Robert Hitchcock

• PhD
• Professor (Full) at University of Utah

The aim was to investigate the feasibility of using an intravaginal intra-abdominal pressure (IAP) sensor worn by female runners during running to evaluate pelvic floor loading, and the association between IAP and running-induced stress urinary incontinence (RI-SUI). Twenty-eight female runners participated in this cross-sectional study (15 with RI...

Lower extremity fractures pose challenges due to prolonged healing times and limited assessment methods. Integrating wearable sensors with machine learning can help overcome these challenges by providing objective assessment and predicting fracture healing. In this retrospective study, data from a gait monitoring insole on 25 patients with closed l...

Significance Damage to the cardiac conduction system remains one of the most significant risks associated with surgical interventions to correct congenital heart disease. This work demonstrates how light-scattering spectroscopy (LSS) can be used to non-destructively characterize cardiac tissue regions. Aim To present an approach for associating ti...

Introduction Pelvic organ prolapse (POP) is a significant health concern for young Nepali women, with potential risk factors including pelvic floor trauma from vaginal delivery and heavy lifting. The prevalence of symptomatic POP (SPOP) among nulliparous women in Nepal is 6%, while the general population of Nepali women aged 15–49 years reports a p...

Importance Surgical correction of congenital heart defects (CHDs) has improved the lifespan and quality of life of pediatric patients. The number of congenital heart surgeries (CHSs) in children has grown continuously since the 1960s. This growth has been accompanied by a rise in the incidence of postoperative heart block requiring permanent pacema...

[This corrects the article DOI: 10.34133/2021/9834163.].

Introduction: Weight-bearing protocols for rehabilitation of lower extremity fractures are the gold standard despite not being data-driven. Additionally, current protocols are focused on the amount of weight placed on the limb, negating other patient rehabilitation behaviors that may contribute to outcomes. Wearable sensors can provide insight int...

Pelvic floor disorders affect 24% of US women, and elevated intra-abdominal pressure may cause pelvic injury through musculoskeletal strain. Activity restrictions meant to reduce pelvic strain after traumatic events, such as childbirth, have shown little benefit to patients. Reported high variability in abdominal pressure suggests that technique pl...

Purpose: Damage to cardiac conduction system is a major risk of congenital cardiac surgery. Localization of conduction system is commonly based on anatomical landmarks which are variable in congenital heart diseases. We introduce a novel technique for identification of conduction tissue regions based on real-time fiberoptic confocal microscopy (FC...

Background While cumulative loading of the pelvic floor during exercise appears to increase the risk of developing pelvic floor disorders, the pathophysiologic role of pelvic floor loading is poorly understood. The aim of this exploratory study was to present a method for evaluating vibrational frequency damping of the female pelvic floor and to in...

Significance: The non-destructive characterization of cardiac tissue composition provides essen- tial information for both planning and evaluating the effectiveness of surgical interventions such as ablative procedures. Although several methods of tissue characterization, such as optical coherence tomography and fiber-optic confocal microscopy, sho...

Light-scattering spectroscopy (LSS) is an established optical approach for characterization of biological tissues. Here, we investigated the capabilities of LSS and convolutional neural networks (CNNs) to quantitatively characterize the composition and arrangement of cardiac tissues. We assembled tissue constructs from fixed myocardium and the aort...

Objectives: This study aimed to explore associations between relative and maximal intra-abdominal pressure (IAP) on pelvic floor outcomes in primiparas delivered vaginally. Methods: At 5-10 weeks and 1 year postpartum, we measured absolute IAP by vaginal sensor while participants lifted a weighted car seat (IAPLIFT) and performed isometric trunk...

Objective and Impact Statement. There is a need to develop platforms delineating inflammatory biology of the distal human lung. We describe a platform technology approach to detect in situ enzyme activity and observe drug inhibition in the distal human lung using a combination of matrix metalloproteinase (MMP) optical reporters, fibered confocal fl...

Objective: To determine whether 2 aspects of trunk recovery after childbirth, intraabdominal pressure (IAP) generation and trunk flexor endurance (TFE), predict measures of pelvic floor health 1 year postpartum. Methods: In this prospective cohort study, we enrolled nulliparas in their third trimester and followed up those delivered vaginally fo...

