Grant Kruger - Academia.edu (original) (raw)

Papers by Grant Kruger

Special Care in Dentistry, Sep 8, 2018

Dentists regularly employ a variety of self-report and sensory techniques to aid in the diagnosis... more Dentists regularly employ a variety of self-report and sensory techniques to aid in the diagnosis and treatment of tooth-related disease. Many of these techniques leverage principles borrowed from psychophysics, the quantitative measurement of the relationship between stimuli and evoked sensations, which falls under the larger umbrella of quantitative sensory testing (QST). However, most clinicians fail to meet the bar for what could be considered quantitative sensory testing, and instead focus on qualitative and dichotomous "yes/no" aspects of sensory experience. With our current subjective measurements for pain assessments, diagnosis and treatment of dental pain in young children and individuals (any age) with severe cognitive impairment rely extensively on third-party observations. Consequently, the limitation of inadequate pain diagnosis can lead to poor pain management. In this review, it discusses mechanisms that underlie acute and chronic dental pain. It details the measurement of somatosensory responses and pulpal blood flow as objective measures of tooth health and pain. It proposes that bridging these varied methodologies will significantly improve diagnosis and treatment of orofacial pain and pathology. It concludes that improving the precision of sensory measurements could yield important improvements in diagnostic challenges in pulpal pathology for noncommunicative and cognitively impaired individuals. K E Y W O R D S cognitive impairment, dental pain, orafacial pain, quantitative sensory testing 1 INTRODUCTION Pain motivates individuals to seek dental care. 1 The perception of pain is a complex process that involves bidirectional communication between the central and peripheral nervous systems. It is now known that individuals vary widely in their pain sensitivity, and there often is a very poor relationship between the degree of peripheral damage/inflammation This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Computers in Biology and Medicine, 2019

Introduction: Atrial Fibrillation (AF) is the most common cardiac arrhythmia, presenting a signif... more Introduction: Atrial Fibrillation (AF) is the most common cardiac arrhythmia, presenting a significant independent risk factor for stroke and thromboembolism. With the emergence of m-Health devices, the importance of automatic detection of AF in an off-clinic setting is growing. This study demonstrates the performance of a bimodal classifier for distinguishing AF from sinus rhythm (SR) that could be used for automated detection of AF episodes. Methods: Surface recordings from a hand-held research device and standard electrocardiograms (ECG) were collected and analyzed from 68 subjects. An additional 48 subjects from the MIT-BIH Arrythmia Database were also analyzed. All ECGs were blindly reviewed by physicians independently of the bimodal algorithm analysis. The algorithm selects an artifact-free 6-s ECG segment out of a 20-s long recording and computes a spectral Frequency Dispersion Metric (FDM) and a temporal R-R interval variability (VRR) index. Results: Scatter plots of the VRR and FDM indices revealed two distinct clusters. The bimodal scattering of the indices revealed a linear classification boundary that could be employed to differentiate the SR from AF waveforms. The selected classification boundary was able to correctly differentiate all the subjects from both datasets into either SR or AF groups, except for 3 SR subjects from the MIT-BIH dataset. Conclusion: Our bimodal classification algorithm was demonstrated to successfully acquire, analyze and interpret ECGs for the presence of AF indicating its potential to support m-Health diagnosis, monitoring, and management of therapy in AF patients.

Journal of Clinical Monitoring and Computing, Sep 30, 2017

The American Society of Anesthesiologists Standards for Basic Monitoring recommends blood pressur... more The American Society of Anesthesiologists Standards for Basic Monitoring recommends blood pressure (BP) measurement every 5 min. Research has shown distractions or technical factors can cause prolonged measurement intervals exceeding 5 min. We investigated the relationship between prolonged non-invasive BP (NIBP) measurement interval and the incidence of hypotension, detected postinterval. Our secondary outcome was to determine independent predictors of these prolonged NIBP measurement intervals. Retrospective data were analyzed from 139,509 general anesthesia cases from our institution's Anesthesia Information Management System (AIMS). Absolute hypotension (AH) was defined a priori as a systolic BP < 80 mmHg and relative hypotension (RH) was defined as a 40% decrease in systolic BP from the preoperative baseline. Odds ratios (OR) with 95% confidence intervals and Pearson's Chi square Test reported the association of prolonged NIBP measurement intervals on hypotension detected post-NIBP measurement interval. Logistic regression models were developed to determine independent predictors of NIBP measurement intervals. The analysis revealed that NIBP measurement intervals greater than 6 and 10 min are associated with an approximately four times higher incidence of a patient transitioning into hypotension (AH/RH > 6 min OR 4.0 / 3.6; AH/RH > 10 min OR 4.3 / 3.9; p< 0.001). A key finding was that the "> 10-minute AH model" indicated that age 41-80, increased co-morbidity profile, obesity and turning (repositioning) of the operative room table were significant predictors of prolonged NIBP measurement intervals (p < 0.001). While we do not suggest NIBP measurement intervals cause hypotension, intervals greater than 6 and 10 min ✉ Grant H. Kruger,

