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Various medical procedures are accomplished by manipulating skin temperature in a nonuniform pattern. Skin temperature monitoring is essential to assess conformance to protocol specifications and to prevent thermal injury. Existing solutions for skin temperature monitoring include single point sensors, such as thermocouples, and two-dimensional methods of sensing surface temperature, such as infrared thermography, and wearable technology. Single point sensors cannot detect the average temperature and consequently their measurements cannot be representative of average surface temperature in a nonuniform temperature field. Infrared thermography requires optical access, and wearable sensors may require complex manufacturing processes and impede the heat exchange with a source by introducing a layer of insulation. Our solution is a two-dimensional resistance temperature detector (2D RTD) created by knitting copper magnet wire into custom shapes. The 2D RTDs were calibrated, compared to one-dimensional sensors and wearable sensors, and analyzed for hysteresis, repeatability, and surface area conformation. Resistance and temperature were correlated with an R2 of 0.99. The 2D RTD proved to be a superior device for measuring average skin temperature exposed to a nonuniform temperature boundary in the absence of optical access such as when a full body thermal control garment is worn.
Laura Namisnak; Sepideh Khoshnevis; Kenneth R. Diller. A Conformable Two-Dimensional Resistance Temperature Detector for Measuring Average Skin Temperature. Journal of Medical Devices 2021, 1 .
AMA StyleLaura Namisnak, Sepideh Khoshnevis, Kenneth R. Diller. A Conformable Two-Dimensional Resistance Temperature Detector for Measuring Average Skin Temperature. Journal of Medical Devices. 2021; ():1.
Chicago/Turabian StyleLaura Namisnak; Sepideh Khoshnevis; Kenneth R. Diller. 2021. "A Conformable Two-Dimensional Resistance Temperature Detector for Measuring Average Skin Temperature." Journal of Medical Devices , no. : 1.
Background: Performance of wrist actigraphy in assessing sleep not only depends on the sensor technology of the actigraph hardware but also on the attributes of the interpretative algorithm (IA). The objective of our research was to improve assessment of sleep quality, relative to existing IAs, through development of a novel IA using deep learning methods, utilizing as input activity count and heart rate variability (HRV) metrics of different window length (number of epochs of data). Methods: Simultaneously recorded polysomnography (PSG) and wrist actigraphy data of 222 participants were utilized. Classic deep learning models were applied to: (a) activity count alone (without HRV), (b) activity count + HRV (30-s window), (c) activity count + HRV (3-min window), and (d) activity count + HRV (5-min window) to ascertain the best set of inputs. A novel deep learning model (Haghayegh Algorithm, HA), founded on best set of inputs, was developed, and its sleep scoring performance was then compared with the most popular University of California San Diego (UCSD) and Actiwatch proprietary IAs. Results: Activity count combined with HRV metrics calculated per 5-min window produced highest agreement with PSG. HA showed 84.5% accuracy (5.3–6.2% higher than comparator IAs), 89.5% sensitivity (6.2% higher than UCSD IA and 6% lower than Actiwatch proprietary IA), 70.0% specificity (8.2–34.3% higher than comparator IAs), and 58.7% Kappa agreement (16–23% higher than comparator IAs) in detecting sleep epochs. HA did not differ significantly from PSG in deriving sleep parameters—sleep efficiency, total sleep time, sleep onset latency, and wake after sleep onset; moreover, bias and mean absolute error of the HA model in estimating them was less than the comparator IAs. HA showed, respectively, 40.9% and 54.0% Kappa agreement with PSG in detecting rapid and non-rapid eye movement (REM and NREM) epochs. Conclusions: The HA model simultaneously incorporating activity count and HRV metrics calculated per 5-min window demonstrates significantly better sleep scoring performance than existing popular IAs.
Shahab Haghayegh; Sepideh Khoshnevis; Michael H. Smolensky; Kenneth R. Diller; Richard J. Castriotta. Deep Neural Network Sleep Scoring Using Combined Motion and Heart Rate Variability Data. Sensors 2020, 21, 25 .
AMA StyleShahab Haghayegh, Sepideh Khoshnevis, Michael H. Smolensky, Kenneth R. Diller, Richard J. Castriotta. Deep Neural Network Sleep Scoring Using Combined Motion and Heart Rate Variability Data. Sensors. 2020; 21 (1):25.
Chicago/Turabian StyleShahab Haghayegh; Sepideh Khoshnevis; Michael H. Smolensky; Kenneth R. Diller; Richard J. Castriotta. 2020. "Deep Neural Network Sleep Scoring Using Combined Motion and Heart Rate Variability Data." Sensors 21, no. 1: 25.
