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  • articleNo Access

    Does Deqi (Needle Sensation) Exist?

    The mechanism, by which acupuncture works is not yet clear, therefore there is no unequivocal consensus about styles and sensations of needling. To enhance the scientific base of acupuncture, needling somehow should be objectified. The term Deqi is understood to represent all or at least the main form of phenomena to acupuncture stimulation. The characteristics of Deqi, however, have always been based on a translation of original Chinese description. Hoping to find a clue to develop sham (placebo) method for subject blinding, we investigated which sensations are frequently expected and experienced, and whether or not these expectations and experiences of sensations are similar in naïve subjects. The acupuncture sensation scale developed by Vincent et al. (1989) was translated into Korean. Thirty-eight healthy acupuncture naïve female volunteers (mean age 29.1, range 25–39) were asked to complete the sensation scale of acupuncture according to what they expected needling to feel like before needling. Needling was done on left Hegu (LI4) point in the hand and consisted of insertion, stimulation for 30 seconds, and removal. Directly after needling, the subjects were asked to complete the same sensation scale according to what they experienced. The subjects expected to feel hurting, penetrating, sharp, tingling, pricking and stinging, and actually experienced aching, spreading, radiating, pricking and stinging more than 60% of the time. Comparison between expectation and experience, the subjects expected more penetrating, tingling, pricking and burning than they experienced, and on the contrary experienced more aching, pulling, heavy, dull, electric and throbbing than they expected. Traditionally described sensations of Deqi are something beyond just a general pain dimension in the Korean population. Further study involving acupuncture experienced subjects or subjects from other cultures need to confirm this finding. Moreover, sham acupuncture should be studied.

  • articleNo Access

    A Neurobiological Theory of Meaning in Perception Part I: Information and Meaning in Nonconvergent and Nonlocal Brain Dynamics

    The aim of this tutorial is to document a novel approach to brain function, in which the key to understanding is the capacity of brains for self-organization. The property that distinguishes animals from plants is the capacity for directed movement through the environment, which requires an organ capable of organizing information about the environment and predicting the consequences of self-initiated actions. The operations of predicting, planning acting, detecting, and learning comprise the process of intentionality by which brains construct meaning. The currency of brains is primarily meaning and only secondarily information. The information processing metaphor has dominated neurocognitive research for half a century. Brains certainly process information for input and output. They pre-process sensory stimuli before constructing meaning, and they post-process cognitive read-out to control appropriate action and express meaning. Neurobiologists have thoroughly documented sensory information processing bottom-up, and neuropsychologists have analyzed the later stages of cognition top-down, as they are expressed in behavior. However, a grasp of the intervening process of perception, in which meaning forms, requires detailed analysis and modeling of neural activity that is observed in brains during meaningful behavior of humans and other animals. Unlike computers, brains function hierarchically. Sensory and motor information is inferred from pulses of microscopic axons. Meaning is inferred from local mean fields of dendrites in mesoscopic and macroscopic populations. This tutorial is aimed to introduce engineers to an experimental basis for a theory of meaning, in terms of the nonlinear dynamics of the mass actions of large neural populations that construct meaning. The focus is on the higher frequency ranges of cortical oscillations. Part I introduces background on information, meaning and oscillatory activity (EEG). Part II details the properties of wave packets. Part III describes the covariance structure of the oscillations. Part IV addresses the amplitude modulations, and Part V deals with the phase modulations. The significance of a theory of meaning lies in applications using population neurodynamics, to open new approaches for treatment of clinical brain disorders, and to devise new machines with capacities for autonomy and intelligence that might approach those of simpler free-living animals.

  • articleNo Access

    Restoring Haptic Feedback in NOTES Procedures with a Novel Wireless Tissue Stiffness Probe

    In the past two decades, several instruments have been developed to overcome the loss of haptic sensation in minimally invasive surgery (MIS). Unfortunately, none of the proposed instruments has been clinically adopted or utilized in natural orifice translumenal endoscopic surgery (NOTES) procedures. The challenge is that NOTES instruments require mounting upon flexible endoscopes thus altering endoscope flexibility and dexterity. We have developed a novel wireless tissue stiffness probe (WTSP) that can be used with a flexible endoscope and create a real-time stiffness distribution map with potential to restore haptic sensation in NOTES. The aim of our study was to assess the performance and feasibility of the WTSP in an ex vivo trial (three phantom models of different elasticity; comparing discrimination of human touch with the WTSP) and in an in vivo trans-colonic access NOTES procedure. Overall, the WTSP was able to detect the stiffness of the three phantoms with a relative error smaller than 3% and a success rate of 100% versus 95% when compared to human perception. The novel WTSP was successful in providing the operator with tactile and kinesthetic feedback for accurate discrimination between tissue phantoms. In vivo tissue palpation was feasible using the WTSP in a trans-colonic NOTES procedure. The WTSP did not encumber the maneuverability or dexterity of the flexible endoscope. This innovative approach to tissue palpation has the potential to open a new paradigm in the field of NOTES where no mechanical link between the external platform and the target region exists.