J Neurol Res

Journal of Neurology Research, ISSN 1923-2845 print, 1923-2853 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Neurol Res and Elmer Press Inc

Journal website http://www.neurores.org

Original Article

Volume 5, Number 1-2, April 2015, pages 167-180

A Non-Invasive Detection and Monitoring of Intracranial Pressure Using Ultrasound Sensors

Figure 14. Graphical representation of appropriate ultrasound penetration frequencies for each dataset.

Figure 17. (a) Part of ultrasound pulses received from the SIMULINK biological system model. (b) Amplified received ultrasound pulse from CSF cells reflections. (c) The multiplexed signal of the original ultrasound pulse and the received amplified ultrasound pulse. (d) The filtered shifted ultrasound pulse (shift frequency) to remove high frequencies.

Figure 18. ICP pulses used for simulations for (a) an abnormal ICP pulse, (b) an abnormal challenging ICP pulse, (c) a normal ICP pulse, and (d) a normal challenging ICP pulse.

**Table 1.** Properties of Various Tissue Regions Used in MATLAB Simulation of Ultrasound Propagation Within the Neck Region
Regions	Properties
Transducer	7,660	5200	-	-
Skin	1,010 - 1,020	1,720 - 1,540	3.300	1.4 - 4
Neck muscle	1,040 - 1,070	1,580 - 1,566	20.000	14 - 27.5, 10 - 14.5
Vertebra column	1,400 - 1,810	3,299 - 4,080	1.000	10 - 13.0
Dura mater	1,010 - 1,020	1,720 - 1,540	0.025	0.4 - 0.9
Cerebrospinal fluid	990 - 1,000	1,527 - 1,519	1.000	0.3 - 0.5
Spinal cord	1,010 - 1,020	1,720 - 1,540	0.025	2 - 3.51

Table 1. Properties of Various Tissue Regions Used in MATLAB Simulation of Ultrasound Propagation Within the Neck Region

Regions

Properties

Density (kg/m³)

Speed of sound (m/s)

Attenuation (Np/m/MHz)

Tissue thickness (mm)

Transducer

7,660

5200

Skin

1,010 - 1,020

1,720 - 1,540

3.300

1.4 - 4

Neck muscle

1,040 - 1,070

1,580 - 1,566

20.000

14 - 27.5, 10 - 14.5

Vertebra column

1,400 - 1,810

3,299 - 4,080

1.000

10 - 13.0

Dura mater

1,010 - 1,020

1,720 - 1,540

0.025

0.4 - 0.9

Cerebrospinal fluid

990 - 1,000

1,527 - 1,519

1.000

0.3 - 0.5

Spinal cord

1,010 - 1,020

1,720 - 1,540

0.025

2 - 3.51

**Table 2.** Dataset Generated Table From Initial Parameters
Region	Range
Density (kg/m³)
Skin	1,010	1,011	1,012	1,013	1,014	1,015	1,016	1,017	1,018	1,020
Muscle	1,040	1,043	1,046	1,050	1,053	1,056	1,060	1,063	1,066	1,070
Vertebra	1,400	1,445	1,491	1,536	1,582	1,627	1,673	1,718	1,764	1,810
Dura	1,010	1,011	1,012	1,013	1,014	1,015	1,016	1,017	1,018	1,020
CSF	990	991	992	993	994	995	996	997	998	1,000
Spine	1,010	1,011	1,012	1,013	1,014	1,015	1,016	1,017	1,018	1,020
Speed of sound (m/s)
Skin	1,720	1,700	1,680	1,660	1,640	1,620	1,600	1,580	1,560	1,540
Muscle	1,580	1,578	1,577	1,575	1,574	1,572	1,571	1,569	1,568	1,566
Vertebra	3,299	3,386	3,472	3,559	3,646	3,733	3,820	3,906	3,993	4,080
Dura	1,720	1,700	1,680	1,660	1,640	1,620	1,600	1,580	1,560	1,540
CSF	1,527	1,526	1,525	1,524	1,523.4	1,523	1,522	1,521	1,520	1,519
Spine	1,720	1,700	1,680	1,660	1,640	1,620	1,600	1,580	1,560	1,540
Thickness (mm)
Skin	1.40	1.70	2.00	2.30	2.60	2.80	3.10	3.40	3.70	4.00
Muscle	27.50, 14.50	26.00, 14.00	24.50, 13.50	23.00, 13.00	21.50, 12.50	20.00, 12.00	18.50, 11.50	17.00, 11.00	15.50, 10.50	14.00, 10.00
Vertebra	10.00	10.30	10.70	11.00	11.30	11.70	12.00	12.30	12.70	13.00
Dura	0.40	0.46	0.51	0.57	0.62	0.70	0.73	0.80	0.84	0.90
CSF	0.30	0.32	0.34	0.37	0.39	0.41	0.43	0.45	0.48	0.50
Spine	2.00	2.20	2.30	2.50	2.70	2.80	3.00	3.20	3.30	3.50

