Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TOUCH”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 145 records · Page 8Linked to original sources
PubMed1999

Touch imprint cytological analysis of sentinel lymph nodes for detecting axillary metastases in patients with breast cancer.

BACKGROUND: Sentinel lymph node biopsy is a procedure that examines the first tumour-draining lymph node. Touch imprint cytology may provide a quick method for intraoperative screening of sentinel lymph nodes for the presence of metastases. METHODS: Touch imprint cytological analysis of sentinel lymph nodes was compared prospectively with the findings obtained on routine paraffin sections. Touch imprint slides from 55 patients with breast cancer were prepared during operation from multiple sections of sentinel lymph nodes, stained with haematoxylin and eosin. A cytopathologist blinded to the histological results interpreted the smears. RESULTS: The concordance between touch imprint and paraffin sections of sentinel lymph nodes was 98 per cent (54 of 55). When touch imprint analysis of sentinel lymph nodes was compared with paraffin sectioning of all lymph nodes from the axillary node dissection, the concordance was 95 per cent (52 of 55). The sensitivity and specificity of sentinel lymph node touch imprints in detecting metastases were 82 and 100 per cent respectively. The positive and negative predictive values were 100 and 93 per cent respectively. CONCLUSION: Touch imprint cytology is potentially useful for the intraoperative evaluation of sentinel lymph nodes in patients with breast cancer.

Axilla↗
PubMed2003

Touch modulates gravity sensing to regulate the growth of primary roots of Arabidopsis thaliana.

Plants must sense and respond to diverse stimuli to optimize the architecture of their root system for water and nutrient scavenging and anchorage. We have therefore analyzed how information from two of these stimuli, touch and gravity, are integrated to direct root growth. In Arabidopsis thaliana, touch stimulation provided by a glass barrier placed across the direction of growth caused the root to form a step-like growth habit with bends forming in the central and later the distal elongation zones. This response led to the main root axis growing parallel to, but not touching the obstacle, whilst the root cap maintained contact with the barrier. Removal of the graviperceptive columella cells of the root cap using laser ablation reduced the bending response of the distal elongation zone. Similarly, although the roots of the gravisensing impaired pgm1-1 mutant grew along the barrier at the same average angle as wild-type, this angle became more variable with time. These observations imply a constant gravitropic re-setting of the root tip response to touch stimulation from the barrier. In wild-type plants, transient touch stimulation of root cap cells, but not other regions of the root, inhibited both subsequent gravitropic growth and amyloplast sedimentation in the columella. Taken together, these results suggest that the cells of the root cap sense touch stimuli and their subsequent signaling acts on the columella cells to modulate their graviresponse. This interaction of touch and gravity signaling would then direct root growth to avoid obstacles in the soil while generally maintaining downward growth.

Arabidopsis↗
PubMed2002

Localization of nitric oxide synthase in saphenous vein grafts harvested with a novel "no-touch" technique: potential role of nitric oxide contribution to improved early graft patency rates.

OBJECTIVE: The use of the saphenous vein in coronary artery bypass graft surgery is associated with high 1-year occlusion rates of as much as 30%. A new "no-touch" technique of saphenous vein harvesting in which the vein is harvested with a pedicle of surrounding tissue and not distended may result in improved early patency rates. We hypothesize that nitric oxide synthase is better preserved with the no-touch technique, and the aim of this study was the investigation of whether nitric oxide synthase distribution and quantity in saphenous veins harvested with the no-touch technique differ from those veins harvested with the conventional technique. The separate contribution of perivascular tissue removal and distension to alterations in nitric oxide synthase was also studied. METHODS: Segments of 10 saphenous veins were harvested from 10 patients who underwent coronary artery bypass grafting surgery with the no-touch and conventional techniques. Samples were also taken from segments that were stripped of surrounding tissue but not distended. Nitric oxide synthase distribution was studied with reduced nicotinamide adenine dinucleotide phosphate--diaphorase histochemistry, and staining was quantified with image analysis. Immunohistochemistry was used for the identification of specific nitric oxide synthase isoforms, and immunomarkers were used for the identification of associated cell types. RESULTS: Nitric oxide synthase content was higher in no-touch vessels as compared with conventionally harvested vessels (35.5%; P <.05, with analysis of variance). This content was associated with endothelial nitric oxide synthase on the lumen while all three isoforms were present in the media. In the intact adventitia of no-touch vessels, all three isoforms of nitric oxide synthase were also present, associated with microvessels and perivascular nerves. Perivascular tissue stripping and venous distension both contribute to the reduced nitric oxide synthase in conventionally harvested veins. CONCLUSION: The new no-touch technique of saphenous vein harvesting preserves nitric oxide synthase, which suggests that improved nitric oxide availability may be an important mechanism in the success of this technique.

