Non-Nutritive Suck Parameters Measurements Using a Custom Pressure Transducer System

My research examines the cross-section of sucking, feeding, and speech emergence across environmental, maternal, physiological, and genetic factors and across patient populations. I seek to determine how factors influence sucking, feeding, and speech emergence with a goal of providing targeted assessments earlier for infants who experience sucking and feeding delays. Our research has established the first standardization of NNS at specific time points in the first year of life, and how characteristics of NNS change across the sample.

We have shown that aspects of NNS relate to neurodevelopmental outcomes and vary across clinical populations of infants. In both research and clinical settings, very few assessment tools exist for quantifying infant NNS. Our protocol bridges this gap by providing a quantitative, physiologically based system to assess infant NNS that is transportable and can be utilized in a variety of clinic and research-based settings.

Data in our lab shows that infant non-nutritive suck is a sensitive indicator of exposures in utero and is linked with subsequent neurodevelopmental outcomes. Ultimately, my goal is to attain enough data to change public policy and allow for a non-nutritive suck screen for all infants soon after birth, much like a newborn hearing screen. Results have consistently demonstrated that quantitative NNS measurement is a sensitive biomarker of neurodevelopment.

This has led to more specific research questions regarding how NNS relates with subsequent communication and neuromotor outcomes and attempts to uncover the underlying mechanisms that link these domains. Future research with the NNS device will focus on describing NNS performance in clinical populations. If we can distinguish typical versus atypical NNS behavior with the device, this would significantly help its clinical utility by identifying children at potential risk for future issues with feeding or oral motor development.

To begin, open the transportable case and remove the device components, including a DAC and its power cord, the customized pressure transducer box, known as the NNS box, with a pacifier receiver handle and a gray cable attached. Also, use a laptop and USB-Log on exit to the DAC along with a pacifier. Plug in the power cord into the DAC in a three-pronged power outlet, the gray cable connected to the NNS box into the first front round port of the DAC, and the USB cord into both the laptop computer and DAC.

Then turn on the DAC using the power switch located at its back and log onto the laptop or computer. Next, wash hands and put on latex gloves. Attach a newly opened pacifier to the pacifier receiver.

To collect the non-nutritive suck data, open the data acquisition and analysis file with the latest calibration date and select start. Turn the NNS box gear from zero to sample. Offer the pacifier to the child in a comfortable position and hold it for them to suck on for a duration of two to five minutes.

Once the child finishes or five minutes have elapsed, retrieve the pacier handle and press stop on the file, then adjust the NNS box gear from sample to zero. Remove the pacifier from the receiver and dispose of it along with the gloves following any institutional sanitary protocols, then wash hands. Save the file by selecting save as, naming it with the participant's ID number and the date of data collection.

Turn off, unplug, and pack up the device components back into the case. To analyze the samples, open the participant's NNS data file in the data acquisition and analysis software. Manually identify suck bursts using the criteria of more than one suck cycle, each with an amplitude of at least one centimeter of water and waveforms within 1000 milliseconds of each other being considered as part of the same suck burst.

To set peak analysis settings, select peak analysis, then settings, then table options. Check the boxes for TStart, TEnd, Height, PeakArea, and Period, leaving all other boxes unchecked. Use the cursor to click and drag a box around the first NNS burst.

Click analyze to identify peaks with specified parameters. Click the burst analysis macro button, which will generate a popup data pad menu. In the data pad, insert a row in the column above the data by right clicking that column, selecting insert row for the first NNS burst, and typing the time for the first burst.

Continue recording the time until all NNS bursts have been tracked. After completing the analysis, select file and save as and save the analyzed NNS file as a participant ID, date, and researcher initials. Also select file and export and select data pad only as text file to save the data pad file separately.

Process the text file through a custom NNS burst macro. This produces an analyzed text file containing burst variables such as duration, frequency, height, burst count, cycles per burst, and cycles per minute for each NNS burst and other parameters used for further analysis. The non-nutritive sucking device has been integral in research assessing infant sucking behaviors, quantifying outcomes like amplitude, frequency, and burst duration.