Table 2. Dataset Generated Table From Initial Parameters

Region

Range

Density (kg/m³)

Skin

1,010

1,011

1,012

1,013

1,014

1,015

1,016

1,017

1,018

1,020

Muscle

1,040

1,043

1,046

1,050

1,053

1,056

1,060

1,063

1,066

1,070

Vertebra

1,400

1,445

1,491

1,536

1,582

1,627

1,673

1,718

1,764

1,810

Dura

1,010

1,011

1,012

1,013

1,014

1,015

1,016

1,017

1,018

1,020

CSF

990

991

992

993

994

995

996

997

998

1,000

Spine

1,010

1,011

1,012

1,013

1,014

1,015

1,016

1,017

1,018

1,020

Speed of sound (m/s)

Skin

1,720

1,700

1,680

1,660

1,640

1,620

1,600

1,580

1,560

1,540

Muscle

1,580

1,578

1,577

1,575

1,574

1,572

1,571

1,569

1,568

1,566

Vertebra

3,299

3,386

3,472

3,559

3,646

3,733

3,820

3,906

3,993

4,080

Dura

1,720

1,700

1,680

1,660

1,640

1,620

1,600

1,580

1,560

1,540

CSF

1,527

1,526

1,525

1,524

1,523.4

1,523

1,522

1,521

1,520

1,519

Spine

1,720

1,700

1,680

1,660

1,640

1,620

1,600

1,580

1,560

1,540

Thickness (mm)

