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Using LabVIEW and NI DAQ Hardware to Verify Devices That Prevent HIV Transmission Between Mother and Child During Breastfeeding

"We have used NI technologies for vital research and development of our medical device, which stands to improve the health of millions of breastfeeding infants around the world."

- Rebekah Scheuerle, Department of Chemical Engineering and Biotechnology, University of Cambridge

The Challenge:

Creating a test system to verify a low-cost nipple shield delivery system (NSDS), which could help in the global fight against infant malnutrition, malaria and HIV by providing a straightforward method of delivering drugs and nutrients to breastfeeding infants.

The Solution:

Using the NI platform to develop a fully controllable simulation system that accurately mimics infant breastfeeding for testing the NSDS prototypes in vitro. This software-defined system is accelerating our research of a simple, robust medical device that will improve global infant health.

Author(s):

Rebekah Scheuerle - Department of Chemical Engineering and Biotechnology, University of Cambridge
Rob Courtney - Department of Chemical Engineering and Biotechnology, University of Cambridge
Furgus Kulasinghe - Department of Chemical Engineering and Biotechnology, University of Cambridge
Neil D’Souza-Mathew - Department of Chemical Engineering and Biotechnology, University of Cambridge
Arron Rodrigues - Department of Chemical Engineering and Biotechnology, University of Cambridge
Nigel Slater - Department of Chemical Engineering and Biotechnology, University of Cambridge
Stephen Gerrard - Department of Chemical Engineering and Biotechnology, University of Cambridge

 

 

Each year, 6.6 million children under the age of five die from malnutrition and communicable diseases, according to the World Health Organization (WHO). Early access to safe and easy-to-administer medications can easily prevent many of these deaths. Unfortunately, WHO research indicates that a lack of local resources challenges existing treatments for infant morbidity and mortality in developing countries. Therapeutics and vitamins that are administered using conventional paediatric syrups and tablets often require refrigeration or potable water, and current delivery methods introduce concerns over sterility and accurate dosage.

 

HIV transmission is a significant part of this problem. Approximately 200,000 babies acquire HIV every year through breastfeeding, which accounts for 40 percent of all mother-to-child HIV transmission cases. According to WHO, “when replacement feeding is acceptable, feasible, affordable, sustainable, and safe, avoidance of all breastfeeding by HIV-infected mothers is recommended.” However, the use of formula milk in low-resource settings increases infant mortality due to diarrhoea and dietary deficiency. As a result, HIV+ mothers are left with no good option.

 

In response, WHO established an urgent call for new medication delivery technologies for the developing world, where existing methods are ineffective. At the University of Cambridge Department of Chemical Engineering and Biotechnology, we are developing the JustMilk Nipple Shield Delivery System a novel medical device that can meet this call.

 

 

The JustMilk Nipple Shield Delivery System

The JustMilk Nipple Shield Delivery System (NSDS) is a novel, safe and convenient method of dosing breastfeeding infants with lifesaving nutrients and medications. The NSDS consists of a conventional nipple shield, commonly used to aid breastfeeding, which is modified to hold a dispersible therapeutic tablet or active pharmaceutical ingredient-loaded insert.

 

The device can deliver a wide-range of active pharmaceutical ingredients including antibiotics, antimalarials, antiretrovirals, vitamins, nutrients and probiotics.

 

The device is also convenient. The mother simply wears the NSDS during feeding. As the infant feeds, the active pharmaceutical ingredient within the device releases into the breast milk thereby dosing the infant directly. 

 

The NSDS device is currently in its preclinical phase. As with all medical devices, extensive laboratory studies, and user acceptability and design feedback studies must be performed to gather evidence of safety, effectiveness and to ensure appropriate implementation. To accurately test our NSDS prototypes, we built the world’s first fully controllable breastfeeding simulation apparatus.

