Combined indocyanine green and quantitative perfusion assessment with hyperspectral imaging during colorectal resections

Anastomotic insufficiencies still represent one of the most severe complications in colorectal surgery. Since tissue perfusion highly affects anastomotic healing, its objective assessment is an unmet clinical need. Indocyanine green-based fluorescence angiography (ICG-FA) and hyperspectral imaging (HSI) have received great interest in recent years but surgeons have to decide between both techniques. For the first time, two data processing pipelines capable of reconstructing an ICG-FA correlating signal from hyperspectral data were developed. Results were technically evaluated and compared to ground truth data obtained during colorectal resections. In 87% of 46 data sets, the reconstructed images resembled the ground truth data. The combined applicability of ICG-FA and HSI within one imaging system might provide supportive and complementary information about tissue vascularization, shorten surgery time, and reduce perioperative mortality.

Effects of Intra-Abdominal Pressure on Lung Mechanics during Laparoscopic Gynaecology. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2021;2021:2091-2094. [PMID: 34891701 DOI: 10.1109/embc46164.2021.9630753]

Investigating the relations between surgical actions and physiological reactions of the patient is essential for developing pre-emptive model-based systems. In this study, the effects of insufflating abdominal cavity with CO₂ in laparoscopic gynaecology on the respiration system were analysed. Real-time recordings of anaesthesiology and surgical data of five subjects were acquired and processed, and the correlation between lung mechanics and the intra-abdominal pressure was evaluated. Alterations of ventilation settings undertaken by the anaesthesiologist were also considered. Experimental results demonstrated the high correlation with a mean Pearson coefficient of 0.931.Clinical Relevance- This study demonstrates the effects of intra-abdominal pressure during laparoscopy on lung mechanics and enables developing predictive models to promote a greater awareness in operating rooms.

Depression, anxiety, fatigue, and quality of life in a large sample of patients suffering from head and neck cancer in comparison with the general population

BACKGROUND

Treatment of head and neck cancer (HNC) often leads to visible and severe functional impairments. In addition, patients often suffer from a variety of psychosocial problems, significantly associated with a decreased quality of life. We aimed to compare depression, anxiety, fatigue and quality of life (QoL) between HNC patients and a large sample of the general population in Germany and to examine the impact of sociodemographic, behavioral and clinical factors on these symptoms.

METHODS

We assessed data of HNC patients during the aftercare consultation at the Leipzig University Medical Center with a patient reported outcome (PRO) tool named "OncoFunction". Depression, anxiety, fatigue and QoL were assessed using validated outcome measures including the PHQ-9, the GAD-2, and the EORTC QLQ-C30 questionnaire.

RESULTS

A total of 817 HNC patients were included in our study and compared to a sample of 5018 individuals of the general German population. HNC patients showed significantly higher levels of impairment in all dimensions assessed. Examination of association between depression, anxiety, fatigue and QoL and clinical as well as sociodemographic variables showed significant relationships between occupational status, ECOG-state, body mass index and time since diagnosis.

CONCLUSIONS

HNC patients suffer significantly from psychological distress. The used questionnaires are suitable for the use in daily routine practice and can be helpful to increase the detection of depression, anxiety and fatigue and therefore can improve HNC aftercare.

[Possibilities and perspectives of hyperspectral imaging in visceral surgery]

HyperSpectral Imaging (HSI) technology enables quantitative tissue analyses beyond the limitations of the human eye. Thus, it serves as a new diagnostic tool for optical properties of diverse tissues. In contrast to other intraoperative imaging methods, HSI is contactless, noninvasive, and the administration of a contrast medium is not necessary. The duration of measurements takes only a few seconds and the surgical procedure is only marginally disturbed. Preliminary HSI applications in visceral surgery are promising with the potential of optimized outcomes. Current concepts, possibilities and new perspectives regarding HSI technology together with its limitations are discussed in this article.

Distance Measures for Surgical Process Models

Background: The development of new resources, such as surgical techniques and approaches, results in continuous modification of surgery. To assess these modifications, it is necessary to use measures that quantify the impact of resources on surgical processes.

Objectives: The objective of this work is to introduce and evaluate distance measurements that are able to represent differences in the courses of surgical interventions as processes.