Skin

1.40

1.70

2.00

2.30

2.60

2.80

3.10

3.40

3.70

4.00

Muscle

27.50, 14.50

26.00, 14.00

24.50, 13.50

23.00, 13.00

21.50, 12.50

20.00, 12.00

18.50, 11.50

17.00, 11.00

15.50, 10.50

14.00, 10.00

Vertebra

10.00

10.30

10.70

11.00

11.30

11.70

12.00

12.30

12.70

13.00

Dura

0.40

0.46

0.51

0.57

0.62

0.70

0.73

0.80

0.84

0.90

CSF

0.30

0.32

0.34

0.37

0.39

0.41

0.43

0.45

0.48

0.50

Spine

2.00

2.20

2.30

2.50

2.70

2.80

3.00

3.20

3.30

3.50

**Table 3.** Fresnel Length for a Range of Speed of Sound for Various Tissue Regions
Speed of sound (m/s)	Fresnel length (mm)	Region thickness (mm)
Skin region
1,720	4.651	6.976	11.627	18.604	23.255	27.906	34.882	41.860	46.511	1.40
1,700	4.705	7.058	11.764	18.823	23.529	28.235	35.294	42.352	47.058	1.70
1,680	4.761	7.142	11.904	19.047	23.809	28.571	35.714	42.857	47.619	2.00
1,660	4.819	7.228	12.048	19.277	24.390	28.915	36.144	43.373	48.192	2.30
1,640	4.878	7.317	12.195	19.512	24.391	29.268	36.585	43.902	48.780	2.60
1,620	4.938	7.407	12.345	19.753	24.691	29.629	37.037	44.444	49.382	2.80
1,600	5.000	7.500	12.500	20.000	25.000	30.000	37.500	45.000	50.000	3.10
1,580	5.063	7.594	12.658	20.253	25.316	30.379	37.974	45.569	50.632	3.40
1,560	5.128	7.692	12.820	20.512	25.641	30.769	38.461	46.153	51.282	3.70
1,540	5.194	7.792	12.987	20.779	25.974	31.168	38.961	46.753	51.948	4.00
Muscle region
1,580	5.063	7.594	12.658	20.253	25.316	30.379	37.974	45.569	50.632	14.0, 10.0
1,578	5.068	7.602	12.670	20.273	25.341	30.409	38.012	45.614	50.682	15.5, 10.5
1,577	5.073	7.609	12.683	20.293	25.366	30.439	38.049	45.659	50.732	17.0, 11.0
1,575	5.078	7.617	12.695	20.313	25.391	30.469	30.087	45.704	50.782	18.5, 11.5
1,574	5.083	7.624	12.708	20.333	25.416	30.499	38.124	45.749	50.833	20.0, 12.0
1,572	5.088	7.632	12.720	20.353	25.441	30.530	38.162	45.795	50.883	21.5, 12.5
1,571	5.093	7.640	12.733	20.373	25.466	30.560	38.200	45.840	50.933	23.0, 13.0
1,569	5.098	7.647	12.746	20.393	25.492	30.590	38.238	45.885	50.984	24.5, 13.5
1,568	5.103	7.655	12.758	20.413	25.517	30.620	38.276	45.931	51.034	26.0, 14.0
1,566	5.108	7.662	12.771	20,434	25,542	30.651	38.314	45.977	51.085	27.5, 14.5
Vertebra region
3,299	2.424	3.637	6.062	9.699	12.124	14.559	18.187	21.824	24.249	10.0
3,386	2.362	3.544	5.907	9.451	11.814	14.176	17.721	21.265	23.628	10.3
3,472	2.303	3.455	5.759	9.215	11.518	13.822	17.278	20.734	23.037	10.7
3,559	2.247	3.371	5.619	8.990	11.238	13.485	16.875	20.228	22.476	11.0
3,646	2.194	3.291	5.485	8.776	10.970	13.164	16.455	19.747	21.941	11.3
