A-Scan
TISSUE OXYGEN SCANNING TECHNOLOGY
- A unique needle probe allows measuring dissolved oxygen at any point along the shaft of the needle.
- NO MECHANICAL MOVEMENT OF THE NEEDLE WITH RESPECT TO THE TISSUE while scanning.
- OPTIMALLY DESIGNED FOR ANIMAL STUDIES.
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: 30 mm or 120 mm (extended range probe).
Probe diameter: 0.8 mm.
Full scan in under 20 seconds (30 mm scan range 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.
Blueberry in a water tank.
Needle probe is inserted through the blueberry
Spatial distribution of dissolved oxygen in the blueberry
Temporal response at a fixed position (14mm) to abrupt removal of the blueberry
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
Probe positioning in a tumor in a hindlimb of a mouse
Tissue oxygen scan through a cancer tumor. Hypoxic core is observed
A-Scan System and Probe
