Soft Failure Research Articles

Reliability analysis for systems with interactive competing degradation processes and mixed shock effects

In this article, an extended mixed shock model is investigated, in which the system suffers from mutually dependent competing soft failure and hard failure processes. The system studied degrades gradually with time and the number of shocks coming from the environment. A soft failure occurs when the overall degradation amount surpasses the soft failure threshold of the system. The extended mixed shock model is a combination of a system-state-dependent extreme shock model and a system-state-dependent δ shock model. A hard failure occurs when the magnitude of a single shock exceeds the threshold D(t), or an inter-arrival time between shocks is less than the recovery time threshold The mutual dependency between the soft failure and hard failure processes is reflected in the fact that: (1) the external shock will accelerate the degradation process of the system by causing an abrupt increment of its degradation amount; (2) the system degradation amount determines the thresholds of the extreme shock model and the δ shock model. The system fails when a hard failure or a soft failure occurs. By using the stochastic process theory, the reliability expression and some reliability indices of the system are obtained. Some special cases of the model are also discussed. Finally, a case study of the pier columns of a sea bridge is presented to illustrate the developed model.

Reliability assessment of a system with multi‐shock sources subject to dependent competing failure processes under phase‐type distribution

AbstractFor a system affected by multiple shock sources, the system usually experiences not only one failure process. This paper develops a reliability model for systems with multi‐shock sources subject to dependent competing failure processes (DCFPs). DCFPs consist of two failure modes: soft and hard failures. Multiple shock sources act on the system as follows: assuming there aremshock sources in total, thekth shock source works on the system at first until the system fails, and then the next shock source re‐acts on the system. Unlike the methods in other papers, the phase‐type distribution is used to build the hard failure reliability model in this paper. We consider the time lag of impacts and assume that the impact magnitudes do not exceed the hard failure threshold as an element in the transition matrix. At the same time, consider these two situations to establish a reliability model. In addition, we divide shock magnitudes into three areas: dead, nondeadly, and safe zones. An application example of a micro‐engine is studied to describe the availability of the developed reliability model. And we conduct the sensitivity analysis to exemplify the influence of the performance of the micro‐engine with parameter changing. With the proposed model, the reliability analysis is more efficient with multi‐shock sources subject to DCFPs

Joint optimization of condition-based maintenance and spares inventory for a series–parallel system with two failure modes

In the field of industrial engineering, the joint optimization of maintenance and spares inventory has attracted more and more attention because it can better balance system availability and cost. However existing studies are usually restricted to a single failure mode and a simple maintenance strategy of the single component systems. To bridge these gaps, this paper investigates the joint optimization of condition-based maintenance and spares inventory for a general series–parallel system with two failure modes. Hard failures are self-announcing, and soft failures are generally caused by the degradation of components and only be discovered through inspection. At the time of each periodic inspection, the corresponding corrective maintenance, preventive maintenance and spare parts ordering policy are determined. Upon a hard failure occurs, an opportunistic inspection will be performed, and it will be determined whether to perform maintenance actions based on the degradation level of the components and spares inventory level. Furthermore, the state transition probability and the expected sojourn time can be derived by the formulated semi-Markov decision process. To minimize the expected average cost per unit time, the optimal preventive maintenance and the spares inventory control policies are jointly determined by applying a simulation method. Finally, a numerical experiment is presented to demonstrate the effectiveness and superiority of the proposed joint optimization model.

Robust Through-Fin Avalanche in Vertical GaN Fin-JFET With Soft Failure Mode

We study the inherent ruggedness of the avalanche through the fin channel, a new avalanche mode in a vertical GaN power Fin-JFET, through single-pulse and repetitive avalanche circuit tests. By turning on the gate during avalanche, the major avalanche current path migrates from the p-GaN gate to the n-GaN fin channel. The single-pulse critical avalanche energy density ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {AVA}}$ </tex-math></inline-formula> ) was measured to be 10 J/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , which is the highest reported in GaN transistors. The Fin-JFET withstood over 3700 repetitive avalanche pulses at 70% of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${E}_{\text {AVA}}$ </tex-math></inline-formula> . It exhibits a failure-to-open-circuit signature in single and repetitive avalanche. This soft failure mode allows the device to retain its full breakdown voltage, which is highly desirable for system robustness. By contrast, the through-gate avalanche in Fin-JFETs and the reported avalanche in Si and SiC transistors all show a destructive, failure-to-short-circuit signature. These results show the viability of soft avalanche failure in power devices, provide key robustness references for GaN devices, and suggest the fundamental superiority of moving the avalanche path away from the major blocking junction.