Background Wearable sleep monitors are of high interest to consumers and researchers because of their ability to provide estimation of sleep patterns in free-living conditions in a cost-efficient way. Objective We conducted a systematic review of publications reporting on the performance of wristband Fitbit models in assessing sleep parameters and stages. Methods In adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we comprehensively searched the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Embase, MEDLINE, PubMed, PsycINFO, and Web of Science databases using the keyword Fitbit to identify relevant publications meeting predefined inclusion and exclusion criteria. Results The search yielded 3085 candidate articles. After eliminating duplicates and in compliance with inclusion and exclusion criteria, 22 articles qualified for systematic review, with 8 providing quantitative data for meta-analysis. In reference to polysomnography (PSG), nonsleep-staging Fitbit models tended to overestimate total sleep time (TST; range from approximately 7 to 67 mins; effect size=-0.51, P<.001; heterogenicity: I2=8.8%, P=.36) and sleep efficiency (SE; range from approximately 2% to 15%; effect size=-0.74, P<.001; heterogenicity: I2=24.0%, P=.25), and underestimate wake after sleep onset (WASO; range from approximately 6 to 44 mins; effect size=0.60, P<.001; heterogenicity: I2=0%, P=.92) and there was no significant difference in sleep onset latency (SOL; P=.37; heterogenicity: I2=0%, P=.92). In reference to PSG, nonsleep-staging Fitbit models correctly identified sleep epochs with accuracy values between 0.81 and 0.91, sensitivity values between 0.87 and 0.99, and specificity values between 0.10 and 0.52. Recent-generation Fitbit models that collectively utilize heart rate variability and body movement to assess sleep stages performed better than early-generation nonsleep-staging ones that utilize only body movement. Sleep-staging Fitbit models, in comparison to PSG, showed no significant difference in measured values of WASO (P=.25; heterogenicity: I2=0%, P=.92), TST (P=.29; heterogenicity: I2=0%, P=.98), and SE (P=.19) but they underestimated SOL (P=.03; heterogenicity: I2=0%, P=.66). Sleep-staging Fitbit models showed higher sensitivity (0.95-0.96) and specificity (0.58-0.69) values in detecting sleep epochs than nonsleep-staging models and those reported in the literature for regular wrist actigraphy. Conclusions Sleep-staging Fitbit models showed promising performance, especially in differentiating wake from sleep. However, although these models are a convenient and economical means for consumers to obtain gross estimates of sleep parameters and time spent in sleep stages, they are of limited specificity and are not a substitute for PSG.
Shahab Haghayegh; Sepideh Khoshnevis; Michael H Smolensky; Kenneth R Diller; Richard J Castriotta. Accuracy of Wristband Fitbit Models in Assessing Sleep: Systematic Review and Meta-Analysis. Journal of Medical Internet Research 2019, 21, e16273 .
AMA StyleShahab Haghayegh, Sepideh Khoshnevis, Michael H Smolensky, Kenneth R Diller, Richard J Castriotta. Accuracy of Wristband Fitbit Models in Assessing Sleep: Systematic Review and Meta-Analysis. Journal of Medical Internet Research. 2019; 21 (11):e16273.
Chicago/Turabian StyleShahab Haghayegh; Sepideh Khoshnevis; Michael H Smolensky; Kenneth R Diller; Richard J Castriotta. 2019. "Accuracy of Wristband Fitbit Models in Assessing Sleep: Systematic Review and Meta-Analysis." Journal of Medical Internet Research 21, no. 11: e16273.
The objective of this study was to test the feasibility of Selective Thermal Stimulation (STS) as a method to upregulate glabrous skin blood flow. STS is accomplished by mild surface heating along the spinal cord. 4 healthy subjects were tested in this study. Each participated in a control experiment and an intervention experiment (STS). Both experiments included establishing a maximum level of vasodilation, considered unique to a subject on a test day, and then cooling to a maximum level of vasoconstriction. Perfusion was measured by a laser Doppler flow probe on the index fingertip. The percent of perfusion in the range of minimum to maximum was the primary outcome variable. The data was fit to a linear mixed effects model to determine if STS had a significant influence on perfusion during whole body cooling. STS had a statistically significant effect on perfusion and increased glabrous skin blood flow by 16.3% (P<.001, CI [13.1%, 19.5%]) as skin temperature was decreased. This study supports the theory that STS improves the heat exchanger efficiency of palmar and plantar surfaces by increasing the blood flow.
Laura H. Namisnak; Sepideh Khoshnevis; Kenneth R. Diller. Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling. Journal of Biomechanical Engineering 2019, 141, 1 .
AMA StyleLaura H. Namisnak, Sepideh Khoshnevis, Kenneth R. Diller. Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling. Journal of Biomechanical Engineering. 2019; 141 (12):1.
Chicago/Turabian StyleLaura H. Namisnak; Sepideh Khoshnevis; Kenneth R. Diller. 2019. "Selective Thermal Stimulation Delays the Progression of Vasoconstriction During Body Cooling." Journal of Biomechanical Engineering 141, no. 12: 1.
