Name: virtual reality tools for assessing unilateral spatial neglect: a novel opportunity for data collection
Uploaded: 2021-03-10T13:30:00
Description: Watch this Scientific Journal Video about Virtual Reality Tools for Assessing Unilateral Spatial Neglect: A Novel Opportunity for Data Collection at JoVE.com

This work was supported by the University Research Fund (URF) from the University of Pennsylvania, and the American Heart Association&#39;s Student Scholarships in Cerebrovascular Disease &#38; Stroke. Special thanks to the researchers, clinicians and staff of the Laboratory for Cognition and Neural Stimulation for their ongoing support.

This study was approved by the local Institutional Review Board and meets all criteria set forth by Good Clinical Practice Guidelines. All participants provided informed consent before any study procedures began. Study participants were expected to participate in three separate sessions (outlined in Table 1). The elements of the experiment are described in stepwise fashion below. Session order was randomized.
<table border="1" fo:keep-together.within-page="always" fo:keep-with-next.within-page="always">
	<tb...

We successfully induced and measured USN symptoms with TMS and VR, respectively. While we did not have significant results when compared to sham trials, we were able to compare multiple metrics of egocentric neglect (average head angle, time spent looking at flowers in either hemispace) and allocentric neglect (performance in selecting flowers with asymmetric petals on the left vs. the right side) between the different experimental groups, and found significant differences in average head angle between subjects stimulate...

