Biomedical Engineering Reference
In-Depth Information
Table 4.3 Applications and Power Consumption
Application
IMD
Battery
Chemistry
Power Requirements
Battery
Duration
Bradycardia
Pacemaker
Li/I
2
30
100
µ
W
5
12 years
Tachycardia,
fibrillation
Cardioverter
defibrillator
Li/SVO,
Li/Ag
2
V
4
O
11
30
W (pacing)
1
10 W for defibrillation
100
4
7 years
µ
Chronic pain, deep
brain stimulation
Spinal cord
stimulator (SCS);
Deep brain
stimulator (DBS)
Li/SOCl
2
300
µ
Wto50mW
3
6 years
Bladder control
Sacral nerve
stimulation (SNS)
Li/SVO,
Li/SOCl
2
300
µ
Wto50mW
3
5 years
Hearing loss
Cochlear Implant
Zinc-Air
200
W to 5 mW
10
60 hours
µ
Spasticity
Drug Pump
Li/SOCl
2
100
µ
W to 2 mW
4
8 years
Schmidt and Skarstad (2001)
Zeng et al. (2008)
done through batteries or by external powering sources (radio fre-
quency).
Table 4.3
overviews the applications, power requirements, and
service life for some of the IMDs.
Finally,
Figure 4.1
makes a comparison of the power consumption
of several biomedical devices against the power generation of reported
energy harvesters in the literature. There are a number of generators
that can be matched to medical applications. For instance, powered
knee and leg prosthesis could use the knee-mounted brace (Li et al.,
2008) or the backpack-generator (Rome et al., 2005). Cochlear
implants and hearing aids could have thermal generators integrated
into their designs for extended battery life. Hearing devices enjoy the
possibility of thermal generator, because locations around the ear or
head could use a large thermal gradient without clothing obstruction.
Analyzing the plot, there are several approaches for powering cardiac
pacemakers or similar power-budget devices. A number of the genera-
tors with relatively large power output were designed to harness energy
while placed inside the shoes, which makes the integration with other
devices challenging. From the summary figure, some electromagnetic
prototypes, such as those presented by Bowers and Arnold (2008) and