BACKGROUND Wearable sleep monitors are of high interest to consumers and researchers because of their ability to provide estimation of sleep patterns in free-living conditions in a cost-efficient way. OBJECTIVE We conducted a systematic review of publications reporting on the performance of wristband Fitbit models in assessing sleep parameters and stages. METHODS In adherence with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we comprehensively searched the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Embase, MEDLINE, PubMed, PsycINFO, and Web of Science databases using the keyword Fitbit to identify relevant publications meeting predefined inclusion and exclusion criteria. RESULTS The search yielded 3085 candidate articles. After eliminating duplicates and in compliance with inclusion and exclusion criteria, 22 articles qualified for systematic review, with 8 providing quantitative data for meta-analysis. In reference to polysomnography (PSG), nonsleep-staging Fitbit models tended to overestimate total sleep time (TST; range from approximately 7 to 67 mins; effect size=-0.51, P<.001; heterogenicity: I2=8.8%, P=.36) and sleep efficiency (SE; range from approximately 2% to 15%; effect size=-0.74, P<.001; heterogenicity: I2=24.0%, P=.25), and underestimate wake after sleep onset (WASO; range from approximately 6 to 44 mins; effect size=0.60, P<.001; heterogenicity: I2=0%, P=.92) and there was no significant difference in sleep onset latency (SOL; P=.37; heterogenicity: I2=0%, P=.92). In reference to PSG, nonsleep-staging Fitbit models correctly identified sleep epochs with accuracy values between 0.81 and 0.91, sensitivity values between 0.87 and 0.99, and specificity values between 0.10 and 0.52. Recent-generation Fitbit models that collectively utilize heart rate variability and body movement to assess sleep stages performed better than early-generation nonsleep-staging ones that utilize only body movement. Sleep-staging Fitbit models, in comparison to PSG, showed no significant difference in measured values of WASO (P=.25; heterogenicity: I2=0%, P=.92), TST (P=.29; heterogenicity: I2=0%, P=.98), and SE (P=.19) but they underestimated SOL (P=.03; heterogenicity: I2=0%, P=.66). Sleep-staging Fitbit models showed higher sensitivity (0.95-0.96) and specificity (0.58-0.69) values in detecting sleep epochs than nonsleep-staging models and those reported in the literature for regular wrist actigraphy. CONCLUSIONS Sleep-staging Fitbit models showed promising performance, especially in differentiating wake from sleep. However, although these models are a convenient and economical means for consumers to obtain gross estimates of sleep parameters and time spent in sleep stages, they are of limited specificity and are not a substitute for PSG.
Shahab Haghayegh; Sepideh Khoshnevis; Michael H. Smolensky; Kenneth R. Diller; Richard J. Castriotta. Accuracy of Wristband Fitbit Models in Assessing Sleep: Systematic Review and Meta-Analysis (Preprint). 2019, 1 .
AMA StyleShahab Haghayegh, Sepideh Khoshnevis, Michael H. Smolensky, Kenneth R. Diller, Richard J. Castriotta. Accuracy of Wristband Fitbit Models in Assessing Sleep: Systematic Review and Meta-Analysis (Preprint). . 2019; ():1.
Chicago/Turabian StyleShahab Haghayegh; Sepideh Khoshnevis; Michael H. Smolensky; Kenneth R. Diller; Richard J. Castriotta. 2019. "Accuracy of Wristband Fitbit Models in Assessing Sleep: Systematic Review and Meta-Analysis (Preprint)." , no. : 1.
Water-based passive body heating (PBHWB) as a warm shower or bath before bedtime is often recommended as a simple means of improving sleep. We searched PubMed, CINAHL, Cochran, Medline, PsycInfo, and Web of Science databases and extracted pertinent information from publications meeting predefined inclusion and exclusion criteria to explore the effects of PBHWB on sleep onset latency (SOL), wake after sleep onset, total sleep time, sleep efficiency (SE), slow wave sleep, and subjective sleep quality. The search yielded 5322 candidate articles of which 17 satisfied inclusion criteria after removing duplicates, with 13 providing comparable quantitative data for meta-analyses. PBHWB of 40 to 42.5oC was associated with both improved self-rated sleep quality and SE, and when scheduled 1-2 hours before bedtime for little as 10 min significant shortening of SOL. These findings are consistent with the mechanism of PBHWB effects being the extent of core body temperature decline achieved by increased blood perfusion to the palms and soles that augments the distal-to-proximal skin temperature gradient to enhance body heat dissipation. Nonetheless, additional investigation is required because the findings regarding PBHWB are limited by the relative scarcity of reported research, especially its optimal timing and duration plus exact mechanisms of effects.
Shahab Haghayegh; Sepideh Khoshnevis; Michael H. Smolensky; Kenneth R. Diller; Richard J. Castriotta. Before-bedtime passive body heating by warm shower or bath to improve sleep: A systematic review and meta-analysis. Sleep Medicine Reviews 2019, 46, 124 -135.
AMA StyleShahab Haghayegh, Sepideh Khoshnevis, Michael H. Smolensky, Kenneth R. Diller, Richard J. Castriotta. Before-bedtime passive body heating by warm shower or bath to improve sleep: A systematic review and meta-analysis. Sleep Medicine Reviews. 2019; 46 ():124-135.