Unilateral spatial neglect (USN) is a syndrome characterized by inattention to or inaction in one side of space that affects between 23-46% of acute stroke survivors, most commonly involving injury to the right cerebral hemisphere and resulting in a tendency to ignore the left side of space and/or the survivor&#39;s body1,2. Although the majority of patients with USN experience significant recovery in the short term, subtle USN symptoms often persist3. USN can increase patient risk for falls and impede activities of daily living2,4 It has also been shown to negatively impact both motor and global functional outcomes5,6.
Deficits in USN can be conceptualized as existing across multiple dimensions, such as whether a person ignores one side of space with respect to their own body (egocentric) or with respect to an external stimulus (allocentric)7,8,9, or whether a person is unable to direct their attention (attentional) or actions (intentional) toward one side of space10. Patients often exhibit a complex constellation of symptoms that can be characterized along more than one of these dimensions. This variability of USN syndromes is thought to result from varying degrees of injury to specific neuroanatomical structures and neuronal networks, which are complex11. Allocentric neglect has been associated with lesions of the angular gyrus (AG) and superior temporal gyrus (STG), while the posterior parietal cortex (PPC) including the supramarginal gyrus (SMG) has been implicated in egocentric processing12,13,14,15. Attentional neglect is thought to involve lesions in the right IPL16, while intentional neglect is thought to be secondary to damage of the right frontal lobe17 or basal ganglia18.
Clinical assessment of USN currently relies on pen-and-paper neuropsychological instruments. These conventional assessment tools may be less sensitive than more technologically sophisticated tools, resulting in misdiagnosing or under-diagnosing some patients with USN19. Better characterization of residual deficits could facilitate the delivery of therapy to patients with milder USN and potentially improve their overall recovery, but such characterization would require very sensitive diagnostic tools. USN poses similar challenges in the laboratory setting, where it can be difficult to isolate from the motor and visual impairments that commonly accompany USN among stroke patients.
Virtual reality (VR) presents a unique opportunity to develop new tools for the diagnosis and characterization of USN. VR is a multisensory 3D environment presented in the first person with real time interactions in which individuals are able to perform tasks involving ecologically valid objects20. It is a promising tool for assessing USN; the ability to precisely control what the user sees and hears allows developers to present a wide variety of virtual tasks to the user. In addition, the sophisticated hardware and software packages currently available allow for real-time collection of a wealth of data about the user&#39;s actions, including eye, head, and limb movements, far exceeding the metrics offered by traditional diagnostic tests21. These data streams are instantaneously available, opening up the possibility for real-time adjustment of diagnostic tasks based on user performance (e.g. targeting the ideal difficulty level for a given task). This feature can facilitate task adaptation to the wide range of severity seen in USN, which is regarded as a priority in the development of new diagnostic tools for USN22. In addition, immersive VR tasks may impose an increased burden on the patients&#39; attentional resources23,24, resulting in increased errors which can facilitate the detection of neglect symptoms; indeed, some VR tasks have been shown to have increased sensitivity when compared to conventional paper-and-pencil measures of USN24,25.
In this study, the goal was to create an assessment tool that requires no expertise in neurology to operate and that can reliably detect and characterize even subtle cases of USN. We built a virtual reality-based, game-like task. We then induced a USN-like syndrome in healthy subjects with transcranial magnetic stimulation (TMS), a noninvasive brain stimulation technique that utilizes electromagnetic pulses emitted from a handheld stimulation coil, which pass through the scalp and skull of the subject and induce electric currents in the subject&#39;s brain that stimulate neurons26,27. This technique has been utilized in the study of USN by others13,17,28,29,30, though to our knowledge never in conjunction with a VR-based assessment tool.
Many researchers are already working on diagnostic and therapeutic applications of VR systems. Recent reviews31,32 explored a number of projects aimed at the assessment of USN with VR-based techniques, and a number of other studies with this aim have been published33,34,35,36,37,38,39,40,41. The majority of these studies do not utilize the full complement of VR technology that is currently available to the consumer market (e.g., a head-mounted display (HMD) and eye-tracking inserts), limiting their datasets to a smaller number of easily-quantifiable metrics. In addition, all of these studies were performed on patients with acquired brain injury leading to USN, requiring screening methods to assure that patients could at least participate in the assessment tasks (e.g., excluding patients with large visual field deficits or cognitive impairment). It is possible that more subtle cognitive, motor, or visual deficits passed under the threshold of these screening methods, possibly confounding the results of these studies. It is also possible that such screening biased the samples of participants in these studies toward a particular subtype of USN.
To avoid the screening biases of prior studies, we recruited healthy subjects and artificially simulated USN symptoms with a standard TMS protocol that is well-described in a recent manuscript15, with the goal of inducing allocentric USN-like symptoms by targeting the STG and egocentric USN-like symptoms by targeting the SMG. We designed the task to actively adjust its difficulty trial to trial and to differentiate between different subtypes of USN, specifically allocentric vs. egocentric symptoms. We also used standard paper &#38; pencil assessments of USN to formally demonstrate that the deficits we induced with rTMS are USN-like. We believe the method will be useful to other researchers who want to test novel VR tools for the assessment and rehabilitation of USN.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>AirFilm Coil (AFC) Rapid Version</td>
			<td>Magstim</td>
			<td>N/A</td>
			<td>Air-cooled TMS coil</td>
		</tr>
		<tr>
			<td>Alienware 17 R4 Laptop</td>
			<td>Dell</td>
			<td>N/A</td>
			<td>NVIDIA GeForce GTX 1060 (full specs at https://topics-cdn.dell.com/pdf/alienware-17-laptop_users-guide_en-us.pdf)</td>
		</tr>
		<tr>
			<td>BrainSight 2.0 TMS Neuronavigation Software</td>
			<td>Rogue Research Inc</td>
			<td>N/A</td>
			<td>TMS neural targeting software</td>
		</tr>
		<tr>
			<td>CED 1902 Isolated pre-amplifier</td>
			<td>Cambridge Electronic Design Limted</td>
			<td>N/A</td>
			<td>EMG pre-amplifier</td>
		</tr>
		<tr>
			<td>CED Micro 401 mkII</td>
			<td>Cambridge Electronic Design Limted</td>
			<td>N/A</td>
			<td>Multi-channel waveform data acquisition unit</td>
		</tr>
		<tr>
			<td>CED Signal 5</td>
			<td>Cambridge Electronic Design Limted</td>
			<td>N/A</td>
			<td>Sweep-based data acquisition and analysis software. Used to measure TMS evoked motor responses.</td>
		</tr>
		<tr>
			<td>HTC Vive Binocular Add-on</td>
			<td>Pupil Labs</td>
			<td>N/A</td>
			<td>HTC Vive, Vive Pro, or Vive Cosmos eye tracking add-on with 2 x 200Hz eye cameras.</td>
		</tr>
		<tr>
			<td>Magstim D70 Remote Coil</td>
			<td>Magstim</td>
			<td>N/A</td>
			<td>Hand-held TMS coil</td>
		</tr>
		<tr>
			<td>Magstim Super Rapid 2 plus 1</td>
			<td>Magstim</td>
			<td>N/A</td>
			<td>Transcranial Magnetic Stimulation Unit</td>
		</tr>
		<tr>
			<td>Unity 2018</td>
			<td>Unity</td>
			<td>N/A</td>
			<td>cross-platform VR game engine</td>
		</tr>
		<tr>
			<td>Vive Pro</td>
			<td>HTC Vive</td>
			<td>N/A</td>
			<td>VR hardware system with external motion sensors; 1440x1600 pixels per eye, 90 Hz refresh rate, 110&#176; FoV</td>
		</tr>
	</tbody>
</table>

