Proceedings of the 8th ACM International Conference on Bioinformatics, Computational Biology,and Health Informatics, 2017
Diabetes afflicts an estimated over 400 million people worldwide. People with diabetes are at the... more Diabetes afflicts an estimated over 400 million people worldwide. People with diabetes are at the risk of a wide range of devastating complications including diabetic peripheral neuropathy, which is commonly referred to as the "diabetic foot" and most often affects the lower extremities (i.e., leg and foot) and can lead to amputations. In this paper, we present a computer aided diagnostic system for diabetic foot. At the core of our system is an improved thermoregulation model that characterizes the thermal recovery process of the extremities of the body (e.g., foot) after a cold stress. The model consists of a series of differential equations which is developed based on physiological characterizations and yet also exhibits analytical solutions. The model has been shown to be accurate and robust. Based on the new thermal regulation model, we have developed a 2D Bayesian classifier. We have applied the classifier to a cohort of 49 subjects (35 with no diabetic peripheral ne...
Beige adipocytes are present in white adipose tissue (WAT) and have thermogenic capacity to orche... more Beige adipocytes are present in white adipose tissue (WAT) and have thermogenic capacity to orchestrate substantial energy metabolism and counteract obesity. However, adipocyte-derived signals that act on progenitor cells to control beige adipogenesis remain poorly defined. Here, we show that adipose-specific depletion of Raptor, a key component of mTORC1, promoted beige adipogenesis through prostaglandins (PGs) synthesized by cyclooxygenase-2 (COX-2). Moreover, Raptor-deficient mice were resistant to diet-induced obesity and COX-2 downregulation. Mechanistically, mTORC1 suppressed COX-2 by phosphorylation of CREB-regulated transcription coactivator 2 (CRTC2) and subsequent dissociation of CREB to cox-2 promoter in adipocytes. PG treatment stimulated PKA and promoted differentiation of progenitor cells to beige adipocytes in culture. Ultimately, we show that pharmacological inhibition or suppression of COX-2 attenuated mTORC1 inhibition-induced thermogenic gene expression in inguina...
Recently, NIH has funded a center for autophagy research named the Autophagy, Inflammation, and M... more Recently, NIH has funded a center for autophagy research named the Autophagy, Inflammation, and Metabolism (AIM) Center of Biomedical Research Excellence, located at the University of New Mexico Health Science Center (UNM HSC), with aspirations to promote autophagy research locally, nationally, and internationally. The center has 3 major missions: (i) to support junior faculty in their endeavors to develop investigations in this area and obtain independent funding; (ii) to develop and provide technological platforms to advance autophagy research with emphasis on cellular approaches for high quality reproducible research; and (iii) to foster international collaborations through the formation of an International Council of Affiliate Members and through hosting national and international workshops and symposia. Scientifically, the AIM center is focused on autophagy and its intersections with other processes, with emphasis on both fundamental discoveries and applied translational research.
Background: Diabetes risk is extremely high for Latinos from low-income households. Health guidel... more Background: Diabetes risk is extremely high for Latinos from low-income households. Health guidelines recommend that individuals learn strategies to self-manage their diabetes, but getting people to adopt required lifestyle changes is challenging and many people are not able to prevent their pre-diabetes from escalating or effectively control their diabetes. Systematic reviews show that culturally competent self-management programs can significantly improve diabetes outcomes and different models for culturally competent programming have been developed. Methods: This patient-engaged study will compare the effectiveness of two distinct evidence-based models for culturally competent diabetes health promotion at two sites that serve a large Latino patient population from lowincome households: 1) The Diabetes Self-Management Support Empowerment Model, an educational session approach, and 2) The Chronic Care Model, a holistic community-based program. Data collection will involve interviews, focus groups, surveys and assessments of each program; and testing of patient participants for A1c, depression, Body Mass Index (BMI), and chronic stress with hair cortisol levels. We will recruit a total of 240 patient-social support pairs: Patients will be adults (men and women over the age of 18) who: 1.) Enter one of the two diabetes programs during the study; 2.) Self-identify as "Latino;" 3.) Are able to identify a social support person or key member of their social network who also agrees to participate with them; 4.) Are not pregnant (participants who become pregnant during the study will be excluded); and 5.) Have household income 250% of the Federal Poverty Level (FPL) or below. Social supports will be adults who are identified by the patient participants. PRIMARY OUTCOME: Improved capacity for diabetes selfmanagement measured through improvements in diabetes knowledge and diabetes-related patient activation. SECONDARY OUTCOME: Successful diabetes self-management as measured by improvements in A1c, depression scale scores, BMI, and circulating levels of cortisol to determine chronic stress. Discussion: Our hypothesis is that the program model that interfaces most synergistically with patients' culture and everyday life circumstances will have the best diabetes health outcomes. Trial registration: This study was registered with ClinicalTrials.gov on December 16, 2016 (Registration #NCT03004664).
