Facilities

Heartlab
Location: Karman 310
The study of hemodynamic aspects of flow through heart valve prostheses was initiated at Caltech in 1993. A significant progress has been made in broadening our knowledge in areas such as events following the closure of mitral mechanical and tissue prostheses, diastolic left ventricular flow characteristics corresponding to different mitral valve prostheses with different mounting configurations and orientations, transaortic flow mapping, transvalvular pressure-flow relationship during a cardiac cycle, and vortical events in the heart. These studies have incorporated the use of flow visualization, Digital Particle Image Velocimetry (DPIV), Doppler ultrasonography, Magnetic Resonance Imaging (MRI) and high-speed videography.

Left Heart Pulsed Flow Simulator
The system uses a hydraulic analog model (VSI, SPS3891) connected to circulation simulator. The oscillatory flows are generated by input of appropriate waveform to the power amplifier (VSI, SPA3891Z) which has a piston position controller. It also consists of a transparent aortic arch and a silicone sac shape as a real ventricle. The system has been primarily designed to investigate systolic transaortic and mitral regurgitation flows by flow visualization and DPIV. We use this sophisticated model of the heart to evaluavte heart valves, assessment of flow related structures on mitral valve dynamics and functionality of ventricular assist devices.

Tow Tank

Advanced Imaging Facility

Blue Wind Tunnel
Location: Guggenheim 304D

Free Surface Water Tunnel

Oil Tunnel
Location: Guggenheim 304D

Nanocarpet Fabrication Facility
Location: Guggenheim 304D
Our nanocarpet fabrication facility is comprised of a standard bench-top tube furnace and gas supply (methane, ethylene, etc.) apparatus with plumbing. Thin layers (a few nanometers thick) of catalyst metal (Fe, Ni, etc.) are deposited onto an arbitrary (but heat-tolerant) substrate (silicon wafer, glass slide, or other). The prepared samples are then placed in a quartz tube inside the furnace and brought to high temperature (700-900 C) following a program of specified pressure, temperature, and gas mixture conditions. The resulting samples have a black, sooty material on the surface, which is the appearance to the naked eye of nanocarpets. These samples can be characterized by Scanning Electron Microscopy yielding high magnification images. The samples are then carefully transferred to a desiccator for storage until further use.

Our facility currently uses ethylene as the carbon feedstock, iron as the catalyst metal, and is operated at temperatures of around 750 C. The controls and flowmeters for the gas lines are mounted in a panel on the wall adjacent to the tube furnace sitting on a benchtop. A vacuum pump sits downstream of the furnace and exhausts into a module where the hot, flammable exhaust gases from the furnace can be diluted to below the flammability limit with nitrogen, rendering the gas stream safe for exhaust. Samples are loaded into the tube furnace from one end prior to sealing and beginning the growth procedure. We are following a system design and parameter choices similar to that outlined in Bronikowski 2005 and Manohara et al., 2004. Our setup is shown in the picture below.

GALCIT Lucas AWWT low speed wind tunnel
http://www.galcit.caltech.edu/galcit-lucas-awwt/

Charyke Biomechanics Laboratory

Computing Laboratories
Location: Karman 312
Numerical simulations are powerful, non-invasive and practical investigation tools, and they may support, complement or provide scientific insight to experiments, especially when investigating complex phenomena or in regions which are difficult to access experimentally.

Ultrasound has a long history of use in biological systems, and are useful in flow tracking. However, due to physical and manufacturing constraints, the trend over the last decade shows the minimum size and maximum number of sensors has flattened. While useful for flows vessels that are large or near the skin, smaller scale flows have traditionally been out of reach. We are working on applying imaging techniques to ultrasound-sensed data to resolve finer structure parameters, and in 3D.

In our Computational Fluid Dynamics (CFD) laboratories we use advanced tools to investigate multiscale biofluid hemodynamics and transport processes in biomedical systems using numerical methods. Our main research is focused on investigating hemodynamics in the cardiovascular system and of cardiovascular devices. we use numerical methods to simulate fluid and structure dynamics in models involving complex geometry, unsteady flow, moving boundaries and fluid-structure interaction (FSI).

See related Cardiovascular Research projects:

• Development of a Blood Pump
• Flow in Large Blood Vessels
• Construction of an Anatomically Correct Heart Model

We have workstations and computers equipped with a wide variety of software among them the commercial finite-element package ADINA (ADINA R&D Inc.), the design validation and optimisation package SolidWorks (including COSMOSWorks).