virtual reality tools for assessing unilateral spatial neglect: a novel opportunity for data collection

Unilateral spatial neglect (USN) is a syndrome characterized by inattention to or inaction in one side of space and affects between 23-46% of acute stroke survivors. The diagnosis and characterization of these symptoms in individual patients can be challenging and often requires skilled clinical staff. Virtual reality (VR) presents an opportunity to develop novel assessment tools for patients with USN.
We aimed to design and build a VR tool to detect and characterize subtle USN symptoms, and to test the tool on subjects treated with inhibitory repetitive transcranial magnetic stimulation (TMS) of cortical regions associated with USN.
We created three experimental conditions by applying TMS to two distinct regions of cortex associated with visuospatial processing- the superior temporal gyrus (STG) and the supramarginal gyrus (SMG) - and applied sham TMS as a control. We then placed subjects in a virtual reality environment in which they were asked to identify the flowers with lateral asymmetries of flowers distributed across bushes in both hemispaces, with dynamic difficulty adjustment based on each subject's performance. 
We found significant differences in average head yaw between subjects stimulated at the STG and those stimulated at the SMG and marginally significant effects in the average visual axis.
VR technology is becoming more accessible, affordable, and robust, presenting an exciting opportunity to create useful and novel game-like tools. In conjunction with TMS, these tools could be used to study specific, isolated, artificial neurological deficits in healthy subjects, informing the creation of VR-based diagnostic tools for patients with deficits due to acquired brain injury. This study is the first to our knowledge in which artificially generated USN symptoms have been evaluated with a VR task.

Data were collected from healthy individuals using the protocol outlined above to demonstrate how the different variables that can be extracted from the virtual reality task can be analyzed to detect subtle differences between groups.
In this study, 7 individuals (2 male) with an average age of 25.6 and an average of 16.8 years of education each underwent three separate sessions of TMS. These subjects were broken into two groups...

Watch this Scientific Journal Video about Virtual Reality Tools for Assessing Unilateral Spatial Neglect: A Novel Opportunity for Data Collection at JoVE.com

Virtual Reality Tools for Assessing Unilateral Spatial Neglect: A Novel Opportunity for Data Collection

The goal was to design, build, and pilot a novel virtual reality task to detect and characterize unilateral spatial neglect, a syndrome affecting 23-46% of acute stroke survivors, expanding the role of virtual reality in the study and management of neurologic disease.

Unilateral spatial neglect (USN) is a syndrome characterized by inattention to or inaction in one side of space and affects between 23-46% of acute stroke ...

