Double Lumen
FLEXIBLY DIVIDED DOUBLE LUMEN ENDOTRACHEAL TUBE
Viren Sunil Kalsekar, Joy Lee, Jenny Qiu, Nicholas Ragosta, Javier Ramos, David Taylor Massachusetts Institute of Technology Cambridge, MA, USA
ABSTRACT Endotracheal tubes (ETT), are used to maintain patient airway access during surgical procedures. The design presented here addresses a current need of the gold standard ETT by allowing for the passage of a larger bronchoscope through the inner lumen of the ETT while keeping outer dimensions constant. This design incorporates a flexible membrane with a wavy geometry to ensure a return to the neutral axis, thus allowing for even ventilation of both lungs. Flow tests simulating surgical ventilation conditions were conducted. These results confirmed that adequate air flow could be obtained independent of any pressure differences across the membrane. Tests of the prototype also confirmed that maximum instrumentation diameter was increased through this design when compared to a commercially available ETT with identical outer dimensions (35 Fr). Finite element analysis was conducted to determine the necessary thickness of the membrane for a safe design. One key design feature of the membrane is that its state of maximum deflection (2.1mm) does not significantly hinder airflow through the smaller lumen. Tests to further evaluate the functional requirements of safety and ease of use are currently under way. Methods of manufacturing this design are also under investigation. Keywords: endotracheal tube, flexible membrane, airway access, neutral axis INTRODUCTION Endotracheal tubes (ETT) are used to maintain patient airway access during surgical procedures. During thoracic surgery it is often necessary to ventilate the lungs separately. This allows one lung to be ventilated, while the other may be deflated. [1] Predicts the number of US thoracic surgeries in 2013 to be 38,500. Most of these surgeries use a double lumen endotracheal tube (DLT). The size of the DLT is
Viren Sunil Kalsekar, Joy Lee, Jenny Qiu, Nicholas Ragosta, Javier Ramos, David Taylor Massachusetts Institute of Technology Cambridge, MA, USA
ABSTRACT Endotracheal tubes (ETT), are used to maintain patient airway access during surgical procedures. The design presented here addresses a current need of the gold standard ETT by allowing for the passage of a larger bronchoscope through the inner lumen of the ETT while keeping outer dimensions constant. This design incorporates a flexible membrane with a wavy geometry to ensure a return to the neutral axis, thus allowing for even ventilation of both lungs. Flow tests simulating surgical ventilation conditions were conducted. These results confirmed that adequate air flow could be obtained independent of any pressure differences across the membrane. Tests of the prototype also confirmed that maximum instrumentation diameter was increased through this design when compared to a commercially available ETT with identical outer dimensions (35 Fr). Finite element analysis was conducted to determine the necessary thickness of the membrane for a safe design. One key design feature of the membrane is that its state of maximum deflection (2.1mm) does not significantly hinder airflow through the smaller lumen. Tests to further evaluate the functional requirements of safety and ease of use are currently under way. Methods of manufacturing this design are also under investigation. Keywords: endotracheal tube, flexible membrane, airway access, neutral axis INTRODUCTION Endotracheal tubes (ETT) are used to maintain patient airway access during surgical procedures. During thoracic surgery it is often necessary to ventilate the lungs separately. This allows one lung to be ventilated, while the other may be deflated. [1] Predicts the number of US thoracic surgeries in 2013 to be 38,500. Most of these surgeries use a double lumen endotracheal tube (DLT). The size of the DLT is