Chicago/Turabian StyleShahab Haghayegh; Sepideh Khoshnevis; Michael H. Smolensky; Kenneth R. Diller; Richard J. Castriotta. 2019. "Before-bedtime passive body heating by warm shower or bath to improve sleep: A systematic review and meta-analysis." Sleep Medicine Reviews 46, no. : 124-135.
Cryotherapy is commonly used for the management of soft tissue injury. The dose effect of the applied cooling temperature has not been quantified previously. Six subjects were exposed during five different experiments to local skin temperatures of 16.6 °C, 19.8 °C, 24.7 °C, 27.3 °C, and 37.2 °C for 1 h of active heat transfer followed by 2 h of passive environmental interaction. Skin blood perfusion and temperature were measured continuously at treatment and control sites. All treatments resulted in significant changes in cutaneous vascular conductance (CVC, skin perfusion/mean arterial pressure) compared to baseline values. The drop in CVC for cooling to both 19.8 °C and 16.6 °C was significantly larger than for 27.3 °C (P < 0.05 and P < 0.0005, respectively). The depression of CVC for cooling to 16.6 °C was significantly larger than at 24.7 °C (P < 0.05). Active warming at 37.2 °C produced more than a twofold increase in CVC (P < 0.05). A simulation model was developed to describe the coupled effects of exposure time and temperature on skin perfusion. The model was applied to define an equivalent cooling dose defined by exposure time and temperature that produced equivalent changes in skin perfusion. The model was verified with data from 22 independent cryotherapy experiments. The equivalent doses were applied to develop a nomogram to identify therapeutic time and temperature combinations that would produce a targeted vascular response. The nomogram may be applied to design cryotherapy protocols that will yield a desired vascular response history that may combine the benefits of tissue temperature reduction while diminishing the risk of collateral ischemic injury.
Sepideh Khoshnevis; R. Matthew Brothers; Kenneth R. Diller. Level of Cutaneous Blood Flow Depression During Cryotherapy Depends on Applied Temperature: Criteria for Protocol Design. Journal of Engineering and Science in Medical Diagnostics and Therapy 2018, 1, 041007 .
AMA StyleSepideh Khoshnevis, R. Matthew Brothers, Kenneth R. Diller. Level of Cutaneous Blood Flow Depression During Cryotherapy Depends on Applied Temperature: Criteria for Protocol Design. Journal of Engineering and Science in Medical Diagnostics and Therapy. 2018; 1 (4):041007.
Chicago/Turabian StyleSepideh Khoshnevis; R. Matthew Brothers; Kenneth R. Diller. 2018. "Level of Cutaneous Blood Flow Depression During Cryotherapy Depends on Applied Temperature: Criteria for Protocol Design." Journal of Engineering and Science in Medical Diagnostics and Therapy 1, no. 4: 041007.
Cryotherapy is a therapeutic technique using ice or cold water applied to the skin to manage soft tissue trauma and injury. While beneficial, there are some potentially detrimental side effects, such as pronounced vasoconstriction and tissue ischemia that are sustained for hours post-treatment. This study tested the hypothesis that this vasoconstriction is mediated by 1) activation of post-synaptic α-adrenergic receptors and/or 2) activation of post-synaptic neuropeptide Y1 (NPY Y1) receptors. 8 subjects were fitted with a commercially available cryotherapy unit with a water perfused bladder on the lateral portion of the right calf. Participants were instrumented with four intradermal microdialysis probes beneath the bladder. The following conditions were applied at the four treatment sites: 1) control (Ringer solution), 2) combined post-synaptic β-adrenergic receptors and neuropeptide (NPY) Y1 receptors blockade (P + B site), 3) combined post-synaptic α-adrenergic receptor, β-adrenergic receptor, and NPY Y1 receptor blockade (Y + P + B site), and 4) blockade of pre-synaptic release of all neurotransmitters from the sympathetic nerves (BT site). Following thermoneutral baseline data collection, 1 °C water was perfused through the bladder for 30 min, followed by passive rewarming for 60 min. Skin temperature (Tskin) fell from ~ 34 °C to ~ 18.5 °C during active cooling across all sites and there was no difference between sites (P > 0.05 vs. control for each site). During passive rewarming Tskin rose to a similar degree in all sites (P > 0.05 relative to the end of cooling). In the first 20 min of cooling %CVC was reduced at all sites however, this response was blunted in the BT and the Y + P + B sites (P > 0.05 for all comparisons). By the end of cooling the degree of vasoconstriction was similar between sites with the exception that the reduction in %CVC in the Y + B + P site was less relative to the reduction in the control site. %CVC was unchanged in any of the sites during passive rewarming such that each remained similar to values obtained at the end of active cooling. These findings indicate that the initial vasoconstriction (i.e. within the 1st 20 min) that occurs during cryotherapy induced local cooling is achieved via activation of post-synaptic α-adrenergic receptors; whereas nonadrenergic mechanisms predominate as the duration of cooling continues. The sustained vasoconstriction that occurs following cessation of the cooling stimulus does not appear to be related to activation of post-synaptic α-adrenergic receptors or NPY Y1 receptor.