Our protocol, investigators can design and validate novel virtual reality tools to assist in the diagnosis and characterization of unilateral spatial neglect. This technique provides a broad array of data sets for the study of unilateral spatial neglect. It also avoids possible confounding effects seen in studies of patients with acquired brain injury.Better characterization of unilateral spatial neglect can facilitate the delivery of therapy to patients with subtle but still debilitating deficits and potentially improve their overall recovery. Demonstrating the procedure will be Sam Cason and Peter Schwab, researchers from my laboratory. To perform the Line Bisection test have the subject sit at a table directly across from the tester and provide the subject with a writing utensil and the stimulus sheet ensuring that the sheet is placed directly in front of the subject.Instruct the subject to quickly and accurately bisect each line printed on the stimulus sheet as close to the middle of each line as possible while keeping their head and shoulders centered as much as possible. To perform the Bells Test provide the subject with the Bells Test stimuli sheet and instruct the subject to circle or cross out all of the bells on the sheet as quickly and accurately as possible while keeping their head and shoulders as centered. To perform the star cancellation test present the subject with the stimulus sheet ensuring that it is placed directly in front of them and instruct the subject to circle or cross out all of the stars on the stimulus sheet as quickly and accurately as possible with their head and shoulders centered.To perform the Otas circle cancellation test provide the subject with the Otas circle cancellation stimulus sheet and instruct the subject to cross out or circle all of the open incomplete circles as quickly and as accurately as possible with their head and shoulders as centered. Before the first TMS session upload the subject's 3TT1 MRI scan into the neuro navigational software and create a 3D representation of the subject's brain. During the first session, have the subject sit in front of an optical tracking camera and use a headband or glasses to place a tracker on the subject.Attach one disposable disc electrode on the subject's right dorsal interosseous, one disc electrode to the subject's second knuckle on the right pointer finger and one ground electrode to the subject's right wrist, right hand, and wrist. Plug the electrodes into an electrode adapter that inputs into an MEP tracking software program and select, new online session to open the subject's project within the neuro navigational software. Select the targets to be stimulated in this session and using a pointer registered to the neuro navigational software touch the subject's face in the same locations that the landmarks were placed.Open the validation tab in the software and use the pointer to touch the subject in various spots on the head, ensuring that the cross hairs on the screen line up with the spot being pointed to on the subject. Plug a handheld TMS coil into the TMS machine and turn on the TMS machine. Set the instrument to single pulse and set an appropriate stimulation intensity.Placing the handheld TMS coil on the left side of the subject's head, deliver stimuli to the motor cortex using TMS single pulses. To identify the location that stimulates the first dorsal interosseous. Alter the stimulation intensity until the stimulation elicits MEP's of at least 50 millivolts exactly five out of 10 times.This intensity is considered the resting motor threshold. Replace the handheld coil with an air cooled TMS coil with a built-in cooling system targeting the SMG or STG for active sessions or the vertex for sham sessions and set the stimulation parameters to repetitive TMS at a rate of one Hertz for 20 minutes at a 110%intensity of the resting motor threshold. Then start stimulation of the target of interest.To perform the virtual reality behavior test place the VR headset onto the seated subject's head with the straps secured tightly but comfortably. Give the subject both controllers and ensure that both eyes are visible by visually confirming they are centered in the pupil core software camera feeds. In the unity editor, open the virtual reality task and press the play button.Ask the subject to look straight ahead and click the tear camera button. Click the begin tutorial button and wait for the subject to complete the tutorial. When subject is finished, click the calibrate eye tracking button and click next trial to begin the first trial.When the subject has completed the trial click the play button again to end the task. In this analysis the average head angle was examined to determine whether the virtual reality task was sensitive enough to identify a difference between the SMG and STG groups. ANCOVA analysis of head angle differences between groups revealed a significant difference in head angle change scores between the pre and post TMS groups.This finding from the virtual reality task is consistent with the results of the traditional paper and pencil task as both demonstrated a pattern in which the SMG group may have had a subtle neglect and looked more toward the right compared to the STG group. To specifically assess for signs of allocentric neglect on an individual target level flowers can be separated by which side of the flower contains the defective petals. In this analysis, participants in the SMG group had a tendency to look further to the right at a higher flower to head angle when searching for the short petal on the right side of the flower compared to the angle observed when the short petals were on the left side of the flower.When the average number of seconds that participants looked at each flower were analyzed no significant difference in mean head angle change score was observed between the SMG and STG groups. This method is limited by the subtle clinical effects achieved with repetitive transcranial magnetic stimulation. So proper stimulation parameters in cortical region targeting are critical.

