Table 5 List of the top 20 keywords with the corresponding frequency

1

internet of thing

2329

11

technology

351

2

wearable sensor

812

12

security

345

3

system

715

13

accelerometer

313

4

healthcare

670

14

wearable

290

5

sensor

644

15

machine learning

272

6

internet

580

16

wireless sensor network

271

7

wearable device

563

17

cloud computing

268

8

health

430

18

big data

264

9

physical activity

366

19

smart home

263

10

thing

352

20

parkinsons disease

256