scholarly journals Surgical Guidance for Removal of Cholesteatoma Using a Multispectral 3D-Endoscope

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5334 ◽  
Author(s):  
Eric L. Wisotzky ◽  
Jean-Claude Rosenthal ◽  
Ulla Wege ◽  
Anna Hilsmann ◽  
Peter Eisert ◽  
...  
Keyword(s):  
Broad Band ◽  
Patient Specific ◽  
Surgical Guidance ◽  
3D Endoscope ◽  
Middle Ear Cholesteatoma ◽  
First Results ◽  
System Properties ◽  
Metric Dimensions ◽  
Filter Wheel

We develop a stereo-multispectral endoscopic prototype in which a filter-wheel is used for surgical guidance to remove cholesteatoma tissue in the middle ear. Cholesteatoma is a destructive proliferating tissue. The only treatment for this disease is surgery. Removal is a very demanding task, even for experienced surgeons. It is very difficult to distinguish between bone and cholesteatoma. In addition, it can even reoccur if not all tissue particles of the cholesteatoma are removed, which leads to undesirable follow-up operations. Therefore, we propose an image-based method that combines multispectral tissue classification and 3D reconstruction to identify all parts of the removed tissue and determine their metric dimensions intraoperatively. The designed multispectral filter-wheel 3D-endoscope prototype can switch between narrow-band spectral and broad-band white illumination, which is technically evaluated in terms of optical system properties. Further, it is tested and evaluated on three patients. The wavelengths 400 nm and 420 nm are identified as most suitable for the differentiation task. The stereoscopic image acquisition allows accurate 3D surface reconstruction of the enhanced image information. The first results are promising, as the cholesteatoma can be easily highlighted, correctly identified, and visualized as a true-to-scale 3D model showing the patient-specific anatomy.

Creation of physiologic rhythm by closed loop stimulation in heart failure patients with severe chronotropic incompetence: worldwide first results of a pilot study

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Proff ◽  
B Merkely ◽  
R Papp ◽  
C Lenz ◽  
P.J Nordbeck ◽  
...  
Keyword(s):  
Heart Rate ◽  
Closed Loop ◽  
Funding Source ◽  
Chronotropic Incompetence ◽  
First Results ◽  
The Mean ◽  
Group 2 ◽  
Group 1

Abstract Background The prevalence of chronotropic incompetence (CI) in heart failure (HF) population is high and negatively impacts prognosis. In HF patients with an implanted cardiac resynchronisation therapy (CRT) device and severe CI, the effect of rate adaptive pacing on patient outcomes is unclear. Closed loop stimulation (CLS) based on cardiac impedance measurement may be an optimal method of heart rate adaptation according to metabolic need in HF patients with severe CI. Purpose This is the first study evaluating the effect of CLS on the established prognostic parameters assessed by the cardio-pulmonary exercise (CPX) testing and on quality of life (QoL) of the patients. Methods A randomised, controlled, double-blind and crossover pilot study has been performed in CRT patients with severe CI defined as the inability to achieve 70% of the age-predicted maximum heart rate (APMHR). After baseline assessment, patients were randomised to either DDD-CLS pacing (group 1) or DDD pacing at 40 bpm (group 2) for a 1-month period, followed by crossover for another month. At baseline and at 1- and 2-month follow-ups, a CPX was performed and QoL was assessed using the EQ-5D-5L questionnaire. The main endpoints were the effect of CLS on ventilatory efficiency (VE) slope (evaluated by an independent CPX expert), the responder rate defined as an improvement (decrease) of the VE slope by at least 5%, percentage of maximal predicted heart rate reserve (HRR) achieved, and QoL. Results Of the 36 patients enrolled in the study, 20 fulfilled the criterion for severe CI and entered the study follow-up (mean age 68.9±7.4 years, 70% men, LVEF=41.8±9.3%, 40%/60% NYHA class II/III). Full baseline and follow-up datasets were obtained in 17 patients. The mean VE slope and HRR at baseline were 34.4±4.4 and 49.6±23.8%, respectively, in group 1 (n=7) and 34.5±12.2 and 54.2±16.1% in group 2 (n=10). After completing the 2-month CPX, the mean difference between DDD-CLS and DDD-40 modes was −2.4±8.3 (group 1) and −1.2±3.5 (group 2) for VE slope, and 17.1±15.5% (group 1) and 8.7±18.8% (group 2) for HRR. Altogether, VE slope improved by −1.8±2.95 (p=0.31) in DDD-CLS versus DDD-40, and HRR improved by 12.9±8.8% (p=0.01). The VE slope decreased by ≥5% in 47% of patients (“responders to CLS”). The mean difference in the QoL between DDD-CLS and DDD-40 was 0.16±0.25 in group 1 and −0.01±0.05 in group 2, resulting in an overall increase by 0.08±0.08 in the DDD-CLS mode (p=0.13). Conclusion First results of the evaluation of the effectiveness of CLS in CRT patients with severe CI revealed that CLS generated an overall positive effect on well-established surrogate parameters for prognosis. About one half of the patients showed CLS response in terms of improved VE slope. In addition, CLS improved quality of life. Further clinical research is needed to identify predictors that can increase the responder rate and to confirm improvement in clinical outcomes. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Biotronik SE & Co. KG