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Medicine

A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which works especially well with poor mask fit.
Can not intubate, can not ventilate" (CICV) is a potentially life threatening situation. In this video we present a simulation of the technique we used in a case of CICV where oxygenation and ventilation were maintained by inserting an endotracheal tube (ETT) nasally down to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.
A 13 year old patient was taken to the operating room for incision and drainage of a neck abcess and direct laryngobronchoscopy. After preoxygenation, anesthesia was induced intravenously. Mask ventilation was found to be extremely difficult because of the swelling of the soft tissue. The face mask could not fit properly on the face due to significant facial swelling as well. A direct laryngoscopy was attempted with no visualization of the larynx. Oxygen saturation was difficult to maintain, with saturations falling to 80%. In order to oxygenate and ventilate the patient, an endotracheal tube was then inserted nasally after nasal spray with nasal decongestant and lubricant. The tube was pushed gently and blindly into the hypopharynx. The mouth and nose of the patient were sealed by hand and positive pressure ventilation was possible with 100% O2 with good oxygen saturation during that period of time. Once the patient was stable and well sedated, a rigid bronchoscope was introduced by the otolaryngologist showing extensive subglottic and epiglottic edema, and a mass effect from the abscess, contributing to the airway compromise. The airway was secured with an ETT tube by the otolaryngologist.This video will show a simulation of the technique on a patient undergoing general anesthesia for dental restorations.

We describe a technique to maintain oxygenation and ventilation using an endotracheal tube inserted nasally to the level of the naso-pharynx while sealing the mouth and nares for successful positive pressure ventilation.

We describe a novel non surgical technique to maintain oxygenation and ventilation in a case of difficult intubation and difficult ventilation, which ...

Collection Protocol for Human Pancreas

This dissection and sampling procedure was developed for the Network for Pancreatic Organ Donors with Diabetes (nPOD) program to standardize preparation of pancreas recovered from cadaveric organ donors. The pancreas is divided into 3 main regions (head, body, tail) followed by serial transverse sections throughout the medial to lateral axis. Alternating sections are used for fixed paraffin and fresh frozen blocks and remnant samples are minced for snap frozen sample preparations, either with or without RNAse inhibitors, for DNA, RNA, or protein isolation. The overall goal of the pancreas dissection procedure is to sample the entire pancreas while maintaining anatomical orientation.
Endocrine cell heterogeneity in terms of islet composition, size, and numbers is reported for human islets compared to rodent islets 1. The majority of human islets from the pancreas head, body and tail regions are composed of insulin-containing &beta;-cells followed by lower proportions of glucagon-containing &alpha;-cells and somatostatin-containing &delta;-cells. Pancreatic polypeptide-containing PP cells and ghrelin-containing epsilon cells are also present but in small numbers. In contrast, the uncinate region contains islets that are primarily composed of pancreatic polypeptide-containing PP cells 2. These regional islet variations arise from developmental differences. The pancreas develops from the ventral and dorsal pancreatic buds in the foregut and after rotation of the stomach and duodenum, the ventral lobe moves and fuses with the dorsal 3. The ventral lobe forms the posterior portion of the head including the uncinate process while the dorsal lobe gives rise to the rest of the organ. Regional pancreatic variation is also reported with the tail region having higher islet density compared to other regions and the dorsal lobe-derived components undergoing selective atrophy in type 1 diabetes4,5.
Additional organs and tissues are often recovered from the organ donors and include pancreatic lymph nodes, spleen and non-pancreatic lymph nodes. These samples are recovered with similar formats as for the pancreas with the addition of isolation of cryopreserved cells. When the proximal duodenum is included with the pancreas, duodenal mucosa may be collected for paraffin and frozen blocks and minced snap frozen preparations.

This video demonstrates a dissection procedure for processing human pancreas into multiple storage formats. Anatomical orientation is maintained throughout the pancreatic regions to allow definition of regional islet composition and density.

