Towards infrared visualization of reflective microbots under phantom tissues

Date

Jan 30, 2018

Time

10:00 AM - 11:00 AM

Speaker

Azaam Aziz

Affiliation

IFW Dresden

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Kristina Krummer-Meier

Description

Miniature technologies, like medical microbots, could revolutionize many fields of medicine by enabling non-invasive diagnosis, drug-delivery and therapeutic procedures. As explained recently in our research group, microbots must clear two major hurdles to enter clinical trials: visualization and control inside the body [1]. Researchers are trying to improve microbot imaging strategies to achieve better resolution and sensitivity. For example, Bradley et al. demonstrated controlled swimming of a swarm of around 10.000 artificial bacterial flagella (ABFs) in a mouse using fluorescence imaging [2]. Sarthak et al. could track the trajectory of a trail of bubbles from fast-moving microjets using ultrasound in a water batch containing hydrogen peroxide [3]. Martel et al. reported the visualization of a cluster of magnetotactic bacteria (5X107 bacterial count per mL) using magnetic resonance imaging (MRI) in a 1.5 mL Progene microtube [4]. Current imaging techniques, such as ultrasound, MRI, and infrared, are too coarse for single-microbot imaging. In radiology and nuclear medicine, X-rays and radioactive isotopes are hazardous. Besides, MRI can resolve structures only down to 100 µm with higher magnetic fields (10-12 Tesla), and the clinical optoacoustic approach can achieve 350 µm resolution down to a depth of 4 cm. All these techniques have insufficient spatial resolution, deep-tissue penetration and sensitivity to track individual moving microbots under biological tissues in real time. To overcome this problem, we have developed a customized infrared imaging (IR) setup which operates in the first biological window towards the visualization of mobile microbots under phantom tissues, using the principle of light reflection. In my first PhD seminar, I will present the preliminary results on the IR imaging of magnetic rotating microtubes, in real time under phantom tissues with a thickness up to 3.1 mm. I will start describing the fabrication and characterization of the reflective microtubes and the employed phantom tissues and discuss the first obtained videos of the mobile microtubes. Image post-processing by using a frequency filter will also be presented as a method to improve the spatial resolution and penetration depth, as shown in Figure 1. To conclude, I will comment on additional strategies to improve the current spatial resolution and the imaging depth. Other techniques such as optoacoustic, ultrasound, and nuclear imaging will also be put into perspective. [1] M. Medina-Sánchez and O. G. Schmidt, Nature, vol. 545, no. 7655, pp. 406–408, (2017) [2] A. Servant et al., Adv. Mater., vol. 27, no. 19, pp. 2981–2988, (2015) [3] A. Sánchez et al., Proc. IEEE RAS EMBS Int. Conf. Biomed. Robot. Biomechatronics, pp. 169–174, (2014) [4] O. Felfoul et al., Annu. Int. Conf. IEEE Eng. Med. Biol. Soc. EMBC’10, vol. 1, pp. 4367–4370, (2010)

Links

• Seminars at the IFW

Last modified: Jan 30, 2018, 8:42:48 AM