Background: Exercise increases intra-abdominal pressure (IAP) acutely, which may impact the pelvic floor of women. IAP during exercise demonstrates high variability among women but is not routinely assessed. Assessing less invasive measures related to IAP during exercise may facilitate study of how IAP impacts the pelvic floor. Methods: The objecti...

Objective: This study aimed to determine whether measures of muscular fitness modify the effect of intra-abdominal pressure (IAP) during lifting on pelvic floor support. Methods: Participants, primiparous women 1 year after vaginal delivery, underwent the Pelvic Organ Prolapse Quantification examination, measurement of IAP via a vaginal sensor w...

Postoperative conduction block requiring lifetime pacemaker placement continues to be a considerable source of morbidity for patients undergoing repair of congenital heart defects. Damage to the cardiac conduction system (CCS) during surgical procedures is thought to be a major cause of the conduction block. Intraoperative identification and avoida...

Localization of the components of the cardiac conduction system (CCS) is essential for many therapeutic procedures in cardiac surgery and interventional cardiology. While histological studies provided fundamental insights into CCS localization, this information is incomplete and difficult to translate to aid in intraprocedural localization. To adva...

Objectives: Intra-abdominal pressure (IAP) increases during physical activity. Activities with high IAP are often restricted for women because of potential pelvic floor overloading. Researchers categorize high IAP activities using absolute values (in centimeters of water). Although essential for descriptive purposes, absolute IAP may not be ideal...

Objectives: The aim of this study was to evaluate the feasibility and safety of fibre-optic confocal microscopy (FCM) using fluorescein sodium dye for the intraoperative location of conduction tissue regions during paediatric heart surgery. Methods: The pilot study included 6 patients undergoing elective surgery for the closure of isolated secun...

This paper provides a synopsis of discussions related to biomedical engineering core curricula that occurred at the Fourth BME Education Summit held at Case Western Reserve University in Cleveland, Ohio in May 2019. This summit was organized by the Council of Chairs of Bioengineering and Biomedical Engineering, and participants included over 300 fa...

Pelvic floor disorders are caused by weakening or damage to the tissues lining the bottom of the abdominal cavity. These disorders affect nearly 1 in every 4 women in the United States and symptoms that drastically diminish a patient’s quality of life. Vaginal closure force is a good measure of pelvic health, but current vaginal dynamometers were n...

Objectives: To describe change in trunk flexor endurance and intra-abdominal pressure (IAP) associated with trunk flexor assessment and explore factors associated with change in trunk flexor endurance during the first postpartum year. Design: Ancillary analysis of an ongoing prospective cohort study. Methods: Participants (N = 282) were primiparous...

Clinical approaches for quantification of atrial fibrosis are currently based on digital image processing of magnetic resonance images. Here, we introduce and evaluate a comprehensive framework based on convolutional neural networks for quantifying atrial fibrosis from images acquired with catheterized fiber-optics confocal microscopy (FCM). FCM im...

Background To promote fracture healing and limit complications, clinicians typically instruct patients with lower extremity fracture to be nonweight or partial-weight bearing or to bear weight as tolerated during the recovery period. Although this practice represents the standard of care, continuous patient compliance to weight-bearing protocols an...

Objective: The aim of the study was to determine whether measures of muscular strength and fitness are associated with pelvic floor muscle (PFM) force 1-year postpartum in a population of primiparous women who delivered vaginally. Methods: This cross-sectional analysis is an ancillary study to an ongoing prospective cohort study and includes 203...

Background Studies have shown that the ambulatory behavior and amount of weight bearing performed by lower leg fracture patients, increases over time. It is likely that gait features, such as center of pressure (CoP), also change over time. Research Question The purpose of this study was to characterize changes in CoP exhibited by lower leg fractu...

We performed preclinical validation of intraoperative fiber-optic confocal microscopy (FCM) and assessed its safety and efficacy in an ovine model of the pediatric heart. Intraoperative imaging was performed using an FCM system (Cellvizio, Mauna Kea Technology, Paris, France) with specialized imaging miniprobe (GastroFlex UHD, Mauna Kea Technologie...