PubMed, May 10, 2023

Impaired upper extremity (UE) function has limited activities of daily living in people with syst... more Impaired upper extremity (UE) function has limited activities of daily living in people with systemic sclerosis (SSc). Exergaming, a combination of gaming and exercises, could be a novel way to improve UE exercise engagement. The objective of this study was to examine the usability of exergaming and to investigate participant experiences after exergaming among people with SSc. Both quantitative and qualitative data were collected. Participants completed questionnaires regarding the usability of exergaming. Semi-structured interviews were conducted directly after exergaming. Descriptive statistics and thematic content analysis were performed. Twenty participants with SSc participated. Exergaming was highly acceptable with a good System Usability Scale score (M = 71.6 ± 9.9). Participants described exergaming as motivating with potential physical and nonphysical benefits. Although results were generally positive, participants expressed some barriers and temporary side effects of using exergaming and needs for improvement. This work stands to inform future exergaming interventions in people with SSc.

Circulation, Nov 10, 2015

Introduction: Home telemetry monitoring with accurate automated rhythm classification can have im... more Introduction: Home telemetry monitoring with accurate automated rhythm classification can have important clinical benefits in the timely diagnosis and appropriate management of patients with atrial fibrillation (AF). We clinically validated a novel personal e-Health device and algorithm developed to distinguish AF from sinus rhythm (SR). Methods: A handheld electrocardiogram (ECG) recording system (Maestro) and signal processing platform were developed. The Maestro provides an LCD interface that continuously shows an ECG, heart rate, and heart rhythm status. Twenty second ECG signals analogous to Lead I were acquired from 66 patients presenting to the arrhythmia clinic at the University of Michigan Hospital either in SR or AF. Electrograms were segmented into non-overlapping 6-second samples and one random segment per patient was selected for analysis by the Maestro system. Simultaneous 5 or 12 lead ECGs were obtained from these patients and 3 expert physicians blinded to the Maestro analysis identified the rhythm as SR or AF. The Maestro system applied several signal conditioning algorithms to each ECG sample. The dimensionless temporal R-R interval variability (VRR) index and spectral frequency dispersion metric (FDM) were computed. Results: The 2-dimensional scatter-gram of the samples demonstrated 2 distinct clusters of VRR and FDM for patients with SR and AF. The VRR index clusters for SR and AF patients were 0.018 ± 0.013 and 0.187 ± 0.073 (mean±std), respectively (p &lt; 0.001). The FDM clusters for SR and AF patients occurred at 10.5 ± 5.916 and 15.892 ± 3.337, respectively (p &lt; 0.001). We developed a Gaussian Mixed Model (GMM) classifier to distinguish between the AF and SR clusters. Only after the GMM classifier was obtained were the Maestro classifications compared to the physicians’ readings. The algorithm correctly categorized AF (N = 46) and SR (N = 20) for all Maestro segments analyzed with 100% specificity and sensitivity. Conclusion: The Maestro handheld telemetry unit utilizes a novel classification algorithm and was demonstrated to acquire and automatically analyze 6-second electrograms for rapid and accurate classification of patients in SR or AF in this initial clinical validation trial.