Aged↗
PubMed2005

Evaluation of voice control, touch panel control and assistant control during steering of an endoscope.

The increasing amount of equipment used in the Operating Room (OR) asks for ergonomical user interfaces. The aim of this study was to investigate in a pelvi-trainer setting the efficiency, reliability and user satisfaction of voice control, touch panel control and conventional manual control by an assistant. Ten subjects had to control the zoom and light intensity of an endoscope, using voice, a touch panel or an assistant. For each interface, the subject received nine tasks to control to a certain level, light, zoom or both. The experiment was repeated three times (three cycles) and the sequences of interfaces were varied per cycle. Experiments were recorded on video and off-line time needed per task and the number of wrongly interpreted tasks were measured. A questionnaire was used to investigate user satisfaction. Voice control was slower than assistant control and touch panel control (92.5 s, 80.2 s and 76.0 s, respectively, p<0.02). There was no significant difference between touch panel control and assistant control. With voice control, 3.1% of the commands were not interpreted and 1.7% were wrongly interpreted. 40% of the subjects experienced voice control as the quickest, 30% touch panel control and 30% assistant control. 48% of the subjects preferred voice control, 28% the touch panel and 24% assistant control. Voice control was less efficient than touch panel control and manual control by an assistant. The subjects experienced voice control as more efficient, however. In the future, voice control should be improved to overcome wrongly interpreted commands. Furthermore, experiments should be performed in a clinical setting in which the surgeon has to perform two-handed tasks to evaluate the effects on the surgeon's performance.

Journal Article↗
PubMed2006

Surface plasmon resonance-based highly sensitive optical touch sensor with a hybrid noise rejection scheme.

A surface plasmon resonance (SPR)-based optical touch sensor structure is proposed that provides high switch sensitivity and requires a weak activating force. Our proposed SPR-based optical touch sensor is arranged in a compact Kretschmann-Raether configuration in which the prism acting as our sensor head is coated with a metal nanofilm. Our optical-based noise rejection scheme relies on wavelength filtering, spatial filtering, and high reflectivity of the metal nanofilm, whereas our electrical-based noise reduction is obtained by means of an electrical signal filtering process. In our experimental proof of concept, a visible laser diode at a 655 nm centered wavelength and a prism made from BK7 with a 50 nm thick gold layer on the touching surface are used, showing a 7.85 dB optical contrast ratio for the first touch. An estimated weak mechanical force of <0.1 N is also observed that sufficiently activates the desired electrical load. It is tested for 51 operations without sensor malfunction under typical and very high illumination of 342 and 3000 lx, respectively. In this case, a measured average optical contrast of 0.80 dB is obtained with a +/-0.47 dB fluctuation, implying that the refractive index change in a small 3.2% of the overall active area is enough for our SPR-based optical touch sensor to function properly. Increasing optical contrast in our SPR-based optical touch sensor can be accomplished by using a higher polarization-extinction ratio and a narrower-bandwidth optical beam. A controlled environment and gold-coated surface using the thin-film sputtering technique can help improve the reliability and the durability of our SPR-based optical touch sensor. Other key features include ease of implementation, prevention of a light beam becoming incident on the user, and the ability to accept both strong and weak activating forces.