Introduction: Ambulation can be used to monitor the healing of lower extremity fractures. However, the ambulatory behavior of tibia fracture patients remains unknown due to an inability to continuously quantify ambulation outside of the clinic. The goal of this study was to design and validate an algorithm to assess ambulation in tibia fracture pat...

Optical molecular imaging is an emerging field, and highresolution optical imaging of the distal lung parenchyma has been made possible with the advent of clinically approved fiber-based imaging modalities. However, currently, there is no single method of allowing the simultaneous imaging and delivery of targeted molecular imaging agents. The objec...

Objectives: High intra-abdominal pressure (IAP) may influence the development of pelvic floor disorders. We and others have used intravaginal pressure transducers to measure IAP in women during exercise and daily activities, but utilizing the transducer for long-term measurements creates compliance issues. Waist-worn accelerometers are prominent i...

Intra-abdominal pressure may be one of the few modifiable risk factors associated with developing a pelvic floor disorder. With one in eight women having surgery to correct a pelvic floor disorder in their lifetimes, intra-abdominal pressure may be a key to understanding the disease etiology and how to mitigate its occurrence and progression. Many...

Objectives: Intra-abdominal pressure (IAP) may contribute to pelvic floor health, although the direction and magnitude of such an effect, if any, are not yet known. Identifying individual characteristics, and in particular modifiable factors, associated with higher IAP during recovery from vaginal childbirth might serve to mitigate early pelvic fl...

Background: The purpose of this prospective, direct observational study was to evaluate limb loading in lower extremity orthopaedic trauma patients using a novel insole sensor, the Ambulatory Tibial Load Analysis System (ATLAS). Methods: Three patients from a level I trauma center, one with a trimalleolar ankle fracture, one with a distal, spiral f...

Introduction Pelvic floor disorders (PFDs), including pelvic organ prolapse (POP), stress and urgency urinary incontinence, and faecal incontinence, are common and arise from loss of pelvic support. Although severe disease often does not occur until women become older, pregnancy and childbirth are major risk factors for PFDs, especially POP. We und...

Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy a...

Supplemental methods. (PDF)

Anatomical overview of the right atrium from fixed rodent heart. The right atrium was labeled with wheat germ agglutinin (yellow) and antihyperpolarization-activated cyclic nucleotide-gated potassium channel 4 (green) to visualize the extracellular space and nodal cells, respectively. Outlined region (blue line) acquired using a 10x objective. (TIF...

Parameters for ROC analysis. (TIF)

Comprehensive summary of human and automated tissue classification. (TIF)

In the urodynamics laboratory setting, a wireless pressure transducer, developed to facilitate research exploring intra-abdominal pressure (IAP) and pelvic floor disorders, was highly accurate. We aimed to study reproducibility of IAP measured using this transducer in women during activities performed in an exercise science laboratory. Fifty-seven...

The objective was to describe the intra-abdominal pressures (IAP) generated during Pilates Mat and Reformer activities, and determine whether these activities generate IAP above a sit-to-stand threshold. Twenty healthy women with no symptomatic vaginal bulge, median age 43 (range 22-59 years), completed Pilates Mat and Reformer exercise routines ea...

Walking speed and carrying technique affect intra-abdominal pressure (IAP) in women. In this study, we tested the feasibility of monitoring IAP outside the laboratory environment and compared IAP while study participants were (1) carrying 13.6 kg (similar to a 3-month old in car seat) in six different ways while walking 100 m; and (2) while walking...

Fiber-optics confocal microscopy (FCM) is an emerging imaging technology with various applications in basic research and clinical diagnosis. FCM allows for real-time in situ microscopy of tissue at sub-cellular scale. Recently FCM has been investigated for cardiac imaging, in particular, for discrimination of cardiac tissue during pediatric open-he...

Systems, devices, and methods for measuring an under foot load profile of a patient during a period of partial weight bearing are described. The system may include a walking boot cast. A housing, including an inner surface and an upper surface that cooperate to define an inner cavity, may be oriented with respect to a patient's leg. The upper surfa...