Investigation of SiC Trench MOSFETs' Reliability under Short-Circuit Conditions.

In this paper, the short-circuit robustness of 1200 V silicon carbide (SiC) trench MOSFETs with different gate structures has been investigated. The MOSFETs exhibited different failure modes under different DC bus voltages. For double trench SiC MOSFETs, failure modes are gate failure at lower dc bus voltages and thermal runaway at higher dc bus voltages, while failure modes for asymmetric trench SiC MOSFETs are soft failure and thermal runaway, respectively. The shortcircuit withstanding time (SCWT) of the asymmetric trench MOSFET is higher than that of the double trench MOSFETs. The thermal and mechanical stresses inside the devices during the short-circuit tests have been simulated to probe into the failure mechanisms and reveal the impact of the device structures on the device reliability. Finally, post-failure analysis has been carried out to verify the root causes of the device failure.

A condition-based maintenance model considering multiple maintenance effects on the dependent failure processes

Maintenance is generally assumed to play a positive role, however, in reality, it is also common that maintenance actions have negative impacts. In this paper, a condition-based maintenance model for repairable systems subject to dependent failure processes (soft failure due to system degradation and hard failure due to random shocks) is proposed. It is a unified model with strong compatibility. The effects of maintenance actions with negative or positive effects incurred by inspection, preventive maintenance and corrective maintenance are all considered. In order to show the effects of maintenance actions intuitively, a vector space spanned by the degradation level, deteriorate rate and hard failure threshold is constructed. It can easily show the complex and multiple effects between maintenance impacts. Finally, the model is used to deal with high-voltage transmission lines’ maintenance optimization problem. The results show that the model is feasible and can be applied in the field of maintenance optimization.

Auditory performance after cochlear reimplantation

AimThe aim of this study was to evaluate the impact of cochlear reimplantation (CR) on hearing performance in children and adults with severe to profound hearing loss. Material and MethodsRetrospective observational study. ObjectivesThe main objective of this study was to determine whether there was a difference in hearing performance before and after CR. Secondary objectives were to analyze reasons for CR; to assess correlations between auditory performance and complete electrode reinsertion during CR, age, gender, explantation-to-CR interval, and interval between first implantation and CR; and to assess difference in APCEI score and the French evaluation protocol for implanted patients before and after CR. ResultsComparison of speech perception scores before and after explantation-reimplantation showed no significant difference (P>0.005) at 1 year or at 2 years after CR. In 80% of cases, reimplantation was due to hard implant failure. In other cases, it was undertaken for soft failure (diminished performance but no abnormalities on integrity testing) (8%), medical reasons (6%), or undetermined reasons (6%). There was no significant correlation between auditory performance at 1 or 2 years and complete or incomplete reinsertion of electrodes, age, gender, explantation-to-CR interval, or interval between first implantation and CR (P>0.005). For the adult subgroup, the French evaluation protocol scores did not differ after reimplantation (P=0.62). Likewise, for the child sub-group, APCEI and CAP results did not deteriorate after reimplantation. ConclusionReimplantation had no negative impact on hearing and speech perception, but provided performance equivalent to or better than after initial implantation.

Cochlear implant failure: diagnosis and treatment of soft failures.

SUMMARYObjectiveEarly diagnosis of cochlear implant failures (CIF) is a critical part of post-implantation follow-up. Diagnosis is challenging and time consuming. Our study aimed to describe diagnoses of CIF with emphasis on soft failures (SF), focusing on symptoms, time from symptoms to replacement, and differences between SF and hard failures (HF).MethodsA retrospective review of medical records in a tertiary care referral paediatric medical centre including all patients who experienced CIF during 2000-2020.ResultsOf 1004 CI surgeries, 72 (7.2%) cases of CIF were included, of which 60 CIF were in children (mean age 3.1 years). Twenty-five cases were due to HF, 26 SF, and 21 due to medical reasons. Patients with SF were more likely to present with headache, dizziness, or tinnitus compared with those with HF. Facial stimulation and disconnections were more common in implants from Advanced Bionics, dizziness and tinnitus in Cochlear, and poor progression in Med-El. Mean time from symptoms to implant replacement surgery was longer in cases with SF compared to HF.ConclusionsSF poses a diagnostic challenge. Symptoms such as headache, dizziness, and tinnitus are common. Diagnosis of failure should often be based on assessments of the implant and rehabilitation teams.