Kevin M. Christmas; Jordan Patik; Sepideh Khoshnevis; Kenneth R. Diller; R. Matthew Brothers. Pronounced and sustained cutaneous vasoconstriction during and following cyrotherapy treatment: Role of neurotransmitters released from sympathetic nerves. Microvascular Research 2017, 115, 52 -57.
AMA StyleKevin M. Christmas, Jordan Patik, Sepideh Khoshnevis, Kenneth R. Diller, R. Matthew Brothers. Pronounced and sustained cutaneous vasoconstriction during and following cyrotherapy treatment: Role of neurotransmitters released from sympathetic nerves. Microvascular Research. 2017; 115 ():52-57.
Chicago/Turabian StyleKevin M. Christmas; Jordan Patik; Sepideh Khoshnevis; Kenneth R. Diller; R. Matthew Brothers. 2017. "Pronounced and sustained cutaneous vasoconstriction during and following cyrotherapy treatment: Role of neurotransmitters released from sympathetic nerves." Microvascular Research 115, no. : 52-57.
R M. Brothers; Kevin M. Christmas; Jordan C. Patik; Sepideh Khoshnevis; Kenneth R. Diller. Mechanisms of Pronounced and Sustained Cutaneous Vasoconstriction during Cryotherapy. Medicine & Science in Sports & Exercise 2016, 48, 311 -311.
AMA StyleR M. Brothers, Kevin M. Christmas, Jordan C. Patik, Sepideh Khoshnevis, Kenneth R. Diller. Mechanisms of Pronounced and Sustained Cutaneous Vasoconstriction during Cryotherapy. Medicine & Science in Sports & Exercise. 2016; 48 ():311-311.
Chicago/Turabian StyleR M. Brothers; Kevin M. Christmas; Jordan C. Patik; Sepideh Khoshnevis; Kenneth R. Diller. 2016. "Mechanisms of Pronounced and Sustained Cutaneous Vasoconstriction during Cryotherapy." Medicine & Science in Sports & Exercise 48, no. : 311-311.
The response of skin to the application of surface cooling is manifested primarily as a local vasoconstriction and reduced blood flow. Major functions of skin blood flow (SBF) are to sustain the metabolic process of the skin cells and to facilitate heat transfer between the body core and the environment via the cutaneous circulation. One consequence of surface cooling is to insulate the body core from the environment by reducing the magnitude of SBF. The magnitude of vasoconstriction has a nonlinear dose response to the applied temperature so that even mild cooling can cause the loss of a significant fraction of SBF. Other thermally sensitive processes are also influenced, in particular metabolism, which decreases with falling temperature. So long as a cold state is maintained, both the blood flow and metabolism remain depressed. When the skin is rewarmed, metabolism will likewise increase proportionately. However, in the absence of an externally applied stimulation, the SBF will remain at depressed levels for many hours, presumably due to the action of locally expressed humoral vasomotive agents that block the vasodilation process. The consequences may be prolonged exposure to an ischemic state in conjunction with a high metabolic rate, which may exacerbate the potential for nonfreezing cold injury (NFCI) expressed as tissue necrosis and neuropathy. The decoupling of temperature and SBF during rewarming gives rise to a hysteresis effect that is independent of the speed of the cooling and warming processes.
Kenneth R. Diller; Sepideh Khoshnevis; Matthew Brothers. Effects of Cold Temperature on the Skin. Dermatological Cryosurgery and Cryotherapy 2016, 39 -43.
AMA StyleKenneth R. Diller, Sepideh Khoshnevis, Matthew Brothers. Effects of Cold Temperature on the Skin. Dermatological Cryosurgery and Cryotherapy. 2016; ():39-43.
Chicago/Turabian StyleKenneth R. Diller; Sepideh Khoshnevis; Matthew Brothers. 2016. "Effects of Cold Temperature on the Skin." Dermatological Cryosurgery and Cryotherapy , no. : 39-43.
Cryotherapy is a therapeutic technique using ice or cold water applied to the skin to reduce bleeding, inflammation, pain, and swelling following soft tissue trauma and injury. While beneficial, there are some side effects such as pronounced vasoconstriction and tissue ischemia that are sustained for hours post-treatment. This study tested the hypothesis that this vasoconstriction is mediated by 1) the Rho-kinase pathway and/or 2) elevated oxidative stress. 9 subjects were fitted with a commercially available cryotherapy unit with a water perfused bladder on the lateral portion of the right calf. Participants were instrumented with three microdialysis probes underneath the bladder. One site received lactated ringers (control site), one received the Rho-Kinase inhibitor Fasudil, and one received Ascorbic Acid. Skin temperature (Tskin) and cutaneous vascular conductance (CVC) was measured at each site. Subjects had 1°C water perfused through the bladder for 30min, followed by passive rewarming for 90min. Tskin fell from ~34°C to ~18.0°C during active cooling across all sites and this response was similar for all sites (P>0.05 for all comparisons). During passive rewarming Tskin rose to a similar degree in all sites (P>0.05 relative to the end of cooling). %CVC was reduced during active cooling in all sites; however, the magnitude of this response was blunted in the Fasudil site relative to control (P0.05 for each comparison). %CVC at the Fasudil site remained elevated during passive rewarming such that values were higher compared to the control and Ascorbic Acid sites throughout the 90min of passive rewarming (P<0.001 main effect of Fasudil). These findings indicate that the Rho-kinase pathway contributes to pronounced vasoconstriction during cryotherapy as well as the sustained vasoconstriction during the subsequent rewarming period post treatment.
