Everything flows. Lucretius
The human being, and all around us – others and environments, and in us (!) – biome, is characterized by continuous dynamic variability. But for reasons historical, and for ease of data gathering, and in accordance with various views of the human being we often use static, point (current pulse, blood pressure) or threshold (is Respiratory Rate >= 20, in SIRS criteria).
Advances make more useful, more insightful, discriminant measures and analytics available to understand the non-linear, continuous dynamics, physiological and psychological of being human. Even attention to dynamics (blood pressure variability) versus static/point measures while using basic analysis like descriptive stats like average, sd, etc. are providing vital insights. (see Rothwell on BPV) Important examples include:
- Physiological process/functions
Heart Rate Variability: HRV in sleep and sleep apnea [14] T. Penzel, J. W. Kantelhardt, L. Grote, J. H. Peter, and A. Bunde, “Comparison of detrended fluctuation analysis and spectral analysis for heart rate variability in sleep and sleep apnea,” IEEE Trans. Biomed. Eng., vol. 50, no. 10, pp. 1143–1151, Oct. 2003
Blood Pressure – Rothwell, Peter M. (2010) Limitations of the usual blood-pressure hypothesis and importance of variability, instability, and episodic hypertension, Lancet 2010; 375: 938–48
Temperature Curve Complexity – Varela, Manuel, et al. (2006) Temperature Curve Complexity Predicts Survival in Critically Ill Patients, Am J Respir Crit Care Med, Vol 174. pp 290–298
Anesthesia/EEG: M. Jospin, P. Caminal, E. W. Jensen, H. Litvan, M. Vallverdu,M. Struys, H. E. Vereecke, and D. T. Kaplan, “Detrended fluctuation analysis of EEG as a measure of depth of anesthesia,” IEEE Trans. Biomed. Eng., vol. 54, no. 5, pp. 840–846, May 2007.
Gait Variability: Chau T. A review of analytical techniques for gait data. Part 1: Fuzzy, statisticaland fractal methods. Gait Posture 2000;13:49–66.
> Peng CK, Hausdorff JM, Goldberger AL. Fractal mechanisms in neural control: Human heartbeat and gait dynamics in health and disease. In Nonlinear Dynamics, Self- Organization, and Biomedicine. Cambridge, UK: Cambridge University Press, 2000; 66–96
Peak Expiratory Variability: G. C. Donaldson, T.A.R. Seemungal, JR Hurst, JA Wedzicha, (2012) Detrended fluctuation analysis of peak expiratory flow and exacerbation frequency in COPD, European Respiratory Journal, Feb 9, 2012
Intracranial pressure: Robert L. Burr*, Senior Member, IEEE, Catherine J. Kirkness, and Pamela H. Mitchell, (2008) Detrended Fluctuation Analysis of Intracranial Pressure Predicts Outcome Following Traumatic, Brain Injury, IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 55, NO. 11, NOVEMBER 2008
2. Physiological – Structures
Retinal Vasculature: Masters, Barry R. (2004) FRACTAL ANALYSIS OF THE VASCULAR TREE IN THE HUMAN RETINA, Annu. Rev. Biomed. Eng. 6:427–52
> Sng, C.C.A et al. (2010) Fractal analysis of the retinal vasculature and chronic kidney disease, Nephrol Dial Transplant 25: 2252-2258.
Lung: Boser, Stacey R., Hannah Park, Steven F. Perry, M. G. Ménache and Francis H. Y. Green (2005) Fractal Geometry of Airway Remodeling in Human Asthma, Am J Respir Crit Care Med, Vol 172, pp 817–823.
Tumor architecture: Gazit, et al (1997) Fractal characteristics of tumor vascular architecture during tumor growth and regression, Microcirculation. 1997 Dec;4(4):395-402.
Trabecular Bone: Wolski M, Podsiadlo P, Stachowiak GW, Lohmander LS, Englund M (2010) Differences in trabecular bone texture between knees with and without radiographic osteoarthritis detected by directional fractal signature method. Osteoarthritis Cartilage. 2010 May;18(5):684-90. doi: 10.1016/j.joca.2010.01.002.
Pain: Jennifer M. Foss, A.Vania Apkarian, and Dante R. Chialvo (2006) Dynamics of Fractal Dimension of Temporal Variability of Spontaneous Pain Differentiates Between Pain States, J Neurophysiol 95: 730–736, 2006
Rheumatoid arthritis: Kamal, 2007, Assessment of autonomic function in patients with rheumatoid arthritis using spectral analysis and approximate entropy method, Neurosciences 2007; Vol. 12 (2): 136-139
3. Psychological
Narrative Sense-Making
Narrative Coherence: Sense of Coherence, SOC-13: Eriksson, Monica, Lindstrom, Validity of Antonovsky’s sense of coherence scale: A systematic review, J Epidemiol Community Health 2005;59: 460-466.
Sense of Coherence & Transplants: Liver transplant recipients’ ability to cope during the first 12 months after transplantation – a prospective study, Forsberg, Anna; Bäckman, Lars1; Svensson, Elisabeth , Scand J Caring Sci; 2002; 16; 345-352
4. Integrated Variability
Emotional Regulation: Endre Visted, et al (2017) The Association between Self-Reported Difficulties in Emotion Regulation and Heart Rate Variability: The Salient Role of Not Accepting Negative Emotions, Front. Psychol. 8:328
> Appelhans, Bradley and Linda J. Luecken, 2006, Heart Rate Variability as an Index of Regulated Emotional Responding, Review of General Psychology, 2006, 10, 3:229-240.
Heart – Brain integration: Thayer, Julian F. and Richard D. Lane, 2009, Claude Bernard and the heart-brain connection: Further elaboration of a model of Neurovisceral integration, Neuroscience and Biobehavioral Reviews, 2009, 33: 81-88
Human Variability 