Joint optimization of condition-based maintenance policy and buffer capacity for a two-unit series system

The purpose of this paper is to address a joint optimization problem of condition-based maintenance policy and buffer capacity for a two-unit series system. The system consists of two machines and an intermediate buffer, both upstream and downstream machines suffer from soft failure, and maintenance actions are taken according to the deterioration state of the system. Different from previous studies that the maintenance strategy and buffer capacity were always be optimized separately, this paper optimizes the maintenance strategy as well as the buffer capacity. All system states and transition probabilities between them are analyzed based on semi-Markov process, and then the expected cost and sojourn time of the system are constructed. By minimizing the average operation and maintenance cost per unit time of the system, joint optimization decision (i.e., optimal maintenance thresholds of upstream and downstream machines and buffer size) were determined. A practical simulation example of production-buffer-assembly system is used to illustrate the superiority of the proposed joint optimization strategy.

Design Calculation for A (G +10) Building (Encode Steel)

The proposed steel building at Mumbai consisting of G+10 storeys, has a built-up area of about 165m2. The typical floor height is 3m above GL and the total height of the building above GL is 33m.Withreference to given plan, the architectural drawings and structural drawings showing plan, elevation, sectional views and connection drawings are drawn by using AUTOCAD 2017.Design calculations (Dead Load, Live Load, Wind Load, Seismic Load) are calculated manually-As per IS codes which are mentioned in technical details. The rolled steel sections for beam and column has been chosen from IS 12778:2004. High tensile steel grade-E350BR has been used for steel sections. And, the analysis of structure is done by using STAAD.Pro V8i SS5.Design of beam and column are manually calculated-As per IS: 800-2007. And, spread sheet has been created to check the beam and column, whether it is safe or not. The connection designs are calculated-As per IS codes by using Welding-As per IS 9595-1996 and Fasteners-As per IS 3757-1985. Bracings are provided in the ground floor between the column to avoid soft storey failure. The material requirements are mentioned based on the design calculations. The total estimation of the building is 1.11cr.

Transient Analysis of Differentiated Breakdown Model

The single server queueing system is investigated. When the system is idle or while serving a customer, it fails at random. System failure is classified into two types: hard failure and soft failure. Hard failure usually necessitates the repairman's physical presence and takes a long time. Soft failure, on the other hand, takes less time because the system can be restored to operation by simply rebooting it. When the system is being repaired, the server is forced to take a vacation and the repair process begins immediately. The model's transient state probabilities are derived and using the final value theorem of the Laplace transform, steady state probabilities are derived from transient state probabilities. Finally, numerical illustrations are provided to demonstrate the system's behaviour as the parameters' values are varied.

Two shock models for single‐component systems subject to mutually dependent failure processes

AbstractIn this paper, the extreme and shock models are studied, in which systems are subject to dependent hard failure and soft failure processes. Under the extreme shock model, a hard failure occurs if the magnitude of a single shock surpasses a critical level, while under the shock model, a hard failure occurs if the interval time between two successive shocks is smaller than a threshold. Under both shock models, soft failure of a system happens if the total volume of degradation surpasses a given soft failure threshold. The hard and soft failure processes are interdependent owing to the fact that external shock will bring abrupt increment in the degradation path of the system, and on the other hand, the amount of total degradation will affect the hard failure threshold of the system. The failure of the system occurs if a hard failure or a soft failure occurs, whichever happens first. The reliability expressions of the systems under two shock models are derived explicitly. Some reliability indices of the system are calculated by utilizing the probability analysis method. A case study of the sliding spool is provided to illustrate the proposed model.

Hybrid Bio-Inspired Structure Based on Nacre and Woodpecker Beak for Enhanced Mechanical Performance.

