doc.: ieee 802. 15-08-0714-00-0006 submission sep 2008 project: ieee p802.15 working group for...

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Submission Title: Channel modeling for medical implanted communication systems by numerical simulation

Date Submitted: [xx Sep, 2008]Source: Jaehwan Kim[ETRI], HyungSoo Lee[ETRI], Jeong Ki Pack[CNU], Tae Hong Kim[CNU]Contact: Jae Whan Kim, ETRI, KoreaVoice: :+82-42-860-5338, E-mail:[email protected]: [n/a]Abstract: Provide needs of channel modeling for medical implanted communication

systemPurpose: To provide basic channel characteristics for the manufacture of medical

implantable communication systemNotice: This document has been prepared to assist the IEEE P802.15. It is offered

as a basis for discussion and is not binding on the contributing individual's or organization's. The material in this document is subject to change in form and content after further study. The contributor's reserves the right to add, amend or withdraw material contained herein.

Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and maybe made publicly available by P802.15.

Slide 1

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Contents

• Channel models for BAN

• Methods for channel modeling

• Channel modeling 1



• Conclusions

Slide 2

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Scenario Description Frequency Band Channel Model

S1 Implant to Implant 402-405 MHz CM1

S2 Implant to Body Surface 402-405 MHz CM2

S3 Implant to External 402-405 MHz CM2

S4 Body Surface to Body Surface (LOS) TBD (f1,… fn) CM3

S5 Body Surface to Body Surface (NLOS) TBD (f1,… fn) CM3

S6 Body Surface to External (LOS) TBD (f1,… fn) CM4

S7 Body Surface to External (NLOS) TBD (f1,… fn) CM4

Channel models for WBAN

CM1

CM2

CM3

CM4

CM1

CM2

CM3

CM4

Sep 2008

Slide 3

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

• Channel modeling - Scenario 1(CM1), Scenario 2(CM2 )

- FDTD method was used for channel modeling

using Remcom XFDTD 6.5

- Frequency: 403.5 MHz

• Human body model - Korean male phantom model

(voxel size : 3 mm)

• TX antenna - Hertzian dipole - Channel models must not be affected by the transmitting antenna pattern. So the proper compensation for directive gain as well as polarization are needed.

Methods for channel modeling

Slide 4

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

• Simulation scenario

Location Device

Deep tissueCapsule endoscope, Capsule for drug delivery(1-4, 6-9)

Near surface

Glucose-Insulin(10-11), Insulin pump(12-13)

Pacemaker(14)

Deep brain stimulator, Parkinson’s disease, Cortical stimulator, Visual neuro-stimulator, Audio-neuro stimulator(15-16)

Central-nerve stimulator(11)

Healthcare shoes (17)

− Transmitter location : 17 positions Near surface implants : 9 Deep tissue implants : 8

Slide 5

17

1

10

1615

2345

96

7

8

1114

1312

− Receiver location : 138 points Implants(in-body) : 78 Body surface : 60

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 6

Channel modeling 1

• Path loss model - Path loss model used in IEEE P802.15-08-0033-05-0006

- PL(d)=PL(d0)+10nlog10(d/d0)+S [dB]

d0 : reference distance, 50 mm

n : path loss exponent S : random scatter around the regression line, N(0, σs)

• Channel modeling - Grouping of the transmitter location

Deep tissue implantNear surface implant

- Grouping of the receiver location In-body (implant) Body surface : from the skin to 2 cm away from the skin

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 7

• Deep tissue implant to another implant (the maximum path length is about 180 cm)

• Near surface implant to another implant (the maximum path length is about 180 cm)

( n=4.33, PL(d0)=47.70, σs=5.77 )

0.2 0.4 0.6 0.8 1 1.2 1.4

-110

-100

-90

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-70

-60

-50

-40

Distance[m]

Pat

h lo

ss [

dB

]

(n=3.65, PL(d0)=46.52, σs=8.84)

Path Loss vs. Distance Scatter Plot(CM1)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

-110

-100

-90

-80

-70

-60

-50

-40

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-20

Distance[m]

Pat

h lo

ss d

B]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 8

• Near surface implant to body surface (the maximum path length is about 180 cm)

• Deep tissue implant to body surface (the maximum path length is about 180 cm)

(n=3.53, PL(d0)=45.37, σs=9.46) (n=5.22, PL(d0)=37.28, σs=5.76)


0.2 0.4 0.6 0.8 1 1.2

-110

-100

-90

-80

-70

-60

-50

-40

Distance[m]

Pat

h lo

ss [

dB

]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

-120

-110

-100

-90

-80

-70

-60

-50

-40

-30

-20

Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=6.17, PL(d0)=34.89, σs=5.44)

Slide 9

• Deep tissue implant to another implant (fitted up to 50 cm)

(n=5.34, PL(d0)=35.48, σs=8.42)

• Near surface implant to another implant (fitted up to 50 cm)