2015 IEEE 25th International Workshop on Machine Learning for Signal Processing (MLSP), 2015
Diabetic peripheral neuropathy (DPN) is a complication of diabetes that leads to foot ulceration ... more Diabetic peripheral neuropathy (DPN) is a complication of diabetes that leads to foot ulceration and amputations. Detection of DPN at an early stage is important for clinical management of the disease. This paper presents characterization of DPN subjects using an infrared imaging device and independent component analysis (ICA). Infrared video sequences are captured after cold provocation of the plantar foot. After the video frames are preprocessed and registered, ICA is performed. The objective of using ICA is to separate the temporal and spatial components that may represent thermo regulatory differences in response to a cold provocation between normal controls and patients with DPN. The independent components of control and DPN subjects are compared and tested for statistically significant differences to the temporal responses to cold stimulus. Our results show 3 independent components that differentiate controls and DPN patients with substantial significance.
The funders had no role in study mg/dl; and triglycerides decreased by 52.0 ± 71.0 mg/dl. All of ... more The funders had no role in study mg/dl; and triglycerides decreased by 52.0 ± 71.0 mg/dl. All of these changes were statistically significant (p<0.05). Conclusion This six month, CHR led and community-oriented educational intervention helps inform standards of practice for the management of diabetes, engages diabetic populations in their own care, and reduces health disparities for the underserved population of Zuni Indians.
Medical Imaging 2014: Computer-Aided Diagnosis, 2014
Diabetic peripheral neuropathy (DPN) refers to the nerve damage that can occur in diabetes patien... more Diabetic peripheral neuropathy (DPN) refers to the nerve damage that can occur in diabetes patients. It most often affects the extremities, such as the feet, and can lead to peripheral vascular disease, deformity, infection, ulceration, and even amputation. The key to managing diabetic foot is prevention and early detection. Unfortunately, current existing diagnostic techniques are mostly based on patient sensations and exhibit significant inter- and intra-observer differences. We have developed a computer aided diagnostic (CAD) system for diabetic peripheral neuropathy. The thermal response of the feet of diabetic patients following cold stimulus is captured using an infrared camera. The plantar foot in the images from a thermal video are segmented and registered for tracking points or specific regions. The temperature recovery of each point on the plantar foot is extracted using our bio-thermal model and analyzed. The regions that exhibit abnormal ability to recover are automatically identified to aid the physicians to recognize problematic areas. The key to our CAD system is the segmentation of infrared video. The main challenges for segmenting infrared video compared to normal digital video are (1) as the foot warms up, it also warms up the surrounding, creating an ever changing contrast; and (2) there may be significant motion during imaging. To overcome this, a hybrid segmentation algorithm was developed based on a number of techniques such as continuous max-flow, model based segmentation, shape preservation, convex hull, and temperature normalization. Verifications of the automatic segmentation and registration using manual segmentation and markers show good agreement.
Advanced Biomedical and Clinical Diagnostic Systems X, 2012
The purpose of this research is to quantify functional signals in the microvascular circulation o... more The purpose of this research is to quantify functional signals in the microvascular circulation of the plantar. Our device is based on thermal and spectral technologies that can be easily adopted in clinical and tele-screening settings. Eightytwo thousand amputations are performed annually on diabetics in the US. The cost of foot disorder diagnosis and management are estimated at $10.9 billion dollars annually. Our experiments on normal controls and diabetics assess the temperature recovery time characteristics due to cold provocation to the bottom of the foot (plantar). A difference in the nature of the recovery time between normal controls and diabetics was observed.