Materials with high strength and toughness have always been pursued by academic and industrial communities. This work presented a novel hybrid brick-and-mortar-like structure by introducing the wavy structure of the woodpecker beak for enhanced mechanical performance. The effects of tablet waviness and tablet wave number on the mechanical performance of the bio-inspired composites were analyzed. Compared with nacre-like composites with a flat tablet, the strength, stiffness and toughness of the novel hybrid nacre-like composite with tablet wave surface increased by up to 191.3%, 46.6% and 811.0%, respectively. The novel failure mode combining soft phase failure and tablet fracture revealed the key to the high toughness of composites. Finite element simulations were conducted to further explore the deformation and stress distribution of the hybrid brick-and-mortar-like structure. It showed that the hybrid brick-and-mortar-like structure can achieve a much better load transfer, which leads to greater tensile deformation in tablet before fracture, thus improving strength and energy absorption. These investigations have implications in the design of composites with high mechanical performance for aerospace, automobile and other manufacturing industries.

A dynamic inspection and replacement policy for a two-unit production system subject to interdependence

This paper proposes a dynamic inspection and replacement policy for a production system composed of two nonidentical units and an inventory system. Unit 1 deteriorates gradually and it is subject to soft failure. Unit 2 experiences hard failures that occur following a general lifetime distribution. The degradation processes of the two units are stochastically interdependent. Condition monitoring is performed to reveal the deterioration state of unit 1 when a certain number of production runs complete or when unit 2 fails, whichever comes first. At each inspection epoch, a decision is made on whether to replace unit 1 and/or unit 2. The objective is to jointly optimize the inspection interval and the replacement policy by minimizing the long-run average cost rate. The optimization problem is formulated in the semi-Markov decision process (SMDP) framework. Economic dependence and structural dependence are also integrated into the maintenance model. A matrix-based approximation method is employed to derive the SMDP quantities. The application of the proposed approach to a fuel oil supply system demonstrates the superiority of the proposed approach in saving operation and maintenance costs. The obtained graphical representation of the obtained policy is supportive during maintenance implementation.

A Solution to Poorly Tolerated Lower Limb Amputations: Osseointegrated Prostheses Prove Cost-effective in the United States

PURPOSE: This study is the first cost–benefit analysis of osseointegrated implant (OI) prostheses compared with socket-suspended (SS) prostheses for lower limb amputees in the United States. The use of traditional SS prostheses for patients with transfemoral and transtibial amputations can be complicated by issues like poor fit, tissue damage, and pain at the socket-limb interface. These complications often require management by plastic surgeons. Osseointegration provides an alternative solution by anchoring the prosthesis directly to an implant in the user’s residual limb; this procedure involves both orthopedic and plastic surgery teams. The operation, materials, and maintenance associated with osseointegration can be expensive, but patient-reported data suggest that OI leads to better quality of life in patients who are dissatisfied with their SS prosthesis. METHODS: We used a Monte Carlo model to project costs and lifetime quality-adjusted life years (QALYs) for patients with OI and SS prostheses. Simulation parameters for the base-case scenario were derived from a cohort of 25 patients who underwent osseointegrated implantation following unilateral lower limb amputations at our institution between October 2017 and February 2020. An IRB-approved retrospective chart review was performed on each patient. CPT codes, material costs, length of surgery, and length of inpatient stay were collected for all encounters related to the amputation site. Utilities and SS prosthesis costs were derived from the literature. We calculated and compared incremental cost-effectiveness ratios (ICERs) for OI and SS prostheses. Parameters were varied individually in one-way sensitivity analyses to evaluate the sensitivity of the results to plausible variations in model inputs. RESULTS: Our patients had an average age of 49.6 years at implantation and were followed for 17 months on overage. In total, 84% of patients had traumatic amputations. We found the average cost of osseointegration surgery to be $54,503. An estimated 20% of patients required a pre-implantation residual limb revision surgery, averaging $49,191. Maintenance of a healthy OI prosthesis cost on average $2626 per year. Complication rates per year and average costs were as follows: soft tissue infection (29%, $435), bone/implant infection (11%, $11,721), painful neuroma (14%, $14,659), and mechanical failure (17%, $46,513). In the base-case scenario, the ICER of OI prostheses compared with SS prostheses was $44,660. A cost effectiveness acceptability curve showed that OI was favored over SS in 71% of cases at a willingness-to-pay of $50,000 per QALY. In one-way sensitivity analyses, the ICER was most sensitive to the mechanical failure rate, mechanical failure cost, and alternative yearly SS prosthesis cost. CONCLUSIONS: Our model suggests that osseointegrated implantation can provide a higher quality of life at affordable costs when compared with poorly tolerated SS prostheses in patients with lower limb amputations in the United States. Intraoperative reconstruction and postoperative management by a plastic surgeon is essential to minimize complications and thus improve cost-effectiveness and patient satisfaction. More follow-up must be done to understand the long-term benefits and risks of OI-based prostheses.