Journal Article↗
PubMedDate not supplied

Comparison of laser versus surface-touch registration for image-guided sinus surgery.

BACKGROUND: Use of image-guidance systems has become more popular in endoscopic sinus surgery. The laser registration technique has been used previously; however, a less expensive surface-touch registration technique recently has been developed. We compared the accuracy and speed of laser and surface-touch registration techniques. METHODS: Localization accuracy after laser and surface-touch registration was examined after 15 endoscopic sinonasal procedures between July and September 2004. Compared anatomic locations included the nasofrontal angle, nasolabial angle, posterior maxillary wall, skull base, and posterior vomer. For each localization point, the degree of error (in millimeters) was measured in superior-inferior (SI), anterior-posterior (AP), and right-left (RL) dimensions. The length of time for each registration procedure was recorded for both techniques. RESULTS: Laser registration was significantly faster (mean, 20 seconds) than surface-touch registration (mean, 20 seconds versus 63 seconds, respectively; p < 0.05). Laser registration was accurate within 0.3 mm in the SI direction, 0.4 mm in the AP direction, and 0.4 mm in the RL direction. Surface-touch registration was accurate within 0.3 mm in the SI direction, 0.4 mm in the AP direction, and 0.3 mm in the RL direction. There was no significant difference between techniques for any anatomic point. In 97.7% of all points, accuracy was within 2 mm or less for both the laser and surface-touch registration. CONCLUSION: Surface-touch registration is significantly slower than laser registration but has virtually no difference in accuracy. Both techniques compare very favorably to the accuracy of other systems reported in the literature.

Endoscopy↗
PubMed2005

Positive touch, the implications for parents and their children with autism: an exploratory study.

The aims of this study were (1) to explore the experience of touch between parents and children with autism before, during, and after a Training and Support Programme (TSP), and (2) to develop a model of the process of touch therapy for this group of parents and children. Fourteen parents and their children agreed to take part in the study. Five of these parents withdrew. Reasons for withdrawal included personal circumstances and ill health. Data were collected by semi-structured interviews with parents before attending the TSP and Home Record Sheets completed by parents during the TSP. Results indicate that before the TSP touch was experienced as out of parents' control. During the TSP, the experience of touch appeared to change. A key benefit gained by parents was the feeling of closeness to children. The key benefits gained by children were perceived by the parents as improved sleep patterns, children were more relaxed after receiving the massage and appeared more amenable to touch. Of interest was children's request for massage at home. At 16-week follow-up both parents and children continue to enjoy giving and receiving touch therapy, respectively.

Adult↗
PubMed1994

Behavioral specializations of SI and SII cortex: a comparative examination of the neural logic of touch in rats, cats, and other mammals.

In what ways do passive touch and active touch require particular properties of cortical physiology? Because it is not easy to make predictions "bottom up" from neurophysiology and anatomy to behavior, there have been surprises in studying behavioral deficits following selective ablations of SI versus SII. For example, in earlier research on cats, unilateral ablation of SI unexpectedly had no effect on passive touch but did cause contralateral losses in posture and movement; it was ablation of SII plus subjacent cortex that led to contralateral losses in passive touch. In contrast, in a recent experiment with rats unilateral ablation of either SI or SII caused contralateral losses both in touch and postural reflexes. Some of the literature on dogs, monkeys, and humans suggests similarities with cats. To better understand these comparative findings, the following theoretical factors are considered: the degree of diffuseness versus specificity in brain input-output relations demanded or permitted by a behavior, the spatial and temporal scales of a behavior, the species' degree of encephalization, the need for stimulus generalization or functional equivalence of movements, and the relative sizes and sensitivities of different parts of the body. Hypotheses are also offered about why the evolution in rats of shortened forelimbs and increased vibrissal function may have entailed a peculiar compromise between active and passive touch and between functions of SI and SII.