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-100

-90

-80

-70

-60

-50

-40

Distance[m]

Pat

h lo

ss [

dB

]

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-100

-90

-80

-70

-60

-50

-40

-30

-20

Distance[m]

Pat

h lo

ss[d

B]


doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=4.34, PL(d0)=40.17, σs=10.09)

Slide 10

• Near surface implant to body surface (fitted up to 50 cm)

(n=6.06, PL(d0)=31.95, σs=5.75)

• Deep tissue implant to body surface (fitted up to 50 cm)


0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-100

-90

-80

-70

-60

-50

-40

Distance [m]

Pat

h lo

ss [

dB

]

0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5

-100

-90

-80

-70

-60

-50

-40

-30

Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 11

• When we fit the path loss model for the whole receiver locations (the maximum path length is about 180 cm), the modeling parameters are slightly different from the results of

IEEE 802.15-08-0519-00-0006. • However, the parameter values are well within the statistical

error bound (one σs value). <Implant to Implant CM1 (Scenario S1)>

<Implant to Body surface CM2 (Scenario S2)>

Summary of the channel modeling 1

Implant to Implant PL(d0) n σs

Deep tissue 47.70 4.33 5.77

Near surface 46.52 3.65 8.84

Implant to body surface PL(d0) n σs

Deep tissue 37.28 5.22 5.76

Near surface 45.37 3.53 9.46

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 12

• When fitted up to 50 cm as shown in IEEE 802.15-08-0519-00-0006, we obtained similar results as in IEEE P802.15-08-0033-05-0006.

<Implant to Implant CM1 (Scenario S1)>


Implant to Implant PL(d0) n σs

Deep tissue 34.89 6.17 5.44

Near surface 35.48 5.34 8.42

Implant to body surface PL(d0) n σs

Deep tissue 31.95 6.06 5.75

Near surface 40.17 4.34 10.09

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 13

Channel modeling 2• Path loss model

- Same as the model used in IEEE P802.15-08-0033-05-0006

• Channel modeling - We tried channel modeling for different scenarios (different grouping of TX’s or RX’s). - Modeling 2A

Path loss was modeled for total implant locations (i. e., the whole TX’s are grouped together for fitting)

- Modeling 2B Path loss was modeled for the total implant locations with the RX points

grouped differently. Receiver groups: head, trunk, lower parts of the body, arms

- Modeling 2C Path loss was modeled for the type of the transmitting implanted devices

(Implant to Implant) Type of devices : capsule endoscope, glucose-insulin, pacemaker, deep

brain stimulator, healthcare shoes

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=3.83, PL(d0)=48.46, σs=8.53)

Slide 14

• Total implant(deep tissue and near surface) to implant

Path Loss vs. Distance Scatter Plot(2A)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8-120

-110

-100

-90

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-50

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Distance [m]

Pat

h lo

ss [

dB

]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

-120

-110

-100

-90

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-70

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Distance [m]

Pat

h lo

ss [

dB

]

(n=4.01,PL(d0)=43.97, σs=8.89)

• Total implant(deep tissue and near surface) to body surface

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 15

Summary of the channel modeling 2A• Modeling parameters fitted for all transmitting implanted devices

PL(d0) n σs

Implant to Implant 48.46 3.83 8.53

Implant to Body surface 43.57 4.01 8.89

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=4.03, PL(d0)=47.11, σs=8.65 ) (n=3.75, PL(d0)=47.89, σs=9.78)

Slide 16

• Implant to head • Implant to lower parts of the body

Path Loss vs. Distance Scatter Plot(2B)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

-110

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Distance [m]

Pat

h lo

ss [

dB

]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8-120

-110

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-90

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Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=4.26, PL(d0)=44.99, σs=8.21 )

(n=3.81, PL(d0)=48.02, σs=7.97)

Slide 17

• Implant to trunk • Implant to arms

Path Loss vs. Distance Scatter Plot(2B)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

-110

-100

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Distance [m]

Pat

h lo

ss [

dB

]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

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-90

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Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

HeadLower parts of

the bodyTrunk Arms

PL(d0) 47.11 47.89 44.99 48.02

n 4.03 3.75 4.26 3.81

σs 8.65 9.78 8.21 7.97

Slide 18

Summary of the channel modeling 2B• Modeling parameters for different RX locations ( Implant to Implant)

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=4.48, PL(d0)=45.57, σs=6.42 )

(n=3.23, PL(d0)=43.52, σs=6.46)

Slide 19

• Capsule endoscope (gullet)

Path Loss vs. Distance Scatter Plot(2C)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

-110

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Distance [m]

Pat

h lo

ss [

dB

]

• Glucose Insulin (right hand)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

-90

-85

-80

-75

-70

-65

-60

-55

-50

-45

Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=4.29, PL(d0)=46.75, σs=6.55 )

(n=3.60, PL(d0)=47.96, σs=10.07)

Slide 20

• Pacemaker(heart)

