Discrimination Thresholds for Passive Tactile Volume Perception by Fingertips

Perception ◽  
2019 ◽  
Vol 48 (12) ◽  
pp. 1252-1267 ◽  
Author(s):  
Jian Zhang ◽  
Zhilin Zhang ◽  
Ritsu Go ◽  
Chunlin Li ◽  
Jinglong Wu

Haptic object perception is still poorly understood up to now. This study investigated the ability of human fingers to discriminate the volume of objects by passive touch. Experiments measured the discrimination threshold of volume using three tasks: passive tactile volume perception, passive tactile area perception, and active tactile volume perception. In each trial, we utilized two plastic cubes to successively stimulate the fingers, and participants were instructed to make comparisons between the stimulus objects’ volume and area. Results showed that there was no significant difference in the discrimination thresholds of tactile volume perception between passive touch and active touch, whereas significant differences in the discrimination thresholds between fingertips, such as the thumb versus the pinky finger. In passive touch, the discrimination thresholds of volume perception were larger than that with surface area perception. We found that the discrimination of the volume of objects is more difficult than the discrimination of the area of the objects.

2021 ◽  
Vol 42 (Supplement_1) ◽  
pp. S146-S146
Author(s):  
Loryn Taylor ◽  
Kimberly Maynell ◽  
Thanh Tran ◽  
David J Smith

Abstract Introduction Prolonged opioid usage remains a concern in pain management in procedural care. Recent evidence also suggests that a considerable number of patients who were prescribed opioids struggle with transitioning to non-opioid pain medications. As a continuous effort to reduce opioid consumption following burn surgical procedures, our institution recently evaluated methadone administration for burn procedural care in patients with 20–30% total burn surface area (TBSA) requiring excision and grafting. Methods After IRB approval, we performed a retrospective chart review of patients who underwent excision and grafting procedure for 20–30% TBSA burn injuries between January 1, 2019 and June 30, 2020. The following data was evaluated: postoperative opioid consumption, postoperative pain intensity (rated as “No Pain” [NRS=0], “Minor Pain” [NRS 1 to 3], “Moderate Pain” [NRS 4 to 6], “Severe Pain” [NRS 7 to 10]), time to physical therapy and time to hospital discharge. Data was analyzed using chi square/Fisher exact test for categorical variables and t-test/Wilcoxon rank sum test for continuous variables. Results Our preliminary data included 12 patients who met inclusion criteria, of which two patients received methadone administration. Our patient sample consisted of average age of 43 years, 75% male, and 24% TBSA (92% were flame burns). Patients in both methadone and non-methadone groups had no significant differences in medical histories and TBSA (23% TBSA in methadone, 25% TBSA in non-methadone). There was no significant difference in reported preoperative pain intensity between the two groups, rating moderate to severe. Postoperative pain intensity remained the same, rating moderate to severe and controlled with fentanyl, oxycodone, morphine and non-opioid analgesics. While there was no difference in postoperative fentanyl, opioid and non-opioid analgesic consumptions between the two groups, morphine consumption was significantly lower in the methadone group compared to non-methadone group (2±2 mg vs 51±54 mg, respectively, p=0.02). There was no significant difference between average time from surgery to first physical therapy session and time to hospital discharge (about 21 days after surgery) between the two groups. Conclusions This evaluation shows a potential trend in reduction of inpatient postoperative opioid consumption with the conjunctive administration of methadone, although a bigger sample size is needed for further assessment.


2021 ◽  
Vol 30 (1) ◽  
pp. 160-169
Author(s):  
Yang-Soo Yoon ◽  
Callie Michelle Boren ◽  
Brianna Diaz