2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012
The goal of this paper is to present a computer-based system for analyzing thermal images in the ... more The goal of this paper is to present a computer-based system for analyzing thermal images in the detection of preclinical stages of peripheral neuropathy (PN) or diabetic foot. Today, vibration perception threshold (VPT) and sensory tests with a monofilament are used as simple, noninvasive methods for identifying patients who have lost sensation in their feet. These tests are qualitative and are ineffective in stratifying risk for PN in a diabetic patient. In our system a cold stimulus applied to the foot causes a thermoregulatory and corresponding microcirculation response of the foot. A thermal video monitors the recovery of the microcirculation in the foot plantar. Thermal videos for 8 age-matched subjects were analyzed. Six sites were tracked and an average thermal emittance calculated. Characteristics of the recovery curve were extracted using coefficients from an exponential curve fitting process and compared among subjects. The magnitude of the recovery was significantly different for the two classes of subjects. Our system shows evidence of differences between both groups, which could lead to a quantitative test to screen and diagnose peripheral neuropathy.
Proceedings of the International Conference on Bioinformatics, Computational Biology and Biomedical Informatics - BCB'13, 2007
Diabetes afflicts an estimated 171 million people worldwide. Diabetic patients are at risk of a w... more Diabetes afflicts an estimated 171 million people worldwide. Diabetic patients are at risk of a wide range of complications including peripheral neuropathy (or diabetic foot). The condition if left untreated will lead to ulcers and eventually lower extremity amputation. Current existing diagnostic techniques for peripheral neuropathy are mostly qualitative procedures based on patient sensations and exhibit significant inter- and intra-observer differences, and an economical quantitative diagnostic technique is still lacking. A system for quantitative early detection of diabetic peripheral neuropathy has been developed based the thermal response of the feet of diabetic patients following cold stimulus. This paper describes the details of the new system, which includes the following key components: (1) A new protocol of using thermal imaging as functional imaging to measure thermal response. (2) Segmentation and tracking of regions of interest (ROIs) for thermal videos. (3) A novel bio-heat transfer model based on thermoregulation. We also report our preliminary patient studies based on two classifiers, which gave strong evidence that the system can used for early quantitative detection of peripheral neuropathy for diabetics.
2014 IEEE 27th International Symposium on Computer-Based Medical Systems, 2014
We present a low-cost medical embedded system for detecting diabetic peripheral neuropathy (DPN).... more We present a low-cost medical embedded system for detecting diabetic peripheral neuropathy (DPN). More specifically, we use low-cost infrared sensors to capture in a noncontact fashion the thermal response of the feet following cold stimulation. The rate of thermal regulation is then calculated based on temperature recovery and used to quantify the degree of the foot sensation. This device and methodology enables early detection of risk for DPN for in-home use or at family care clinics where fancy, expensive tests cannot be conducted.
Medicine &amp Science in Sports &amp Exercise, 1997
The purpose of this investigation was to determine the effects of transdermal estradiol (E2) repl... more The purpose of this investigation was to determine the effects of transdermal estradiol (E2) replacement on substrate utilization during exercise. Amenorrheic females (N = 6) performed three exercise trials following 72 h of placebo (C 72) and 72 and 144 h of medicated transdermal estradiol (E2) treatment (E2 72 and E2 144). Exercise involved 90 min of treadmill running at 65% VO2max followed by timed exercise to exhaustion at 85% VO2max. Resting blood samples were obtained for glucose, insulin, free fatty acids (FFA), and E2. Exercise blood samples were obtained for E2, lactate, epinephrine, and norepinephrine. Rates of appearance and disposal were calculated for glucose and glycerol using a primed, continuous infusion of [6,6-2H] glucose and [2H5] glycerol. Medicated transdermal placement increased E2 significantly at rest, before exercise (35.03 +/- 12.3, 69.5 +/- 20.1, and 73.1 +/- 31.6 pg.mL-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). Resting FFA increased significantly following E2 treatment (0.28 +/- 0.16, 0.41 +/- 0.27, and 0.40 +/- 0.21 mmol.L-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). Glucose Ra was significantly decreased during exercise as a result of E2 replacement (21.9 +/- 7.7, 18.9 +/- 6.2, and 18.9 +/- 5.6 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). Average glucose Rd also decreased during exercise as a result of E2 replacement (21.3 +/- 7.8, 18.5 +/- 6.4, and 18.6 +/- 5.8 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). However, the estimated relative contribution of plasma glucose and muscle glycogen to total carbohydrate oxidation was similar among the trials. Epinephrine values were significantly lower late in exercise during the E2 72 and E2 144 trials, compared with the C 72 trial (P &amp;amp;lt; 0.05). These results indicate that elevated E2 levels can alter glucose metabolism at rest and during moderate intensity exercise as a result of decreased gluconeogenesis, epinephrine secretion, and/or glucose transport.
