Development of an automated plasmapheresis system for the treatment of sepsis

  • Khaled Mohammed A Alshareef

Student thesis: Doctoral Thesis

Abstract

Background: Sepsis is one of the leading cause of death in ICU. The causes of sepsis could be viral, bacterial, fungal infection, also, and in some instances trauma. When a local response to the infection becomes a systemic response, the immune system becomes chaotic. Cytokines are produced in an uncontrolled way, resulting in a cytokines storm. The immune system enters a hyperactivation status that leads to multiple organ failures. Despite advances in the medical treatment and clinical experience, there is currently no single medication approved for treating sepsis. Thus, removal of the plasma that contains the inflammatory mediators is a potential solution to reduce their effect in the body. Objectives: The aim of this project is to develop a device that is able to separate plasma from whole blood. The device should be able to generate secondary flow to enhance the performance by reducing the formation of cake layer. In addition, the device should be fully automated in order to simplify the technology for the end user. Approach: Design using computer aided design employing different methods for producing secondary flow, investigate the impact of these techniques on formed blood element, by assessment of shear stress. The design was 3D printed to investigate the performance in term of plasma filtration using different membranes with different effective pore area. The next step was to increase the dimension of the rig and test the increase in surface area on flux rate. In addition, an automation system was designed and assembled in order to control the transmembrane pressure, blood pump and plasma replacement pump through feedback from sensors read by a microcontroller. Results: The device was able to separate the plasma from the blood. The polyethersulfone membrane that has higher effective pore size had higher filtration rate. By increasing the size of the rig, the filtration volume increased. Also, the methods used to increase the flux were able to improve the flux rate. The automation system was tested and functioned well. Different flow rates were tested to investigate the performance of the system, and the results demonstrated the relationship between the flow rate and flux rate. In the TMP range 40-50 mmHg, at 260 ml/min flow rate, was the optimum flux rate. The device had the ability to run for 12 hours with a constant flux rate. The device achieved this with little haemolysis (pfHb
Date of Award23 Nov 2019
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorTerry Gourlay (Supervisor) & Mary Grant (Supervisor)

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