Question

1. Calculate the battery life in years when a pacemaker has the following characteristics: Battery Ampere-hours = 1.5 Pulse voltage = 2V Pulse width = 1.5 msec Pulse time period = 1 sec Electrode heart resistance = 150Ω Current drain on the battery = 1.25 µA

Answer 1

battery life in year = 9 years and 48 days

Step-by-step explanation:

given data

Battery Ampere-hours = 1.5

Pulse voltage = 2 V

Pulse width = 1.5 m sec

Pulse time period = 1 sec

Electrode heart resistance = 150 Ω

Current drain on the battery = 1.25 µA

to find out

battery life in years

solution

we get first here duty cycle that is express as

duty cycle =
`(width)/(period)` ...............1

duty cycle = 1.5 ×
`10^(-3)`

and applied voltage will be

applied voltage = duty energy × voltage ...........2

applied voltage = 1.5 ×
`10^(-3)` × 2

applied voltage = 3 mV

so current will be

current =
`(applied\ voltage)/(resistance)` ................3

current =
`(3)/(150)`

current = 20 µA

so net current will be

net current = 20 - 1.25

net current = 18.75 µA

so battery life will be

battery life =
`(1.5)/(18.75*10^(-6))`

battery life = 80000 hours

battery life in year =
`(80000)/(8760)`

battery life in year = 9.13 years

battery life in year = 9 years and 48 days