scholarly journals Risk Factors for Failure in Conservatively Treated Osteoporotic Vertebral Fractures: A Systematic Review

2021 ◽  
pp. 219256822098227
Author(s):  
Max J. Scheyerer ◽  
Ulrich J. A. Spiegl ◽  
Sebastian Grueninger ◽  
Frank Hartmann ◽  
Sebastian Katscher ◽  
...  
Keyword(s):  
Risk Factors ◽  
Systematic Review ◽  
Treatment Failure ◽  
Patient Specific ◽  
Mineral Density ◽  
Radiographic Findings ◽  
Specific Risk ◽  
Fracture Development ◽  
Predict Treatment Failure

Study Design: Systematic review. Objectives: Osteoporosis is one of the most common diseases of the elderly, whereby vertebral body fractures are in many cases the first manifestation. Even today, the consequences for patients are underestimated. Therefore, early identification of therapy failures is essential. In this context, the aim of the present systematic review was to evaluate the current literature with respect to clinical and radiographic findings that might predict treatment failure. Methods: We conducted a comprehensive, systematic review of the literature according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) checklist and algorithm. Results: After the literature search, 724 potentially eligible investigations were identified. In total, 24 studies with 3044 participants and a mean follow-up of 11 months (range 6-27.5 months) were included. Patient-specific risk factors were age >73 years, bone mineral density with a t-score <−2.95, BMI >23 and a modified frailty index >2.5. The following radiological and fracture-specific risk factors could be identified: involvement of the posterior wall, initial height loss, midportion type fracture, development of an intravertebral cleft, fracture at the thoracolumbar junction, fracture involvement of both endplates, different morphological types of fractures, and specific MRI findings. Further, a correlation between sagittal spinal imbalance and treatment failure could be demonstrated. Conclusion: In conclusion, this systematic review identified various factors that predict treatment failure in conservatively treated osteoporotic fractures. In these cases, additional treatment options and surgical treatment strategies should be considered in addition to follow-up examinations.

scholarly journals Brain Tumor Resection in Elderly Patients: Potential Factors of Postoperative Worsening in a Predictive Outcome Model

Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2320
Author(s):  
Paolo Ferroli ◽  
Ignazio Gaspare Vetrano ◽  
Silvia Schiavolin ◽  
Francesco Acerbi ◽  
Costanza Maria Zattra ◽  
...  
Keyword(s):  
Brain Tumor ◽  
Postoperative Complications ◽  
Elderly Patients ◽  
Performance Status ◽  
Tumor Resection ◽  
Patient Specific ◽  
Invasive Treatment ◽  
Tertiary Referral Center ◽  
Surgical Complexity

