Physiological Vibration Acceleration (Phybrata) Sensor Assessment of Multi-System Physiological Impairments and Sensory Reweighting Following Concussion

Figures & data

Figure 1 Phybrata sensor attached to the mastoid using an adhesive patch.

Figure 2 Sample eyes open (Eo) and eyes closed (Ec) x(anterior-posterior, AP), y(vertical), z(medial-lateral, ML) acceleration time series data and AP/ML acceleration spatial scatter plots for age/gender-matched (A) healthy baseline participant (B) patient with diagnosed concussion.

Table 1 ANOVA Summary of Phybrata Measurements vs. Eye State and Gender for 83 Healthy Baseline Patients (43F, 40M).

Measure	Condition	Mean	95% CI	F-Ratio	P
Female: phybrata power	Eyes open	0.288	0.248–0.322	F(1,84) = 19.45	< 0.0001
	Eyes closed	0.413	0.370–0.457
Male: phybrata power	Eyes open	0.303	0.278–0.328	F (1,78) = 28.05	< 0.0001
	Eyes closed	0.419	0.388–0.450
Eo power	Female	0.288	0.248–0.322	F(1,81) = 1.48	0.23
	Male	0.303	0.278–0.328
Ec power	Female	0.413	0.370–0.457	F(1,81) = 0.41	0.53
	Male	0.419	0.388–0.450
(Eo + Ec)/2	Female	0.351	0.312–0.384	F(1,81) = 0.95	0.33
	Male	0.361	0.338–0.384
Ec/Eo ratio	Female	1.520	1.387–1.653	F(1,81) = 0.63	0.43
	Male	1.445	1.319–1.569

Abbreviations: Eo, eyes open; Ec, eyes closed.

Table 2 ANOVA Summary of Phybrata Measurements vs. Eye State and Gender for 92 Patients (51F, 41M) with Diagnosed Concussions.

Measure	Condition	Mean	95% CI	F-Ratio	p
Female: phybrata power	Eyes open	0.936	0.703–1.137	F(1100) = 18.65	< 0.0001
	Eyes closed	2.587	0.986–3.609
Male: phybrata power	Eyes open	0.836	0.569–1.054	F(1,80) = 17.42	< 0.0001
	Eyes closed	1.600	0.945–2.054
Eo power	Female	0.936	0.703–1.137	F(1,90) = 0.34	0.56
	Male	0.836	0.569–1.054
Ec power	Female	2.587	0.986–3.609	F(1,90) = 1.03	0.31
	Male	1.600	0.945–2.054
(Eo+Ec)/2	Female	1.758	0.951–2.350	F(1,90) = 0.86	0.36
	Male	1.212	0.834–1.528
Ec/Eo ratio	Female	2.516	1.916–3.007	F(1,90) = 0.38	0.54
	Male	2.286	1.801–2.775

Abbreviations: Eo, eyes open; Ec, eyes closed.

Table 3 MANOVA Summary of 4 Phybrata Metrics for Patient Sub-Populations with and without (a) Concussion (CN); (b) Vestibular Impairment (VI); (c) Neurological Impairment (NI).

Population	Measure	Condition	Mean	95% CI	F-ratio	P
(a) Concussion CN=0: 83 CN=1: 92	Eo power	CN = 0	0.296	0.272–0.316	F(1171) = 104.6	< 0.0001
		CN = 1	0.891	0.718–1.050
	Ec power	CN = 0	0.416	0.387–0.444	F(1171) = 154.8	< 0.0001
		CN = 1	2.145	1.277–2.781
	(Eo + Ec)/2	CN = 0	0.356	0.332–0.378	F(1171) = 164.4	< 0.0001
		CN = 1	1.508	1.020–1.904
	Ec/Eo	CN = 0	1.484	1.395–1.570	F(1171) = 15.09	0.00015
		CN = 1	2.421	2.019–2.767
(b) Vestibular Impairment VI=0: 123 VI=1: 52	Eo power	VI = 0	0.295	0.270–0.317	F(1167) = 1.60	0.21
		VI = 1	0.892	0.712–1.047
	Ec power	VI = 0	0.416	0.388–0.442	F(1167) = 117.6	< 0.0001
		VI = 1	2.132	1.298–2.784
	(Eo + Ec)/2	VI = 0	0.356	0.333–0.377	F(1167) = 66.01	< 0.0001
		VI = 1	1.501	1.062–1.894
	Ec/Eo	VI = 0	1.484	1.389–1.574	F(1167) = 162.9	< 0.0001
		VI = 1	2.420	2.018–2.762
(c) Neurological Impairment NI=0: 109 NI=1: 66	Eo power	NI = 0	0.305	0.285–0.323	F(1167) = 191.2	< 0.0001
		NI = 1	1.114	0.883–1.302
	Ec power	NI = 0	0.559	0.481–0.627	F(1167) = 132.7	< 0.0001
		NI = 1	2.569	1.409–3.466
	(Eo + Ec)/2	NI = 0	0.432	0.386–0.472	F(1167) = 170.0	< 0.0001
		NI = 1	1.842	1.182–2.364
	Ec/Eo	NI = 0	1.876	1.658–2.070	F(1167 = 1.13)	=0.29
		NI = 1	2.141	1.626–2.536

Note: Shaded rows indicate phybrata measure showing strongest statistical correlation with each condition.

Abbreviations: Eo, eyes open; Ec, eyes closed.

Figure 3 Cumulative probability distributions vs. gender and eye state for phybrata metrics for: (A and B), 83 healthy baseline patients (HB); (C and D), 92 patients with diagnosed concussions (CN).

Abbreviations: F, female; M, male; Eo, eyes open; Ec, eyes closed.