3,733	2.143	3.214	5.357	8.572	10.715	12.858	16.073	19.288	21.431	11.7
3,820	2.094	3.141	5.236	8.377	10.472	12.566	15.708	18.849	20.944	12.0
3,906	2.047	3.071	5.119	8.191	10.239	12.287	17.359	18.431	20.478	12.3
3,993	2.003	3.005	5.008	8.013	10.016	12.020	15.025	18.030	20.033	12.7
4,080	1.960	2.941	4.901	7.843	9.803	11.764	14.705	17.647	19.607	13.0
Dura region
1,720	4.651	6.976	11.627	18.604	23.255	27.906	34.882	41.860	46.511	0.40
1,700	4.705	7.058	11.764	18.823	23.529	28.235	35.294	42.352	47.058	0.46
1,680	4.761	7.142	11.904	19.047	23.809	28.571	35.714	42.857	47.619	0.51
1,660	4.819	7.228	12.048	19.277	24.390	28.915	36.144	43.373	48.192	0.57
1,640	4.878	7.317	12.195	19.512	24.391	29.268	36.585	43.902	48.780	0.62
1,620	4.938	7.407	12.345	19.753	24.691	29.629	37.037	44.444	49.382	0.70
1,600	5.000	7.500	12.500	20.000	25.000	30.000	37.500	45.000	50.000	0.73
1,580	5.063	7.594	12.658	20.253	25.316	30.379	37.974	45.569	50.632	0.80
1,560	5.128	7.692	12.820	20.512	25.641	30.769	38.461	46.153	51.282	0.84
1,540	5.194	7.792	12.987	20.779	25.974	31.168	38.961	46.753	51.948	0.90
CSF region
1,527	5.239	7.858	13.097	20.956	26.195	31.434	39.292	47.151	52.390	0.30
1,526	5.242	7.863	13.105	20.968	26.210	31.452	39.315	47.187	52.420	0.32
1,525	5.245	7.867	13.112	20.980	26.225	31.470	39.338	47.206	52.451	0.34
1,524	5.248	7.872	13.120	20.992	26.240	31.489	39.631	47.233	52.481	0.37
1,523.4	5.251	7.876	13.128	21.005	26.256	31.507	39.384	47.261	52.512	0.39
1,523	5.254	7.881	13.135	21.017	26.271	31.525	39.407	47.288	52.543	0.41
1,522	5.257	7.886	13.143	21.029	26.286	31.544	39.430	47.316	52,573	0.43
1,521	5.260	7.890	13.151	21.041	26.302	31.562	39.453	47.344	52.604	0.45
1,520	5.263	7.895	13.158	21.054	26.317	31.581	39.476	47.371	52.635	0.48
1,519	5.266	7.899	13.166	21.066	26.333	31.599	39.499	47.399	52.666	0.50
Spinal region
1,720	4.651	6.976	11.627	18.604	23.255	27.906	34.882	41.860	46.511	2.00
1,700	4.705	7.058	11.764	18.823	23.529	28.235	35.294	42.352	47.058	2.20
1,680	4.761	7.142	11.904	19.047	23.809	28.571	35.714	42.857	47.619	2.30
1,660	4.819	7.228	12.048	19.277	24.390	28.915	36.144	43.373	48.192	2.50
1,640	4.878	7.317	12.195	19.512	24.391	29.268	36.585	43.902	48.780	2.70
1,620	4.938	7.407	12.345	19.753	24.691	29.629	37.037	44.444	49.382	2.80
1,600	5.000	7.500	12.500	20.000	25.000	30.000	37.500	45.000	50.000	3.00
1,580	5.063	7.594	12.658	20.253	25.316	30.379	37.974	45.569	50.632	3.20
1,560	5.128	7.692	12.820	20.512	25.641	30.769	38.461	46.153	51.282	3.30
1,540	5.194	7.792	12.987	20.779	25.974	31.168	38.961	46.753	51.948	3.50