Kevin M. Christmas; Jordan Patik; Sepideh Khoshnevis; Kenneth R. Diller; R. Matthew Brothers. Sustained cutaneous vasoconstriction during and following cyrotherapy treatment: Role of oxidative stress and Rho kinase. Microvascular Research 2016, 106, 96 -100.
AMA StyleKevin M. Christmas, Jordan Patik, Sepideh Khoshnevis, Kenneth R. Diller, R. Matthew Brothers. Sustained cutaneous vasoconstriction during and following cyrotherapy treatment: Role of oxidative stress and Rho kinase. Microvascular Research. 2016; 106 ():96-100.
Chicago/Turabian StyleKevin M. Christmas; Jordan Patik; Sepideh Khoshnevis; Kenneth R. Diller; R. Matthew Brothers. 2016. "Sustained cutaneous vasoconstriction during and following cyrotherapy treatment: Role of oxidative stress and Rho kinase." Microvascular Research 106, no. : 96-100.
The goal of this study was to investigate the persistence of cold-induced vasoconstriction following cessation of active skin-surface cooling. This study demonstrates a hysteresis effect that develops between skin temperature and blood perfusion during the cooling and subsequent rewarming period. An Arctic Ice cryotherapy unit (CTU) was applied to the knee region of six healthy subjects for 60 min of active cooling followed by 120 min of passive rewarming. Multiple laser Doppler flowmetry perfusion probes were used to measure skin blood flow (expressed as cutaneous vascular conductance (CVC)). Skin surface cooling produced a significant reduction in CVC (P < 0.001) that persisted throughout the duration of the rewarming period. In addition, there was a hysteresis effect between CVC and skin temperature during the cooling and subsequent rewarming cycle (P < 0.01). Mixed model regression (MMR) showed a significant difference in the slopes of the CVC–skin temperature curves during cooling and rewarming (P < 0.001). Piecewise regression was used to investigate the temperature thresholds for acceleration of CVC during the cooling and rewarming periods. The two thresholds were shown to be significantly different (P = 0.003). The results show that localized cooling causes significant vasoconstriction that continues beyond the active cooling period despite skin temperatures returning toward baseline values. The significant and persistent reduction in skin perfusion may contribute to nonfreezing cold injury (NFCI) associated with cryotherapy.
Sepideh Khoshnevis; Natalie K. Craik; R. Matthew Brothers; Kenneth R. Diller. Cryotherapy-Induced Persistent Vasoconstriction After Cutaneous Cooling: Hysteresis Between Skin Temperature and Blood Perfusion. Journal of Biomechanical Engineering 2016, 138, 0310041 -0310048.
AMA StyleSepideh Khoshnevis, Natalie K. Craik, R. Matthew Brothers, Kenneth R. Diller. Cryotherapy-Induced Persistent Vasoconstriction After Cutaneous Cooling: Hysteresis Between Skin Temperature and Blood Perfusion. Journal of Biomechanical Engineering. 2016; 138 (3):0310041-0310048.
Chicago/Turabian StyleSepideh Khoshnevis; Natalie K. Craik; R. Matthew Brothers; Kenneth R. Diller. 2016. "Cryotherapy-Induced Persistent Vasoconstriction After Cutaneous Cooling: Hysteresis Between Skin Temperature and Blood Perfusion." Journal of Biomechanical Engineering 138, no. 3: 0310041-0310048.
Cryotherapy involves the surface application of low temperatures to enhance the healing of soft tissue injuries. Typical devices embody a remote source of chilled water that is pumped through a circulation bladder placed on the treatment site. In contrast, the present device uses thermoelectric refrigeration modules to bring the cooling source directly to the tissue to be treated, thereby achieving significant improvements in control of therapeutic temperature while having a reduced size and weight. A prototype system was applied to test an oscillating cooling and heating protocol for efficacy in regulating skin blood perfusion in the treatment area. Data on 12 human subjects indicate that thermoelectric coolers (TECs) delivered significant and sustainable changes in perfusion for both heating (increase by (±SE) 173.0 ± 66.0%, P < 0.005) and cooling (decrease by (±SE) 57.7 ± 4.2%, P < 0.0005), thus supporting the feasibility of a TEC-based device for cryotherapy with local temperature regulation.
