Optical Transmission Measurement of a Biological Sample, Lab Report Example

 Introduction

This laboratory experiment seeks to find out the measurement of a pig cornea optimal transmission. In the experiment, the following questions will be addressed with specific answers to the questions provided.

  1. How the beam of a laser is aligned.
  2. How an optimal design of a beam expander is set up
  3. How the power of a laser beam is measured. This is done using a power meter
  4. How the transmission of the sample is calculated. This is done using measurements from transmitted power and from the incident.

 Objective

In order to give answers to the above questions, a diluted Indian ink solution commonly known as (Nigrosin) will be used. This solution has different tissue samples and placed in plastic cuvettes. These concentrations will be used to model or come up with tissue samples that are different. The will be also repeated measurements of pig cornea that are similar to this. These measurements will be treated with different compounds in order to demonstrated and find out how absorption in tissues can be modified. This is modification is possible through the use of photoinitiators that are added to them. A lens holder will be used to hold the corneas while a beam that is low-powered but visible is used as a source of light. The incident is then measured using a power meter with a transmitted power which has been passed through the sample. These measurements will be treated with different compounds in order to demonstrated and find out how absorption in tissues can be modified. Beuthan et al   (1998).

 Theory

To determine the absorptive quality of a transmission measurement process of a tissue that is specific. Some typical set-up has to be taken during this laboratory session. A spectrophotometric cell is used in the process of which involve biological tissue and fluid. This cell is rectangular in shape or a container in the form of quartz. This principle of transmission measurement in samples of fluids is highly dependent on measurements. The mostly commonly used instrument of measurement is oxymeter Beuthan et al   (1998).

The container should have high precision and a thickness that is calibrated. The container should also be homogenous and highly parallel with output windows. The light path for every typical range is from 0.01 mm to several centimeters. The efficiency of transmission is the calculated.

Based on the theoretical principle, when light passes through tissues, fluids like skin or blood its intensity decreases progressively. This is also the case in tissues and fluids. There is also is energy transformation into either thermal or chemical energy. For instance the absorption of ultraviolet radiations by the skin produces chemical reaction (Basic, 1962).

There is also calculation of many kinds in biology which can relate well with this experiment which include absorption of blood, oxygen concentration in the c\se of measure of oxygen level of patients who are bed written. This principle of transmission measurement in samples of fluids is highly dependent on measurements. The mostly commonly used instrument of measurement is oxymeter. Beuthan et al   (1998).

Corneal transplant in this case is a visual rehabilitation and the most used technique is is ultraviolet (UVA) light with the help of riboflavin which is vitamin B2 used to increase the uptake of UVA light by normal cornea which under normal state does not take in ultraviolet radiation (Basic, 1962).

References

Beuthan, Jürgen, Olaf Minet, and Gerhard J. Müller. Selected Papers on Optical Tomography: Fundamentals and Applications in Medicine. Bellingham, Wash: SPIE Optical Engineering Press, 1998. Print.

B.a.s.i.c. Philadelphia: BioSciences Information Service of Biological Abstracts [etc., 1962. Print.