Table 3. Fresnel Length for a Range of Speed of Sound for Various Tissue Regions

Speed of sound (m/s)

Fresnel length (mm)

Region thickness (mm)

2 MHz

3 MHz

5 MHz

8 MHz

10 MHz

12 MHz

15 MHz

18 MHz

20 MHz

Skin region

1,720

4.651

6.976

11.627

18.604

23.255

27.906

34.882

41.860

46.511

1.40

1,700

4.705

7.058

11.764

18.823

23.529

28.235

35.294

42.352

47.058

1.70

1,680

4.761

7.142

11.904

19.047

23.809

28.571

35.714

42.857

47.619

2.00

1,660

4.819

7.228

12.048

19.277

24.390

28.915

36.144

43.373

48.192

2.30

1,640

4.878

7.317

12.195

19.512

24.391

29.268

36.585

43.902

48.780

2.60

1,620

4.938

7.407

12.345

19.753

24.691

29.629

37.037

44.444

49.382

2.80

1,600

5.000

7.500

12.500

20.000

25.000

30.000

37.500

45.000

50.000

3.10

1,580

5.063

7.594

12.658

20.253

25.316

30.379

37.974

45.569

50.632

3.40

1,560

5.128

7.692

12.820

20.512

25.641

30.769

38.461

46.153

51.282

3.70

1,540

5.194

7.792

12.987

20.779

25.974

31.168

38.961

46.753

51.948

4.00

Muscle region

1,580

5.063

7.594

12.658

20.253

25.316

30.379

37.974

45.569

50.632

14.0, 10.0

1,578

5.068

7.602

12.670

20.273

25.341

30.409

38.012

45.614

50.682

15.5, 10.5

1,577

5.073

7.609

12.683

20.293

25.366

30.439

38.049

45.659

50.732

17.0, 11.0

1,575

5.078

7.617

12.695

20.313

25.391

30.469

30.087

45.704

50.782

18.5, 11.5

1,574

5.083

7.624

12.708

20.333

25.416

30.499

38.124

45.749

50.833

20.0, 12.0

1,572

5.088

7.632

12.720

20.353

25.441

30.530

38.162

45.795

50.883

21.5, 12.5

1,571

5.093

7.640

12.733

20.373

25.466

30.560

38.200

45.840

50.933

23.0, 13.0

1,569

5.098

7.647

12.746

20.393

25.492

30.590

38.238

45.885

50.984

24.5, 13.5

1,568

5.103

7.655

12.758

20.413

25.517

30.620

38.276

45.931

51.034

26.0, 14.0

1,566

5.108

7.662

12.771

20,434

25,542

30.651

38.314

45.977

51.085

27.5, 14.5

Vertebra region

3,299

2.424

3.637

6.062

9.699

12.124

14.559

18.187

21.824

24.249

10.0

3,386

2.362

3.544

5.907

9.451

11.814

14.176

17.721

21.265

23.628

10.3

3,472

2.303

3.455

5.759

9.215

11.518

13.822

17.278

20.734

23.037

10.7

3,559

2.247

3.371

5.619

8.990

11.238

13.485

16.875

20.228

22.476

11.0

3,646

2.194

3.291

5.485

8.776

10.970

13.164

16.455

19.747

21.941

11.3

3,733

2.143

3.214

5.357

8.572

10.715

12.858

16.073

19.288

21.431

11.7

3,820

2.094

3.141

5.236

8.377

10.472

12.566

15.708

18.849

20.944

12.0

3,906

2.047

3.071

5.119

8.191

10.239

12.287

17.359

18.431

20.478

12.3

3,993

2.003

3.005

5.008

8.013

10.016

12.020

15.025

18.030

20.033

12.7

4,080

1.960

2.941

4.901

7.843

9.803

11.764

14.705

17.647

19.607

13.0

Dura region

1,720

4.651

6.976

11.627

18.604

23.255

27.906

34.882

41.860

46.511

0.40

1,700

4.705

7.058

11.764

18.823

23.529

28.235

35.294

42.352

47.058

0.46

1,680

4.761

7.142

11.904

19.047

23.809

28.571

35.714

42.857

47.619

0.51

1,660

4.819

7.228

12.048

19.277

24.390

28.915

36.144

43.373

48.192

0.57

1,640