The risk for complications and reoperations with the use of mega prostheses in bone reconstructions

BackgroundDespite a relatively high risk for complications and reoperations, mega prostheses are considered a useful method for reconstruction of bone defects after tumour resections. The total number of reoperations has not previously been described, and little is known about the complication rate of mega prostheses used for other indications than primary bone tumours.Questions/purposesThe current retrospective observational study aimed to describe the patient population treated with mega prostheses at Sahlgrenska University Hospital, Sweden, during 14 consecutive years, reports the complications leading to reoperation and the number and type of reoperations for different kinds of complications, and reports on implant survival.MethodsAll patients treated with a mega prosthesis, regardless of surgical indication and anatomical location, at Sahlgrenska University Hospital during the period 2006–2019 were identified. The medical records for all patients were reviewed. Data regarding age, sex, diagnosis, site of disease, bone resection length, chemotherapeutical treatment and postoperative complications including infections and oncological outcome, were collected and evaluated.ResultsOne hundred and fourteen patients treated with 116 mega prostheses were included in the study. The predominant indication for primary surgery with a mega prosthesis was sarcoma of either bone or soft tissue (53.5% of the patients). In total 51 prostheses (44%) did not require any reoperation after the primary surgery. The most common reason for reoperation was infection (22%) followed by soft tissue failure (13%). The risk for prosthetic infection was significantly higher in the group of patients operated due to sarcoma compared with all other indications for surgery regardless of surgical site (p = 0.004).ConclusionThe study reveals a total reoperation rate of 56% after reconstructive surgery using mega prostheses. Despite the high reoperation rates, at the end of the study period, 83% of the patients had still a functioning prosthesis. Therefore, the use of mega prostheses can be considered a reliable method for reconstruction of large bone defects in selected patients.Level of EvidenceLevel IV, therapeutic study.

Speech Audiometrical Results Before and After Reimplantation of Cochlear Implants

Objectives: This study aimed to compare the audiological outcomes of cochlear reimplantation with those of the first cochlear implant (CI). Design: A retrospective analysis was performed on the data of all CI recipients who received the first CI at the age of 8 years or above and who were subsequently reimplanted on the same side. All participants who received their first implant after January 1, 2000, and who were reimplanted before January 1, 2021, were included. CI recipients who were unable to perform an open-set of Flemish monosyllable speech audiometry were excluded. The participants’ clinical files were reviewed in terms of the cause of hearing loss, age at the first and second implantation, device types, the time between the first and second surgery, speech reception scores before and after reimplantation, and the reason for reimplantation. Results: Reimplantation was due to device failure in 19 out of 22 patients, performance decrement in two patients, and medical reasons in one patient. The interval between the first and second CI ranged from 8 to 218 mo. Within-subject analysis showed the speech reception performance with the second CI to be significantly better than that with the first CI at all follow-up time points, with average within-patient gains of 17%, 16%, 12%, and 15% at 3 mo, 9 mo, 3 years, and the highest scores achieved, respectively. After reimplantation, the performance was better than the last results before reimplantation, and this was significant from 9 mo after reimplantation onwards. Three patients (14%) had a performance degradation with the second CI, which was probably owing to (1) difficulties in reimplantation surgery leading to a reduced number of active channels, (2) insufficient experience with the second CI as the reimplantation has been performed recently, and (3) advanced fenestral and retrofenestral otosclerosis. Conclusions: The present study shows that speech reception performance after reimplantation yields faster and better results than the first implant. It takes a couple of months to get better results than those before the reimplantation. Only in a minority of participants, a small deterioration may be observed. It seems that soft failures in the absence of measurable technical abnormalities call for caution with regard to reimplantation.

Cochlear Implant Failure in the Pediatric Population.