Purpose To measure the effect of testing conditions (in the soundproof booth vs. quiet room), test order, and number of test sessions on spectral and temporal processing in normal-hearing (NH) listeners. Method Thirty-two adult NH listeners participated in the three experiments. For all three experiments, the stimuli were presented to the left ear at the subjects' most comfortable level through headphones. All tests were administered in an adaptive three-alternative forced-choice paradigm. Experiment 1 was designed to compare the effect of soundproof booth and quiet room test conditions on amplitude modulation detection threshold and modulation frequency discrimination threshold with each of the five modulation frequencies. Experiment 2 was designed to compare the effect of two test orders on the frequency discrimination thresholds under the quiet room test conditions. The thresholds were first measured in the ascending and descending order of four pure tones, and then with counterbalanced order. For Experiment 3, the amplitude discrimination threshold under the quiet room testing condition was assessed 3 times to determine the effect of the number of test sessions. Then the thresholds were compared over the sessions. Results Results showed no significant effect of test environment. The test order is an important variable for frequency discrimination, particularly between piano tunes and pure tones. Results also show no significant difference across test sessions. Conclusions These results suggest that a controlled test environment may not be required in spectral and temporal assessment for NH listeners. Under the quiet test environment, a single outcome measure is sufficient, but test orders should be counterbalanced.


2016 ◽  
Vol 6 (6) ◽  
pp. 20160056 ◽  
Author(s):  
R. Pruna ◽  
F. Palacio ◽  
M. Martínez ◽  
O. Blázquez ◽  
S. Hernández ◽  
...  

Fabrication and organosilane-functionalization and characterization of nanostructured ITO electrodes are reported. Nanostructured ITO electrodes were obtained by electron beam evaporation, and a subsequent annealing treatment was selectively performed to modify their crystalline state. An increase in geometrical surface area in comparison with thin-film electrodes area was observed by atomic force microscopy, implying higher electroactive surface area for nanostructured ITO electrodes and thus higher detection levels. To investigate the increase in detectability, chemical organosilane-functionalization of nanostructured ITO electrodes was performed. The formation of 3-glycidoxypropyltrimethoxysilane (GOPTS) layers was detected by X-ray photoelectron spectroscopy. As an indirect method to confirm the presence of organosilane molecules on the ITO substrates, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were also carried out. Cyclic voltammograms of functionalized ITO electrodes presented lower reduction-oxidation peak currents compared with non-functionalized ITO electrodes. These results demonstrate the presence of the epoxysilane coating on the ITO surface. EIS showed that organosilane-functionalized electrodes present higher polarization resistance, acting as an electronic barrier for the electron transfer between the conductive solution and the ITO electrode. The results of these electrochemical measurements, together with the significant difference in the X-ray spectra between bare ITO and organosilane-functionalized ITO substrates, may point to a new exploitable oxide-based nanostructured material for biosensing applications. As a first step towards sensing, rapid functionalization of such substrates and their application to electrochemical analysis is tested in this work. Interestingly, oxide-based materials are highly integrable with the silicon chip technology, which would permit the easy adaptation of such sensors into lab-on-a-chip configurations, providing benefits such as reduced size and weight to facilitate on-chip integration, and leading to low-cost mass production of microanalysis systems.


2018 ◽  
Vol 120 (5) ◽  
pp. 2423-2429 ◽  
Author(s):  
Derek Olczak ◽  
Vaishnavi Sukumar ◽  
J. Andrew Pruszynski

Previous studies investigating the perceptual attributes of tactile edge orientation processing have applied their stimuli to an immobilized fingertip. Here we tested the perceptual attributes of edge orientation processing when participants actively touched the stimulus. Our participants moved their finger over two pairs of edges, one pair parallel and the other nonparallel to varying degrees, and were asked to identify which of the two pairs was nonparallel. In addition to the psychophysical estimates of edge orientation acuity, we measured the speed at which participants moved their finger and the forces they exerted when moving their finger over the stimulus. We report four main findings. First, edge orientation acuity during active touch averaged 12.4°, similar to that previously reported during passive touch. Second, on average, participants moved their finger over the stimuli at ~20 mm/s and exerted contact forces of ~0.3 N. Third, there was no clear relationship between how people moved their finger or how they pressed on the stimulus and their edge orientation acuity. Fourth, consistent with previous work testing tactile spatial acuity, we found a significant correlation between fingertip size and orientation acuity such that people with smaller fingertips tended to have better orientation acuity. NEW & NOTEWORTHY Edge orientation acuity expressed by the motor system during manipulation is many times better than edge orientation acuity assessed in psychophysical studies where stimuli are applied to a passive fingertip. Here we show that this advantage is not because of movement per se because edge orientation acuity assessed in a psychophysical task, where participants actively move their finger over the stimuli, yields results similar to previous passive psychophysical studies.