Methods: Hence, we present four different distance measures for surgical processes: the Jaccard distance, Levenshtein distance, Adjacency distance, and Graph matching distance. These measures are formally introduced and evaluated by applying them to clinical data sets from laparoscopic training in pediatric surgery.

Results: We analyzed the distances of 450 surgical processes using these four measures with a focus on the difference in surgical processes performed by novices and by experienced surgeons. The Levenshtein and Adjacency distances were best suited to measure distances between surgical processes.

Conclusion: The measurement of distances between surgical processes is necessary to estimate the benefit of new surgical techniques and strategies.

Surgical Workflow Management Schemata for Cataract Procedures

Objective: Workflow guidance of surgical activities is a challenging task. Because of variations in patient properties and applied surgical techniques, surgical processes have a high variability. The objective of this study was the design and implementation of a surgical workflow management system (SWFMS) that can provide a robust guidance for surgical activities. We investigated how many surgical process models are needed to develop a SWFMS that can guide cataract surgeries robustly.

Methods: We used 100 cases of cataract surgeries and acquired patient-individual surgical process models (iSPMs) from them. Of these, randomized subsets iSPMs were selected as learning sets to create a generic surgical process model (gSPM). These gSPMs were mapped onto workflow nets as work-flow schemata to define the behavior of the SWFMS. Finally, 10 iSPMs from the disjoint set were simulated to validate the workflow schema for the surgical processes. The measurement was the successful guidance of an iSPM.

Results: We demonstrated that a SWFMS with a workflow schema that was generated from a subset of 10 iSPMs is sufficient to guide approximately 65% of all surgical processes in the total set, and that a subset of 50 iSPMs is sufficient to guide approx. 80% of all processes.

Conclusion: We designed a SWFMS that is able to guide surgical activities on a detailed level. The study demonstrated that the high inter-patient variability of surgical processes can be considered by our approach.

Application fields for the new Object Management Group (OMG) Standards Case Management Model and Notation (CMMN) and Decision Management Notation (DMN) in the perioperative field

PURPOSE

Medical processes can be modeled using different methods and notations. Currently used modeling systems like Business Process Model and Notation (BPMN) are not capable of describing the highly flexible and variable medical processes in sufficient detail.

METHODS

We combined two modeling systems, Business Process Management (BPM) and Adaptive Case Management (ACM), to be able to model non-deterministic medical processes. We used the new Standards Case Management Model and Notation (CMMN) and Decision Management Notation (DMN).

RESULTS

First, we explain how CMMN, DMN and BPMN could be used to model non-deterministic medical processes. We applied this methodology to model 79 cataract operations provided by University Hospital Leipzig, Germany, and four cataract operations provided by University Eye Hospital Tuebingen, Germany. Our model consists of 85 tasks and about 20 decisions in BPMN. We were able to expand the system with more complex situations that might appear during an intervention.

CONCLUSION

An effective modeling of the cataract intervention is possible using the combination of BPM and ACM. The combination gives the possibility to depict complex processes with complex decisions. This combination allows a significant advantage for modeling perioperative processes.

Online time and resource management based on surgical workflow time series analysis

PURPOSE

Hospitals' effectiveness and efficiency can be enhanced by automating the resource and time management of the most cost-intensive unit in the hospital: the operating room (OR). The key elements required for the ideal organization of hospital staff and technical resources (such as instruments in the OR) are an exact online forecast of both the surgeon's resource usage and the remaining intervention time.

METHODS

This paper presents a novel online approach relying on time series analysis and the application of a linear time-variant system. We calculated the power spectral density and the spectrogram of surgical perspectives (e.g., used instrument) of interest to compare several surgical workflows.

RESULTS

Considering only the use of the surgeon's right hand during an intervention, we were able to predict the remaining intervention time online with an error of 21 min 45 s ±9 min 59 s for lumbar discectomy. Furthermore, the performance of forecasting of technical resource usage in the next 20 min was calculated for a combination of spectral analysis and the application of a linear time-variant system (sensitivity: 74 %; specificity: 75 %) focusing on just the use of surgeon's instrument in question.

CONCLUSION

The outstanding benefit of these methods is that the automated recording of surgical workflows has minimal impact during interventions since the whole set of surgical perspectives need not be recorded. The resulting predictions can help various stakeholders such as OR staff and hospital technicians. Moreover, reducing resource conflicts could well improve patient care.