Background and ObjectivesIn cochlear implant (CI) surgery, the results and causes of revision and reimplantation may guide surgeons in establishing surgical protocols for revision surgery with safe audiological outcomes. The aim of this study was to review our experience in terms of etiology, surgical strategy, and hearing outcomes in pediatric patients who underwent CI removal and reimplantation.Subjects and MethodsAll patients received implants of the same brand. Pre and postoperative Categories of Auditory Performance score and aided free-field pure tone audiometry thresholds were noted. In vivo integrity tests were performed for each patient and the results of ex vivo tests of each implant were obtained from manufacturer.ResultsA total of 149 CIs were placed in 121 patients aged <18 years. The revision rate in children was 6.7% (10/121 children). Six patients had a history of head injury leading to a hard failure. The causes of reimplantation in others were soft failure (n=1), electrode migration (n=1), infection (n=1), and other (n=1). All patients showed better or similar postreimplantation audiological performance compared with pre-reimplantation results.ConclusionsIt is very important to provide a safe school and home environment and educate the family for reducing reimplantation due to trauma. Especially for active children, psychiatric consultation should be continued postoperatively.

Drilling head knives degradation modelling based on stochastic diffusion processes backed up by state space models

System quality requirements are typically formed by consideration of reliability and safety performance. Failures caused by system weakness, degradation or fatigue may cause undesired, and potentially dangerous, consequences. For various reasons, not all processes of system degradation are easily monitored in the lifecycle of a system. Degradation evolution leads to changes in both performance and reliability characteristics.In this article, we investigate a mining system consisting of dataset records on in-field operational characteristics of a drilling head. We work with these data in order to get a picture of system degradation and actual condition. For data assessment and modelling, we apply both improved and specific new mathematical models. We examine the data using extended and enhanced state space models, which are suitable for system state and condition investigation. Our time series approaches are based on a modified Kalman-type backpropagation recursion. The improved and modified state space models are accompanied by improved forms of selected stochastic diffusion processes. The diffusion processes are used both for degradation modelling and also for forecasting potential failure occurrence. All of these models are expected to help both with deterioration propagation assessment and with the indication of when the degradation of the system under investigation is predicted to reach the critical limit. Such a limit is represented by threshold performance characteristics that may lead to either soft or hard failure with related faults. The outcomes presented in this article may help with i) failure occurrence prediction, ii) residual useful life prognosis, iii) safer system operation, iv) system utilisation rationalisation and v) maintenance forecasting.

Socio-demographic profile and its influences on rehabilitation in children undergoing revision cochlear implantation – MERF experience

IntroductionRevision cochlear implant surgery (RIS) is an unusual and unfortunate event, but not an uncommon occurrence in today's time, with more and more children being implanted. It is accepted that a pediatric cochlear implant recipient may require one or two revision procedures during their lifetime. The indication of RIS can be due to a multitude of causes like trauma, device failure (hard failure or soft failure), infection at the implant site, electrode extrusion, device migration, magnet migration, and upgradation in the technology. Scenarios, where the child is deprived of hearing once again is worrisome for the family. And, they need financial and psychological assistance as well. Aims and objectives(1) To scrutinize the socio-demographic profile of children who underwent RIS. (2)To profile the social, intellectual, and economic backgrounds of these families. Material and methodsA retrospective, observational, non-interventional, cohort study conducted at the Implantation otology department of Madras ENT Research Foundation (MERF), Chennai, Tamil Nadu, India. Data collection: (1) Detailed medical records of all the children who satisfied the inclusion criteria were reviewed.(2)This was followed up by a telephonic interview with the guardian of the consenting patients, to obtain further data based on a customized questionnaire. Sample size: Of the 99 children who underwent RIS, 80 families consented to be part of the study. Statistical analysis:(1) Cause of revision implant surgery and Family system Risk estimate.(2) Correlation of sex, family system, patient non-compliance to habilitation, and residential area with RIS.(3) Correlation of the residential area of the patient with completion of 1-year habilitation. ResultsA significant association observed between RIS and Sex (P = 0.03). A significant co-relation between patient non-compliance to habilitation and cause of revision implant surgery observed (P = 0.02). A significant co-relation was seen between residential area (Rural/Urban) and cause of RIS (P = 0.02). A statistically significant correlation seen with the residential area (Rural/Urban) of the child and completion of 1-year habilitation (P = 0.01). Uni-variant association was found between patients that have completed one year of habilitation, patient compliance, and modified Kuppuswamy Socio-Economic status. ConclusionThe current data has aided in refining our institutional management protocols and predicting high-risk candidates who may need revision surgery in the future. Based on the data, all cochlear implantees and their families especially in the lower socio-economic strata, are now being meticulously educated about device care, the possible reasons for failures, and the importance of timely re-intervention.