Path Loss vs. Distance Scatter Plot(2C)• Deep brain stimulator

(right throat)

0.2 0.4 0.6 0.8 1 1.2

-100

-90

-80

-70

-60

-50

Distance[m]

Pat

h lo

ss [

dB

]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

-110

-100

-90

-80

-70

-60

-50

-40

-30

Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

(n=3.83, PL(d0)=36.72, σs=5.54 )

Slide 21

• Healthcare shoes (sole)

Path Loss vs. Distance Scatter Plot(2C)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8

-110

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Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Summary of the channel modeling 2C

Capsule endoscope

(gullet)

Glucose-Insulin

(right hand)

Pacemaker(heart)

Deep brain stimulator

(right throat)

Healthcare shoes (sole)

PL(d0) 45.57 43.52 46.75 47.96 36.72

n 4.48 3.23 4.29 3.60 3.83

σs 6.42 6.46 6.55 10.07 5.54

Slide 22

• Modeling parameters for different transmitting implanted devices (Implant to Implant)

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 23

• We have modeled WBAN channels for three different modeling scenarios(2A, 2B, 2C).• The results of the modeling scenario 2A are similar to those of the channel modeling 1. Thus, it seems that the modeling scenario in IEEE 802.15-08-0519-00-0006 could be simplified.• The results of the modeling scenario 2B show that there are no large difference in the model parameters for different body parts. So, the modeling scenario in IEEE 802.15-08-0519-00-0006 seems to be good.

Summaries of the channel modeling 2

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 24

• When we classify the transmitting implants in more detail(modeling scenario 2C), the parameter values are similar to the results of the modeling scenario 2A.

• Thus, the detailed classification of the transmitting implants does not seem to be necessary.

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

• Path loss model - PL(d)=PL(d0)+10nlog10(d/d0)+ a*d +S [dB]

d0 : reference distance, 50 mm

a : coefficient for absorption loss n : path loss exponent, N(0, σs)

S : random scatter around the regression line

- The absorption loss of biological tissues is very large. Because the absorption loss is a linear term in a log scale, we tried a modified path loss model by adding the first order term to WBAN channel more accurately.

• Channel modeling - Same as in the channel modeling 1

Slide 25

0 0.5 1 1.5-350

-300

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0

Distance[m]

Pat

h lo

ss [

dB

]

Attenuation lossRadiation lossTotal loss

Channel modeling 3

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Path loss vs. Distance Scatter Plot(CM1)

Slide 26

• Deep tissue implant to another implant

• Near surface implant to another implant

(n=5.87, PL(d0)=36.80, a=-19.70, σs=8.22)

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

-100

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-40

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0

Distance [m]

Pat

h lo

ss [

dB

]

(n=7.39, PL(d0)=33.58, a=-28.00, σs=5.07)

0.2 0.4 0.6 0.8 1 1.2 1.4

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Distance [m]

Pat

h lo

ss [

dB

]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Path loss vs. Distance Scatter Plot(CM2)

Slide 27

• Near surface implant to body surface• Deep tissue implant to body surface

(n=4.89, pl=39.83, a=-13.44, σs=9.30)

(n=7.38, PL(d0)=29.37, a=-24.96, σs=5.45)

0.2 0.4 0.6 0.8 1 1.2

-110

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Distance [m]

Pat

h lo

ss [

dB

]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

-120

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-60

-40

-20

Distance [m]P

ath

loss

[d

B]

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 28

• The comparison of the results of the channel modeling 3 shows that the modified pass loss model seems to be better, in terms of the modeling accuracy (i. e. standard deviation σs).

<Implant to Implant CM1 (Scenario S1)>


Implant to Implant PL(d0) n a σs

Deep tissue 33.58 7.39 -28.00 5.07

Near surface 36.80 5.87 -19.70 8.22

Implant to body surface PL(d0) n a σs

Deep tissue 29.37 7.38 -24.96 5.45

Near surface 39.83 4.89 -13.44 9.30

Summary of the channel modeling 3

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Conclusions• We have modeled WBAN channel by two path loss

models.• We also tried different scenarios for channel modeling.• Extensive simulation to characterize the MICS path loss

has been performed and statistical path loss models at 403.5 MHz are derived.

• The models are based on 9 near surface implants and 8 deep tissue implants for the Korean male phantom model.

Slide 29

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

• The modeling results show that Classification of the implants to two groups(deep

tissue and near surface) might not be necessary. The modified path loss model seems to work better. The modeling parameters could be different

depending on the path length for fitting, the location of TX’s or RX’s, but they are well within the statistical error bound (one σs value).

Slide 30

doc.: IEEE 802. 15-08-0714-00-0006

Submission

Sep 2008

Slide 31

References• Doc : 15-08-0519-00-0006 A statistical path loss model for MICS

• Doc : 15-08-0033-05-0006 Channel model for body area network (BAN)

doc.: ieee 802. 15-08-0714-00-0006 submission sep 2008 project: ieee p802.15 working group for...

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