1970 ◽  
Vol 32 (2) ◽  
pp. 36-43 ◽  
Author(s):  
P Kayastha ◽  
S Paudel ◽  
DM Shrestha ◽  
RJ Ghimire ◽  
S Pradhan

Introduction: The purpose of this study was to establish reference ranges of total thyroid volume among clinically euthyroid Nepalese population using Ultrasonography and correlate this volume with age, sex, individual’s built and geographic location. Methods: This was a prospective cross sectional study involving 485 clinically euthyroid individuals. B - mode Ultrasonography was used to measure the total thyroid volume by combining the volume of both the lobes obtained by using formula for prolate ellipsoid. Age specific reference values for thyroid volume were obtained and Pearson correlation test was used to see the relationship with various factors. Results: Among 485 individuals between 1 to 83 years of age, 221(45.57%) were males and 264(54.43%) were females. Maximum [354 individuals (72.99%)] were from hilly region and minimum [16 individual (3.30%)] were from Himalayan region. Mean thyroid volume was 6.629 ± 2.5025 ml. In general, thyroid volume was found to be more in older individuals than in young age group. There was no significant difference of thyroid volume between males and females. Thyroid volume best correlated with body surface area (r=0.444, p<0.0001). The volume had a positive correlation with weight (r=0.443, p<0.0001), body mass index (r=0.371, p<0.0001) and height (r=0.320, p<0.0001) of the individual. Conclusions: This study estimated the reference range of total thyroid volume for Nepalese population. These ranges are significantly lower than the WHO/ICCIDD thyroid volume references and reference values obtained in various other countries. Total thyroid volume best correlated with Body surface area. Keywords: Body surface area; clinically euthyroid; total thyroid volume; ultrasonography DOI: http://dx.doi.org/10.3126/joim.v32i2.4944 Journal of Institute of Medicine, August, 2010; 32: 36-43


1963 ◽  
Vol 18 (3) ◽  
pp. 519-522 ◽  
Author(s):  
M. C. Hart ◽  
M. M. Orzalesi ◽  
C. D. Cook

The respiratory anatomic dead space has been measured by the single breath nitrogen washout method of Fowler in 73 normal subjects ranging from 4 to 42 years of age. The volume of the anatomic dead space correlated closely with height (Vd (ml) = 7.585 x Ht (cm)2.363 x 10-4·ɣ = .917), but also with body weight, surface area, and functional residual capacity. When compared on the basis of any of these parameters there was no significant difference between the anatomic dead space values for males and females. Comparisons with available data for newborn infants suggest that the value of the anatomic dead space has a relatively constant relation to height from birth to adulthood. Dead space appears to increase more rapidly than weight, surface area, and functional residual capacity during, at least, the early period of somatic growth. Note: (With the Technical Assistance of J. H. Shaw) Submitted on October 25, 1962


Author(s):  
Zhilin Zhang ◽  
Chunlin Li ◽  
Jian Zhang ◽  
Qiang Huang ◽  
Ritsu Go ◽  
...  

Author(s):  
Chang Xu ◽  
Yuxiang Wang ◽  
Steven C. Hauser ◽  
Gregory J. Gerling

In our ability to discriminate compliant, or ‘soft,’ objects, we rely upon information acquired from interactions at the finger pad. We have yet to resolve the most pertinent perceptual cues. However, doing so is vital for building effective, dynamic displays. By introducing psychophysical illusions through spheres of various size and elasticity, we investigate the utility of contact area cues, thought to be key in encoding compliance. For both active and passive touch, we determine finger pad-to-stimulus contact areas, using an ink-based procedure, as well as discrimination thresholds. The findings indicate that in passive touch, participants cannot discriminate certain small compliant versus large stiff spheres, which generate similar contact areas. In active touch, however, participants easily discriminate these spheres, though contact areas remain similar. Supplementary cues based on stimulus rate and/or proprioception seem vital. One cue that does differ for illusion cases is finger displacement given a volitionally applied force.