The decision of whether to operate on elderly patients with brain tumors is complex, and influenced by pathology-related and patient-specific factors. This retrospective cohort study, based on a prospectively collected surgical database, aims at identifying possible factors predicting clinical worsening after elective neuro-oncological surgery in elderly patients. Therefore, all patients ≥65 years old who underwent BT resection at a tertiary referral center between 01/2018 and 12/2019 were included. Age, smoking, previous radiotherapy, hypertension, preoperative functional status, complications occurrence, surgical complexity and the presence of comorbidities were prospectively collected and analyzed at discharge and the 3-month follow-up. The series included 143 patients (mean 71 years, range 65–86). Sixty-five patients (46%) had at least one neurosurgical complication, whereas 48/65 (74%) complications did not require invasive treatment. Forty-two patients (29.4%) worsened at discharge; these patients had a greater number of complications compared to patients with unchanged/improved performance status. A persistent worsening at three months of follow-up was noted in 20.3% of patients; again, this subgroup presented more complications than patients who remained equal or improved. Therefore, postoperative complications and surgical complexity seem to influence significantly the early outcome in elderly patients undergoing brain tumor surgery. In contrast, postoperative complications alone are the only factor with an impact on the 3-month follow-up.

scholarly journals The STAFF-DWP wave instrument on the DSP equatorial spacecraft: description and first results

2005 ◽  
Vol 23 (8) ◽  
pp. 2785-2801 ◽  
Author(s):  
N. Cornilleau-Wehrlin ◽  
H. St. Alleyne ◽  
K. H. Yearby ◽  
B. de la Porte de Vaux ◽  
A. Meyer ◽  
...  
Keyword(s):  
Electromagnetic Waves ◽  
Broad Band ◽  
Temporal Analysis ◽  
Time Interval ◽  
Magnetic Fluctuations ◽  
Quiet Time ◽  
Waveform Data ◽  
Power Intensity ◽  
First Case ◽  
First Results

Abstract. The STAFF-DWP wave instrument on board the equatorial spacecraft (TC1) of the Double Star Project consists of a combination of 2 instruments which are a heritage of the Cluster mission: the Spatio-Temporal Analysis of Field Fluctuations (STAFF) experiment and the Digital Wave-Processing experiment (DWP). On DSP-TC1 STAFF consists of a three-axis search coil magnetometer, used to measure magnetic fluctuations at frequencies up to 4 kHz and a waveform unit, up to 10 Hz, plus snapshots up to 180 Hz. DWP provides several onboard analysis tools: a complex FFT to fully characterise electromagnetic waves in the frequency range 10 Hz-4 kHz, a particle correlator linked to the PEACE electron experiment, and compression of the STAFF waveform data. The complementary Cluster and TC1 orbits, together with the similarity of the instruments, permits new multi-point studies. The first results show the capabilities of the experiment, with examples in the different regions of the magnetosphere-solar wind system that have been encountered by DSP-TC1 at the beginning of its operational phase. An overview of the different kinds of electromagnetic waves observed on the dayside from perigee to apogee is given, including the different whistler mode waves (hiss, chorus, lion roars) and broad-band ULF emissions. The polarisation and propagation characteristics of intense waves in the vicinity of a bow shock crossing are analysed using the dedicated PRASSADCO tool, giving results compatible with previous studies: the broad-band ULF waves consist of a superimposition of different wave modes, whereas the magnetosheath lion roars are right-handed and propagate close to the magnetic field. An example of a combined Cluster DSP-TC1 magnetopause crossing is given. This first case study shows that the ULF wave power intensity is higher at low latitude (DSP) than at high latitude (Cluster). On the nightside in the tail, a first wave event comparison - in a rather quiet time interval - is shown. It opens the doors to future studies, such as event timing during substorms, to possibly determine their onset location.