 

The Breastfeeding Simulation Apparatus

We designed the breastfeeding simulation apparatus to closely mimic the infant breastfeeding process. In the apparatus, human breast milk is pumped from a reservoir and heated to physiological temperature in a heat exchanger. A breast pump then sucks the milk in the pattern of a suckling infant through an NSDS affixed to a synthetic human nipple. As the breast milk passes through the NSDS, the active pharmaceutical ingredient dissolves and supplements the breast milk with active pharmaceutical ingredients. The supplemented breast milk is then pumped to a fraction collector which takes samples over time. We use these samples to study the drug release properties of the NSDS to aid device development.

 

 

System Design

Built with NI technologies, our tightly integrated system includes remote control of the pumps used to mimic a mother’s lactation. The same system also produces frequency and amplitude varying waveforms, which control the vacuum pumps to accurately simulate infant suckling patterns, whilst simultaneously monitoring the resulting pressures in real time to ensure the accuracy of our experiments.

 

From a hardware perspective, the NI CompactDAQ platform made building and maintaining the apparatus incredibly efficient. The modular I/O featured with NI CompactDAQ helped us define a data acquisition system to meet our exact requirements, whilst the built-in signal conditioning simplified connectivity with our various milk feed pumps, vacuum pumps and pressure sensors. Additionally, the plug-and-play USB interface simplified data streaming to our central computing hardware for processing and storage. This has been vital to our documentation and post-experiment analysis.

 

From a software perspective, NI LabVIEW delivered all of the data acquisition, processing and recording functionality we required. We combined the LabVIEW built-in operational logic and advanced signal processing libraries to calibrate, filter and display real-time pressure and pumping profiles during our experiments. Also, since LabVIEW is compatible with a multitude of file formats, we can import the pressure data files that detail the infant suckling patterns necessary for running our breastfeeding simulations. 

 

Through the combination of hardware and software, the NI platform enabled our team of scientists to produce a flexible research apparatus that will scale with our evolving requirements – something that we could not have achieved with alternative approaches and programming languages. The software defined nature of our system will also allow us to repurpose existing technology to meet future requirements, conferring major savings in cost and time.

 

In addition, National Instruments services proved very useful.  NI engineers not only supported the development of our simulation algorithms through laboratory visits, but also delivered instructor-led training classes at the University of Cambridge to accelerate our LabVIEW proficiency.

 

The Evolution of Our System

We are continuing to utilize National Instruments technologies as we further develop our simulation apparatus. We are integrating additional feed pumps, controlled and monitored by LabVIEW, into our system to study how various milk compositions impact drug release. We are also integrating a suckling infant tongue mimic into our breastfeeding simulation apparatus which we will be monitoring with piezoresistive pressure sensors. This will help us understand how the pressures exerted by an infant tongue during feeding contribute to drug release. We will use LabVIEW and NI hardware to produce pump control signals and analyse the new sensor data. We will then record and monitor vital pressure profile information to gain a better understanding of how interactions between an infant and the NSDS impact therapeutic dosing.

 

Conclusion

The NI system has empowered us to critically test our nipple shield delivery system in an array of possible infant feeding conditions, so we can develop a robust, efficient and safe drug delivery device for improving global infant health. 

 

Now, we are conducting contextual studies in Limpopo, South Africa to understand the needs of potential NSDS users. With the support of a USAID Saving Lives at Birth Grant, we are continuing further research and development of the NSDS and breastfeeding simulation apparatus. Within the next few years, we aim to have completed primary clinical trials for several target indications.

 

We have used NI technologies for vital research and development of our medical device, which stands to improve the health of millions of breastfeeding infants around the world. 

 

Author Information:

Rebekah Scheuerle
Department of Chemical Engineering and Biotechnology, University of Cambridge
University of Cambridge, Department of Chemical Engineering and Biotechnology, Pembroke Street
Cambridge CB2 3RA
United Kingdom
Rebekah.Scheuerle@justmilk.org

Figure 1. JustMilk Nipple Shield Delivery System Prototype
Figure 2. JustMilk NSDS Illustration
Figure 3. Breastfeeding Simulation Apparatus Process Flow Diagram