4.878

7.317

12.195

19.512

24.391

29.268

36.585

43.902

48.780

0.62

1,620

4.938

7.407

12.345

19.753

24.691

29.629

37.037

44.444

49.382

0.70

1,600

5.000

7.500

12.500

20.000

25.000

30.000

37.500

45.000

50.000

0.73

1,580

5.063

7.594

12.658

20.253

25.316

30.379

37.974

45.569

50.632

0.80

1,560

5.128

7.692

12.820

20.512

25.641

30.769

38.461

46.153

51.282

0.84

1,540

5.194

7.792

12.987

20.779

25.974

31.168

38.961

46.753

51.948

0.90

CSF region

1,527

5.239

7.858

13.097

20.956

26.195

31.434

39.292

47.151

52.390

0.30

1,526

5.242

7.863

13.105

20.968

26.210

31.452

39.315

47.187

52.420

0.32

1,525

5.245

7.867

13.112

20.980

26.225

31.470

39.338

47.206

52.451

0.34

1,524

5.248

7.872

13.120

20.992

26.240

31.489

39.631

47.233

52.481

0.37

1,523.4

5.251

7.876

13.128

21.005

26.256

31.507

39.384

47.261

52.512

0.39

1,523

5.254

7.881

13.135

21.017

26.271

31.525

39.407

47.288

52.543

0.41

1,522

5.257

7.886

13.143

21.029

26.286

31.544

39.430

47.316

52,573

0.43

1,521

5.260

7.890

13.151

21.041

26.302

31.562

39.453

47.344

52.604

0.45

1,520

5.263

7.895

13.158

21.054

26.317

31.581

39.476

47.371

52.635

0.48

1,519

5.266

7.899

13.166

21.066

26.333

31.599

39.499

47.399

52.666

0.50

Spinal region

1,720

4.651

6.976

11.627

18.604

23.255

27.906

34.882

41.860

46.511

2.00

1,700

4.705

7.058

11.764

18.823

23.529

28.235

35.294

42.352

47.058

2.20

1,680

4.761

7.142

11.904

19.047

23.809

28.571

35.714

42.857

47.619

2.30

1,660

4.819

7.228

12.048

19.277

24.390

28.915

36.144

43.373

48.192

2.50

1,640

4.878

7.317

12.195

19.512

24.391

29.268

36.585

43.902

48.780

2.70

1,620

4.938

7.407

12.345

19.753

24.691

29.629

37.037

44.444

49.382

2.80

1,600

5.000

7.500

12.500

20.000

25.000

30.000

37.500

45.000

50.000

3.00

1,580

5.063

7.594

12.658

20.253

25.316

30.379

37.974

45.569

50.632

3.20

1,560

5.128

7.692

12.820

20.512

25.641

30.769

38.461

46.153

51.282

3.30

1,540

5.194

7.792

12.987

20.779

25.974

31.168

38.961

46.753

51.948

3.50

**Table 4.** Ultrasound Characteristics for Various Tissue Lengths From Simulation
Region thickness (mm)	Wavelength (mm)	Travel time (µs)	Attenuation (Gain)	Coefficients
Test set 1 - 10 MHz
1.40	0.1720	0.81	0.81	0.9999	0.9999	0.8398	0.8398	0.1602	0.1602
14.0, 10.0	0.1580	8.90	17.33	0.9935	0.9967	0.0008	0.0008	0.9999	0.9992
10.0	0.3299	3.03	-	0.9801	-	0.2257	-	0.7742	-
0.40	0.1720	0.23	0.23	0.9999	0.9999	0.2055	0.2055	0.7945	0.7945
0.30	0.1527	0.20	0.20	0.9999	0.9999	0.0048	0.0048	0.9952	0.9952
2.00	0.1720	1.20	1.20	0.9999	0.9999	0.0048	0.0048	0.9952	0.9952
Test set 2 - 10 MHz
1.70	0.1700	1.00	1.00	0.9999	0.9999	0.8400	0.8400	0.1600	0.1600
15.5, 10.5	0.1578	8.87	16.5	0.9936	0.9779	0.0005	0.0005	0.9995	0.9995
10.3	0.3386	3.04	-	0.9790	-	0.2466	-	0.7534	-
0.46	0.1700	0.27	0.27	0.9999	0.9999	0.3145	0.3145	0.6855	0.6854
0.32	0.1526	0.21	0.21	0.9999	0.9999	0.7056	0.7056	0.2944	0.2944
2.20	0.1700	1.29	1.29	0.9999	0.9999	0.0041	0.0041	0.9959	0.9959
