Illustrating orientation changes of the insertion trajectory during cochlear implant electrode array insertion

Introduction: Recent investigations focused on the optimization of atraumatic cochlear implant surgery have highlighted the relevance of the electrode array (EA) insertion trajectory. This is particularly studied in the context of minimally-invasive “keyhole” and robotic-assisted approaches, e.g. to avoid injuring structures inside and outside the cochlea. However, little is known about the natural, manual movements and trajectory followed during the insertion process. The present work illustrates the orientation changes within the trajectory a surgeon follows during insertions of EAs into a human cadaveric cochlea. Methods: An EA insertion tool equipped with a gyroscope was developed in our laboratory. During the insertion trials, the gyroscope captures the tool’s spatial orientation. A human head specimen and a single EA were used to perform insertions into a cochlea. A cochlear implant surgeon performed all insertion trials. The recorded orientations were compared to the initial orientation upon cochlea entry to assess the surgeon’s range of motion by calculating the angle between orientation vectors. Results: Fifteen EA insertions were performed with a median maximal deviation from the initial orientation of 7.2° (5.3 -11.1°) across trials. The largest orientation changes were seen towards the last half of each insertion trial. A negative relationship between degree of axis change and number of insertion trial was observed (r = -0.5). Conclusion: Manual EA insertions into a cadaveric cochlea revealed an insertion trajectory with maximum orientation changes of approximately < 10° degrees. The observed trend on decreasing range of motion with increasing number of insertion trials may be attributed to surgeon’s familiarization with the insertion trajectory for this specific specimen but other contributing factors (e.g. EA softening) need to be further elucidated with several EAs. Future evaluations can help determine if this orientation change is influenced by surgeon expertise.

Volunteering as an Explanatory Factor of Social Entrepreneurship: An Analysis of an Educational Context

The promotion of entrepreneurial intention in educational contexts is a priority that is increasingly present in academic planning, especially at university level. Furthermore, social entrepreneurship has been gaining prominence not only as a formula for improving the welfare and equity of society as a whole, but also as a mechanism for professional development. Taking into account both aspects, this paper analyzes the effect of university students participating in volunteer activities on their intention to carry out social entrepreneurship projects. With this objective, this study is based on the Theory of Planned Action of Ajzen. A sample of 208 university students was analyzed, 96 of whom had some experience of volunteering. The results confirm that taking part in volunteering, during students’ education, positively affects their intention to start social entrepreneurship projects. This result allows us to conclude that encouraging volunteering could be a good methodological tool to promote social entrepreneurship within the educational field. In addition, the implementation of this type of social project could benefit university students not only by making social improvements to their environment, but also as a labor insertion tool.

Hydraulic insertions of cochlear implant electrode arrays into the human cadaver cochlea: preliminary findings

Objectives (1) To evaluate the feasibility of a non-invasive, novel, simple insertion tool to perform automated, slow insertions of cochlear implant electrode arrays (EA) into a human cadaver cochlea; (2) to estimate the handling time required by our tool. Methods Basic science study conducted in an experimental OR. Two previously anonymized human cadaver heads, three commercially available EAs, and our novel insertion tool were used for the experiments. Our tool operates as a hydraulic actuator that delivers an EA at continuous velocities slower than manually feasible. Intervention(s): the human cadaver heads were prepared with a round-window approach for CI surgery in a standard fashion. Twelve EA insertion trials using our tool involved: non-invasive fixation of the tool to the head; directing the tool to the round window and EA mounting onto the tool; automated EA insertion at approximately 0.1 mm/s driven by hydraulic actuation. Outcome measurement(s): handling time of the tool; post-insertion cone-beam CT scans to provide intracochlear evaluation of the EA insertions. Results Our insertion tool successfully inserted an EA into the human cadaver cochlea (n = 12) while being attached to the human cadaver head in a non-invasive fashion. Median time to set up the tool was 8.8 (7.2–9.4) min. Conclusion The first insertions into the human cochlea using our novel, simple insertion tool were successful without the need for invasive fixation. The tool requires < 10 min to set up, which is clinically acceptable. Future assessment of intracochlear trauma is needed to support its safety profile for clinical translation.