Exploring the Perth Hamstring Assessment Tool and Lower Extremity Functional Scale in a Proximal Hamstring Avulsion Cohort: A Cross-sectional Study

2021 ◽  
pp. 036354652110085
Author(s):  
Elsa Pihl ◽  
Kenneth B. Jonsson ◽  
Mida Berglöf ◽  
Nina Brodin ◽  
Olof Sköldenberg ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Assessment Tool ◽  
Patient Specific ◽  
Activity Limitations ◽  
Functional Tests ◽  
Functional Scale ◽  
Proximal Hamstring Avulsion ◽  
Proximal Hamstring ◽  
Lower Extremity Functional Scale

Background: The goal of treatment for a proximal hamstring avulsion (PHA) is an objectively restored muscle and a subjectively satisfied, pain-free patient at follow-up. Different self-reported and performance-based outcome measures have been used to evaluate recovery, but their validity is poorly investigated. Purpose: To investigate 1) the correlation between the commonly used self-reported outcome measurements, the Perth Hamstring Assessment Tool (PHAT) and the Lower Extremity Functional Scale (LEFS); 2) to what extent these scores can be explained by physical dysfunction as measured by performance-based tests; 3) whether performance-based tests can discriminate between the injured and uninjured extremity; and 4) which activity limitations are perceived by patients several years after the injury. Study design: Cohort study (Diagnosis); Level of evidence, 3. Methods: We included a consecutive series of patients treated for or diagnosed with PHA in our department between 2007 and 2016 having at least 2 tendons avulsed from the ischial tuberosity. Participants attended 2 study visits, answered questionnaires (PHAT, LEFS, and Patient-Specific Functional Scale [PSFS]), and performed physical performance–based tests (single-leg hop tests, single–step down test, and isometric and isokinetic strength tests). Results: A total of 50 patients were included (26 men [52%], 24 women [48%]; mean age, 50.9 years [SD, 9.8 years]). The mean follow-up time was 5.5 years (SD, 2.7 years), and 74% had been surgically treated. The correlation between PHAT and LEFS was strong ( r = 0.832) and statistically significant ( P < .001). Seven of the performance-based tests exhibited a statistically significant but weak correlation with LEFS (0.340-0.488) and 3 of the tests to PHAT (–0.304 to 0.406). However, only peak torque could significantly discriminate between the extremities. The activity limitation most commonly mentioned in PSFS was running (16 patients [32%]). Conclusion: Although PHAT and LEFS correlated strongly, the correlations between functional tests and the patient-reported outcome scores were weak, and most functional tests failed to discriminate between the injured and uninjured lower extremity in patients with PHA 5 years after injury. In general, patients alleged few activity limitations, but running difficulty was a common sequela after PHA.

The Near-Earth Objects Follow-Up Program: First Results

Icarus ◽  
1995 ◽  
Vol 117 (1) ◽  
pp. 62-70 ◽  
Author(s):  
S Mottola
Keyword(s):  
First Results ◽  
Near Earth Objects

scholarly journals A multispectral 3D-Endoscope for Cholesteatoma Removal

2020 ◽  
Vol 6 (3) ◽  
pp. 257-260
Author(s):  
Eric L. Wisotzky ◽  
Jean-Claude Rosenthal ◽  
Anna Hilsmann ◽  
Peter Eisert ◽  
Florian C. Uecker
Keyword(s):  
Multispectral Imaging ◽  
Narrow Band ◽  
Tissue Classification ◽  
Step Size ◽  
3D Endoscope ◽  
Before And After ◽  
Overlay Technique ◽  
Ct Data ◽  
Metric Dimensions ◽  
20 Nm

AbstractWe present a stereo-multispectral endoscopic prototype using a filter-wheel to guide the removal of cholesteatoma tissue in the middle ear. An image-based method is used that combines multispectral tissue classification for the detection of tissue to be removed and 3Dreconstruction to determine its metric dimensions. The multispectral illumination used for tissue classification ranges from λ = 400 nm to λ = 500 nm with step-size of 20 nm, which results in six different narrow-band illumination modes. For classical RGB imaging and metric calculations, a broadband illumination mode is applied before and after the narrow-band illumination. The spectral information is augmented into the broadband mode using an overlay technique. The combination of multispectral imaging with stereoscopic 3D-reconstruction results in new valuable visualization of intraoperative data. This allows to generate a 3D-model of the patients anatomy highlighting the identified malicious tissue and compare the anatomical dimensions with pre-operative CT data.