Animals↗
PubMed1993

The role of single touch domes in tactile perception.

Detection thresholds to step indentations applied to touch domes were measured and compared with threshold values obtained on adjacent areas of hairy skin. The mean of the detection thresholds determined on touch domes for five subjects was 504 +/- 27 microns (SEM). The detection thresholds found off the touch domes (2-3 mm away) were somewhat higher in all ten cases (two studies per subject), with a mean value of 587 +/- 28 microns, which was significant at the 0.01 level. These thresholds are an order of magnitude greater than those that elicit responses in touch-dome-associated slowly adapting type I (SAI) fibres in cats, and, together with the small difference between the detection thresholds determined on and off touch domes, indicate that the activity of single touch dome SAI fibres does not mediate the detection of steady indentation in the hairy skin.

Adult↗
PubMed1991

Measurement of light touch perception threshold by contingent negative variation.

An objective method developed to measure the threshold of light touch perception using contingent negative variation (CNV) is described. The light touch stimulus was a slight indentation of the skin produced through a displacement controlled stimulating probe (tip diameter of 2 mm). It was applied as the conditioning (S1) stimulus of the classical CNV paradigm of S1, S2, and R. To increase the CNV amplitude, the S2 stimulus was either a red or a yellow LED. The subjects were required to respond to only one of two by pressing a button. When the light touch stimulus was perceived, the CNV was recorded in all 19 healthy adult volunteers. In 14 of them, a systematic determination of the threshold of the ball of the thumb and index finger, thenar, hypothenar, face, shoulder, anterior thigh, foot dorsum and great toe ball, have been done. The thresholds of the light touch perception as defined by objective CNV measurement are very close to the results of the subjective psychophysiological determinations in normals. The amplitude of the averaged CNV (12 responses) started to decrease when stimulus intensity was reduced to the point that the subjects were able to perceive only a fraction of the presented touch stimuli. We believe, therefore, that the objective CNV determination of the light touch perception threshold is precise and sensitive enough to be used in research as well as in clinical applications.

Adult↗
PubMed2003

Reliability of perception of fever by touch.

OBJECTIVE: To assess the reliability of touch to predict fever in children. METHODS: 200 children who reported with fever formed the study material. Group I consisted of 100 children between 0-1 year of age and Group II consisted of 100 children between 6-12 years of age. Preterm, neonates under warming device, tachypnoeic and hypothermic were excluded from the study. The caregiver (CG) and the medical staffs (MS) response regarding presence or absence of fever by touch was noted in each child. Both were blinded to each other's response. Immediately temperature was recorded by calibrated rectal thermometer in Group I and calibrated axillary thermometer in Group II. RESULTS: The CG's touch had a sensitivity of 70.5% specificity of 40.9%, PPV of 38% NPV of 72.9%, PLR was 1.16 and NLR was 0.75. The MS's touch had a sensitivity of 78.0%, specificity of 63.6%, PPV of 38.0% NPV 84.8%, PLR of 2.08 and NLR of 0.36. There is over and under diagnosis of fever by both, the former being more by the CG reflecting the parental anxiety. The MS's touch is better to affirm or negative fever as compared to CG. The best site to palpate for presence of fever was abdomen, neck and forehead. CONCLUSION: Touch is not a valid screening test for fever. It is recommended that a thermometer must always be used by the MS to record fever and CG must be motivated for the same.

Child↗
PubMed2005

Simultaneity constancy: detecting events with touch and vision.

