LASER DOPPLER BLOOD FLOWMETER.pptx

Laser Doppler blood flow meter is a non invasive method to estimate the blood flow rate.
Laser Flow Blood Flow meter is an accurate and reliable method for assessing Blood flow rate.
The structure of sensor consists of two compartments with a photo detector and a laser diode in each. The size and weight of sensor and overall weight of system is very less.

1. LASER DOPPLER BLOOD FLOWMETER FAIZAAN MEHRAJ

2. What is blood flow? Blood flow refers to the movement of blood through the vessels. From arteries to capillaries and then into veins .

3. Blood flow rate Depends on two factors . Pressure exerted by heart. Resistance of vessel.

4. Pressure exerted by heart. If the pressure exerted by heart is higher the blood flow rate is also higher. Pressure exerted by heart is directly proportional to blood flow. BLOOD FLOW PRESSURE EXERTED BY HEART  

5. Resistance of vessel. The resistance of a blood vessel to the blood flow. Resistance occur due to the width or cross section area of vessels. BLOOD FLOW  

6. BLOOD FLOW  

7. What is laser doppler blood flow meter. Laser Doppler Flowmetry (LDF) is a non-invasive method to estimate the blood flow rate. Laser Doppler Flowmetry (LDF) is an accurate and reliable method for assessing blood flow rate. The structure of the sensor consists of two compartments with a photo detector and a laser diode in each. The size & weight of sensor & overall system is very less.

8. Doppler effect The apparent change in the frequency of a wave caused by relative motion between the source of the wave and the observer.

9. Working of laser doppler blood flow meter. When a laser beam falls on the tissue the absorption and scattering takes place . RADATION SCATTERED IN, Movable structures like blood cells shifts in frequency due to doppler effect. Non movable soft tissue remain unshifted in frequency. Both shifted and non shifted beams are received by light detector or photo sensor. Mixing of optical signals take place.

10. Practical setup for LDF blood flow meter.

11. PORTABLE LDF BLOOD FLOW METER

12. Blood flow measurement taken by LDF blood flow meter. Type of blood vessels Theoretical values of blood flow Values measured by LDF Aorta 40-60 Cm/s Around 50 Cm/s Artery 30-50 Cm/s Around 40 Cm/s Veins 30-50 Cm/s Around 40 Cm/s Arteriole 20-40 Cm/s Around 30 Cm/s

13. Advantages of laser doppler blood flow meter . The LDF technique offers the continuous measurement of micro vascular blood perfusion. LDF may be used non-invasively (since the sensor is not actually required to touch the surface of the body) and in no way harms or disturbs the normal physiological state. Receptive to small changes. Continuous/real-time – response. Reduce anxiety in patients. Reduce bacterial infection(sterilize the area being worked on).

14. What are the limitations of LDF. Sensitive to tissue and cable movement. Site to site variation as probe is moved.(Due to variation in tissue optics)

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