OBJECTIVE To explore the hypothesis that CD36, a scavenger receptor and fatty acid translocase, i... more OBJECTIVE To explore the hypothesis that CD36, a scavenger receptor and fatty acid translocase, is upregulated in peripheral blood mononuclear cells (PBMCs) among patients with type 2 diabetes and is a biomarker of PBMC activation and inflammation. RESEARCH DESIGN AND METHODS We used a cross-sectional observational design to study a multi-racial/ethnic population sample consisting of Caucasians, Hispanics, and Native Americans with type 2 diabetes (n = 33) and nondiabetic control subjects (n = 27). PBMC CD36 mRNA/protein and plasma high sensitivity (hs) C-reactive protein (hsCRP), hs–interleukin-6 (hsIL-6), and adiponectin were measured. RESULTS Unadjusted PBMC CD36 mRNA and protein were 1.56- and 1.63-fold higher, respectively, among type 2 diabetic subjects versus control subjects. PBMC CD36 protein was directly associated with CD36 mRNA, plasma hsCRP, and hsIL-6 and inversely associated with plasma adiponectin in both groups. CONCLUSIONS Increased CD36 expression is a biomarker o...
Background: The masked continuous glucose monitoring system (Masked-CGMS) differs from standard C... more Background: The masked continuous glucose monitoring system (Masked-CGMS) differs from standard CGMSs in three ways: (1) there is no feedback to the user so that no immediate regimen changes can be made; (2) it can only be worn for up to 5 days; and (3) there are no alarms to warn of hyperglycemia or hypoglycemia. Since 2008 masked-CGMS has become popular for identifying reasons that a patient's hemoglobin A1C does not correlate closely with his or her capillary blood glucose measurements. To date only one study addressing the clinical utility of Masked-CGMS for improving A1C in diabetes has been published. No studies are available specifically examining the variability and correlation of Masked-CGMS and A1C. Subjects and Methods: We performed 156 Masked-CGMS studies (40 patients studied sequentially a maximum of four times each) in type 1 diabetes patients. We then analyzed the resulting interstitial glucose levels obtained from the Masked-CGMS compared with an A1C measurement performed within 1 week of the Masked-CGMS study. Results: There was a very low correlation between the A1C and the Masked-CGMS-derived mean interstitial glucose level. This statistic did not provide sufficiently predictive information to be clinically useful for changing an individual patient's intensive insulin therapy regimen. Conclusions: Our data demonstrate that a very weak correlation exists between 5 days of masked CGMS and a concurrently measured A1C level. For the individual type 1 diabetes patient, this relationship would unlikely to be clinically useful in altering the individual's treatment regimen.
The masked continuous glucose monitoring system (Masked-CGMS) differs from standard CGMSs in thre... more The masked continuous glucose monitoring system (Masked-CGMS) differs from standard CGMSs in three ways: (1) there is no feedback to the user so that no immediate regimen changes can be made; (2) it can only be worn for up to 5 days; and (3) there are no alarms to warn of hyperglycemia or hypoglycemia. Since 2008 masked-CGMS has become popular for identifying reasons that a patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s hemoglobin A1C does not correlate closely with his or her capillary blood glucose measurements. To date only one study addressing the clinical utility of Masked-CGMS for improving A1C in diabetes has been published. No studies are available specifically examining the variability and correlation of Masked-CGMS and A1C. We performed 156 Masked-CGMS studies (40 patients studied sequentially a maximum of four times each) in type 1 diabetes patients. We then analyzed the resulting interstitial glucose levels obtained from the Masked-CGMS compared with an A1C measurement performed within 1 week of the Masked-CGMS study. There was a very low correlation between the A1C and the Masked-CGMS-derived mean interstitial glucose level. This statistic did not provide sufficiently predictive information to be clinically useful for changing an individual patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s intensive insulin therapy regimen. Our data demonstrate that a very weak correlation exists between 5 days of masked CGMS and a concurrently measured A1C level. For the individual type 1 diabetes patient, this relationship would unlikely to be clinically useful in altering the individual&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s treatment regimen.
