Signal Space Separation Method for a Biomagnetic Sensor Array Arranged on a Flat Plane for Magnetocardiographic Applications: A Computer Simulation Study

<div>Results of the same experiments in which the SSS extractors are applied to <svg height="12.5794pt" id="M242" style="vertical-align:-3.29107pt" version="1.1" viewbox="-0.0498162 -9.28833 25.4113 12.5794" width="25.4113pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M196 417V703C139 687 58 673 7 667V636C63 632 68 623 68 566V24C137 -2 188 -12 244 -12C390 -12 504 97 504 243C504 355 418 454 297 454C277 454 261 447 233 434L196 417ZM196 382C211 387 221 389 238 389C301 389 365 339 365 212C365 87 316 27 262 28C230 29 207 59 201 75C198 83 196 94 196 108V382Z" id="g13-96"></path></g><g transform="matrix(.0091,0,0,-0.0091,6.942,3.132)"><path d="M463 633C453 636 427 644 417 648C388 660 349 667 316 667C183 667 100 592 100 483C100 398 176 335 223 305L259 282C321 242 358 203 358 149C358 66 301 22 234 22C110 22 70 131 57 208L24 205L28 48C51 23 128 -17 215 -17C342 -17 446 60 446 174C446 262 394 310 317 361L284 383C229 420 183 455 183 515C183 569 222 628 298 628C384 628 418 563 428 481L461 487C459 527 458 593 463 633Z" id="g50-84"></path></g><g transform="matrix(.013,0,0,-0.013,11.806,0)"><path d="M300 -147C201 -63 143 98 143 270S200 602 300 686L282 710C136 610 70 450 70 271V270C70 89 136 -72 282 -170L300 -147Z" id="g113-41"></path></g><g transform="matrix(.013,0,0,-0.013,16.304,0)"><path d="M324 430H196L233 583L223 592L145 529L120 430H54L29 396L31 388H111L56 126C33 15 54 -12 77 -12C137 -12 214 57 250 95L233 119C208 92 155 59 138 59C126 59 120 70 131 125L186 390L298 394L324 430Z" id="g113-117"></path></g><g transform="matrix(.013,0,0,-0.013,20.738,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z" id="g113-42"></path></g></svg> and <span class="nowrap"><svg height="12.4698pt" id="M243" style="vertical-align:-3.18147pt" version="1.1" viewbox="-0.0498162 -9.28833 25.0093 12.4698" width="25.0093pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M196 417V703C139 687 58 673 7 667V636C63 632 68 623 68 566V24C137 -2 188 -12 244 -12C390 -12 504 97 504 243C504 355 418 454 297 454C277 454 261 447 233 434L196 417ZM196 382C211 387 221 389 238 389C301 389 365 339 365 212C365 87 316 27 262 28C230 29 207 59 201 75C198 83 196 94 196 108V382Z" id="g13-96"></path></g><g transform="matrix(.0091,0,0,-0.0091,6.942,3.132)"><path d="M418 650H141L133 618C225 611 232 604 218 531L141 120C126 45 119 37 33 32L24 0H301L308 32C220 37 214 44 227 120L305 531C319 605 325 611 411 618L418 650Z" id="g50-74"></path></g><g transform="matrix(.013,0,0,-0.013,11.404,0)"><path d="M300 -147C201 -63 143 98 143 270S200 602 300 686L282 710C136 610 70 450 70 271V270C70 89 136 -72 282 -170L300 -147Z" id="g113-41"></path></g><g transform="matrix(.013,0,0,-0.013,15.902,0)"><path d="M324 430H196L233 583L223 592L145 529L120 430H54L29 396L31 388H111L56 126C33 15 54 -12 77 -12C137 -12 214 57 250 95L233 119C208 92 155 59 138 59C126 59 120 70 131 125L186 390L298 394L324 430Z" id="g113-117"></path></g><g transform="matrix(.013,0,0,-0.013,20.336,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z" id="g113-42"></path></g></svg>,</span> assuming a helmet-type sensor array used in MEG. (a) Locations of sensors in the helmet-type array assumed in this computer simulation. The sensor arrangement is from the 275-channel whole head sensor array of the Omega™ (VMS Medtech, Coquitlam, Canada). (b) The upper and lower panels, respectively, show <svg height="12.584pt" id="M244" style="vertical-align:-3.29567pt" version="1.1" viewbox="-0.0498162 -9.28833 43.9923 12.584" width="43.9923pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M42 650V615C112 608 121 601 121 516V133C121 48 112 41 37 34V0H347V34C262 41 253 48 253 133V271L321 254C332 254 347 254 362 256C468 269 567 330 567 464C567 529 540 579 493 611C453 639 397 650 318 650H42ZM253 570C253 585 255 595 262 601C268 606 280 611 299 611C360 611 423 574 423 461C423 326 343 300 307 300C286 300 265 305 253 310V570Z" id="g13-78"></path></g><g transform="matrix(.0091,0,0,-0.0091,7.787,3.132)"><path d="M138 535C169 535 191 560 191 589C191 620 168 644 139 644S85 620 85 589C85 560 110 535 138 535ZM257 0V30C192 35 185 43 185 109V453C142 435 94 422 40 414V386C101 378 104 372 104 311V109C104 41 97 35 33 30V0H257Z" id="g58-103"></path></g><g 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710C136 610 70 450 70 271V270C70 89 136 -72 282 -170L300 -147Z" id="g113-41"></path></g><g transform="matrix(.013,0,0,-0.013,35.167,0)"><path d="M324 430H196L233 583L223 592L145 529L120 430H54L29 396L31 388H111L56 126C33 15 54 -12 77 -12C137 -12 214 57 250 95L233 119C208 92 155 59 138 59C126 59 120 70 131 125L186 390L298 394L324 430Z" id="g113-117"></path></g><g transform="matrix(.013,0,0,-0.013,39.6,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z" id="g113-42"></path></g></svg>.</span> In the sensor time courses in (b), they are normalized to the maximum value from the upper panel, and the sensor time courses in (c), they are normalized to the maximum value from the lower panel.</div>

Journal of Healthcare Engineering

fig5

Figure 5

Figure 5: Signal Space Separation Method for a Biomagnetic Sensor Array Arranged on a Flat Plane for Magnetocardiographic Applications: A Computer Simulation Study 

Figure 5 | Signal Space Separation Method for a Biomagnetic Sensor Array Arranged on a Flat Plane for Magnetocardiographic Applications: A Computer Simulation Study 