Knee osteoarthritis, the most common form of arthritis, which results in stiffness, pain, and impaired movement, is a major cause of disability in elderly populations around the globe. In the course of treating this disease, patients have to endure enormous pains travel to hospitals to meet medical professionals. The motivation behind this project is to support those patients with limited physical mobility to travel fewer times to the hospital but still, communicate well with doctors and nurses. The goal is to build a VR clinic that simulates the real consultation room and facilities in the hospital.
An ethnographic study was conducted at a local hospital in Delft to map the patient treatment journey from the first consultation meeting to the last meetings after surgery. The patient education part of the patient journey was chosen as the focus of this thesis since it involves most of the patient-nurse communications compared to other parts of the journey. Based on the results of the ethnographic study, a social VR clinic was designed and implemented to assist the nurse in explaining the treatment process, and to show the anatomy models and the surgery room to the patient.
The main contribution of this thesis is the design and evaluation of a social VR clinic, based on the use case of knee pain treatment. Future research can expand the consultation to other diseaseses, explore the impact of using more realistic avatars on the VR clinal experience. Other perspectives can be probed into to describe user portraits on their attitude of having VR consultations.

Halomonas bluephagenesis has been developed as a platform strain for the next generation industrial biotechnology (NGIB) with advantages of resistances to microbial contamination and high cell density growth (HCD), especially for production of polyhydroxyalkanoates (PHA) including poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). However, little is known about the mechanism behind PHA accumulation under oxygen limitation. This study for the first time found that H. bluephagenesis utilizes NADH instead of NADPH as a cofactor for PHB production, thus revealing the rare situation of enhanced PHA accumulation under oxygen limitation. To increase NADH/NAD⁺ ratio for enhanced PHA accumulation under oxygen limitation, an electron transport pathway containing electron transfer flavoprotein subunits α and β encoded by etf operon was blocked to increase NADH supply, leading to 90% PHB accumulation in the cell dry weight (CDW) of H. bluephagenesis compared with 84% by the wild type. Acetic acid, a cost-effective carbon source, was used together with glucose to balance the redox state and reduce inhibition on pyruvate metabolism, resulting in 22% more CDW and 94% PHB accumulation. The cellular redox state changes induced by the addition of acetic acid increased 3HV ratio in its copolymer PHBV from 4% to 8%, 4HB in its copolymer P34HB from 8% to 12%, respectively, by engineered H. bluephagenesis. The strategy of systematically modulation on the redox potential of H. bluephagenesis led to enhanced PHA accumulation and controllable monomer ratios in PHA copolymers under oxygen limitation, reducing energy consumption and scale-up complexity.

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