Cardiovascular Simulator

The product is an artificial heart and circulatory system that simulates human anatomy and physiology.  The device is used to develop and demonstrate new medical devices and to train practitioners on their use.





User Interface








Project Overview

Soloosion was asked to redesign the product in order to consolidate it into a single travel case for transport, make heavier use of off the shelf components, and make the device easier to use.  During the course of development, Soloosion was able to deliver on these requests and identify and realize numerous other improvements in order to bring the device well beyond what the customer had even envisioned.  

Challenge Identification

The original product was unwieldy to transport and cumbersome to use. It was transported in three separate travel cases and the various subsystems had to be connected to several hoses and wires for use. The devices consisted of numerous manual valves, gauges, and adjustable components. The user was required to cycle the valves to different states for drain and fill operations and to manually adjust several components while monitoring an analog pressure gauge in order to dial in physiologically representative operation. The device provided no indication or control over the actual flow rates through the system.

Developmental Discoveries

During the course of development, Soloosion re-imagined the central pumping concept of the device and replaced a motor driven air piston with an off the shelf diaphragm pump. Soloosion also invented a novel adjustable compliance chamber that was very simple to construct, yet facilitated automatic compliance adjustments.

CAD Simulation Studies

Soloosion developing 3D models of the system allowing for fluid simulations and analysis done in parallel with the development of the physical prototypes. This enabled rapid engineering discoveries, and system architecture design.


While the system requirements were still in flux, Soloosion prototyped a control PCB using off the shelf evaluation boards and hand-wired interface circuitry and used this prototype controller to validate the complete operation of the system as well as the design requirements for the custom PCB. Soloosion was able to rapidly test and refine the control algorithms in real time while monitoring the system performance.

Electronics Breadboarding

Soloosion developed feedback control systems with automated adjustments which are able to hit target operational values without any direct user intervention. Parameters such as flow rate, heart rate, and systolic and diastolic pressures can all be adjusted automatically. In addition, the system is able to automatically fill and drain itself during setup and break down, with no other user intervention than pouring water into a reservoir or attaching a drain hose.

System Interface Improvements

In order to take advantage of the new found capabilities of the system, Soloosion replaced the original speed control knob and on/switch with a wireless tablet,connected by Bluetooth.  The tablet allows the user to control the operate/fill/drain operation of the tablet.  It also allows the user to specify operating parameters such as heart rate, head and body flow rates, and systolic and diastolic pressures.  During operation,the tablet displays live plots of system pressures, identical to those a doctor would view while in the operating room. The plots not only confirm that the system is hitting the target operating parameters, they also illustrate the physiological accuracy of the pressure wave forms.

Testing & Improvement

Soloosion prototyped the entire system; ran bench-top performance and system stability tests discovering reliability improvements and ways to reduce costs by leveraging off-the-shelf components.

Detail Design

Once the system was successfully prototyped, Soloosion proceeded to develop a production version of the product.  Soloosion developed a control board using an STM32F4 Micro-controller from ST Microelectronics and an AC power management for the board.

Assembly Plan

Soloosion was able to rapidly and efficiently port the software from the hand wired development board to the target hardware.  In addition, Soloosion packaged the entire product in an aesthetically pleasing enclosure, consisting of a chassis for mounting the various electronics, hydraulic, and pneumatic subsystems and an external cover to contain the functional components and expose the anatomical components.  

Production Assembly

Soloosion incorporated numerous production technologies to realize the product, including sheet metal bracketry for the internal components, a roto-molded fluid reservoir, a vacuum formed system cover, and custom molded silicone tubing and manifolds. In addition to the control electronics, Soloosion developed and produced the internal cable harnesses for the system.

The Finished Product

The end result is a product that is vastly superior to the starting point.  The product can be transported in a single travel case.  It automatically adjusts and fills and drains itself, and it provides much more accurate simulations of human physiology than the original product could.

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