Marianne Maktabi

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

PurposeHospitals’ 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.MethodsThis 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.ResultsConsidering 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: 74xa0%; specificity: 75xa0%) focusing on just the use of surgeon’s instrument in question.ConclusionThe 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.

Hyperspectral based discrimination of thyroid and parathyroid during surgery

Abstract Unintended injuring of anatomical structures during endocrine neck operations can have severe consequences for patient. Especially the nerves and the parathyroid gland can be hard to identify visually. Therefore, intraoperative methods are needed to support the surgeon in this task. Hyperspectral imaging (HSI) is a new approach in the medical area which combines a camera with a spectrometer. It showed promising results for the discrimination of tissue. In this work, HSI-data of seven patients were acquired during thyroid and parathyroid operations. The mean absorbance spectra of both glands showed differences in the range between 600 and 700 nm and at 760 and 960 nm. This means that thyroid and parathyroid have different oxygenation states and different contents of deoxygenated hemoglobin and water. From these observations, it is possible to define spectral signatures to characterize both glands. We showed on one patient how spectral signatures can be used in classification algorithms to automatically identify the thyroid and parathyroid from other structures.

Hyperspektral-Imaging bei gastrointestinalen Anastomosen

ZusammenfassungEinleitungAnastomoseninsuffizienzen (AIs) sind die schwerwiegendsten Komplikationen in der gastrointestinalen Chirurgie mit assoziierter Verlängerung des stationären Aufenthalts und signifikanter Mortalität. Hyperspektralbildgebung („hyperspectral imaging“, HSI) ist ein relativ neues Bildgebungsverfahren, das für die Erkennung von Strukturen und für die Auswertung der Gewebedurchblutung, -oxygenierung sowie dessen Wasserhaushalts in der Wundtherapie vielversprechende Ergebnisse gezeigt hat. Zur In-vivo-Beurteilung gastrointestinaler Anastomosen liegen allerdings bisher noch keine Daten vor.MethodikEs wurde die intraoperative HS-Bildgebung mit dem TIVITA™ Tissue-Kamerasystem der Firma Diaspective Vision GmbH (Pepelow, Deutschland) angewandt. Bei 47xa0Patienten mit gastrointestinalen (GI) Anastomosen an Ösophagus, Magen, Pankreas, Dünn- und Dickdarm sowie Rektum wurden 97xa0auswertbare Aufnahmen generiert. Es wurden an den Anastomosen die Parameter Gewebeoxygenierung („tissue O2 saturation“, StO2), Gewebe-Hämoglobin-Index („tissue hemoglobin index“, THI), Nahinfrarot-Perfusions-Index („near-infrared[NIR] perfusion index“) und Gewebe-Wasser-Index („tissue water index“, TWI) erhoben.ErgebnisseDie Anwendung der nichtinvasiven HSI war bei allen Anastomosierungen technisch gut praktikabel mit robusten Ergebnissen. Dabei fand sich ein NIR-Gradient längs und quer entlang der Anastomose. Auch die Gewebewasserverteilung und -oxygenierung zeigten spezifische Verläufe rund um die Anastomosenregion.SchlussfolgerungHSI bietet als kontaktfreie, nichtinvasive und kontrastmittellose intraoperative Bildgebungsmethode eine objektive Real-time-Messung physiologischer Anastomosenparameter, die möglicherweise dazu beitragen kann, die „ideale“ Anastomosenregion/-höhe zu determinieren. Hierzu ist eine weitere Etablierung der Methodik in der Viszeralchirurgie mit Generierung von Norm- bzw. Cut-off-Werten für die unterschiedlichen intestinalen Anastomosenarten erforderlich.AbstractIntroductionAnastomotic insufficiency (AI) remains the most feared surgical complication in gastrointestinal surgery, which is closely associated with axa0prolonged inpatient hospital stay and significant postoperative mortality. Hyperspectral imaging (HSI) is axa0relatively new medical imaging procedure which has proven to be promising in tissue identification as well as in the analysis of tissue oxygenation and water content. Until now, no data exist on the in vivo HSI analysis of gastrointestinal anastomoses.MethodsIntraoperative images were obtained using the TIVITA™ tissue system HSI camera from Diaspective Vision GmbH (Pepelow, Germany). In 47xa0patients who underwent gastrointestinal surgery with esophageal, gastric, pancreatic, small bowel or colorectal anastomoses, 97xa0assessable recordings were generated. Parameters obtained at the sites of the anastomoses included tissue oxygenation (StO2), the tissue hemoglobin index (THI), near-infrared (NIR) perfusion index, and tissue water index (TWI).ResultsObtaining and analyzing the intraoperative images with this non-invasive imaging system proved practicable and delivered good results on axa0consistent basis. Axa0NIR gradient along and across the anastomosis was observed and, furthermore, analysis of the tissue water and oxygenation content showed specific changes at the site of anastomosis.ConclusionThe HSI method provides axa0non-contact, non-invasive, intraoperative imaging procedure without the use of axa0contrast medium, which enables axa0real-time analysis of physiological anastomotic parameters, which may contribute to determine the ”ideal“ anastomotic region. In light of this, the establishment of this methodology in the field of visceral surgery, enabling the generation of normal or cut off values for different gastrointestinal anastomotic types, is an obvious necessity.

Frequency based assessment of surgical activities

Abstract In hospitals the duration of surgeries plays a decisive role in many areas, such as patient safety or financial aspects. By utilizing accurate automated online prediction efficient surgical patient care and effective resource management can be attained. In this work several surgical activities during an intervention were examined for their potential to forecast the remaining intervention time. The method used was based on analysing in the frequency domain of time series which represented the status of surgical activities during an intervention. A nonparametric estimation of power spectral density was calculated for single surgical tasks during an intervention. The power spectral densities (PSD) of different surgical activities were compared in a leave-one-out cross validation of forty surgical workflow recordings of lumbar discectomies. The results showed that the activity irrigate with a mean prediction error of 26 min 23 s is best-suited for determining the remainder of the intervention. To construct a scheduling support for a wider range of surgery types the actions conducted by the surgeon’s right and left hand would eminently be more suitable; the error of the action right hand was 41 min 39 s, yet. In conclusion sophistication into the presented frequency based method might support time and resource management in a general manner.