PLOS ONE, May 24, 2018

Analgesic trials frequently fail to demonstrate efficacy of drugs known to be efficacious. Poor p... more Analgesic trials frequently fail to demonstrate efficacy of drugs known to be efficacious. Poor pain reporting accuracy is a possible source for this low essay-sensitivity. We report the effects of Accurate-Pain-Reporting-Training (APRT) on the placebo response in a trial of Pregabalin for painful-diabetic-neuropathy. The study was a two-stage randomized, doubleblind trial: In Stage-1 (Training) subjects were randomized to APRT or No-Training. The APRT participants received feedback on the accuracy of their pain reports in response to mechanical stimuli, measured by R-square score. In Stage-2 (Evaluation) all subjects entered a placebo-controlled, cross-over trial. Primary (24-h average pain intensity) and secondary (current, 24-h worst, and 24-h walking pain intensity) outcome measures were reported. Fifty-one participants completed the study. APRT patients (n = 28) demonstrated significant (p = 0.036) increases in R-square scores. The APRT group demonstrated significantly (p = 0.018) lower placebo response (0.29 ± 1.21 vs. 1.48 ± 2.21, mean difference ± SD =-1.19±1.73). No relationships were found between the R-square scores and changes in pain intensity in the treatment arm. In summary, our training successfully increased pain reporting accuracy and resulted in a diminished placebo response. Theoretical and practical implications are discussed.

The Clinical Journal of Pain, Apr 7, 2020

ObjectivesQuantitative sensory testing (QST) may help predict treatment responses in individuals ... more ObjectivesQuantitative sensory testing (QST) may help predict treatment responses in individuals with chronic pain. Our objective was to determine if evoked pain sensitivity at baseline predicted preferential treatment responses to either emotional awareness and expression therapy (EAET) or cognitive behavioral therapy (CBT) in individuals with fibromyalgia.MethodsThis was a secondary analysis of a previous randomized clinical trial, in which individuals with fibromyalgia were randomized to EAET, CBT, or Education as a control intervention. Only females who completed baseline and post treatment assessments were analyzed (n = 196). The primary outcome was change in overall clinical pain severity from pre-treatment to post-treatment, and the primary predictor of interest was pressure pain tolerance at baseline.ResultsAmong patients with low pain tolerance at baseline (n = 154), both EAET and CBT led to small but significant improvements in clinical pain severity (CBT mean [95% CI] = 0.66 [0.24, 1.07]; EAET = 0.76 [0.34, 1.17]). Conversely, in patients with normal pain tolerance (n = 42), there was no significant improvement in clinical pain after CBT (0.13 [−0.88, 1.14]), a small improvement after FM Education (.81 [.14, 1.48]), but a much larger and statistically significant improvement after EAET (2.14 [1.23, 3.04]).DiscussionNormal levels of pressure pain tolerance at baseline predicted greater improvement in clinical pain severity following EAET than CBT. QST may provide insights about individual responses to psychologically-based therapies for individuals with chronic pain.

The Journal of Urology, Sep 1, 2021

INTRODUCTION AND OBJECTIVE:It has been hypothesized that some overactive bladder (OAB) patients m... more INTRODUCTION AND OBJECTIVE:It has been hypothesized that some overactive bladder (OAB) patients may have central sensitization and/or increased sensitivity to sensory stimuli (“sensory/afferent hyp...

Contemporary Clinical Trials, Aug 1, 2021

Background Persistent cancer-related fatigue is one of the most common and burdensome symptoms ex... more Background Persistent cancer-related fatigue is one of the most common and burdensome symptoms experienced by ovarian cancer survivors. Despite the high burden of fatigue in ovarian cancer survivors, there are few available treatments. Previous research has shown self-acupressure to be a safe method for improving persistent fatigue, sleep, and quality of life among fatigued breast cancer survivors, yet there are no studies examining self-acupressure for fatigue in ovarian cancer survivors. Methods A three group parallel, randomized controlled trial will be conducted to evaluate the efficacy of self-acupressure taught and delivered via a patient-designed, custom-built mobile app ("MeTime") and accompanying hand-held device ("AcuWand") to help guide correct pressure application. A sample of 165 ovarian cancer survivors, who have completed primary cancer treatment will be recruited from tumor registries in Michigan and Los Angeles. Participants will be mailed a tablet preloaded with the app and a device, and all visits will be conducted remotely. Participants will be randomized to 6-weeks of daily self-acupressure via the app and device, or a sham app and device, or no care group. Self-report measures will be completed at baseline, 6-weeks (post-intervention), 3-, and 6-months. Primary outcome is the Brief Fatigue Inventory; secondary outcomes are sleep, quality of life, and symptoms commonly associated with persistent fatigue. Discussion An app based self-acupressure treatment may be an easily-accessible and inexpensive treatment to reduce fatigue in ovarian cancer survivors. The results of the study will provide information on the possible benefits of app-based self-acupressure for fatigue in ovarian cancer survivors. Trial registration: This study is registered at ClinicalTrials.gov Identifier: NCT03763838, date registered on December 4, 2018.