Figure 4 Box plots showing distributions of 4 phybrata metrics for 83 healthy baseline patients (HB) and 92 patients with diagnosed concussions (CN).

Abbreviations: Eo, eyes open; Ec, eyes closed.

Figure 5 Eyes open (Eo) and eyes closed (Ec) phybrata power histograms (left) and anterior-posterior/medial-lateral (AP/ML) acceleration spatial scatter plots (right) for (A) baseline testing of 5 healthy athletes; (B) post-concussion testing of 5 athletes with vestibular impairments; (C) post-concussion testing of 5 athletes with neurological impairments.

Figure 6 Box plots and graphs comparing means of 4 phybrata metrics (A) Eo (B) Ec/Eo (C) Ec (D) (Eo+Ec)/2 for 83 healthy baseline patients (HB); 26 concussion patients with vestibular impairments (VI) only; 40 concussion patients with neurological impairments (NI) only; 26 concussion patients with both vestibular and neurological impairments (VNI).

Abbreviations: Eo, eyes open; Ec, eyes closed.

Figure 7 Scatter plots of Ec/Eo power ratio vs. Eo power for healthy baseline patients (HB) and concussion patients with vestibular impairments (VI), neurological impairments (NI), and both vestibular and neurological impairments (VNI).

Abbreviations: Eo, eyes open; Ec, eyes closed.

Table 4 Summary of Receiver Operating Characteristic (ROC) Curves for (Eo+Ec)/2 as a Diagnostic Measure for Concussion (CN), Ec/Eo as a Diagnostic Metrics for Vestibular Impairment (VI), and Eo as a Diagnostic Measure for Neurological Impairment (NI).

Phybrata Metric	Sub-Population	Number	AUC	95% CI	Cutoff	TP	FP	FN	TN	Sensitivity TP/(TP+FN)	Specificity TN/(TN+FP)	Precision TP/(TP+FP)	Accuracy (TP+TN)/(TP+FP+FN+TN)
(Eo+Ec)/2	CN = 0,1	83, 92	0.981	0.956–0.992	0.49	86	5	6	78	0.935	0.940	0.945	0.937
Ec/Eo	VI = 0,1	123, 52	0.951	0.904–0.976	1.95	47	12	5	111	0.904	0.902	0.80	0.903
Eo	NI = 0,1	109, 66	0.975	0.944–0.989	0.45	61	7	5	102	0.924	0.936	0.897	0.931

Abbreviations: Eo, eyes open; Ec, eyes closed; AUC, area under the curve; TP, true positive; FP, false positive; FN, false negative; TN, true negative.

Figure 8 Receiver operating characteristic (ROC) curves for 4 clinical diagnostic criteria: (A) concussion (CN=0,1); (B) vestibular impairment (VI=0,1); (C) neurological impairment (NI=0,1); and (D) both vestibular and neurological impairments (VNI), for all possible cutoff values of the 4 phybrata metrics Eo, Ec, (Eo+Ec)/2, Ec/Eo.

Abbreviations: Eo, eyes open; Ec, eyes closed.

Figure 9 Normalized ensemble eyes-open (Eo) anterior-posterior (AP) time-resolved phybrata power spectral density (NPSD) plots (left) and spectrograms (right) for (A and B) baseline testing of 5 healthy patients; (C and D) post-concussion testing of 5 patients with vestibular impairment; (E and F) post-concussion testing of 5 patients with neurological impairment.

Figure 10 Normalized ensemble eyes-closed (Ec) anterior-posterior (AP) time-resolved phybrata power spectral density (NPSD) plots (left) and spectrograms (right) for (A and B) baseline testing of 5 healthy patients; (C and D) post-concussion testing of 5 patients with vestibular impairment; (E and F) post-concussion testing of 5 patients with neurological impairment.

Figure 11 Normalized ensemble eyes-open (Eo) medial-lateral (ML) time-resolved phybrata power spectral density (NPSD) plots (left) and spectrograms (right) for (A and B) baseline testing of 5 healthy patients; (C and D) post-concussion testing of 5 patients with vestibular impairment; (E and F) post-concussion testing of 5 patients with neurological impairment.

Figure 12 Normalized ensemble eyes-closed (Ec) medial lateral (ML) time-resolved phybrata power spectral density (NPSD) plots (left) and spectrograms (right) for (A and B) baseline testing of 5 healthy patients; (C and D) post-concussion testing of 5 patients with vestibular impairment; (E and F) post-concussion testing of 5 patients with neurological impairment.

Figure 13 Change in normalized ensemble power spectral density (PSD) between eyes-open (Eo) and eyes-closed (Ec) for 5 healthy baseline patients (HB). Ensemble average {AP, ML} PSD changes are summed over phybrata frequency bands corresponding to visual, vestibular, central nervous system (CNS), and proprioceptive control.

Abbreviations: AP, anterior-posterior; ML, medial-lateral.

Figure 14 Change in normalized ensemble power spectral density (PSD) between 5 healthy baseline patients (HB) and: 1) 5 concussion patients with vestibular impairment (VI); and 2) 5 concussion patients with neurological impairment (NI). For each group, ensemble average {Eo, Ec, AP, ML} PSD changes are summed over phybrata frequency bands corresponding to visual, vestibular, central nervous system (CNS), and proprioceptive control.

Abbreviations: Eo, eyes open; Ec, eyes closed; AP, anterior-posterior; ML, medial-lateral.

Figure 15 Normalized eyes-closed (Ec) anterior-posterior (AP) time-resolved phybrata power spectral density (NPSD) plots (top) and spectrograms (middle), along with phybrata spatial scatter plots (bottom, left), and phybrata power bar graphs (bottom, right) for an athlete tested (A) healthy/baseline; (B) 6 days post-concussion with neurological impairment; (C) 14 days post-concussion; and (D) 21 days post-concussion.