Proceedings of the 8th ACM International Conference on Bioinformatics, Computational Biology,and Health Informatics, 2017
Diabetes afflicts an estimated over 400 million people worldwide. People with diabetes are at the... more Diabetes afflicts an estimated over 400 million people worldwide. People with diabetes are at the risk of a wide range of devastating complications including diabetic peripheral neuropathy, which is commonly referred to as the "diabetic foot" and most often affects the lower extremities (i.e., leg and foot) and can lead to amputations. In this paper, we present a computer aided diagnostic system for diabetic foot. At the core of our system is an improved thermoregulation model that characterizes the thermal recovery process of the extremities of the body (e.g., foot) after a cold stress. The model consists of a series of differential equations which is developed based on physiological characterizations and yet also exhibits analytical solutions. The model has been shown to be accurate and robust. Based on the new thermal regulation model, we have developed a 2D Bayesian classifier. We have applied the classifier to a cohort of 49 subjects (35 with no diabetic peripheral ne...
Beige adipocytes are present in white adipose tissue (WAT) and have thermogenic capacity to orche... more Beige adipocytes are present in white adipose tissue (WAT) and have thermogenic capacity to orchestrate substantial energy metabolism and counteract obesity. However, adipocyte-derived signals that act on progenitor cells to control beige adipogenesis remain poorly defined. Here, we show that adipose-specific depletion of Raptor, a key component of mTORC1, promoted beige adipogenesis through prostaglandins (PGs) synthesized by cyclooxygenase-2 (COX-2). Moreover, Raptor-deficient mice were resistant to diet-induced obesity and COX-2 downregulation. Mechanistically, mTORC1 suppressed COX-2 by phosphorylation of CREB-regulated transcription coactivator 2 (CRTC2) and subsequent dissociation of CREB to cox-2 promoter in adipocytes. PG treatment stimulated PKA and promoted differentiation of progenitor cells to beige adipocytes in culture. Ultimately, we show that pharmacological inhibition or suppression of COX-2 attenuated mTORC1 inhibition-induced thermogenic gene expression in inguina...
Recently, NIH has funded a center for autophagy research named the Autophagy, Inflammation, and M... more Recently, NIH has funded a center for autophagy research named the Autophagy, Inflammation, and Metabolism (AIM) Center of Biomedical Research Excellence, located at the University of New Mexico Health Science Center (UNM HSC), with aspirations to promote autophagy research locally, nationally, and internationally. The center has 3 major missions: (i) to support junior faculty in their endeavors to develop investigations in this area and obtain independent funding; (ii) to develop and provide technological platforms to advance autophagy research with emphasis on cellular approaches for high quality reproducible research; and (iii) to foster international collaborations through the formation of an International Council of Affiliate Members and through hosting national and international workshops and symposia. Scientifically, the AIM center is focused on autophagy and its intersections with other processes, with emphasis on both fundamental discoveries and applied translational research.
Background: Diabetes risk is extremely high for Latinos from low-income households. Health guidel... more Background: Diabetes risk is extremely high for Latinos from low-income households. Health guidelines recommend that individuals learn strategies to self-manage their diabetes, but getting people to adopt required lifestyle changes is challenging and many people are not able to prevent their pre-diabetes from escalating or effectively control their diabetes. Systematic reviews show that culturally competent self-management programs can significantly improve diabetes outcomes and different models for culturally competent programming have been developed. Methods: This patient-engaged study will compare the effectiveness of two distinct evidence-based models for culturally competent diabetes health promotion at two sites that serve a large Latino patient population from lowincome households: 1) The Diabetes Self-Management Support Empowerment Model, an educational session approach, and 2) The Chronic Care Model, a holistic community-based program. Data collection will involve interviews, focus groups, surveys and assessments of each program; and testing of patient participants for A1c, depression, Body Mass Index (BMI), and chronic stress with hair cortisol levels. We will recruit a total of 240 patient-social support pairs: Patients will be adults (men and women over the age of 18) who: 1.) Enter one of the two diabetes programs during the study; 2.) Self-identify as "Latino;" 3.) Are able to identify a social support person or key member of their social network who also agrees to participate with them; 4.) Are not pregnant (participants who become pregnant during the study will be excluded); and 5.) Have household income 250% of the Federal Poverty Level (FPL) or below. Social supports will be adults who are identified by the patient participants. PRIMARY OUTCOME: Improved capacity for diabetes selfmanagement measured through improvements in diabetes knowledge and diabetes-related patient activation. SECONDARY OUTCOME: Successful diabetes self-management as measured by improvements in A1c, depression scale scores, BMI, and circulating levels of cortisol to determine chronic stress. Discussion: Our hypothesis is that the program model that interfaces most synergistically with patients' culture and everyday life circumstances will have the best diabetes health outcomes. Trial registration: This study was registered with ClinicalTrials.gov on December 16, 2016 (Registration #NCT03004664).