Systems, devices, and methods for measuring an under foot load profile of a tibial fracture patient during a period of partial weight bearing are described. The system may include a walking boot cast. A housing, including an inner surface and an upper surface that cooperate to define an inner cavity, may be oriented with respect to a patient's tibi...

To design a flux controlled pump (FCP) capable of 30-day, controlled release of macromolecules to the vaginal mucosa. The FCP is composed of a single chamber fabricated from a rigid thermoplastic with orifices and encloses a pellet of water-swellable polymer containing the drug substance. We performed testing both in vitro and in rabbits. To ensure...

Abstract Strenuous physical activity has been linked to pelvic floor disorders in women. Using a novel wireless intra-vaginal pressure transducer, intra-abdominal pressure was measured during diverse activities in a laboratory. Fifty-seven women performed a prescribed protocol using the intra-vaginal pressure transducer. We calculated maximal, area...

A system and method for confocal imaging of tissue in vivo and in situ, e.g., for minimally invasive diagnosis of patients. A catheter is provided that has a dye carrier coupled to the distal end of a fiber optics bundle, which allows for the introduction of at least one fluorescent dye therein the dye carrier into a portion of the tissue of intere...

Ischemic Heart Disease (IHD) still represents the "Number One Killer" worldwide accounting for the death of numerous patients. However the capacity for self-regeneration of the adult heart is very limited and the loss of cardiomyocytes in the infarcted heart leads to continuous adverse cardiac-remodelling which often leads to heart-failure (HF). Th...

Weight-bearing protocols should optimize fracture healing while avoiding fracture displacement or implant failure. Biomechanical and animal studies indicate that early loading is beneficial, but high-quality clinical studies comparing weight-bearing protocols after lower extremity fractures are not universally available. For certain fracture patter...

Caps can be used to cover and disinfect medical connectors. Some caps can create a seal with the medical connectors to prevent antiseptic from entering a fluid paths defined by a connector. Support members can aid in creating or maintaining the seal.

Partial Weight Bearing Therapy (PWB) is used during in rehabilitation of lower-extremity fractures, but optimal outcomes are limited by the paucity of data supporting the current standard of care, the inability of clinicians to assess patients' compliance to the prescribed therapy, and by the patient's inability to apply clinical loading guidelines...

-Risks associated with pediatric reconstructive heart surgery include injury of the sinoatrial node (SAN) and atrioventricular node (AVN), requiring cardiac rhythm management using implantable pacemakers. These injuries are result of difficulties in identifying nodal tissues intraoperatively. Here, we describe an approach based on confocal microsco...

Activities thought to induce high intra-abdominal pressure (IAP), such as lifting weights, are restricted in women with pelvic floor disorders. Standardized procedures to assess IAP during activity are lacking and typically only focus on maximal IAP, variably defined. Our intent in this methods paper is to establish the best strategies for calculat...

Quantifying structural features of native myocardium in engineered tissue is essential for creating functional tissue that can serve as a surrogate for in vitro testing or the eventual replacement of diseased or injured myocardium. We applied three-dimensional confocal imaging and image analysis to quantitatively describe the features of native and...

Physicians routinely prescribe partial weight bearing in a walking boot following fractures of the lower limbs in order to produce the needed mechanical environment to facilitate healing. Plantar pressure measurements can provide key information regarding the mechanical environment experienced by lower limb bones. The effect of walking boots on pla...

Objective To describe the development, feasibility and validity of a wireless intra-vaginal pressure transducer (IVT) which can be used to measure intra-abdominal pressure in real-world settings. Study design A feasibility study was conducted in sixteen physically active women to determine retention and comfort of various IVT prototype designs duri...

Continuous force measurement can provide valuable insight to the efficacy of limb loading regimes during fracture rehabilitation. Currently there is no load monitoring device that is capable of more than 1 h of continuous recording. To enable continuous underfoot load monitoring a piezoresistive pressure sensor was encapsulated in a non-compressibl...

Pelvic floor disorders (PFD) affect one of every four women in the United States. Elevated intra-abdominal pressure (IAP) during daily activity or strenuous physical activity has been identified as a risk factor in the prevalence of PFD. However, the relationship between IAP and physical activity is poorly understood and oftentimes activity restric...

