1. The problem is to ensure the bevel cutting of an IV cannula is balanced. 2. The balance ratio is defined as the ratio of the shorter side cutting length to the longer side cutting length. 3. Let the shorter side cutting length be $L_s$ and the longer side cutting length be $L_l$. 4. The balance condition is: $$\frac{L_s}{L_l} \geq 0.8$$ 5. This means the shorter side must be at least 80% of the longer side to be considered balanced. 6. If the ratio is less than 0.8, the bevel cutting is unbalanced and may affect the cannula's performance. 7. To check balance, measure both side lengths $L_1$ and $L_2$, identify which is shorter and which is longer, then compute the ratio. 8. Example: If $L_1 = 4$ mm and $L_2 = 5$ mm, then $$\frac{4}{5} = 0.8$$ which meets the balance requirement. 9. If $L_1 = 3$ mm and $L_2 = 5$ mm, then $$\frac{3}{5} = 0.6 < 0.8$$ which is unbalanced. 10. Maintaining this ratio ensures proper bevel shape and function of the cannula.