Flow controlled air puff generator towards in-situ brain tumor detection based on MHz optical coherence elastography

Detrez, Nicolas; Rewerts, Katharina; Matthiae, Moritz; Buschschlüter, Steffen; Bonsanto, Matteo M.; Theisen-Kunde, Dirk; Brinkmann, Ralf

doi:10.1117/12.2615022

Cited by 7 publications

(5 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because of the brain tissue specific viscoelastic mechanical properties, we developed a novel Air-Jet excitation source [3], (Fig. 1) which can emit very stable gas jets with a duration between 20 ms and 700 ms.…”

Section: Methodsmentioning

confidence: 99%

Air-Jet based optical coherence elastography: processing and mechanical interpretation of brain tumor data

Detrez

Burhan

Rewerts

et al. 2023

Optical Elastography and Tissue Biomechanics X

View full text Add to dashboard Cite

The long-term aim of this project is to establish optical coherence elastography for tumor delineation in the field of neurosurgery. Because of the challenging highly viscoelastic properties of brain tissue, we developed a new Air-Jet based excitation source. With pulse duration of up to 700 ms and real time force measurement, this novel system allows the sample to reach a semi-steady state. In parallel with a 3.2 MHz swept-source optical coherence tomography system over 800 line scans are acquired over the whole sample excitation process. The phase data is extracted, unwrapped and the displacement per pixel is calculated. This system enables the measurement of mechanical properties like stiffness and Young’s modulus, similar to the standard indentation measurement. As well as viscoelastic properties i.e. relaxation times, in non-contact. The first processing step is to split the excitation progression into three main time ranges: the high dynamic, the steady state, and the viscoelastic range. In each range typical features of the displacement curve are extracted for every pixel in the B-scan. For those features, various mechanical parameters are calculated mainly, the stiffness and Young’s modulus and stored as feature matrices. The results are processed, visualized and overlaid with either the OCT intensity image or the histological sections. Strain stress curves are generated for some selected positions in the B-scan leading to a specific viscoelastic hysteresis. The feature matrices will be utilized as a fingerprint for each tissue, and are the first step for an AI based classification of the tissue.

show abstract

Section: Methodsmentioning

confidence: 99%

Air-Jet based optical coherence elastography: processing and mechanical interpretation of brain tumor data

Detrez

Burhan

Rewerts

et al. 2023

Optical Elastography and Tissue Biomechanics X

View full text Add to dashboard Cite

show abstract

“…We developed a novel Air-Jet excitation source [3]. Which can emit very stable pulses with a duration between 20 ms and 700 ms.…”

Section: Methodsmentioning

confidence: 99%

Air-jet based optical coherence elastography of brain tumor tissue: stiffness evaluation by structural histological analysis

Detrez,

Burhan,

Strenge

et al. 2023

Emerging Technologies for Cell and Tissue Characterization II

View full text Add to dashboard Cite

An accurate tumor delineation in neurosurgery is still a very challenging problem which we are addressing with optical coherence elastography (OCE). Because of the highly viscoelastic properties of brain tissue, we developed a new Air-Jet based tissue excitation source and evaluated the tissue stiffness with a 3.2 MHz swept-source Optical Coherence Tomography (OCT) system with a line scan rate of 2.45 kHz. The phase based displacement per pixel is measured and stiffness maps are calculated for brain tumor samples. However, certain features in the stiffness maps are seemingly not correlatable to the tissue features in the histological sections. Therefore, the structural properties of the histological sections e.g. fiber orientation, cell nuclei concentration and the "onion structure" with their rotational direction for meningioma were given greater consideration. The structural information are extracted from the histological sections via color deconvolution and structural tensor analysis. First results show that the stiffness transitions correlate with some structures of the histological sections. In summary, the Air-Jet OCE seems to be capable of measuring the stiffness as well as the structural composition of the sample. The long-term aim of this project is to establish OCE to support tumor delineation in the field of neurosurgery.

show abstract

“…Telecentric scanning was performed using a lens with an effective focal length of 54 mm and a working distance of 42.3 mm (LSM04, Thorlabs Inc., USA). To stress the tissue mechanically, a home-built non-contact air-jet system that can be operated at adjustable flow rates between 0.25 and 20 l/min corresponding to forces between about 0.2 mN and 40 mN is used for excitation [2]. Two nozzles are located on each side of the scan objective at 10 mm to the sample, ensuring that the maximum air flow is in the center of the OCT image, as shown in Figure 1.…”

Section: Methodsmentioning

confidence: 99%

Advanced FFT-based contrast approach for MHz optical coherence elastography

Burhan,

Detrez,

Göb

et al. 2023

Optical Coherence Imaging Techniques and Imaging in Scattering Media V

View full text Add to dashboard Cite

Optical coherence elastography represents mechanical characteristics of biological tissue in so-called mechanical contrast maps. In addition to the standard intensity image, the contrast map illustrates numerous mechanical tissue features that would otherwise be undetectable. This is of great interest as abnormal physiological changes influence the mechanical behavior of the tissue. We demonstrate an advanced mechanical contrast approach based on the phase signal of our 3.2 MHz optical coherence tomography system. The robustness and performance of this contrast approach is evaluated and discussed based on preliminary results.

show abstract

Flow controlled air puff generator towards in-situ brain tumor detection based on MHz optical coherence elastography

Cited by 7 publications

References 5 publications

Air-Jet based optical coherence elastography: processing and mechanical interpretation of brain tumor data

Air-Jet based optical coherence elastography: processing and mechanical interpretation of brain tumor data

Air-jet based optical coherence elastography of brain tumor tissue: stiffness evaluation by structural histological analysis

Advanced FFT-based contrast approach for MHz optical coherence elastography

Contact Info

Product

Resources

About