This dissection and sampling procedure was developed for the Network for Pancreatic Organ Donors with Diabetes (nPOD) program to standardize preparation ...

Development of an Audio-based Virtual Gaming Environment to Assist with Navigation Skills in the Blind

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio based cues and set within the context of a video game metaphor, users gather relevant spatial information regarding a building's layout. This allows the user to develop an accurate spatial cognitive map of a large-scale three-dimensional space that can be manipulated for the purposes of a real indoor navigation task. After game play, participants are then assessed on their ability to navigate within the target physical building represented in the game. Preliminary results suggest that early blind users were able to acquire relevant information regarding the spatial layout of a previously unfamiliar building as indexed by their performance on a series of navigation tasks. These tasks included path finding through the virtual and physical building, as well as a series of drop off tasks. We find that the immersive and highly interactive nature of the AbES software appears to greatly engage the blind user to actively explore the virtual environment. Applications of this approach may extend to larger populations of visually impaired individuals.

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind.

Audio-based Environment Simulator (AbES) is virtual environment software designed to improve real world navigation skills in the blind. Using only audio ...

Identification of Disease-related Spatial Covariance Patterns using Neuroimaging Data

The scaled subprofile model (SSM)1-4 is a multivariate PCA-based algorithm that identifies major sources of variation in patient and control group brain image data while rejecting lesser components (Figure 1). Applied directly to voxel-by-voxel covariance data of steady-state multimodality images, an entire group image set can be reduced to a few significant linearly independent covariance patterns and corresponding subject scores. Each pattern, termed a group invariant subprofile (GIS), is an orthogonal principal component that represents a spatially distributed network of functionally interrelated brain regions. Large global mean scalar effects that can obscure smaller network-specific contributions are removed by the inherent logarithmic conversion and mean centering of the data2,5,6. Subjects express each of these patterns to a variable degree represented by a simple scalar score that can correlate with independent clinical or psychometric descriptors7,8. Using logistic regression analysis of subject scores (i.e. pattern expression values), linear coefficients can be derived to combine multiple principal components into single disease-related spatial covariance patterns, i.e. composite networks with improved discrimination of patients from healthy control subjects5,6. Cross-validation within the derivation set can be performed using bootstrap resampling techniques9. Forward validation is easily confirmed by direct score evaluation of the derived patterns in prospective datasets10. Once validated, disease-related patterns can be used to score individual patients with respect to a fixed reference sample, often the set of healthy subjects that was used (with the disease group) in the original pattern derivation11. These standardized values can in turn be used to assist in differential diagnosis12,13 and to assess disease progression and treatment effects at the network level7,14-16. We present an example of the application of this methodology to FDG PET data of Parkinson's Disease patients and normal controls using our in-house software to derive a characteristic covariance pattern biomarker of disease.

Multivariate techniques including principal component analysis (PCA) have been used to identify signature patterns of regional change in functional brain images. We have developed an algorithm to identify reproducible network biomarkers for the diagnosis of neurodegenerative disorders, assessment of disease progression, and objective evaluation of treatment effects in patient populations.

The scaled subprofile model (SSM)1-4 is a multivariate PCA-based algorithm that identifies major sources of variation in patient and control group brain ...

A Novel Model of Mild Traumatic Brain Injury for Juvenile Rats

Despite growing evidence that childhood represents a major risk period for mild traumatic brain injury (mTBI) from sports-related concussions, motor vehicle accidents, and falls, a reliable animal model of mTBI had previously not been developed for this important aspect of development. The modified weight-drop technique employs a glancing impact to the head of a freely moving rodent transmitting acceleration, deceleration, and rotational forces upon the brain. When applied to juvenile rats, this modified weight-drop technique induced clinically relevant behavioural outcomes that were representative of post-concussion symptomology. The technique is a rapidly applied procedure with an extremely low mortality rate, rendering it ideal for high-throughput studies of therapeutics. In addition, because the procedure involves a mild injury to a closed head, it can easily be used for studies of repetitive brain injury. Owing to the simplistic nature of this technique, and the clinically relevant biomechanics of the injury pathophysiology, the modified weight-drop technique provides researchers with a reliable model of mTBI that can be used in a wide variety of behavioural, molecular, and genetic studies.