Most current approaches of modelling cardiac electro-physiology assume myocytes to be the exclusive cell type and are based on simplified geometries. Fibroblasts are a further cell type in cardiac tissue and their inclusion in modelling promises new insights in physiology. They occupy a small volume fraction but they are the most numerous cell type...

Gap junctions play a fundamental role in intercellular communication in cardiac tissue. Various types of heart disease including hypertrophy and ischemia are associated with alterations of the spatial arrangement of gap junctions. Previous studies applied two-dimensional optical and electron-microscopy to visualize gap junction arrangements. In nor...

Scaffold-based tissue engineering provides cells with an engineered matrix to enhance and direct cell attachment, proliferation and differentiation. One critical limitation to current tissue engineering approaches is the inability to create densely populated constructs thicker than a few 100 μm. We hypothesized that development of porous, channeled...

Neonatal rat ventricular cardiomyocytes were used to investigate mechanisms underlying transient changes in intracellular free Ca2+ concentration ([Ca2+]i) evoked by pulsed infrared radiation (IR, 1862 nm). Fluorescence confocal microscopy revealed IR-evoked [Ca2+]i events with each IR pulse (3-4 ms pulse⁻¹, 9.1-11.6 J cm⁻² pulse⁻¹). IR-evoked [Ca2...

A microsystem is a collection of electromechanical and electronic elements that have been reduced in size using advanced lithographic and machining techniques. Many types of medical devices rely on microsystem architecture to improve the health and well-being of millions of people. These systems are found in devices which are used for short and lon...

Limitations of the standard urogynecological pressure transducers have not adequately provided reliable measurements of intra-abdominal pressure (IAP) during physical activities. A previous novel intravaginal pressure transducer (IVT) was developed in order to overcome the shortcomings in existing technology. The design of the IVT was validated tho...

Partial weight bearing prescriptions for tibial fracture care are made with little data to support their efficacy. To provide long term tibial load data that can be used to study, guide, and monitor partial weight bearing, we developed a novel load sensor that can record the load placed on an injured limb over a two-week period of time. The prototy...

Bacterial colonization of needleless injection sites (NISs) frequently results in catheter related bloodstream infections (CRBSIs). Hospitals have instituted protocols aimed at disinfecting NIS prior to access. Furthermore, several manufactures have developed devices that facilitate disinfection of NIS. Despite these steps, the incidence of CRBSI i...

Controlling environmental conditions, such as mechanical stimuli, is critical for directing cells into functional tissue. This study reports on the development of a bioreactor capable of controlling the mechanical environment and continuously measuring force-displacement in engineered tissue. The bioreactor was built from off the shelf components,...

This paper reports a method to fabricate anisotropic scaffolds of tunable porosity and mechanical properties. Scaffolds were fabricated using a computer controlled sprayed phase separation technique. Following fabrication, the sheets were elongated 0, 35 or 70% of their original length to induce varying degrees of scaffold alignment and anisotropy....

Despite their sophistication and value, single-use medical devices have become commodity items in the developed world. Cheap raw materials along with large scale manufacturing and distribution processes have combined to make many medical devices more expensive to resterilize, package and restock than to simply discard. This practice is not sustaina...

Elevated intra-abdominal pressure (IAP) may be a potentially modifiable risk factor for pelvic floor disorders. However, limited evidence exists due to the lack of instruments suitable to measure abdominal pressures in real world settings. The aim of this study was to develop and test a vaginal sensor prototype to measure intra-abdominal pressure i...

Limitations of standard clinical pressure transducers have hampered our ability to provide reliable measurements of intra-abdominal pressure (IAP) during physical activities. To overcome these limitations, a novel intravaginal transducer (IVT) capable of accurate, reliable, and continuous IAP measurements during normal activity was developed. The d...

Pelvic floor disorders among women have become increasingly prevalent [1]. In an attempt to minimize incidence, progression and recurrence of pelvic floor disorders, doctors commonly advise women at risk to refrain from physical exertion based on the supposition that certain physical activities significantly raise intra-abdominal pressure (IAP). Th...

