Browsing by Author "Sujesh, S"

Now showing 1 - 3 of 3
  • Item
    An automated data acquisition system for capturing physiological parameters during animal trials of artificial heart valves
    (International journal of Biomedical Engineering and Technology, 2012-10) Sujesh, S; Rajeev, A; Shenoy Sachin, J; Umashankar, PR; Muraleedharan, CV
    Animal trials form an important phase of any medical device development, especially in the context of implantable devices like artificial heart valves. Monitoring and recording parameters such as physiological pressures and Electrocardiogram (ECG) is essential for assessing the performance of the valve. A dedicated automated data acquisition system was developed for capturing these vital characteristics during implantation, immediately post operative and prior to the explantation of the device. The hardware was designed around the PXI (Pci eXtension for Instrumentation) modular data acquisition chassis and the software was developed using LabVIEW (both National Instruments, USA). A set of transducers was identified, validated and incorporated into the system for converting physical signals to analogue electrical signals. The system was employed in more than fifteen animal experiments and found to be extremely useful for automated data capturing. It provided valuable sets of additional data for many specific studies like analysis of valve sounds, which would not have been possible if the conventional approach to animal experiments and data collection was used. A well planned strategy for collecting maximum useful data from animal experiments goes well along with the reduction alternative of the 3R strategies of replacement, reduction and refinement of animal experiments.
  • Item
  • Item
    TTK Chitra tilting disc heart valve model TC2: An assessment of fatigue life and durability
    (Proc Inst Mech Eng H., 2017-08) Subhash, NN; Rajeev, A; Sujesh, S; Muraleedharan, CV
    Average age group of heart valve replacement in India and most of the Third World countries is below 30 years. Hence, the valve for such patients need to be designed to have a service life of 50 years or more which corresponds to 2000 million cycles of operation. The purpose of this study was to assess the structural performance of the TTK Chitra tilting disc heart valve model TC2 and thereby address its durability. The TC2 model tilting disc heart valves were assessed to evaluate the risks connected with potential structural failure modes. To be more specific, the studies covered the finite element analysis-based fatigue life prediction and accelerated durability testing of the tilting disc heart valves for nine different valve sizes. First, finite element analysis-based fatigue life prediction showed that all nine valve sizes were in the infinite life region. Second, accelerated durability test showed that all nine valve sizes remained functional for 400 million cycles under experimental conditions. The study ensures the continued function of TC2 model tilting disc heart valves over duration in excess of 50 years. The results imply that the TC2 model valve designs are structurally safe, reliable and durable.