2015 IEEE 25th International Workshop on Machine Learning for Signal Processing (MLSP), 2015
Diabetic peripheral neuropathy (DPN) is a complication of diabetes that leads to foot ulceration ... more Diabetic peripheral neuropathy (DPN) is a complication of diabetes that leads to foot ulceration and amputations. Detection of DPN at an early stage is important for clinical management of the disease. This paper presents characterization of DPN subjects using an infrared imaging device and independent component analysis (ICA). Infrared video sequences are captured after cold provocation of the plantar foot. After the video frames are preprocessed and registered, ICA is performed. The objective of using ICA is to separate the temporal and spatial components that may represent thermo regulatory differences in response to a cold provocation between normal controls and patients with DPN. The independent components of control and DPN subjects are compared and tested for statistically significant differences to the temporal responses to cold stimulus. Our results show 3 independent components that differentiate controls and DPN patients with substantial significance.
The funders had no role in study mg/dl; and triglycerides decreased by 52.0 ± 71.0 mg/dl. All of ... more The funders had no role in study mg/dl; and triglycerides decreased by 52.0 ± 71.0 mg/dl. All of these changes were statistically significant (p<0.05). Conclusion This six month, CHR led and community-oriented educational intervention helps inform standards of practice for the management of diabetes, engages diabetic populations in their own care, and reduces health disparities for the underserved population of Zuni Indians.
Medical Imaging 2014: Computer-Aided Diagnosis, 2014
Diabetic peripheral neuropathy (DPN) refers to the nerve damage that can occur in diabetes patien... more Diabetic peripheral neuropathy (DPN) refers to the nerve damage that can occur in diabetes patients. It most often affects the extremities, such as the feet, and can lead to peripheral vascular disease, deformity, infection, ulceration, and even amputation. The key to managing diabetic foot is prevention and early detection. Unfortunately, current existing diagnostic techniques are mostly based on patient sensations and exhibit significant inter- and intra-observer differences. We have developed a computer aided diagnostic (CAD) system for diabetic peripheral neuropathy. The thermal response of the feet of diabetic patients following cold stimulus is captured using an infrared camera. The plantar foot in the images from a thermal video are segmented and registered for tracking points or specific regions. The temperature recovery of each point on the plantar foot is extracted using our bio-thermal model and analyzed. The regions that exhibit abnormal ability to recover are automatically identified to aid the physicians to recognize problematic areas. The key to our CAD system is the segmentation of infrared video. The main challenges for segmenting infrared video compared to normal digital video are (1) as the foot warms up, it also warms up the surrounding, creating an ever changing contrast; and (2) there may be significant motion during imaging. To overcome this, a hybrid segmentation algorithm was developed based on a number of techniques such as continuous max-flow, model based segmentation, shape preservation, convex hull, and temperature normalization. Verifications of the automatic segmentation and registration using manual segmentation and markers show good agreement.
Advanced Biomedical and Clinical Diagnostic Systems X, 2012
The purpose of this research is to quantify functional signals in the microvascular circulation o... more The purpose of this research is to quantify functional signals in the microvascular circulation of the plantar. Our device is based on thermal and spectral technologies that can be easily adopted in clinical and tele-screening settings. Eightytwo thousand amputations are performed annually on diabetics in the US. The cost of foot disorder diagnosis and management are estimated at $10.9 billion dollars annually. Our experiments on normal controls and diabetics assess the temperature recovery time characteristics due to cold provocation to the bottom of the foot (plantar). A difference in the nature of the recovery time between normal controls and diabetics was observed.