Test set 3 - 12 MHz
2.00	0.1680	1.20	1.20	0.9999	0.9999	0.8430	0.8430	0.1570	0.1570
17.0, 11.0	0.1577	8.56	15.53	0.9765	0.9765	0.0002	0.0002	0.9998	0.9998
10.7	0.3472	3.08	-	0.9730	-	0.2670	-	0.7330	-
0.51	0.1640	0.30	0.30	0.9999	0.9999	0.2556	0.0002	0.7444	0.9998
0.34	0.1525	0.23	0.23	0.9999	0.9999	0.0034	0.0034	0.9966	0.9966
2.30	0.1700	1.37	1.37	0.9999	0.9999	0.0034	0.0034	0.9966	0.9966
Test set 4 - 12 MHz
2.30	0.1660	1.40	1.40	0.9999	0.9999	0.8445	0.8445	0.1554	0.1554
18.5, 11.5	0.1575	8.30	14.6	0.9933	0.9793	0.0001	0.0001	0.9999	0.9999
11.0	0.3559	3.10	-	0.9714	-	0.2867	-	0.7133	-
0.57	0.1660	0.34	0.34	0.9999	0.9999	0.2804	0.0001	0.7196	0.9999
0.37	0.1524	0.24	0.24	0.9999	0.9999	0.0028	0.0028	0.9972	0.9972
2.50	0.1660	1.56	1.56	0.9999	0.9999	0.0028	0.0028	0.9972	0.9972
Test set 5 - 12 MHz
2.60	0.1640	1.60	1.60	0.9999	0.9999	0.8461	0.8461	0.1539	0.1539
20.0, 12.0	0.1574	7.90	14.0	0.9938	0.9819	0.0001	0.0001	0.9999	0.9999
11.3	0.3646	3.10	-	0.9698	-	0.3064	-	0.6935	-
0.62	0.1640	0.38	0.38	0.9999	0.9999	0.3051	0.0001	0.6948	0.9999
0.39	0.15234	0.26	0.26	0.9999	0.9999	0.0021	0.0021	0.9978	0.9978
2.70	0.1640	1.65	1.65	0.9999	0.9999	0.0021	0.0021	0.9978	0.9978
Test set 6 - 12 MHz
2.80	0.1620	1.73	1.73	0.9999	0.9999	0.8477	0.8477	0.1523	0.1523
21.5, 12.5	0.1572	7.63	12.72	0.9943	0.9843	0.0001	0.0001	0.9999	0.9999
11.7	0.3733	3.13	-	0.9676	-	0.3257	-	0.6743	-
0.70	0.1620	0.43	0.43	0.9999	0.9999	0.3293	0.0001	0.6706	0.9999
0.41	0.1523	0.27	0.27	0.9999	0.9999	0.0016	0.0016	0.9983	0.9983
2.80	0.1620	1.73	1.73	0.9999	0.9999	0.0016	0.0016	0.9983	0.9983
Test set 7 - 15 MHz
3.10	0.1600	1.94	1.94	0.9998	0.9998	0.8493	0.8493	0.1510	0.1510
23.0, 13.0	0.1571	7.32	11.80	0.9948	0.9865	0.0001	0.0002	0.9998	0.9998
12.0	0.3820	3.14	-	0.9660	-	0.3441	-	0.6560	-
0.73	0.1600	0.46	0.46	0.9999	0.9999	0.3533	0.0002	0.6466	0.9998
0.43	0.1522	0.28	0.28	0.9999	0.9999	0.0012	0.0012	0.9988	0.9988
3.00	0.1600	1.90	1.90	0.9998	0.9998	0.0012	0.0012	0.9988	0.9988
Test set 8 - 15 MHz
3.40	0.1580	2.15	2.15	0.9998	0.9998	0.8510	0.8510	0.1491	0.1491
24.5, 13.5	0.1569	7.01	10.83	0.9952	0.9886	0.0003	0.0003	0.9997	0.9997
12.3	0.3906	3.15	-	0.9643	-	0.3622	-	0.6377	-
0.80	0.1580	0.51	0.51	0.9999	0.9999	0.3765	0.0003	0.6234	0.9997
0.45	0.1521	0.30	0.30	0.9999	0.9999	0.0008	0.0008	0.9991	0.9991
3.20	0.1580	2.02	2.02	0.9998	0.9998	0.0008	0.0008	0.9991	0.9991
Test set 9 - 15 MHz
3.70	0.1560	2.37	2.37	0.9998	0.9998	0.8525	0.8525	0.1475	0.1475
26.0, 14.0	0.1568	6.70	9.88	0.9956	0.9905	0.0007	0.0007	0.9993	0.9993
12.7	0.3993	3.18	-	0.9620	-	0.3799	-	0.6200	-
0.84	0.1560	0.54	0.54	0.9999	0.9999	0.3994	0.0007	0.6005	0.9993
0.48	0.1520	0.32	0.32	0.9999	0.9999	0.0005	0.0005	0.9995	0.9995
3.30	0.1560	2.12	2.12	0.9998	0.9998	0.0005	0.0005	0.9995	0.9995
Test set 10 - 15 MHz
4.00	0.1540	2.60	2.60	0.9998	0.9998	0.8539	0.8539	0.1460	0.1460
27.5, 14.5	0.1566	6.40	8.94	0.9960	0.9923	0.0010	0.0010	0.9989	0.9989
13.0	0.4080	3.20	-	0.9602	-	0.3971	-	0.6029	-
0.90	0.1540	0.58	0.58	0.9999	0.9999	0.4215	0.4215	0.5785	0.9989
0.50	0.1519	0.33	0.33	0.9999	0.9999	0.0003	0.0003	0.9997	0.9997
3.50	0.1540	2.27	2.27	0.9998	0.9998	0.0003	0.0003	0.9997	0.9997