The modified weight-drop technique is an easy, cost-effective procedure used for the induction of mild traumatic brain injury in juvenile rats. This novel technique produces clinically relevant symptomology that will advance the study of mild traumatic brain injury (mTBI) and concussion.

Despite growing evidence that childhood represents a major risk period for mild traumatic brain injury (mTBI) from sports-related concussions, motor ...

A Murine Model of Irreversible and Reversible Unilateral Ureteric Obstruction

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive nephropathy induced by unilateral ureteric obstruction (UUO), which can either be irreversible (UUO) or reversible (R-UUO). In the irreversible UUO model, the ureter may be obstructed for variable periods of time in order to induce increasingly severe renal inflammation and interstitial fibrotic scarring. In the reversible R-UUO model the ureter is obstructed to induce hydronephrosis, tubular dilation and inflammation. After a suitable period of time the ureteric obstruction is then surgically reversed by anastomosis of the severed previously obstructed ureter to the bladder in order to allow complete decompression of the kidney and restoration of urinary flow to the bladder. The irreversible UUO model has been used to investigate various aspects of renal inflammation and scarring including the pathogenesis of disease and the testing of potential anti-inflammatory or anti-fibrotic therapies. The more challenging model of R-UUO has been used by some investigators and does offer significant research potential as it allows the study of inflammatory and immune processes and tissue remodeling in an injured and scarred kidney following the removal of the injurious stimulus. As a result, the R-UUO model offers investigators the opportunity to explore the resolution of kidney inflammation together with key aspects of tissue repair. These experimental models are of relevance to human disease as patients often present with obstruction of the renal tract that requires decompression and are commonly left with significant residual kidney impairment that has no current treatment options and may lead to eventual end stage kidney failure.

The murine model of irreversible unilateral ureteric obstruction (UUO) is presented together with the model of reversible UUO in which the ureteric obstruction is relieved by anastomosis of the severed ureter into the bladder. These models enable the study of renal inflammation and scarring as well as tissue remodeling.

Obstruction of the kidney may affect native or transplanted kidneys and results in kidney injury and scarring. Presented here is a model of obstructive ...

A Novel Clinical Grade Isolation Method for Human Kidney Perivascular Stromal Cells

Mesenchymal Stromal Cells (MSCs) are tissue homeostatic and immune modulatory cells that have shown beneficial effects in kidney diseases and transplantation. Perivascular Stromal Cells (PSCs) share characteristics with bone marrow MSCs (bmMSCs). However, they also possess, most likely due to local imprinting, tissue-specific properties and play a role in local tissue homeostasis. This tissue specificity may result in tissue specific repair, also within the human kidney. We previously showed that human kidney PSCs (kPSCs) have enhanced kidney epithelial wound healing whereas bmMSCs did not have this potential. Moreover, kPSCs can ameliorate kidney injury in vivo. Therefore, kPSCs constitute an interesting source for cell therapy, particularly for kidney diseases and renal transplantation. Here we show the detailed isolation and culture method for kPSCs from transplant-grade human kidneys based on whole-organ perfusion of digestive enzymes via the renal artery and enrichment for the perivascular marker NG2. In this way, large cell quantities can be obtained that are suitable for cellular therapy.

Here we present a novel clinical grade isolation and culture method for kidney Perivascular Stromal Cells (kPSCs) based on whole organ perfusion with digestive enzymes and NG2-cell enrichment. With this method, it is possible to acquire sufficient cell numbers for cellular therapy.

Mesenchymal Stromal Cells (MSCs) are tissue homeostatic and immune modulatory cells that have shown beneficial effects in kidney diseases and ...

