Development and Validation of a Mixed Reality Configuration of a Simulator for a Minimally Invasive Spine Surgery Using the Workspace of a Haptic Device and Simulator Users

Most surgical simulators leverage virtual or bench models to simulate reality. This study proposes and validates a method for workspace configuration of a surgical simulator which utilizes a haptic device for interaction with a virtual model and a bench model to provide additional tactile feedback based on planned surgical manoeuvers. Numerical analyses were completed to determine the workspace and position of a haptic device, relative to the bench model, used in the surgical simulator, and the determined configuration was validated using device limitations and user data from surgical and nonsurgical users. For the validation, surgeons performed an identical surgery on a cadaver prior to using the simulator, and their trajectories were then compared to the determined workspace for the haptic device. The configuration of the simulator was determined appropriate through workspace analysis and the collected user trajectories. Statistical analyses suggest differences in trajectories between the participating surgeons which were not affected by the imposed haptic workspace. This study, therefore, demonstrates a method to optimally position a haptic device with respect to a bench model while meeting the manoeuverability needs of a surgical procedure. The validation method identified workspace position and user trajectory towards ideal configuration of a mixed reality simulator.

A bench-to-bedside study about trigger asynchronies induced by the introduction of external gas into the non-invasive mechanical ventilation circuit

Treatments that require the introduction of external gas into the non-invasive ventilation (NIV) circuit, such as aerosol and oxygen therapy, may influence the performance of the ventilator trigger system. The aim of the study was to determine the presence and type of asynchronies induced by external gas in the NIV circuit in a bench model and in a group of patients undergoing chronic NIV. Bench study: Four ventilators (one with two different trigger design types) and three gas sources (continuous flow at 4 and 9 l/min and pulsatile flow at 9 l/min) were selected in an active simulator model. The sensitivity of the trigger, the gas introduction position, the ventilatory pattern and the level of effort were also modified. The same ventilators and gas conditions were used in patients undergoing chronic NIV. Bench: the introduction of external gas caused asynchronies in 35.9% of cases (autotriggering 73%, ineffective effort 27%). Significant differences (p < 0.01) were detected according to the ventilator model and the gas source. In seven patients, the introduction of external gas induced asynchrony in 20.4% of situations (77% autotriggering). As in the bench study, there were differences in the occurrence of asynchronies depending on the ventilator model and gas source used. The introduction of external gas produces alterations in the ventilator trigger. These alterations are variable, and depend on the ventilator design and gas source. This phenomenon makes it advisable to monitor the patient at the start of treatment.

Validation of Bench Training Model for Cleft Palate Surgery

Background Cleft palate is one of the most common congenital malformations worldwide. It can be non-syndromic or it can appear as a part of a syndrome or recurrence pattern. Aim of the Work To provide a valid life-size realistic training model of cleft palate surgery that aids in pre-operative training of residents and improvement of their skills in life surgery. Patients and Methods This interventional pilot study was done after approval of institutional ethics committee in Ain Shams University Hospitals operating theatres and in plastic surgery department’s skill lab for 6 months and obtaining an informed written consent from parents. It was designed to develop a bench model of cleft palate for pre-operative training of surgeons and assess its validity. Results In our study we found that the performance of trainees after using our developed bench model of cleft palate shows statistically significant improvement according to GRITS score by 63.2% compared to those who proceeded to live cases directly without training Conclusion This study further demonstrates the effective use of a novel cleft palate bench model as a training tool. After a single session, we observed improvement in cleft palate procedural skills, confidence, knowledge and time taken to finish the operation among trainees both with and without previous cleft experience. Additional research is needed to assess the durability of these improvements over time, and also the benefit of additional sessions with the bench model.

Trigger Asynchronies Induced by the Introduction of External Gas Into the Non-Invasive Mechanical Ventilation Circuit: A Bench-to-Bedside Study

Background and objective: Treatments that require the introduction of external gas into the non-invasive ventilation (NIV) circuit, such as aerosol and oxygen therapy, may influence the performance of the ventilator trigger system. The aim of the study was to determine the presence and type of asynchronies induced by external gas in the NIV circuit in a bench model and in a group of patients undergoing chronic NIV.Methods: Bench study: Four ventilators (one with two different trigger design types) and three gas sources (continuous flow at 4 and 9 l/min and pulsatile flow at 9 l/min) were selected in an active simulator model. The sensitivity of the trigger, the gas introduction position, the ventilatory pattern and the level of effort were also modified.Clinical study: The same ventilators and gas conditions were used in patients undergoing chronic NIV.Results: Bench: The introduction of external gas caused asynchronies in 35.9% of cases (autotriggering 73%, ineffective effort 27%). Significant differences (p<0.01) were detected according to the ventilator model and the gas source.Clinical study: In seven patients, the introduction of external gas induced asynchrony in 20.4% of situations (77% autotriggering). As in the bench study, there were differences in the occurrence of asynchronies depending on the ventilator model and gas source used.Conclusion: The introduction of external gas produces alterations in the ventilator trigger. These alterations are variable, and depend on the ventilator design and gas source. This phenomenon makes it advisable to monitor the patient at the start of treatment.

Laterite Nickel Mine Sequence Modeling Based on Total Reserve at Block 5A, “Bonus” Pit by Surpac 6.3.2 at PT Bintang Delapan Mineral in Bahodopi District, Morowali Regency, Central Sulawesi

PT. Bintang Delapan Mineral is an active nickel mine company that produces 300,000 tons of nickel per month by open pit method. During the mine operation, the company needs to calculate the reserves periodically due to decreasing nickel reserves in the long time period. Mineral reserves estimation is a process to determine and define the grade and boundary of a mineral deposit. Reserves estimation can be done manually using several methods. One method is called block modeling which presents the estimation process in block model type by applying a mining software, called Surpac 6.3.2. It was able to present the progress of mine site activity (pushback). The result of nickel reserves estimation by Surpac 6.3.2 block modeling is 48730 m3 or equal to 73096 tons. The nickel reserves have an average grade of 1.64%. By this reserve estimation, mine sequences could be created into 7 sequences in considering bench height. Bench model specifications are bench high 4 m, berm 2 m, and 60º slope.