Circulation, 2015

The University of Michigan Pathology Department generates roughly 2,500 glass slides every day. T... more The University of Michigan Pathology Department generates roughly 2,500 glass slides every day. The department uses the slides for analysis and diagnosis purposes. The information associated with these slides is very important for correct diagnosis. In the process of developing the slides, they are manually labeled and placed in their appropriate viewing tray. The process of labeling and placing is done in a repetitive and tedious manner for all 2,500 slides, as this can take two and a half hours to complete for two full time employees. It is estimated that 3 % of slides are mislabeled or misplaced during this part of the slide preparation progression. A system of this kind causes a bottle neck in the process of slide development, and it can lead to costly mistakes, thus a misdiagnosis of illnesses. This problem has been identified as a common occurrence in all of the eight thousand Pathology labs in the nation, so correction can add major benefit. There has been work in the field o...

Journal of Urology, 2021

The Journal of Pain, 2018

Recent advances in psychological science are revealing the powerful role of one's mindset in mode... more Recent advances in psychological science are revealing the powerful role of one's mindset in moderating, buffering, and in some cases eliminating the negative impact of stress on human health. In particular, stress mindset-the overarching belief that stress is either debilitating or enhancing for human health and performancehas been shown to significantly impact and buffer health outcomes. Yet, stress mindset has never been examined within the context of chronic pain. We present a preliminary investigation of the nature and role of stress mindset in children and young adults with chronic pain disorders. Forty-six patients with chronic pain (11-17 years, 83% female) and fourteen healthy controls (11-24 years, 79% female) completed a pediatric version of the Stress Mindset Measure (SMM), with higher scores indicating a stress-is-enhancing mindset. Additional measures assessed pain-specific distress (FOPQ-C), general distress (CDI-2; STAI-C), perceived levels of recent distress (PDS), and functional disability (FDI). Chronic pain patients were significantly more likely to believe that stress is detrimental and debilitating (M = 1.54, SD = .60) than healthy controls (M = 1.94, SD = .65; t(57) = −2.13, P < .05). Amongst patients, a stress-is-debilitating mindset was significantly associated with perceived levels of recent distress (r = −.88, P < .05), pain-specific distress (r = −.36, P < .05), and functional disability (r = −.42, P < .05). Associations with general distress were not significant (STAIC: r = −.43, P = ns, CDI-2: r = −.06, P = ns), suggesting that stress mindset is a unique construct that does not extensively overlap with general mental health in this population. This study presents preliminary support for stress mindset as a distinct and meaningful variable in children and young adults with chronic pain. Future studies could investigate the buffering effects of a stress-is-enhancing mindset on the course and impact of chronic pain disorders across the lifespan.

Volume 1: Processes, 2017

Friction stir forming utilizes a friction stirring action to soften and extrude a base material i... more Friction stir forming utilizes a friction stirring action to soften and extrude a base material into a cavity in a substrate material thereby forming a joint. In this research, Abaqus software was used to model the process in order to understand the key joint features of interest and provide direction for experimental optimization. A three dimensional, thermo-mechanical finite element model was developed and applied to simulate the process and obtain detailed stress and temperature distribution plots. Adaptive mesh and contact features were utilized for large deformation of the aluminum work material. It was found that the model accurately predicted the shape of the joint and flash extrusion during the process. The maximum temperature was found at the outer radius of the tool, but was much lower than temperatures in friction stir welding.

