Progress

First prototype for the Hokie Heart Design

The first prototype was developed in November of 2021, which can be seen to the left. This prototype followed the basic ideas of the design with some modifications, for example water was used instead of perfusate as this solution is not fully developed. Along with that a fish tank pump was utilized to demonstrate the idea behind the device's pumping of the perfusate to and from the perfusate reservoir, however, this selection will not likely be included in the final design.


Gathering Perfusate Materials

The process of gathering all of the materials required to create the perfusate solution was started and nearly finished. Along with having all of the materials for our final design perfusate, the solution is required to be able to test the techniques of monitoring the organ's viability. This will be done by utilizing a RAMAN spectroscopy device to monitor the perfusate and through following the levels of required materials like glucose, oxygen levels, etc.

3D Printed Heart for Design Testing

Our team 3D printed a heart to have the ability to effectively test our prototypes of the design and demonstrate a more accurate flow of the perfusate through the organ system.

Bovine Heart Plumbing Studies

With the help of our advisor Dr. Bob, the team dissected and investigated the inner mechanics and workings of bovine hearts to better understand the necessary pump elements for our final design.

Second Prototype

The device components were placed in this initial container design for making the design mobile. This container is clear to be able to monitor the components along with being on wheels for mobility.

Pulse Generator Design

This device was designed by the team to control the flow of the perfusate throughout the system, and in order to make this a pulsing system to mimic the conditions the heart would be under within the body. This design was created by the team and manufactured by Floyd Custom Machine & Design.

First Prototype Circuit

The team put together a circuit with all aspects of the device in order of their flow for the final design. Flow was demonstrated through the circuit and the team discovered initial issues with the pumping of the fluid which was addressed by adding another pumping device.

Updated Circuit

Aspects that were addressed after the initial circuit was put together included adding a pumping device other than the pulse generator, using medical grade tubing, and where to insert the Raman Spectra testing.

Heart Chamber

The heart will be stored within a chamber that will include a mesh netting and a viscous fluid. The netting will support the heart and absorb any shock along with the fluid which will also simulate the environmental conditions within the human body.

Before

After

Pulse Generator Update

When the team attempted to place the pulse generator within the travel case for the next prototype it was not able to fit within the case without restricting the tubing. The device was then updated to decrease the unneeded space around the rotating cylinder along with adjusting the tubing to be coming out vertically with a right angle elbow attachment.

Arrangement of Device Components within the Suitcase

The team was able to organize device components within the travel case. An update that will need to be made is attaching metal angle brackets on the inside walls of the suitcase to mount plexi-glass shelves where the heart chamber and controller for the pulse generator will sit.

Reservoir Update

The reservoir container was updated from an IV bag to a container to allow better application of the required sensors for monitoring the perfusate composition. This design has an attachment which can be seen in this image that allows the controlled exit of the perfusate into the rest of the unit. The container also has an opening for the returning perfusate at the top. This device will need to be updated further with the attachment of velcro to the sides of the container to allow the easy attachment of the sensors. This addition will allow the sensors to be easily taken in and out to allow for calibration.

Updated Circuit Design

The circuit was updated with the addition of the flow meter, new reservoir, and updated tubing. This new circuit allows for no leakage and shows the flow of the perfusate accurately.

Testing of the Unit

Our unit was connected to a liver in order to visualize the pulsing of the fluid and the mechanism of the device with an actual organ. Connectors were also attached to a pig heart to demonstrate that connection ability.

Ideas for Future Iterations

  • Retrofitting design to accommodate a lighter carrying capacity.

  • Ability to immediately and precisely control the pulse generator.

  • Optimize perfusate composition

  • Implementing an advanced monitoring display.

  • Update reservoir design

  • Improve organ container design

  • Include a built in pump and flow meter within the pulse generator design.