Current bioreactors, although suitable for various functions, are often times costly, unreliable and difficult to set up [1,2]. Unlike standard tissue culture equipment, these systems are complex and difficult to operate [1,2]. Due to these limitations our aim was to develop a bioreactor that utilizes common cell culture equipment, is easy to set u...

The University of Utah offers a two semester capstone biomedical engineering design course (bioDesign) where products are developed and prototyped using the guidance of FDA Design Control mandates. During the two semesters, students are required to develop a project plan, marketing requirements, specifications, test plan, results and working protot...

Methods of creating a scaffold for tissue engineering that allow for modification of properties such as pore size, porosity, and anisotropy are essential for tissue engineering applications. For example the pore size and material anisotropy have been shown to affect cardiomyocyte elongation and alignment [1]. Phase-inversion spray polymerization (P...

Evaluation of engineered tissue is often limited to endpoint analyses, such as characterizing histology, gene expression and solutes [1]. Most of these applied analysis approaches are based on immunochemistry procedures that require excision, fixation and sectioning of the tissue as well as cell membrane perforation and labeling of proteins [2]. Th...

This work presents a methodology for modeling of cardiac tissue micro-structure. The approach is based on catheter-based confocal imaging systems, which are emerging as tools for diagnosis in various clinical disciplines. A limitation of these systems is that a fluorescent marker must be available in sufficient concentration in the imaged region. W...

Life-Cycle Analysis (LCA) is used to understand the holistic flow of energy and materials throughout a product's life. As part of a comprehensive approach to design next-generation dialysers, we performed a LCA of an Optiflux F180NR dialyser. Combining LCA insights with a functional analysis of each product component, we analysed which components c...

In order to improve performance, image preprocessing for enhancement is essential in a fingerprint recognition system. Most prominent fingerprint enhancement methods perform well for relatively high-quality images but less effectively for low-quality images, especially where the ridge patterns are very noisy and corrupt. To enhance such images, thi...

Subcutaneous tissue is frequently the target site for placement of continuous, real-time metabolic sensors. Since the 1960s, numerous research groups have developed needle-like sensor designs, patterned after the Clarke Electrode, to monitor glucose in subcutaneous tissue. These designs perform well in vitro but often fail in vivo due to sensor ins...

Rapid induction of matrix production and mechanical strengthening is essential to the development of bio-artificial constructs for repair and replacement of load-bearing connective tissues. Toward this end, we describe the development of a mechanical bioreactor and its application to investigate the influence of cyclic strain on fibroblast prolifer...

The transplantation of a variety of naturally occurring and genetically modified cell types has been shown to be an effective experimental method to achieve sustained delivery of therapeutic molecules to specific target areas in the brain. To acquire a better understanding of dosing, implant mechanism of action, and how certain cell types affect re...

Criteria are outlined for the design of a bioreactor that can simulate the vibrational stresses in vocal fold movement during speech. Requirements are 0-1 mm amplitudes in the 20-200 Hz frequency range, a variable on-off stress regime, and maintenance of tissue viability over several days. The bioreactor uses dual drivers, one for low frequency (or...

Using quantitative immunohistological methods, we examined the brain tissue response to hollow fiber membranes (HFMs) that were either implanted intraparenchymally, as in a cell encapsulation application, or were attached to the skull as in a biosensor application (transcranially). We found that the reaction surrounding transcranially implanted HFM...

Three-dimensional elastic substrates were fabricated from a commercially available polyurethane with an internal porosity of approximately 70% and elastic modulus of 27.4+/-2.76 KPa and examined for suitability in vocal fold tissue engineering. Using immunohistochemistry, biomechanical testing, and RT-PCR; we examined human fibroblast viability, di...

The use hollow fiber membranes for cell encapsulation is being developed as an experimental transplantation technology in which a permselective membrane physically isolates grafted cells from directly interacting with host cells or tissue. Although laboratory characterization of commercial ultrafiltration and dialysis membranes using multi-fiber te...

Studies geared towards understanding the interaction between skeletal muscle and biomaterials may provide useful information for the development of various emerging technologies, ranging from novel delivery vehicles for genetically modified cells to fully functional skeletal muscle tissue. To determine the utility of elastomeric materials as substr...