Table 4. Ultrasound Characteristics for Various Tissue Lengths From Simulation

Region thickness (mm)

Wavelength (mm)

Travel time (µs)

Attenuation (Gain)

Coefficients

Reflection

Transmission

Test set 1 - 10 MHz

1.40

0.1720

0.81

0.9999

0.8398

0.1602

14.0, 10.0

0.1580

8.90

17.33

0.9935

0.9967

0.0008

0.9999

0.9992

10.0

0.3299

3.03

0.9801

0.2257

0.7742

0.40

0.1720

0.23

0.9999

0.2055

0.7945

0.30

0.1527

0.20

0.9999

0.0048

0.9952

2.00

0.1720

1.20

0.9999

0.0048

0.9952

Test set 2 - 10 MHz

1.70

0.1700

1.00

0.9999

0.8400

0.1600

15.5, 10.5

0.1578

8.87

16.5

0.9936

0.9779

0.0005

0.9995

10.3

0.3386

3.04

0.9790

0.2466

0.7534

0.46

0.1700

0.27

0.9999

0.3145

0.6855

0.6854

0.32

0.1526

0.21

0.9999

0.7056

0.2944

2.20

0.1700

1.29

0.9999

0.0041

0.9959

Test set 3 - 12 MHz

2.00

0.1680

1.20

0.9999

0.8430

0.1570

17.0, 11.0

0.1577

8.56

15.53

0.9765

0.0002

0.9998

10.7

0.3472

3.08

0.9730

0.2670

0.7330

0.51

0.1640

0.30

0.9999

0.2556

0.0002

0.7444

0.9998

0.34

0.1525

0.23

0.9999

0.0034

0.9966

2.30

0.1700

1.37

0.9999

0.0034

0.9966

Test set 4 - 12 MHz

2.30

0.1660

1.40

0.9999

0.8445

0.1554

18.5, 11.5

0.1575

8.30

14.6

0.9933

0.9793

0.0001

0.9999

11.0

0.3559

3.10

0.9714

0.2867

0.7133

0.57

0.1660

0.34

0.9999

0.2804

0.0001

0.7196

0.9999

0.37

0.1524

0.24

0.9999

0.0028

0.9972

2.50

0.1660

1.56

0.9999

0.0028

0.9972

Test set 5 - 12 MHz

2.60

0.1640

1.60

0.9999

0.8461

0.1539

20.0, 12.0

0.1574

7.90

14.0

0.9938

0.9819

0.0001

0.9999

11.3

0.3646

3.10

0.9698

0.3064

0.6935

0.62

0.1640

0.38

0.9999

0.3051

0.0001

0.6948

0.9999

0.39

0.15234

0.26

0.9999

0.0021

0.9978

2.70

0.1640

1.65

0.9999

0.0021

0.9978

Test set 6 - 12 MHz

2.80

0.1620

1.73

0.9999

0.8477

0.1523

21.5, 12.5

0.1572

7.63

12.72

0.9943

0.9843

0.0001

0.9999

11.7

0.3733

3.13

0.9676

0.3257

0.6743

0.70

0.1620

0.43

0.9999

0.3293

0.0001

0.6706

0.9999

0.41

0.1523

0.27

0.9999

0.0016

0.9983

2.80

0.1620

1.73

0.9999

0.0016

0.9983

Test set 7 - 15 MHz

3.10

0.1600

1.94

0.9998

0.8493

0.1510

23.0, 13.0

0.1571

7.32

11.80

0.9948

0.9865

0.0001

0.0002

0.9998

12.0

0.3820

3.14

0.9660

0.3441

0.6560

0.73

0.1600

0.46

0.9999

0.3533

0.0002

0.6466

0.9998

0.43

0.1522

0.28

0.9999

0.0012

0.9988

3.00

0.1600

1.90

0.9998

0.0012

0.9988

Test set 8 - 15 MHz

3.40

0.1580

2.15

0.9998

0.8510

0.1491

24.5, 13.5

0.1569

7.01

10.83

0.9952

0.9886

0.0003

0.9997

12.3

0.3906

3.15

0.9643

0.3622

0.6377

0.80

0.1580

0.51

0.9999

0.3765

0.0003

0.6234

0.9997

0.45

0.1521

0.30

0.9999

0.0008

0.9991

3.20

0.1580

2.02

0.9998

0.0008

0.9991

Test set 9 - 15 MHz

3.70

0.1560

2.37

0.9998

0.8525

0.1475

26.0, 14.0

0.1568

6.70

9.88

0.9956

0.9905

0.0007

0.9993

12.7

0.3993

3.18

0.9620

0.3799

0.6200

0.84

0.1560

0.54

0.9999

0.3994

0.0007

0.6005

0.9993

0.48

0.1520

0.32

0.9999

0.0005

0.9995

3.30

0.1560

2.12

0.9998

0.0005

0.9995

Test set 10 - 15 MHz

4.00

0.1540

2.60

0.9998

0.8539

0.1460

27.5, 14.5

0.1566

6.40

8.94

0.9960

0.9923

0.0010

0.9989

13.0

0.4080

3.20

0.9602

0.3971

0.6029

0.90

0.1540

0.58

0.9999

0.4215

0.5785

0.9989

0.50

0.1519

0.33

0.9999

0.0003

0.9997

3.50

0.1540

2.27

0.9998

0.0003

0.9997