Variable Independent Pressure System

In medical device development and medical professional fields, limited methods incorporate the simulation of bodily fluid flow. The lack of such an apparatus delays the launch of medical devices due to the extended periods it takes for product validation through health and medical administrations. This also limits the abilities of medical professionals to practice their skills and experiment on hypothetical operations without the risk of life. Implementing an apparatus that could simulate the flow of bodily fluids in a vast range of pressures up to 4 psi would allow medical device development teams to test and validate their products before sending the product and product information to a health and medical administration board. The validations and data to prove the device is successful will reduce the time it takes for approval to move forward with the product. This will allow more medical products to reach the market and provide a tool to enhance such devices. Medical professionals are also in need of such an apparatus so that they may learn, test, and enhance their surgical skills on an organ that has fluid flowing through, rather than practicing on static objects such as latex mats, grapes, and pig feet or animal organs both in vitro and vivo which however requires administrative approval. This apparatus will allow for practice surgery ex vivo, giving medical professionals the tools they need to strengthen their surgical ability on patients. Hypothetical medical operations could also be conducted to advance the medical professional or act as a study to propel modern medicine into futuristic medicine. This is all achieved by a pressure apparatus in which any organ can be attached as long as the inlet and outlet of the organ are circular in shape. The organ will be clamped down onto a hose with a soft silicone O-ring to protect the organ's tissue and allow for multiple tests on the same organ. The organ will be suspended in a tank filled with water on a heating table that will heat the water to match the internal body temperature. Connected to the inlet of the organ is tubing that connects an attached reservoir with a submersible water pump implemented into the reservoir which will then be suspended in the water or solution pumped through the tested organ. The reservoir will then be connected to the tank's outlet, making a continuous loop-system that pumps the same solution through the apparatus until the system is stopped. The apparatus will also provide validation by visual queues, such as seeing the solution leak out of the organ into the clear surrounding water and by pressure readings from the inlet and outlet of the system to compare for any pressure drops indicating a leak or flaw in the simulation. This Variable Independent Pressure System provides the medical industry with a tool to help advance the industry with medical products and skills.

My main contribution was the pressure system which used an arduino and two pressure transducers. The two pressure transducers and an Arduino were used to take the output voltage from the pressure sensors and convert it into a pressure value in millimeters of mercury or mmHg. The code was first written in Arduino’s coding language and the analog inputs from both pressure sensors were read in and then converted to a pressure value. During the first five seconds of the program being run, the pressure sensors are calibrated for when the pressure values should be at 0 psi/mmHg. Both pressure values are converted from a decimal to a string, to be able to send the values into Python. In Python, the pressure values were read in and a Graphical User Interface, or GUI, was created. The GUI allows the user to be able to connect to the Arduino Serial Port directly from the application. The pressure readings that are taken in from the arduino and dynamically updates and displays the values on the GUI.

Pressure Readings Graphical User Interface

The pressure readings are displayed in two different colors depending on the pressure difference between the inlet and outlet. If the pressure difference is less than 1.5 mmHg the boxes are displayed in green boxes, and if the pressure difference is greater than 1.5 mmHg the boxes are displayed in red boxes. The 1.5 mmHg range is needed due to the noise that may be generated by the wires used to connect the sensors to the arduino. The pressure values and the time are recorded to a CSV file to be able to determine the results of each test, and be able analyze the results later on.