What are the consequences of visual and tactile neural processing time differences when combining multisensory information about an event on the body's surface? Visual information about such events reaches the brain at a time that is independent of the location of the event. However, tactile information about such events takes different amounts of time to be processed depending on the distance between the stimulated surface and the brain. To investigate the consequences of these differences, we measured reaction times to touches and lights on different parts of the body and the perceived subjective simultaneity (PSS) for various combinations. The PSSs for pairs of stimuli were predicted by the differences in reaction times. When lights and touches were on different body parts (i.e. the hand and foot) a trend towards compensation for any processing time differences was found, such that simultaneity was veridically perceived. When stimuli were both on the foot, subjects perceived simultaneity when the light came on significantly earlier than the touch, despite similar processing times for these stimuli. When the stimuli were both on the hand, however, there was complete compensation for the significant processing time differences between the light and touch such that simultaneity was correctly perceived, a form of simultaneity constancy. To identify if there was a single simultaneity constancy mechanism or multiple parallel mechanisms, we altered the PSS of an auditory-visual stimulus pair and looked for effects on the PSS of a visual-touch pair. After repeated exposure to a light/sound pair with a fixed time lag between them, there was no effect on the PSS of a touch-light pair, suggesting multiple parallel simultaneity constancy mechanisms.

Adult↗
PubMed1992

The effect of social support and physical touch on cardiovascular reactions to mental stress.

To examine the effects of social support on cardiovascular reactions to behavioral stress, the present study tested the relative contribution of three elements of social support: the presence of another person in the laboratory; the presence of a person considered to be a friend; and physical touch. Sixty undergraduate females were assigned to one of the following groups: alone (A); friend present-touch (FT); friend present-no touch (FNT); stranger present-touch (ST); and stranger present-no touch (SNT). Heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) measures were obtained across baseline phases and during presentation of two behavioral challenges (mental arithmetic, mirror-tracing). The findings suggest that neither the presence of a stranger nor physical touch are related to attenuated cardiovascular reactions to stress; rather, if the extent of cardiovascular reactivity is related to social support, the presence of a friend may be the important mediating variable.

Adult↗
PubMed2005

Performance study on touch-pens size in three screen tasks.

Experiments were aimed at investigating the performance of various sizes of touch-pens. The touch-pens were of three different lengths (80, 110 and 140 mm) and four different diameters (5.5, 8, 11 and 15 mm). Three screen tasks were used for determining a reference of ideal dimensions of a pen-based product. Sixteen subjects used 12 touch-pens to perform pointing-and-clicking, writing and drawing tasks. The subjects were asked to rank their preference after each task in the test. The results showed that the length of touch-pens should be designed to extend beyond the handbreadth when gripped. A touch-pen that facilitates natural pointing-and-clicking, writing and drawing tasks each requires a suitable diameter size. However, these tasks are typically performed together, in particular, the pointing-and-clicking and writing tasks. The recommended diameter for all three combined tasks is 8 mm. This finding indicates that selecting a touch-pen with a diameter of 8 mm and a length of 100 mm or longer is suitable for all pen-based devices.

Adult↗
PubMed2004

Maternal touch and maternal child-directed speech: effects of depressed mood in the postnatal period.

BACKGROUND: Postnatal depression affects the emotional state of mothers and the quality of mother-infant interaction. METHOD: Touch behaviour and content of child-directed speech were analysed for 72 mothers and their infants during pleasurable play. Infants (18) of mothers with depressed mood and 18 controls were seen when they were 6 months old; and 18 infants of mothers with depressed mood and 18 controls were seen when they were 10 months old. RESULTS: Depressed mothers in comparison with non-depressed mothers lifted their infants more, restraining their behaviours. Infants of depressed mothers in contrast to infants of non-depressed mothers spent greater periods of time in touching self rather than mother or toy, compensating for the lack of positive touch from their mothers. Mothers with depressed mood of 6-month-old infants included fewer affective and informative features in their speech than their controls. Non-depressed mothers of younger babies showed a higher use of affective features when compared with non-depressed mothers of older infants. In contrast, depressed mothers of 6- and 10-month-old babies showed similar frequencies of affect-salient speech during interactions in spite of their infants' changing developmental demands. LIMITATIONS: Mothers in this study were only mildly depressed, as assessed by the Edinburgh Postnatal Depression Scale (EPDS). Nevertheless, the findings indicate that mothers with depressive symptoms differ from non-depressed mothers in relation to touch and content of speech when interacting with their infants. CONCLUSIONS: These results suggest that postnatal depression may influence touch behaviour as well as the affective and informative content of maternal speech. The effect is that mothers with depressed mood in comparison with non-depressed mothers touch their infants more negatively and their speech is less well adjusted concerning the amount of emotional vs. information-related content thereby preventing depressed mothers from responding effectively to their infants' developmental needs.