Author(s):  
Kevin J. Burnett ◽  
Ashwani K. Gupta ◽  
Jim S. Cowart

Abstract The Navy has a wide range of diesel engines with bore sizes varying by a factor of four. In general, diesel engines can have bore scaling over a full order of magnitude. As an engine cylinder gets larger its surface area to volume ratio reduces significantly, which in turn affects in-cylinder heat transfer. In this study, a fundamental generalized thermodynamic model of diesel engines was developed. The various key model effects were systematically analyzed along with engine bore size. Further, cylinder wall temperature was varied across a range of cold start to stabilized operating temperatures. The results of this study show that smaller bore diesel engines are always more sensitive to cold start conditions. The effect is reduced with increasing wall temperature yet smaller diesel engines have cooler end-of-compression temperatures as comparted to larger engines. The effects of engine speed, in which mean piston speed is held constant, tend to modestly reduce the differences between various size diesel engines due to non-linear heat transfer effects. When variable specific heat effects are correctly considered, end-of-compression air charge temperatures are only modestly different as a function of engine bore size. The most significant difference is the overall reduced heat transfer in larger engines due to the surface area to volume effect. A difference of a factor of three for in cylinder heat transfer relative to in-cylinder inducted air mass is predicted being much greater for the smaller engines. Higher exhaust temperatures are also characteristic of the larger bore engines. This allows more combustion work to be delivered to the piston with a correspondingly higher thermal efficiency for larger diesel engines. Future work will evaluate fuel effects on varying bore size.


2019 ◽  
Vol 4 (4) ◽  
pp. 2473011419S0042
Author(s):  
Gean C. Viner ◽  
Eildar Abyar ◽  
Leonardo Moraes ◽  
Haley McKissack ◽  
Martim Pinto ◽  
...  

Category: Arthroscopy, Basic Sciences/Biologics, Midfoot/Forefoot Introduction/Purpose: First metatarsophalangeal (MTP) joint fusion has been proven to be an effective treatment for a variety of conditions such as osteoarthritis, rheumatoid arthritis, hallux rigidus/valgus, and failed first MTP arthroplasties. Multiple surgical techniques have been described in the literature with regards to bone preparation and different fixation with varying degrees of success. Studies have demonstrated that one of the complications of MTP fusion is first ray shortening, which can lead to symptomatic forefoot disorders such as transfer metatarsalgia of the lesser toes. Patients can develop altered gait mechanics that manifest as decreased ankle plantarflexion at toe-off and decreased step gait. The purpose of this study was to compare the amount of first ray shortening that occurs during MTP fusions with open versus arthroscopic technique. Methods: Ten specimens were divided into two groups. Group one was arthroscopic and group two was open technique. For arthroscopy, the long extensor (EHL) tendon and first MTP joint were identified. Dorsomedial and dorsolateral ports were created at the level of the MTP joint. A small curette was used to prepare the joint. For open technique, an incision was made on the dorsum of the first MTP joint and carried down to the subcutaneous tissue. The EHL tendon was dissected and a capsulotomy was performed. The head of the first metatarsal and the base of the proximal phalanx were exposed. Dome-shaped reamers were used to prepare the joint. A lag screw was used for fixation. AP and lateral radiographs were obtained. The length of the first ray was measured from the base of the first metatarsal to the distal end of the proximal phalanx. Pre and post fixation lengths were compared. Results: A comparison of pre and post fixation first ray length demonstrated that there was an average decrease of 2.2 mm in the arthroscopic group and 2.1 mm in the open technique group. Even though both techniques shortened the average length of the first ray, there was no statistically significant difference between the groups (p = 0.934). Comparison of the average percentage of surface area prepared of the head of the first metatarsal showed a statistically significant difference (p = 0.035) between both techniques. In contrast, comparison of the average percentage of surface area prepared of the base of the proximal phalanx and total surface area prepared did not show a statistically significant difference (p = 0.159 and p = 0.051) between the groups. Conclusion: First metatarsophalangeal (MTP) joint fusion has been proven to be an effective treatment for a variety of conditions that affect the first ray. First ray shortening can lead to symptomatic forefoot disorders and altered gait patterns. The results of our study indicate that there is no statistically significant difference in first ray length after MTP fusion performed by either arthroscopic or open technique. Our study also showed that even though the average percentage of surface area prepared of the head of the first metatarsal was statistically different between both groups the average percentage of total surface area prepared was not.


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