LD Integrated Technologies characterizes medical device flows using LabVIEW pressure control

LDIT-logoLD Integrated Technologies is a consulting firm that specializes in system integration and automated testing projects. The firm often develops custom hardware, circuit design, embedded firmware and software to meet the needs of their customers. LDIT focuses especially on integration projects within the medical device, aerospace, manufacturing, automotive and oil and gas industries.

LabVIEW Pressure Control Makes for Easy Medical Device Flow Characterization

LD Integrated Technologies was working with a medical device company to develop a system that would visually track a slow-moving object as a means to determine flow rate for a diabetes-related application. The system would incorporate a camera, syringe pump and pressure transducer and communicate with LabVIEW to accomplish this task.

Early in the development of this system, LDIT designed a high-fidelity prototype that would determine product feasibility. The prototype required the use of a pressure controller that could mimic the design pressure characteristics of the medical device and its operation in relation to a human body. The testing process was to incorporate flow characterization of the prototype throughout the full range of possible real-world pressures it might encounter. This would ensure that the device exhibited the desired flow rates at each of these test pressures.

Alicat dual-valve pressure controller for closed volumes

Alicat dual-valve pressure controller for closed volumes, with remote pressure sense port

The pressure controller needed to be capable of maintaining a stable pressure at a precise point within a closed volume, while receiving positive pressure at its inlet and exhausting to a vacuum pump. It also needed to have stainless steel construction to accommodate the fluids without corrosion. In this particular application, the medical device company was already using LabVIEW as its control software, so the pressure controller would need to play nicely with LabVIEW as well. Such compatibility would also keep development costs down.

Given the above requirements, LDIT turned to Alicat Scientific for a pressure controller that would fit the bill. LDIT found our easy-to-use LabVIEW drivers first. These allow for remote monitoring of flow data and control of instrument setpoint and other functions. (For those who do not already have LabVIEW, we also offer a stand-alone interface that uses the same software engine.) For the instrument itself, we built for LDIT a dual-valve pressure controller with remote sense port. Built with an absolute pressure sensor for seamless control down to sub-atmospheric pressures, this pressure controller uses both valves to precisely regulate the pressure within a closed volume. The remote pressure sense port can be plumbed to any point in the system to ensure that the operation of the pressure controller maintains the desired pressure at that specific point.

LDIT station setup with Alicat LabVIEW drivers

LDIT station setup with Alicat LabVIEW drivers

During the integration stage of a project, LDIT considers timing to be key. When issues arise that require technical assistance, they need to get answers right away so they can ship the test setup to the customer. Here, good customer support is one of the most important criteria for determining the successful outcome of the project; if help is not forthcoming, the project can be set back a whole day, which could result in loss of the contract in some scenarios. The immediate and ongoing support that Alicat provided, both for the operation of our instrument and for integrating our LabVIEW drivers, enabled LDIT to ship its system to its customer on time.


The test system that LD Integrated Technologies designed and built made the medical device company’s R&D process more efficient, because the LabVIEW-controlled pressure controller could quickly represent any possible pressure scenario. This made it easy to mimic real-world situations and put the prototype medical device through its next phase.