2012 Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2012
The goal of this paper is to present a computer-based system for analyzing thermal images in the ... more The goal of this paper is to present a computer-based system for analyzing thermal images in the detection of preclinical stages of peripheral neuropathy (PN) or diabetic foot. Today, vibration perception threshold (VPT) and sensory tests with a monofilament are used as simple, noninvasive methods for identifying patients who have lost sensation in their feet. These tests are qualitative and are ineffective in stratifying risk for PN in a diabetic patient. In our system a cold stimulus applied to the foot causes a thermoregulatory and corresponding microcirculation response of the foot. A thermal video monitors the recovery of the microcirculation in the foot plantar. Thermal videos for 8 age-matched subjects were analyzed. Six sites were tracked and an average thermal emittance calculated. Characteristics of the recovery curve were extracted using coefficients from an exponential curve fitting process and compared among subjects. The magnitude of the recovery was significantly different for the two classes of subjects. Our system shows evidence of differences between both groups, which could lead to a quantitative test to screen and diagnose peripheral neuropathy.
Proceedings of the International Conference on Bioinformatics, Computational Biology and Biomedical Informatics - BCB'13, 2007
Diabetes afflicts an estimated 171 million people worldwide. Diabetic patients are at risk of a w... more Diabetes afflicts an estimated 171 million people worldwide. Diabetic patients are at risk of a wide range of complications including peripheral neuropathy (or diabetic foot). The condition if left untreated will lead to ulcers and eventually lower extremity amputation. Current existing diagnostic techniques for peripheral neuropathy are mostly qualitative procedures based on patient sensations and exhibit significant inter- and intra-observer differences, and an economical quantitative diagnostic technique is still lacking. A system for quantitative early detection of diabetic peripheral neuropathy has been developed based the thermal response of the feet of diabetic patients following cold stimulus. This paper describes the details of the new system, which includes the following key components: (1) A new protocol of using thermal imaging as functional imaging to measure thermal response. (2) Segmentation and tracking of regions of interest (ROIs) for thermal videos. (3) A novel bio-heat transfer model based on thermoregulation. We also report our preliminary patient studies based on two classifiers, which gave strong evidence that the system can used for early quantitative detection of peripheral neuropathy for diabetics.
2014 IEEE 27th International Symposium on Computer-Based Medical Systems, 2014
We present a low-cost medical embedded system for detecting diabetic peripheral neuropathy (DPN).... more We present a low-cost medical embedded system for detecting diabetic peripheral neuropathy (DPN). More specifically, we use low-cost infrared sensors to capture in a noncontact fashion the thermal response of the feet following cold stimulation. The rate of thermal regulation is then calculated based on temperature recovery and used to quantify the degree of the foot sensation. This device and methodology enables early detection of risk for DPN for in-home use or at family care clinics where fancy, expensive tests cannot be conducted.
Medicine &amp Science in Sports &amp Exercise, 1997
The purpose of this investigation was to determine the effects of transdermal estradiol (E2) repl... more The purpose of this investigation was to determine the effects of transdermal estradiol (E2) replacement on substrate utilization during exercise. Amenorrheic females (N = 6) performed three exercise trials following 72 h of placebo (C 72) and 72 and 144 h of medicated transdermal estradiol (E2) treatment (E2 72 and E2 144). Exercise involved 90 min of treadmill running at 65% VO2max followed by timed exercise to exhaustion at 85% VO2max. Resting blood samples were obtained for glucose, insulin, free fatty acids (FFA), and E2. Exercise blood samples were obtained for E2, lactate, epinephrine, and norepinephrine. Rates of appearance and disposal were calculated for glucose and glycerol using a primed, continuous infusion of [6,6-2H] glucose and [2H5] glycerol. Medicated transdermal placement increased E2 significantly at rest, before exercise (35.03 +/- 12.3, 69.5 +/- 20.1, and 73.1 +/- 31.6 pg.mL-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). Resting FFA increased significantly following E2 treatment (0.28 +/- 0.16, 0.41 +/- 0.27, and 0.40 +/- 0.21 mmol.L-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). Glucose Ra was significantly decreased during exercise as a result of E2 replacement (21.9 +/- 7.7, 18.9 +/- 6.2, and 18.9 +/- 5.6 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). Average glucose Rd also decreased during exercise as a result of E2 replacement (21.3 +/- 7.8, 18.5 +/- 6.4, and 18.6 +/- 5.8 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P &amp;amp;lt; 0.05). However, the estimated relative contribution of plasma glucose and muscle glycogen to total carbohydrate oxidation was similar among the trials. Epinephrine values were significantly lower late in exercise during the E2 72 and E2 144 trials, compared with the C 72 trial (P &amp;amp;lt; 0.05). These results indicate that elevated E2 levels can alter glucose metabolism at rest and during moderate intensity exercise as a result of decreased gluconeogenesis, epinephrine secretion, and/or glucose transport.
