts were injection moulded using medical grade polycarbonate. Vasantha Tool Crafts Pvt. Ltd. has collaborated with the team and taken up the task for the design of the moulds and initial manufacturing of the injection moulded pump head and impeller. To assemble the pump halves, biocompatible adhesive is used. A robotic arm and UV equipment are proposed to be procured for high quality assembly of the parts.

The motor is being developed by Laxven Systems. The motor works on Maglev principle, which levitates and rotates the impeller which is inside the pump without any physical contact. The team is also developing a console unit for the motor.

Simultaneously, in-vivo control studies are being performed with existing LVAD/ECMO devices on sheep at Palamur Bioscience Labs. In March 23, the US team visited the animal facility and assisted the team in conducting a successful 5-day sheep study using CentriMag. 

The injection moulded pump and CentriMag are being tested for hemolysis, activated thrombosis and hydrodynamics. Along with this, in-vitro testing for von Willebrand factor accrued deficiency is being developed at AIG Hospital, Hyderabad.

Motor and Controller:

Test rig was designed and fabricated to study 3D properties of the magnet. This setup measures variation in magnetic field due to linear movement (X, Y, and Z) and rotation. Controller unit to also be fabricated at Laxven Systems and will be completed by Dec 2023.

Pump casing and Impeller:

• Vasantha Tool Crafts is handling the design and manufacturing of the pump casing and impeller moulds. Medical grade polycarbonate is used for the manufacturing of pump parts. 
• Modifications in the impeller design- height of the impeller, ID/OD of the impeller were made to accommodate the best fit for the magnets. Magnets were also inspected for dimensions at VTC. Exploring to import or get the required magnets indigently if it meets the requirement 
• Design changes in the pump casing were made and samples were sent for the ultrasonic welding trials at AMTZ. 

Gluing:

A specialized glue dispensing robot and UV curing equipment has been proposed for purchase at KITS Warangal. Quotations for the equipment were received (Total Approx Rs. 13 Lakhs). 5 sets of pumps were sent to Delhi to be glued by this equipment. The glue was UV cured and tested for leakage. No leaks were observed. Parallelly, the ultrasonic welding of the pump casing is being explored at AMTZ, Vizag. Hydrodynamic testing for leakage is done for the pumps at high pressures. Suitable adhesive for sealing the impeller is being explored and vacuum testing on impellers done for quality control.

Hydrodynamic Test:

Hydrodynamic tests are performed to check for leakage of the pump at high pressures. (500mmHg). the tests are also done to evaluate pump performance by generating the H-Q curves. It consists of pressure and flow sensors to evaluate the data from the mock loop.

The INDUS and CentriMag centrifugal pumps will be tested for the hydrodynamics and the H-Q curves will be superimposed and compared. The curves aid in evaluating the pump performance and efficiency.

Hemolysis Test: Hemolysis is the rupture of the red blood cells, due to which hemoglobin enters the plasma. In a continuous flow blood pump, the blood undergoes a lot of shear and hence, mechanical damage of red blood cells causes hemolysis. A test facility was set up at AIG Hospital to conduct the mock loop experiments for hemolysis on Centrimag and the INDUS. 

Total 18 hemolysis tests have been conducted so far on Centrimag and the 3D-printed prototypes and the injection moulded pump. More hemolysis tests to be conducted at different flow rates and pressure conditions to establish the hemocompatibility.

Activated Thrombosis Test:

With the guidance of Dr. Barry Gellman, the ‘mickey mouse’ connector was designed to eliminate ring thrombosis effect in the mock loop. The ring thrombus is mainly formed at the joints where tube and the barbed connectors meet. Hence a connector, which would be placed on the tube, is designed to reduce the gap and thereby eliminating the thrombus formation. Activated thrombosis test was performed on the CentriMag, without the ‘mickey mouse’ connectors. The test was successful with ring thrombus and clots observed in the loop. Further testing to be done using the 3D printed connectors.

Von Willebrand factor (VWF).

VWF is an essential protein in clotting mechanism. Qualitative or quantitative defect of it causes bleeding. Mechanical pumping of blood to result in breakdown of protein. Dedicated personnel has been appointed at AIG to conduct the VWF tests along with other team members. Platelet poor plasma is used to test the pump. The mock loop is prepared, and hourly samples collected from the running loop. These samples are tested for the following.

1. VWF Antigen level (ELISA kit)
2. VWF Collagen binding activity (ELISA kit)
3. VWF multimer analysis

One loop test was conducted on Centrimag. The samples were collected and analysed for the antigen level and collagen binding activity for VWF. 4.93% decrease in VWF: CB/Ag was observed from the baseline. Consumables for the multimer analysis are to be procured.  

Animal Testing:

A major milestone of our program was achieved with a 96-hours long sheep study successfully conducted at Palamuru lab under the supervision of Dr. Sharma, Dr. Sukesh Reddy and other team members. The test was done using Centrimag impeller and controller. The study provided data on surgical cannulation and post-operative management of the sheep. Animal survival throughout the surgical procedure and post extubating was successfully achieved. One day sheep experiment is costed about Rs 3.5 lacs.

Our attempts to develop skills at Palamur Bioscience laboratories to keep sheep alive on Left Ventricular Assist Device (LVAD- “Artificial Heart”) for 30 days are ongoing. Four experts from Pittsburgh visited the facility and imparted training in care of the sheep for 5 days on External LVAD available in the market (Centrimag).