# An Open Access Chamber Designed for the Acoustic Characterisation of Microbubbles
## 5 Conclusions  
In this work, a chamber for the characterisation of microbubbles was developed. The chamber was assessed with an experiment to measure the scattering characteristics of SonoVue\({}^{\text{\textregistered}}\). For all acoustic measurements used in the determination of the scattering characteristics, t-tests were performed to ensure the measured data were statistically significant when compared to the control data. Scattering at the fundamental frequency and at the second harmonic were determined. The measurements were found to be in agreement with previously published measurements. These findings give confidence that the design is suitable for performing acoustic scattering measurements of UCAs. By releasing the MACC as open access, the chamber is well placed for wider adoption by the research community. This will facilitate direct comparison across research groups and will allow other researchers to contribute to the evolution of the design.  
The following are available online at [[https://www.mdpi.com/article/10.3390/app12041818/s1](https://www.mdpi.com/article/10.3390/app12041818/s1)]([https://www.mdpi.com/article/10.3390/app12041818/s1](https://www.mdpi.com/article/10.3390/app12041818/s1)), S1: Scattering Data, S2: T1 Transmit Average RMS Amplitude Spectrums, S3: T2 Transmit Average RMS Amplitude Spectrums, S5: T4 Transmit Average RMS Amplitude Spectrums, S6: T5 Transmit Average RMS Amplitude Spectrums, S7: T6 Transmit Average RMS Amplitude Spectrums. The follow is available online at [[https://github.com/UARPGitHub/MACCProcessing](https://github.com/UARPGitHub/MACCProcessing)]([https://github.com/UARPGitHub/MACCProcessing](https://github.com/UARPGitHub/MACCProcessing)), S8: MATLAB\({}^{\text{\textregistered}}\) Processing Code For Supplementary Files S2-S7. The follow is available online at [[https://github.com/UARPGitHub/MACC](https://github.com/UARPGitHub/MACC)]([https://github.com/UARPGitHub/MACC](https://github.com/UARPGitHub/MACC)), S9: Microbubble Acoustic Characterisation Design Files. The follow is available online at [[https://github.com/UARPGitHub/MACC/wiki](https://github.com/UARPGitHub/MACC/wiki)]([https://github.com/UARPGitHub/MACC/wiki](https://github.com/UARPGitHub/MACC/wiki)), S10: Microbubble Acoustic Characterisation Knowledge Base And Assembly Guide.  
Conceptualization, E.S., J.M., D.C. and S.F.; methodology, E.S., L.N., J.M. and S.F.; software, E.S., H.C. and T.C.; validation, E.S.; formal analysis, E.S.; investigation, E.S.; resources, J.M., D.C. and S.F.; data curation, E.S.; writing--original draft preparation, E.S.; writing--review and editing, E.S., L.N., J.M., H.C., T.C., D.C., S.E., A.F.F. and S.F.; visualization, E.S.; supervision, S.F., A.F.F. and S.E.; project administration, S.F.; funding acquisition, S.F. and S.E. All authors have read and agreed to the published version of the manuscript.  
This research was funded by EPSRC grants number EP/P023266/1 and EP/V04799X/1. A.F.F. is partially funded by a RAEng Chair in Emerging Technologies (CiET1819/19)  
Not applicable.  
Data Availability Statement: The data presented in this study are available in Supplementary Material S1-S7.  
The author would like to thank the Microbubble Consortium at the University of Leeds.  
The authors declare no conflict of interest.  
The following abbreviations are used in this manuscript:  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{1}{c}{**Frequency**} & \multicolumn{6}{c}{**Scattering**} \\ \multicolumn{1}{c}{**(MHz)**} & \multicolumn{6}{c}{**(dB)**} \\ \hline  & T1/T1 & T2/T2 & T3/T3 & T4/T4 & T5/T5 & T6/T6 \\ \hline  
\hline \hline \end{tabular}
\end{table}
Table 11: Mean backscatter at the fundamental frequency over the frequency range 1.6–6.4 MHz for the 1:1000 dilutions of SonoVue®. The transmitter receiver configuration is denoted transmitter/receiver.