OBJECTIVE To explore the hypothesis that CD36, a scavenger receptor and fatty acid translocase, i... more OBJECTIVE To explore the hypothesis that CD36, a scavenger receptor and fatty acid translocase, is upregulated in peripheral blood mononuclear cells (PBMCs) among patients with type 2 diabetes and is a biomarker of PBMC activation and inflammation. RESEARCH DESIGN AND METHODS We used a cross-sectional observational design to study a multi-racial/ethnic population sample consisting of Caucasians, Hispanics, and Native Americans with type 2 diabetes (n = 33) and nondiabetic control subjects (n = 27). PBMC CD36 mRNA/protein and plasma high sensitivity (hs) C-reactive protein (hsCRP), hs–interleukin-6 (hsIL-6), and adiponectin were measured. RESULTS Unadjusted PBMC CD36 mRNA and protein were 1.56- and 1.63-fold higher, respectively, among type 2 diabetic subjects versus control subjects. PBMC CD36 protein was directly associated with CD36 mRNA, plasma hsCRP, and hsIL-6 and inversely associated with plasma adiponectin in both groups. CONCLUSIONS Increased CD36 expression is a biomarker o...
Background: The masked continuous glucose monitoring system (Masked-CGMS) differs from standard C... more Background: The masked continuous glucose monitoring system (Masked-CGMS) differs from standard CGMSs in three ways: (1) there is no feedback to the user so that no immediate regimen changes can be made; (2) it can only be worn for up to 5 days; and (3) there are no alarms to warn of hyperglycemia or hypoglycemia. Since 2008 masked-CGMS has become popular for identifying reasons that a patient's hemoglobin A1C does not correlate closely with his or her capillary blood glucose measurements. To date only one study addressing the clinical utility of Masked-CGMS for improving A1C in diabetes has been published. No studies are available specifically examining the variability and correlation of Masked-CGMS and A1C. Subjects and Methods: We performed 156 Masked-CGMS studies (40 patients studied sequentially a maximum of four times each) in type 1 diabetes patients. We then analyzed the resulting interstitial glucose levels obtained from the Masked-CGMS compared with an A1C measurement performed within 1 week of the Masked-CGMS study. Results: There was a very low correlation between the A1C and the Masked-CGMS-derived mean interstitial glucose level. This statistic did not provide sufficiently predictive information to be clinically useful for changing an individual patient's intensive insulin therapy regimen. Conclusions: Our data demonstrate that a very weak correlation exists between 5 days of masked CGMS and a concurrently measured A1C level. For the individual type 1 diabetes patient, this relationship would unlikely to be clinically useful in altering the individual's treatment regimen.
The masked continuous glucose monitoring system (Masked-CGMS) differs from standard CGMSs in thre... more The masked continuous glucose monitoring system (Masked-CGMS) differs from standard CGMSs in three ways: (1) there is no feedback to the user so that no immediate regimen changes can be made; (2) it can only be worn for up to 5 days; and (3) there are no alarms to warn of hyperglycemia or hypoglycemia. Since 2008 masked-CGMS has become popular for identifying reasons that a patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s hemoglobin A1C does not correlate closely with his or her capillary blood glucose measurements. To date only one study addressing the clinical utility of Masked-CGMS for improving A1C in diabetes has been published. No studies are available specifically examining the variability and correlation of Masked-CGMS and A1C. We performed 156 Masked-CGMS studies (40 patients studied sequentially a maximum of four times each) in type 1 diabetes patients. We then analyzed the resulting interstitial glucose levels obtained from the Masked-CGMS compared with an A1C measurement performed within 1 week of the Masked-CGMS study. There was a very low correlation between the A1C and the Masked-CGMS-derived mean interstitial glucose level. This statistic did not provide sufficiently predictive information to be clinically useful for changing an individual patient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s intensive insulin therapy regimen. Our data demonstrate that a very weak correlation exists between 5 days of masked CGMS and a concurrently measured A1C level. For the individual type 1 diabetes patient, this relationship would unlikely to be clinically useful in altering the individual&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s treatment regimen.
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