Adolescent↗
PubMed2003

In vivo imaging of C. elegans mechanosensory neurons demonstrates a specific role for the MEC-4 channel in the process of gentle touch sensation.

In the nematode C. elegans, genes encoding components of a putative mechanotransducing channel complex have been identified in screens for light-touch-insensitive mutants. A long-standing question, however, is whether identified MEC proteins act directly in touch transduction or contribute indirectly by maintaining basic mechanoreceptor neuron physiology. In this study, we used the genetically encoded calcium indicator cameleon to record cellular responses of mechanosensory neurons to touch stimuli in intact, behaving nematodes. We defined a gentle touch sensory modality that adapts with a time course of approximately 500 ms and primarily senses motion rather than pressure. The DEG/ENaC channel subunit MEC-4 and channel-associated stomatin MEC-2 are specifically required for neural responses to gentle mechanical stimulation, but do not affect the basic physiology of touch neurons or their in vivo responses to harsh mechanical stimulation. These results distinguish a specific role for the MEC channel proteins in the process of gentle touch mechanosensation.

Animals↗
PubMed2003

Effect of light finger touch on postural sway after lower-limb muscular fatigue.

OBJECTIVE: To investigate whether a light finger touch can compensate for the increased postural sway induced by lower-limb muscular fatigue. DESIGN: Before-after trials. SETTING: General community. PARTICIPANTS: Nine healthy university students (mean age, 23.8+/-2.6y; mean body weight, 72.7+/-6.9 kg; mean height, 177.2+/-7.5 cm). INTERVENTIONS: Participants stood with their feet together and eyes closed. They were asked to sway as little as possible in 4 conditions: no fatigue/no touch, no fatigue/touch, fatigue/no touch, and fatigue/touch. Calf muscle fatigue was induced by having participants stand on their toes until exhaustion. Touch conditions involved a gentle light touch with the right index finger on a nearby surface at waist height. MAIN OUTCOME MEASURES: Center of pressure displacements were recorded by using a force platform. RESULTS: Light finger touch resulted in decreased postural sway in the no-fatigue and fatigue conditions. Interestingly, this stabilizing effect was more accentuated in the fatigue condition. CONCLUSIONS: Results suggest that the contribution of the haptic cues from the finger for regulating postural sway increases after muscular fatigue. These findings could have implications in clinical and rehabilitative areas.

Adult↗
PubMed2002

Identification of genes expressed in C. elegans touch receptor neurons.

The extent of gene regulation in cell differentiation is poorly understood. We previously used saturation mutagenesis to identify 18 genes that are needed for the development and function of a single type of sensory neuron--the touch receptor neuron for gentle touch in Caenorhabditis elegans. One of these genes, mec-3, encodes a transcription factor that controls touch receptor differentiation. By culturing and isolating wild-type and mec-3 mutant cells from embryos and applying their amplified RNA to DNA microarrays, here we have identified genes that are known to be expressed in touch receptors, a previously uncloned gene (mec-17) that is needed for maintaining touch receptor differentiation, and more than 50 previously unknown mec-3-dependent genes. These genes are randomly distributed in the genome and under-represented both for genes that are co-expressed in operons and for multiple members of gene families. Using regions 5' of the start codon of the first 20 genes, we have also identified an over-represented heptanucleotide, AATGCAT, that is needed for the expression of touch receptor genes.

Amino Acid Sequence↗