A-Scan Advantage​ at a Glance 

  • Optical Scanning:  A-Scan introduces the first oxygen scanning needle-probe that uses an optical scanner. Optical scanning makes the measurement of the pO2 profile easy, precise, and robust.

  • Automated depth scanning: A-Scan probe's design allows for a fully automated scanning along the needle's axis.

  • Internal scanning:  A-Scan probe features an internal probe, embedded inside the needle. This design eliminates the need for mechanical manipulation of a needle probe in tissue thereby avoiding excessive tissue damage and assuring high-quality data.

  • Applications: 

    • Pre-clinical testing

    • Small animal studies

    • Tissue engineering

 

 

Scanning Tissue Oxygen Probe

A-Scan tissue oxygen scanner is uniqely designed for reseachers. It combines a rugged design for repeated use in tissue with an easy and intuitive depth scanning.

The sensor is constructed of a robust polymer-coated glass capillary, combining longitudinal rigidity for easy tissue penetration, with high flexibility for off-axis forces. Oxygen level can be measured at any point along the side of the probe. Automatic scanning can be programmed and repeated periodically with NO relative motion between the probe and the tissue. This feature is ideal for pre-clinical studies in animal models. Oxygen gradients are accurately recorded in a form of a full pO2 depth profile. Dynamic response to treatment or other ques can be explored by programming repeated scans in short time intervals.

 

Technical Specifications (highlights)

  • Scan length: 25 mm or 45 mm (extended range probe).

  • Probe diameter: 0.36 mm.

  • Full scan in under 3 minutes (25 mm at 0.4 mm step).

  • Number of repeated scans: Unlimited

  • pO2 measurement range: 0 to 160 mmHg.

  • Spatial Resolution: 0.4 mm

  • Temporal Response: 5.0 s

  • Accuracy: 5% (pO2 > 20 mmHg), 10% (pO2 < 20 mmHg)

  • System compatibility: PC (Windows 10 / 11)

  • Data Connectivity: Excel, Matlab, Origin, Python

The Blueberry Test

Fruits respiration, the process of consuming oxygen for ATP production, continue even after harvesting, packaging, and transport to your local grocery store. The limited rate of oxygen diffusion through the outer shell of the fruit results in a low pO2 level in the inner parts of the fruit.

Here in A-Scan's lab we love blueberries. They are perfect for testing. Since their skin is pretty thin, we can estimate the spatial resolution of the system by scanning a blueberry. The figure below shows a resolution of better than 0.4 mm.

We can also use them to estimate the response time of the sensor. Starting a pO2 measurement at a fixed point inside the blueberry as a function of time and then abruptly removing the blueberry from the probe is our equivalent of a step response test. The results show a response time of approximately 5 s.

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An Application Example

A scan through a cancer tumor in a mouse cancer model demonstrating a sharp decrease of pO2 in the tumor core. For more details see S. Ashkenazi et. al.

Ashkenazi S., Cho D., Song C.W. (2021) Scanning Tissue Oxygen Needle Probe. In: Nemoto E.M., Harrison E.M., Pias S.C., Bragin D.E., Harrison D.K., LaManna J.C. (eds) Oxygen Transport to Tissue XLII. Advances in Experimental Medicine and Biology, vol 1269. Springer, Cham. https://doi.org/10.1007/978-3-030-48238-1_8

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A-Scan system and a scanning needle probe