When we run our fingers over the surface of an object, we acquire information about its microgeometry and material properties. Texture information is widely believed to be conveyed in spatial patterns of activation evoked across one of three populations of cutaneous mechanoreceptive afferents that innervate the fingertips. Here, we record the responses evoked in individual cutaneous afferents in Rhesus macaques as we scan a diverse set of natural textures across their fingertips using a custom-made rotating drum stimulator. We show that a spatial mechanism can only account for the processing of coarse textures. Information about most natural textures, however, is conveyed through precise temporal spiking patterns in afferent responses, driven by high-frequency skin vibrations elicited during scanning. Furthermore, these texture-specific spiking patterns predictably dilate or contract in time with changes in scanning speed; the systematic effect of speed on neuronal activity suggests that it can be reversed to achieve perceptual constancy across speeds. The proposed temporal coding mechanism involves converting the fine spatial structure of the surface into a temporal spiking pattern, shaped in part by the mechanical properties of the skin, and ascribes an additional function to vibration-sensitive mechanoreceptive afferents. This temporal mechanism complements the spatial one and greatly extends the range of tangible textures. We show that a combination of spatial and temporal mechanisms, mediated by all three populations of afferents, accounts for perceptual judgments of texture.

https://www.pnas.org/content/pnas/110/42/17107.full.pdf

Spatial and temporal codes mediate the tactile perception of natural textures

An absorbent article, preferably a disposable absorbent article such as a diaper, is disclosed having an absorbent core which imparts increased wearing comfort to the article and makes it thin and dry. The absorbent core useful for an absorbent article comprises a substrate layer, a discontinuous layer of absorbent material, and a layer of thermoplastic material. A second surface of the discontinuous layer of absorbent material is in at least partial contact with a first surface of the substrate layer. Portions of a second surface of the layer of thermoplastic material are in direct contact with the first surface of the substrate layer and portions of said second surface of the layer of thermoplastic material are in direct contact with a first surface of the discontinuous layer of absorbent material. A process for providing a storage layer for an absorbent core useful in an absorbent article is further disclosed.

Thin and dry diaper

A composite wound dressing apparatus promotes healing of a wound via the use of a micropump system housed within or above a wound dressing member. The micropump system includes a miniature pump that applies a subatmospheric pressure to the wound to effectively draw wound fluid or exudate away from the wound bed without the need for a cumbersome external vacuum source. Hence, the wound dressing and micropump system is portable which allows the patient mobility that is unavailable when an external vacuum source is used. The patient does not need to be constrained for any period of time while exudate is being removed from the wound.

Self contained wound dressing with micropump

Biomimetic Intraneural Sensory Feedback Enhances Sensation Naturalness, Tactile Sensitivity, and Manual Dexterity in a Bidirectional Prosthesis.

The present disclosure provides modified nucleosides, nucleotides, and nucleic acids, and methods of using them.

Modified nucleosides, nucleotides, and nucleic acids, and uses thereof

Because tactile perception relies on the response of large populations of receptors distributed across the skin, we seek to characterize how a mechanical deformation of the skin at one location affects the skin at another. To this end, we introduce a novel non-contact method to characterize the surface waves produced in the skin under a variety of stimulation conditions. Specifically, we deliver vibrations to the fingertip using a vibratory actuator and measure, using a laser Doppler vibrometer, the surface waves at different distances from the locus of stimulation. First, we show that a vibration applied to the fingertip travels at least the length of the finger and that the rate at which it decays is dependent on stimulus frequency. Furthermore, the resonant frequency of the skin matches the frequency at which a subpopulation of afferents, namely Pacinian afferents, is most sensitive. We show that this skin resonance can lead to a two-fold increase in the strength of the response of a simulated afferent population. Second, the rate at which vibrations propagate across the skin is dependent on the stimulus frequency and plateaus at 7 m/s. The resulting delay in neural activation across locations does not substantially blur the temporal patterning in simulated populations of afferents for frequencies less than 200 Hz, which has important implications about how vibratory frequency is encoded in the responses of somatosensory neurons. Third, we show that, despite the dependence of decay rate and propagation speed on frequency, the waveform of a complex vibration is well preserved as it travels across the skin. Our results suggest, then, that the propagation of surface waves promotes the encoding of spectrally complex vibrations as the entire neural population is exposed to essentially the same stimulus. We also discuss the implications of our results for biomechanical models of the skin.

/pdf/the-effect-of-surface-wave-propagation-on-neural-responses-54592gqs0g.pdf

The effect of surface wave propagation on neural responses to vibration in primate glabrous skin

An absorbent structure (31) having a longitudinal axis, a lateral axis, a z-direction axis normal to the longitudinal and lateral axes, longitudinally opposite ends (23) and laterally opposite side edges (25). An upper surface (41) of the absorbent structure has a three-dimensional topography relative to the longitudinal and lateral axes and defines a plurality of peaks (51) and valleys (53) of the upper surface relative to the z-direction. A lower surface (43) of the absorbent structure has a three-dimensional topography relative to the longitudinal and lateral axes and defines a plurality of the peaks (55) and valleys (57) of the lower surface relative to the z-direction. The absorbent structure has a projected area as determined by a Topography Analysis Method, and the upper surface of the absorbent structure has a vertical area as determined by the Topography Analysis Method of at least about 0.1 cm2; per 1.0 cm2; projected area of the absorbent structure.

Absorbent structure having three-dimensional topography on upper and lower surfaces

The present invention includes a microneedle assembly having a support that includes a first surface and a second surface, the second surface further including a slanted surface. A plurality of microneedles are provided which project outwardly from the second surface of the support. A pathway through the microneedle assembly is formed and includes an aperture extending between the first surface of the support and the second surface of the support, a channel disposed on the exterior surface of at least one microneedle, the channel having a surface, the channel being in alignment with at least a portion of the aperture to form a junction through which fluids may pass.

Transdermal device containing microneedles

A method and device for monitoring thermal stress in a user is described. The device is designed to include a material having specific thermodynamic properties and physical dimensions defined as a function of those thermodynamic properties. A system for thermal stress monitoring including a thermal stress monitoring device configured within a garment is also described.

Method and device for monitoring thermal stress

Embodiments of the invention provide methods and systems for determining hydration of an article and/or a person. The physical and/or electrical properties of a device in the absorbent article may be altered by hydration received in the absorbent article. The alteration of the physical or electrical properties may indicate the amount of hydration in the absorbent article. Furthermore, a time period for receiving the hydration in the absorbent article may also be determined. The hydration of the person may be determined based on a fluid output rate from the person computed using the amount of hydration output from the person and the time period for receiving the hydration.

Andrew T. Baker

Papers

The effect of surface wave propagation on neural responses to vibration in primate glabrous skin

Absorbent structure having three-dimensional topography on upper and lower surfaces

Transdermal device containing microneedles

Method and device for monitoring thermal stress

Systems and methods for hydration sensing and monitoring