Supplementary Material

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Supplementary Material

Stabilizing Breathing Pattern Using Local Mechanical Vibrations:

Comparison of Deterministic and Stochastic Stimulations in Rodent Models of Apnea of Prematurity

Dean Zeldich¹, Samer Bou Jawde¹, Jacob Herrmann¹, Leen Arnaout¹, Meghan Griffin¹, Noam Grunfeld¹, Yu Zhang¹, Ramaswamy Krishnan², Erzsébet Bartolák-Suki¹, Béla Suki¹

1Department of Biomedical Engineering, Boston University, Boston, MA

2Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA

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Figure S1: Stimulation signals. A deterministic square wave signal of mean 1.5 V and frequency 50 Hz was compared to a pseudorandom noise (PRN) signal and Band-Limited White Noise with a random combination of frequencies. The mean of all 3 signals was centered around 1.5V.

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Figure S2. Stimulation signals. Illustration of the difference in the time domain between the low- frequency Light Repetitive Poking and Strong Repetitive poking signals LRP can be approximated as 1.2V at 1Hz, and SRP can be approximated as 2.5V at 1Hz. It is also noteworthy that the repetitive poking signals start as slightly different timings (0.6 seconds).

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Figure S3. Spectrogram of the 1.5V,50Hz deterministic signal, and the light and strong repetitive poking signals. The D and SRP signals are both square signals with a 1:1 distribution of on/off times, therefore we see straight lines as a slop of -2 and a frequency shift between them. The LRP is the same frequency as the SRP but since it is created to not be 1:1 on/off times, the line is not quite straight and has fluctuations.

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Figure S4. Visual representation of the spectrum of frequencies found in one period of the

Pseudorandom and Band-Limited White noise signals. The PRN and WN span the same range of frequencies but the PRN signal seems to have more power in some higher frequencies and less even distribution in the lower frequencies. The WN power spectrum remains very flat until around 200Hz.

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Measurement Cycles Control Stimulation - Deterministic

3V, 25Hz 3V, 50Hz 1V, 25Hz 1V, 50Hz CO2 % 50 2.94±0.25 2.95±0.25 2.93±0.24 2.94±0.25 2.87±0.26

SPO2 % 57.1±11.8 52.9±12.8 52.8±11.4 56.1±11.1 53.0±11.1 Table S1: Mouse 3 physiological results. There was no significance between control and any of the stimulations for CO2% and SPO2%.