[Introduction of the Screening Tool OncoFunction for Functional Follow-up of Head and Neck Patients]

INTRODUCTION

The follow-up for head and neck cancer (HNC) focussed on therapy control. Accessory long term functionality is important. Impairment of function is observed, but a comparable documentation is not established. Additional we frequently see psychooncological comorbidities, what complicates the assessment. This was the reason why Tschiesner et al. developed on the base of the "ICF Core set for head and neck cancer" a guideline for the Assessment of Function in HNC. In consequence of good results in other tumour entities we developed an electronic version (OncoFunction).

METHODS

In a proof of concept study all patients of our follow up consultation from 07/13 to 03/14 were included. OncoFunction was given to patients in a digital form using tablet computers. The results were visible to the physician in a concentrated form before consultation and were supplemented by a physician questionnaire. Furthermore we evaluated the usability in 202 patients.

RESULTS

We had 682 patient contacts. 530 patient contacts (77, 7%) used the questionnaire. The physician questionnaire was answered in 470 times. Finally there are from 69.8% of the patient contacts full datasets available. Between users and non-users of the questionnaire we see no difference.

CONCLUSION

The use of a computer-based screening and feedback system (OncoFunction) in clinical use is feasible and excellent assessed by patients. The patient data are visible in a compact form for the physician and problems can clear addressed to the patient. One more benefit is the standardized follow up documentation and the use of comparable data in research.

[The 'Surgical Deck': a new generation of integrated operational rooms for ENT]

BACKGROUND

Existing operating room concepts do not meet modern technological opportunities anymore. The "Surgical Deck" is supposed to represent a prototype for a new operating room generation. The objective of the project is to achieve a better integration of functions and to develop an innovative concept for a highly developed surgical workstation.

MATERIAL AND METHODS

3 working areas are defined: Surgical, Airway and Technical Cockpit. The evaluation was conducted on 284 surgeries carried out from 01.08. 2011 to 31.01. 2012. The evaluation team consisted of 6 surgeons, 3 surgery nurses, 3 anesthesiologists and 4 anesthesia nurses. Within a detailed analysis, the data of 50 FESS surgeries were compared to those of a control group.

RESULTS

Within the FESS group, the average slot time was reduced by 13%. 88.2% of those questioned assessed ergonomics as being better than in the conventional OR. 71.5% stated that the Surgical Deck provided an added value with regard to the surgical procedure. 91.3% confirmed that the system control required additional training. 79.3% described the cost-benefit-ratio as appropriate. For 96% of the surgeries, respondents said that they were feeling adequately supported by the technology.

CONCLUSION

The results show a clear advantage of the system architecture. The Surgical Deck may present a solid foundation with regard to the transfer of the system into the clinical practice. This is relevant for new assistance functions such as process control software or navigation-based collision warning systems. It is to be expected that the project will significantly contribute to further develop the future surgical workstation and its standardization.

Manual accuracy in comparison with a miniature master slave device--preclinical evaluation for ear surgery

Manual accuracy in microsurgery is reduced by tremor and limited access. A surgical approach through the middle ear also puts delicate structures at risk, while the surgeon is often working at an unergonomic position. At this point a micromanipulator could have a positive influence. A system was developed to measure "working accuracy", time and precision during manipulation in the middle ear. 10 ENT-surgeons simulated a perforation of the stapedial footplate on a modified 3D print of a human skull in a mock OR. Each trial was repeated more than 200 times aiming manually and using a micro-manipulator. Data of over 4000 measurements was tested and graphically processed. Work strain was evaluated with a questionnaire. Accuracy for manual and micromanipulator perforation revealed a small difference. Learning curves showed a stronger decrease both in deviation and time when the micromanipulator was used. Also a lower work strain was apparent. The micromanipulator has the potential as an aiding device in ear surgery.

First clinical evaluation of the navigated controlled drill at the lateral skull base

Surgery on the lateral skull base puts delicate structures at risk. To support the surgeon in identifying and protecting the risk structures the principle of Navigated Control (NC) can be used for preventing iatrogenic injuries. In this paper the application of Navigated Control for surgery on the lateral skull base was investigated for the first time in clinical use. There was no risk structure damage with NC. Navigated Control in lateral skull base surgery seems to have a great potential for safe risk structure protection, a morbidity reduction and in a relief of strain for the surgeon.