Real-world experience with the insertion of a new implantable cardiac monitor

Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Biotronik SE & Co.KG OnBehalf BIO|CONCEPT.BIOMONITOR III study group, BIO|MASTER.BIOMONITOR III study group, BIO|STREAM-ICM study group Background Implantable Cardiac Monitors (ICM) provide continuous long-term heart rhythm monitoring. The new ICM BIOMONITOR III / IIIm (BM III) is provided with a single-step insertion tool. Purpose To report on the insertion procedure of the BM III in a large real-world patient population. Methods The BM III combines a low cross-section (4.5 x 8.5 mm) with an extended ICM length (77 mm, including flexible antenna). It is inserted into subcutaneous tissue with an ‘injection’ tool that forms the pocket and delivers the device in a single step. We report results of the insertion procedure from a pooled data set from the BIO|CONCEPT BM III (completed) and the BIO|MASTER BM III and BIO|STREAM-ICM (ongoing) studies. Results From 54 investigational sites in 11 countries, 455 insertions were reported (including 39 BM IIIm). The patients were 63 ± 16 years old, had a BMI of 27.6 ± 5.4, and 43% were women. The indications were syncope or pre-syncope (57%), cryptogenic stroke (23%), management of AF (11%) or other (9%). Insertions took 1.7 ± 1.8 minutes until removal of the insertion tool, 4.7 ± 3.4 minutes until wound closure, and 7.1 ± 5.6 minutes including wound cleaning. The wound was sutured (79%) or closed with staples (10%) or adhesive strips (10%). General anaesthesia was used in 8% of the patients and antibiotic prophylaxis in 50% (44% systemic and 6% local). Insertions took place in the catheter laboratory (62%), operating theatre (22%) or in a consultation room (16%) without specific precautional equipment. The insertion site was parallel to the heart"s long axis (56%), parasternal (39%), in the 2nd/3rd intercostal space (3.5%), axillary (0.9%) or at the clavicula (0.7%). The device was repositioned in one case (0.2%). 13 adverse events were reported in connection to the insertion procedure. 5 cases of device pocket bleeding or hematoma occurred. In 5 further cases, the device migrated, posing the risk of extrusion, or actually extruded. Three of these cases used only adhesive strips or no wound closure at all. In two cases, an incorrect usage of the incision tool and substantial subcutaneous fatty tissue may have contributed. One device was damaged by a 200 J defibrillation shock with a shock electrode placed over the device. One patient suffered from dyspnoea, possibly due to psychogenic hyperventilation. One patient had a vasovagal syncope due to pain after an insertion with insufficient local anaesthesia. No infections were reported until the day of analysis, which was more than 30 days after insertion in 92% of all cases. Conclusion The new BM III was inserted in typically less than 5 minutes until wound closure. A relevant number of insertions took place in a consultation room. Prophylactic antibiotics may be unnecessary, because no pocket infections were reported, although no antibiotic prophylaxis was used in one half of all cases (N = 229). In summary, the insertion with the new tool is fast and has a low risk of complications.

Clinical Translation of an Insertion Tool for Minimally Invasive Cochlear Implant Surgery

The objective of this paper is to describe the development of a minimally invasive cochlear implant surgery (MICIS) electrode array insertion tool concept to enable clinical translation. First, analysis of the geometric parameters of potential MICIS patients (N = 97) was performed to inform tool design, inform MICIS phantom model design, and provide further insight into MICIS candidacy. Design changes were made to the insertion tool based on clinical requirements and parameter analysis results. A MICIS phantom testing model was built to evaluate insertion force profiles in a clinically realistic manner, and the new tool design was evaluated in the model and in cadavers to test clinical viability. Finally, after regulatory approval, the tool was used for the first time in a clinical case. Results of this work included first, in the parameter analysis, approximately 20% of the population was not considered viable MICIS candidates. Additionally, one 3D printed tool could accommodate all viable candidates with polyimide sheath length adjustments accounting for interpatient variation. The insertion tool design was miniaturized out of clinical necessity and a disassembly method, necessary for removal around the cochlear implant, was developed and tested. Phantom model testing revealed that the force profile of the insertion tool was similar to that of traditional forceps insertion. Cadaver testing demonstrated that all clinical requirements (including complete disassembly) were achieved with the tool, and the new tool enabled 15% deeper insertions compared to the forceps approach. Finally, and most importantly, the tool helped achieve a full insertion in its first MICIS clinical case. In conclusion, the new insertion tool provides a clinically viable solution to one of the most difficult aspects of MICIS.

A simple tool to automate the insertion process in cochlear implant surgery

Purpose Automated insertion of electrode arrays (EA) in cochlear implant surgery is presumed to be less traumatic than manual insertions, but no tool is widely available in the operating room. We sought (1) to design and create a simple tool able to automate the EA insertion process; and (2) to perform preliminary evaluations of the designed prototype. Methods A first prototype of a tool with maximum simplicity was designed and fabricated to take advantage of hydraulic actuation. The prototype facilitates automated forward motion using a syringe connected to an infusion pump. Initial prototype evaluation included: (1) testing of forward motion at different velocities (2) EA insertion trials into an artificial cochlear model with force recordings, and (3) evaluation of device handling, fixation and positioning using cadaver head specimens and a surgical retractor. Alignment of the tool was explored with CT imaging. Results In this initial phase, the prototype demonstrated easy assembly and ability to respond to hydraulic actuation driven by an infusion pump at different velocities. EA insertions at an ultra-slow velocity of 0.03 mm/s revealed smooth force profiles with mean maximum force of 0.060 N ± 0.007 N. Device positioning with an appropriate insertion axis into the cochlea was deemed feasible and easy to achieve. Conclusions Initial testing of our hydraulic insertion tool did not reveal any serious complications that contradict the initially defined design specifications. Further meticulous testing is needed to determine the safety of the device, its reliability and clinical applicability.