Integrating Augmented Reality Tools in Breast Cancer Related Lymphedema Prognostication and Diagnosis

Breast cancer related lymphedema (BCRL) is a detrimental condition characterized by fluid accumulation in the upper limb in breast cancer patients subjected to axillary surgery and/or radiations. Its etiology is multifactorial and include also tumor-specific pathological features, such as lymphovascular invasion (LVI) and extranodal extension (ENE). To date, no widely employed guidelines for the early diagnosis of BCRL are available. Here, we illustrate a protocol for a digitally assisted BCRL assessment using a 3D laser scanner (3DLS) and a tablet computer. It has been specifically optimized in a discovery cohort of high-risk breast cancer patients. This study provides a proof-of-principle that augmented reality tools, such as 3DLS, can be incorporated into the clinical workup of BCRL to allow for a precise, reproducible, reliable, and cheap diagnosis.

Breast cancer related lymphedema is frequent in breast cancer survivors, but there are not widely employed guidelines for its diagnosis and quantification. Here, we introduce a reliable and cost-effective protocol to define, quantify, and compare upper limb volume in breast cancer patients.

Breast cancer related lymphedema (BCRL) is a detrimental condition characterized by fluid accumulation in the upper limb in breast cancer patients ...

Augmented Reality Navigation-Guided Core Decompression for Osteonecrosis of Femoral Head

Osteonecrosis of the femoral head (ONFH) is a common joint disease in young and middle-aged patients, which seriously burdens their lives and work. For early-stage ONFH, core decompression surgery is a classical and effective hip preservation therapy. In traditional procedures of core decompression with Kirschner wire, there are still many problems such as X-ray exposure, repeated puncture verification, and damage to normal bone tissue. The blindness of the puncture process and the inability to provide real-time visualization are crucial reasons for these problems.
To optimize this procedure, our team developed an intraoperative navigation system on the basis of augmented reality (AR) technology. This surgical system can intuitively display the anatomy of the surgical areas and render preoperative images and virtual needles to intraoperative video in real-time. With the guide of the navigation system, surgeons can accurately insert Kirschner wires into the targeted lesion area and minimize the collateral damage. We conducted 10 cases of core decompression surgery with this system. The efficiency of positioning and fluoroscopy is greatly improved compared to the traditional procedures, and the accuracy of puncture is also guaranteed.

Augmented reality technology was applied to core decompression for osteonecrosis of the femoral head to realize real-time visualization of this surgical procedure. This method can effectively improve the safety and precision of core decompression.

Osteonecrosis of the femoral head (ONFH) is a common joint disease in young and middle-aged patients, which seriously burdens their lives and work. For ...

﻿Low-Dose Computed Tomography (LDCT) Data Collection for Detecting Pulmonary Nodules

Low-Dose Computed Tomography (LDCT) Data Collection for Detecting Pulmonary Nodules  

To begin, obtain written consent from the patient for acquiring the DICOM data. After obtaining the images, transfer the data to the designated working directory in the computer. Then, identify the data directory with the highest number of scanning layers and the thinnest layer thickness to optimize the accuracy based on the file information.Generally, the more DICOM scan files, the thinner is the scan layer thickness. Using the DICOM info function and DICOM files as the function parameters in the MATLAB environment, obtain the slice thickness and pixel-spacing parameters, which are essential for setting the 3D volume display rate. Next, using the function dicominfo, read the location data of each image by giving info.sliceLocation as input into the MATLAB workspace. Implement the SliceLocation function to store the location array for a variable and create a plot of the location array. Use the data tips button at the top right of the graphical user interface, or GUI, and add a data tip to the plot on the point representing the maximum location value of the normal sequence.Using the VolumeResort function, sort all the images and then extract the images from one to the maximum location value. Store the volumes of the valid images with the sorted index, which will help to trace back the important nodules. Move the crosshair to the horizontal axis to browse all the images in the coronal axis.Note that the crosshair is in the same spatial coordinates and moving it on one axis will change the location of the images in the other two axes. Use the VolumeInspect function to display the axial, coronal, and sagittal views of the constructed volume. In the VolumeInspect function, use the default intensity window for the lung in the GUI.Hold the left mouse button to adjust the filter performance and drag it on the axis. Direct data preparation and volume calculation results in lung images appearing in the axial, coronal, and sagittal planes.