Natalia Mejia; Karl Dedow; Lindsey Nguy; Patrick Sullivan; Sepideh Khoshnevis; Kenneth R. Diller. An On-Site Thermoelectric Cooling Device for Cryotherapy and Control of Skin Blood Flow. Journal of Medical Devices 2015, 9, 044502 -445026.
AMA StyleNatalia Mejia, Karl Dedow, Lindsey Nguy, Patrick Sullivan, Sepideh Khoshnevis, Kenneth R. Diller. An On-Site Thermoelectric Cooling Device for Cryotherapy and Control of Skin Blood Flow. Journal of Medical Devices. 2015; 9 (4):044502-445026.
Chicago/Turabian StyleNatalia Mejia; Karl Dedow; Lindsey Nguy; Patrick Sullivan; Sepideh Khoshnevis; Kenneth R. Diller. 2015. "An On-Site Thermoelectric Cooling Device for Cryotherapy and Control of Skin Blood Flow." Journal of Medical Devices 9, no. 4: 044502-445026.
Kevin M. Christmas; Jordan C. Patik; Sepideh Khoshnevis; Kenneth R. Diller; R. Matthew Brothers. Adrenergic Control of the Cutaneous Circulation during Cryotherapy. Medicine and Science in Sports and Exercise 2015, 47, 158 .
AMA StyleKevin M. Christmas, Jordan C. Patik, Sepideh Khoshnevis, Kenneth R. Diller, R. Matthew Brothers. Adrenergic Control of the Cutaneous Circulation during Cryotherapy. Medicine and Science in Sports and Exercise. 2015; 47 (5S):158.
Chicago/Turabian StyleKevin M. Christmas; Jordan C. Patik; Sepideh Khoshnevis; Kenneth R. Diller; R. Matthew Brothers. 2015. "Adrenergic Control of the Cutaneous Circulation during Cryotherapy." Medicine and Science in Sports and Exercise 47, no. 5S: 158.
We have investigated thermal operating characteristics of 13 commercially available cryotherapy units (CTUs) and their associated cooling pads using IR imaging. Quantitative examination of the temperature profiles from pad IR images shows diverse, nonuniform temperature distribution patterns. The extent of heterogeneity of the temperature fields was quantified via standard image analysis methods, including thresholding, spatial gradient diagrams, and frequency histogram distributions. A primary conclusion of this study is that it is a misnomer to characterize the thermal performance of a CTU and cooling pad combination in terms of a single therapeutic temperature.
Sepideh Khoshnevis; Jennifer E. Nordhauser; Natalie K. Craik; Kenneth R. Diller. Quantitative Evaluation of the Thermal Heterogeneity on the Surface of Cryotherapy Cooling Pads. Journal of Biomechanical Engineering 2014, 136, 074503 -0745037.
AMA StyleSepideh Khoshnevis, Jennifer E. Nordhauser, Natalie K. Craik, Kenneth R. Diller. Quantitative Evaluation of the Thermal Heterogeneity on the Surface of Cryotherapy Cooling Pads. Journal of Biomechanical Engineering. 2014; 136 (7):074503-0745037.
Chicago/Turabian StyleSepideh Khoshnevis; Jennifer E. Nordhauser; Natalie K. Craik; Kenneth R. Diller. 2014. "Quantitative Evaluation of the Thermal Heterogeneity on the Surface of Cryotherapy Cooling Pads." Journal of Biomechanical Engineering 136, no. 7: 074503-0745037.
Localized cooling is widely used in treating soft tissue injuries by modulating swelling, pain, and inflammation. One of the primary outcomes of localized cooling is vasoconstriction within the underlying skin. It is thought that in some instances, cryotherapy may be causative of tissue necrosis and neuropathy via cold-induced ischaemia leading to nonfreezing cold injury (NFCI). The purpose of this study is to quantify the magnitude and persistence of vasoconstriction associated with cryotherapy. Data are presented from testing with four different FDA approved cryotherapy devices. Blood perfusion and skin temperature were measured at multiple anatomical sites during baseline, active cooling, and passive rewarming periods. Local cutaneous blood perfusion was depressed in response to cooling the skin surface with all devices, including the DonJoy (DJO, p = 2.6 × 10−8), Polar Care 300 (PC300, p = 1.1 × 10−3), Polar Care 500 Lite (PC500L, p = 0.010), and DeRoyal T505 (DR505, p = 0.016). During the rewarming period, parasitic heat gain from the underlying tissues and the environment resulted in increased temperatures of the skin and pad for all devices, but blood perfusion did not change significantly, DJO (n.s.), PC300 (n.s.), PC500L (n.s.), and DR505 (n.s.). The results demonstrate that cryotherapy can create a deep state of vasoconstriction in the local area of treatment. In the absence of independent stimulation, the condition of reduced blood flow persists long after cooling is stopped and local temperatures have rewarmed towards the normal range, indicating that the maintenance of vasoconstriction is not directly dependent on the continuing existence of a cold state. The depressed blood flow may dispose tissue to NFCI.