scholarly journals Baseline local hemodynamics as predictor of lumen remodeling at 1-year follow-up in stented superficial femoral arteries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Monika Colombo ◽  
Yong He ◽  
Anna Corti ◽  
Diego Gallo ◽  
Stefano Casarin ◽  
...  
Keyword(s):  
Predictive Marker ◽  
Patient Specific ◽  
Lumen Area ◽  
Major Drawback ◽  
Area Change ◽  
Stent Restenosis ◽  
Computed Tomography Images ◽  
Relative Residence Time ◽  
The Impact

AbstractIn-stent restenosis (ISR) is the major drawback of superficial femoral artery (SFA) stenting. Abnormal hemodynamics after stent implantation seems to promote the development of ISR. Accordingly, this study aims to investigate the impact of local hemodynamics on lumen remodeling in human stented SFA lesions. Ten SFA models were reconstructed at 1-week and 1-year follow-up from computed tomography images. Patient-specific computational fluid dynamics simulations were performed to relate the local hemodynamics at 1-week, expressed in terms of time-averaged wall shear stress (TAWSS), oscillatory shear index and relative residence time, with the lumen remodeling at 1-year, quantified as the change of lumen area between 1-week and 1-year. The TAWSS was negatively associated with the lumen area change (ρ = − 0.75, p = 0.013). The surface area exposed to low TAWSS was positively correlated with the lumen area change (ρ = 0.69, p = 0.026). No significant correlations were present between the other hemodynamic descriptors and lumen area change. The low TAWSS was the best predictive marker of lumen remodeling (positive predictive value of 44.8%). Moreover, stent length and overlapping were predictor of ISR at follow-up. Despite the limited number of analyzed lesions, the overall findings suggest an association between abnormal patterns of WSS after stenting and lumen remodeling.

Abstract 562: Human Carotid Atherosclerosis Plaque Progression and Vessel Material Stiffness at Follow Up Had Positive Correlation: An in vivo Vessel Stiffness MRI Follow Up Study

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Qingyu Wang ◽  
Dalin Tang ◽  
Gador Canton ◽  
Jian Guo ◽  
Xiaoya Guo ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Material Properties ◽  
Stretch Ratio ◽  
Patient Specific ◽  
Plaque Progression ◽  
Material Stiffness ◽  
Variation Rate ◽  
Vessel Material

It is hypothesized that artery stiffness may be associated with plaque progression. However, in vivo vessel material stiffness follow-up data is lacking in the literature. In vivo 3D multi-contrast and Cine magnetic resonance imaging (MRI) carotid plaque data were acquired from 8 patients with follow-up (18 months) with written informed consent obtained. Cine MRI and 3D thin-layer models were used to determine parameter values of the Mooney-Rivlin models for the 81slices from 16 plaques (2 scans/patient) using our established iterative procedures. Effective Young’s Modulus (YM) values for stretch ratio [1.0,1.3] were calculated for each slice for analysis. Stress-stretch ratio curves from Mooney-Rivlin models for the 16 plaques and 81 slices are given in Fig. 1. Average YM value of the 81 slices was 411kPa. Slice YM values varied from 70 kPa (softest) to 1284 kPa (stiffest), a 1734% difference. Average slice YM values by vessel varied from 109 kPa (softest) to 922 kPa (stiffest), a 746% difference. Location-wise, the maximum slice YM variation rate within a vessel was 306% (139 kPa vs. 564 kPa). Average slice YM variation rate within a vessel for the 16 vessels was 134%. Average variation of YM values from baseline (T1) to follow up (T2) for all patients was 61.0%. The range of the variation of YM values was [-28.4%, 215%]. For progression study, YM increase (YMI=YM T2 -TM T1 ) showed negative correlation with plaque progression measured by wall thickness increase (WTI), (r= -0.6802, p=0.0634). YM T2 showed strong negative correlation with WTI (r= -0.7764, p=0.0235). Correlation between YM T1 and WTI was not significant (r= -0.4353, p= 0.2811). Conclusion In vivo carotid vessel material properties have large variations from patient to patient, along the vessel segment within a patient, and from baseline to follow up. Use of patient-specific, location specific and time-specific material properties could potentially improve the accuracy of model stress/strain calculations.

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