Journal of Urology, 2021

Purpose: The objective of this study was to investigate the presence of nonbladder sensory abnorm... more Purpose: The objective of this study was to investigate the presence of nonbladder sensory abnormalities in participants with overactive bladder syndrome (OAB). Materials and Methods: Symptoms of Lower Urinary Tract Dysfunction Research Network (LURN) study participants with OAB symptoms and controls were recruited from 6 U.S. tertiary referral centers. Quantitative sensory testing (QST) was performed to determine pressure pain sensitivity at the thumbnail bed and auditory sensitivity. Fixed and mixed effect multivariable linear regressions and Weibull models were used to compare QST responses between groups. Pearson correlations were used to assess the relationship between QST measures. Associations between QST and self-reported symptoms were explored with linear regression. Results: A total of 297 participants were analyzed (191 OAB, 106 controls; 76% white, 51% male). OAB cases were older than controls (57.4 vs 52.2 years, p=0.015). No significant differences in experimental thumbnail (nonbladder) pain or auditory sensitivity were detected between OAB cases and controls. Correlations between pressure and auditory derived metrics were weak to moderate overall for both groups, with some significantly stronger correlations for cases. Exploratory analyses indicated increased pressure pain and auditory sensitivity were modestly associated with greater self-reported bladder pain and pain interference with physical function. Conclusions: As a group, no significant differences between OAB cases and controls were observed in experimental nonbladder pain or auditory sensitivity during QST. Associations between QST outcomes and clinical pain raise the possibility of centrally mediated sensory amplification in some individuals with OAB.

Contemporary Clinical Trials, 2021

PLOS ONE, 2018

Pain, 2019

Experimental pain sensitivity was assessed in individuals with urologic chronic pelvic pain syndr... more Experimental pain sensitivity was assessed in individuals with urologic chronic pelvic pain syndrome (UCPPS) as part of the Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network. A series of computer-controlled pressure stimuli were delivered to the thumbnail bed, an asymptomatic site distant from the area of UCPPS pain that is considered to be indicative of overall body pain threshold. Stimuli were rated according to a standardized magnitude estimation protocol. Pain sensitivity in participants with UCPPS was compared with healthy controls and a mixed pain group composed of individuals with other chronic overlapping pain conditions, including fibromyalgia, chronic fatigue, and irritable bowel syndromes. Data from 6 participating MAPP testing sites were pooled for analysis. Participants with UCPPS (n = 153) exhibited an intermediate pain sensitivity phenotype: they were less sensitive relative to the mixed pain group (n = 35) but significantly more s...

Journal of clinical monitoring and computing, Jan 30, 2017

2015 Pattern Recognition Association of South Africa and Robotics and Mechatronics International Conference (PRASA-RobMech), 2015

This paper investigates the self-learning of inverse kinematics for the feed-forward control of a... more This paper investigates the self-learning of inverse kinematics for the feed-forward control of a robot to position intracardiac catheters. Cardiac ablation is routinely performed to treat Atrial Fibrillation, and requires a catheter be accurately positioned in the heart, by hand or by a robot, under feedback control. This is typically a slow process and methods to reduce procedure times are needed. To investigate our proposed method, a robotic system to manipulate a standard intracardiac catheter was constructed. To safely develop our proposed learning system, a comprehensive dataset was collected using a magnetic tracking system to measure the catheter tip positions versus robot actuator positions. Initially, the robot began with no model of its kinematics. A Genetic Algorithm was used to decide on the next actuator sequence that would reduce the uncertainty in a Feedforward Neural Network (FFNN) based inverse kinematic model. An automated iterative process was followed where the robot would perform virtual experiments, to grow its knowledge of its inverse kinematics. After 791 learning cycles the final analysis revealed that the complete inverse kinematic relationship has been explored with the given constraints. A validation dataset indicated the learned FFNN model was able to predict x, y and z positions of the catheter tip to within ±0.17 mm, ±0.73 mm and ±0.62 mm, respectively. The robot successfully self-learned its inverse kinematic model using the proposed methodology. Future work is required to investigate the influence of disturbances on positioning accuracy.

Special Care in Dentistry, Sep 8, 2018

Computers in Biology and Medicine, 2019

Journal of Clinical Monitoring and Computing, Sep 30, 2017

PubMed, May 10, 2023

Circulation, Nov 10, 2015

PLOS ONE, May 24, 2018

The Clinical Journal of Pain, Apr 7, 2020

The Journal of Urology, Sep 1, 2021

Contemporary Clinical Trials, Aug 1, 2021

Circulation, 2015

Journal of Urology, 2021

The Journal of Pain, 2018

Volume 1: Processes, 2017

Journal of Urology, 2021

Contemporary Clinical Trials, 2021

PLOS ONE, 2018

Pain, 2019

Journal of clinical monitoring and computing, Jan 30, 2017

2015 Pattern Recognition Association of South Africa and Robotics and Mechatronics International Conference (PRASA-RobMech), 2015