Sepideh Khoshnevis; Natalie K. Craik; Kenneth R. Diller. Cold-induced vasoconstriction may persist long after cooling ends: an evaluation of multiple cryotherapy units. Knee Surgery, Sports Traumatology, Arthroscopy 2014, 23, 2475 -2483.
AMA StyleSepideh Khoshnevis, Natalie K. Craik, Kenneth R. Diller. Cold-induced vasoconstriction may persist long after cooling ends: an evaluation of multiple cryotherapy units. Knee Surgery, Sports Traumatology, Arthroscopy. 2014; 23 (9):2475-2483.
Chicago/Turabian StyleSepideh Khoshnevis; Natalie K. Craik; Kenneth R. Diller. 2014. "Cold-induced vasoconstriction may persist long after cooling ends: an evaluation of multiple cryotherapy units." Knee Surgery, Sports Traumatology, Arthroscopy 23, no. 9: 2475-2483.
Cryotherapy has been used in the treatment of soft tissue trauma and other ailments since the time of Hippocrates. Currently it is commonly applied in conjunction with surgical procedures and by athletic trainers and physical therapists to control pain, swelling, bleeding, and inflammation. Localized cooling also results in slowing of the nerve conduction velocity and reduced muscle spasm and secondary hypoxic injury1,2. Cooling is commonly used for soft tissue injuries in combination with rest, compression and elevation to minimize inflammation.
Sepideh Khoshnevis; Kenneth R. Diller. Cryosurgery Causes Profound and Persistent Ischemia. ASME 2012 Summer Bioengineering Conference, Parts A and B 2012, 631 -632.
AMA StyleSepideh Khoshnevis, Kenneth R. Diller. Cryosurgery Causes Profound and Persistent Ischemia. ASME 2012 Summer Bioengineering Conference, Parts A and B. 2012; ():631-632.
Chicago/Turabian StyleSepideh Khoshnevis; Kenneth R. Diller. 2012. "Cryosurgery Causes Profound and Persistent Ischemia." ASME 2012 Summer Bioengineering Conference, Parts A and B , no. : 631-632.
Localized cooling is commonly used after orthopedic surgery and in sports medicine to reduce bleeding, inflammation, metabolism, muscle spasm, pain, and swelling following musculoskeletal trauma and injury. The therapeutic application of cold therapy has a long history dating from the time of Hippocrates and has been widely documented in the literature1–3. Nonetheless, there remains to the present time considerable controversy over the appropriate protocol for application of cryotherapy. One extreme camp advocates continuous use of cryotherapy to a treatment site with no break in cooling for days or even weeks4–5, whereas other practitioners recommend a maximum application duration of 20 to 30 minutes followed by a cessation period of about 2 hours6–7. Although continuous cooling appears to be tolerated by many patients, there has been a large number of reported incidences in which continuous application of cryotherapy device led directly to extensive tissue necrosis and/or nerve injury in the treatment area, sometimes with dire medical consequences6,8.
Sepideh Khoshnevis; Daniel W. Hensley; Kenneth R. Diller. Measurement and Analysis of Cutaneous Perfusion Depression During Cryotherapy. ASME 2011 Summer Bioengineering Conference, Parts A and B 2011, 115 -116.
AMA StyleSepideh Khoshnevis, Daniel W. Hensley, Kenneth R. Diller. Measurement and Analysis of Cutaneous Perfusion Depression During Cryotherapy. ASME 2011 Summer Bioengineering Conference, Parts A and B. 2011; ():115-116.
Chicago/Turabian StyleSepideh Khoshnevis; Daniel W. Hensley; Kenneth R. Diller. 2011. "Measurement and Analysis of Cutaneous Perfusion Depression During Cryotherapy." ASME 2011 Summer Bioengineering Conference, Parts A and B , no. : 115-116.
The goal of this study was to evaluate post-thermal stress cell survival in canine prostatic epithelial and stromal cells. Epithelial and stromal cells isolated from canine prostate were exposed to thermal stress using a water bath. Post-thermal stress cell viability was measured by flow cytometry and analyzed using FlowJo software. An ongoing analysis also measures Heat Shock Protein expression for the same stress protocols.
Sepideh Khoshnevis; Kenneth R. Diller. Response of Normal Canine Prostate Tissue to Thermal Therapy. ASME 2008 Summer Bioengineering Conference, Parts A and B 2008, 471 -472.
AMA StyleSepideh Khoshnevis, Kenneth R. Diller. Response of Normal Canine Prostate Tissue to Thermal Therapy. ASME 2008 Summer Bioengineering Conference, Parts A and B. 2008; ():471-472.
Chicago/Turabian StyleSepideh Khoshnevis; Kenneth R. Diller. 2008. "Response of Normal Canine Prostate Tissue to Thermal Therapy." ASME 2008 Summer Bioengineering Conference, Parts A and B , no. : 471-472.