Partial Hardware Research Articles

Lateral lumbar and thoracic interbody fusion (LLIF) for thoracolumbar spine trauma (Trauma LLIF): A single-center, retrospective observational cohort study

BackgroundPain, disability and progressive kyphosis is a common problem after traumatic injury of the thoracolumbar (TL-) junction. Surgical treatment may include long-segment posterior or short-segment anterior-posterior fusion. We aim to report our experience with the application of short-segment posterior instrumented fusion with anterior column support using lateral lumbar or thoracic interbody (LLIF) cages. MethodsIn this retrospective, single-center observational cohort study we included consecutive patients treated surgically for traumatic injury of the TL-junction (Th10/11-L2/3) by posterior instrumentation/fusion and LLIF. We measured segmental kyphosis, complications, and outcomes until last follow-up (about 3 years postoperative). ResultsWe identified 61 patients (mean age 39.0 years (SD 13.3); 23 females (37.7%)) with A3 fractures without (n=48; 78.7%) or with additional sagittal split component (n=11; 18.0%. Additional posterior tension band injury was present in n=26 (42.6%). The affected levels of injury were Th12/L1 in n=25 (41.0%) and Th11/12 in n=22 (36.1%). The segmental kyphotic angle was 14.6° (6.7°) preoperative and remained significantly reduced at all times of follow-up at discharge (5.4°±5.5°; p<0.001), at 90 days (7.2°±5.5°; p<0.001), after partial hardware removal (7.2°±6.0°; p<0.001) and at last follow-up (8.1°±6.3°; p<0.001). We noticed a tendency for less progression of kyphosis in the group with two-staged, compared to single-staged bisegmental surgery (mean difference (MD) 3.1° after partial hardware removal, p=0.064). During follow-up, n=11 experienced complications (18%), n=58 (95.1%) had an excellent or good outcome and solid fusion was noticed in n=60 (98.4%). Conclusions“Trauma LLIF” should be considered as possibility for short-segment anterior-posterior fusion for injuries of the TL- junction. We observed most reproducible and long-lasting kyphosis reduction with a temporary bisegmental, two-staged procedure resulting in monosegmental fusion (posterior instrumentation/fusion with delayed LLIF and partial hardware removal to release the non-injured caudal motion segment).

The Use of Salvage Procedures for Wound Complications in Neuromodulation

Wound complications are a prevalent concern for neuromodulation procedures. While removal of the device was recommended, attempts to salvage expensive hardware have become commonplace. We examine our management in wound issues to aid in providing guidance for these situations. We identified 40 patients over an 8-year period in a large neuromodulation practice, who underwent washout or partial salvage of hardware. We examined the efficacy of washout and partial explants on the ability to salvage the implants. Covariates including age, sex, body mass index, smoking status, anticoagulation, and device type were considered. There were 29 washouts and 10 partial hardware removal cases. Washouts were successful in 15/29 cases (51.7%), partial hardware removal was successful in 2/10 cases (20%), and removal with replacement was not successful (0 of 1). Washouts tended to be more successful than partial removal procedures (P= 0.08). In cases of successful washout, the average duration between infectious symptoms and washout was 7.27 ± 2.19days. None of the demographic variables were associated with increased likelihood of washout failure. Our results demonstrate a higher rate of washout failure in those who underwent partial device removal and in the presence of purulence at the surgical site. Further investigation must be conducted to determine the instances in which hardware removal is indicated to prevent failure or removal due to infection. Identification of these parameters will optimize therapeutic benefit and long-term financial impact.

Management of deep surgical site infections of the spine: a Canadian nationwide survey.

Deep surgical site infections after spinal instrumentation represent a significant source of patient morbidity and poorer outcomes. Given lack of evidence or guidelines on the variety of procedural options in the management of deep spine surgical site infections, the purpose of this survey was to document and investigate the use of these techniques across Canada. A 34-question survey evaluating surgical techniques for irrigation and debridement in postoperative thoracolumbar infection was distributed to Canadian adult spine surgeons. Results were analyzed qualitatively, and comparisons by specialty, years of training, and number of cases were completed using Fischer's exact tests. We defined consensus as >70% agreement. We received 53 responses (62% response rate) from a comprehensive sample of Canadian adult spine surgeons. There was a consensus to retain hardware (80%) and interbody implants (93%) in acute infection, to retain interbody implants in chronic/recurrent infection (71%), and application of topical antibiotics in recurrent infection (85%). There was consensus on the use of absorbable suture to close fascia in acute (83%) and chronic (87%) infection. Eighty-five percent of surgeons used nonabsorbable materials such as Nylon or staples for skin closure in chronic infection, however, there was no consensus in acute infection. Surgeons varied significantly in type, volume and pressure of fluids, adjuvant solvents, graft management, use of topical antibiotics acutely, and the use of negative pressure wound therapy. Partial hardware exchange was controversial. Additionally, specialty or surgeon experience had no impact on management strategy. This survey demonstrates significant heterogeneity amongst Canadian adult spine surgeons regarding key steps in the surgical management of deep instrumented spine infection, concordant with scarce literature addressing these steps.

Trans-fracture approach for ORIF of coronal shear fractures of the distal humerus

IntroductionOpen reduction and internal fixation (ORIF) of comminuted coronal shear fractures of the distal humerus is challenging. When a concomitant lateral condyle fracture is present, it may be used for a trans-fracture approach to facilitate exposure and fracture reduction. This study aimed to investigate the frequency of lateral condyle fractures in coronal shear fractures of the distal humerus and analyze fracture reduction, fracture union and clinical results following ORIF through a trans-fracture approach.Materials and methodsAll adult patients who underwent treatment for an acute distal humerus fracture during a three-year period in our level-one trauma center were identified. All fractures were classified according to the Orthopaedic Trauma Association (OTA/AO) fracture classification system and all B3 fractures were classified according to the Dubberley classification. B3 fractures with a concomitant radial condyle fracture were identified. The clinical and radiological results, (Mayo Elbow Performance Score = MEPS, Visual Analogue Scale = VAS, range of motion), complications and revision surgeries were analyzed.Results53 patients (mean age 52 ± 19 years) were identified. 13 fractures (24.5%) were B3 fractures. Four of them (30.8%) had a concomitant radial condyle fracture. All of these patients underwent ORIF with headless cannulated compression screws and a (postero-)lateral locking plate through a trans-fracture approach. At a minimum follow-up of 24 months, the MEPS was 88 ± 12 points, the VAS was 2 ± 1 and the range of motion was 118° ± 12°. All fractures showed anatomic reduction. One patient developed partial avascular necrosis and underwent arthrolysis at 6 months. One patient underwent partial hardware removal and lateral collateral ligament bracing at 6 months.ConclusionsLateral condyle fractures are present in about one third of coronal shear fractures of the distal humerus. This injury can be used for a trans-fracture approach to facilitate exposure and to reliably achieve anatomic fracture reduction.

Bubble-Proof Algorithm for Wave Union TDCs

Nowadays state-of-the-art time-to-digital converters (TDCs) are commonly implemented in field-programmable gate array (FPGA) devices using different variations of the wave union method. To take full advantage of this method many design challenges need to be overcome, one of which is an efficient data encoding. In this work, we describe in detail an effective algorithm to decode raw output data from a newly designed multisampling wave union TDC. The algorithm is able to correct bubble errors and detect any number of transitions, which occur in the wave union TDC output code. This allows us to reach a mean resolution as high as 0.39 ps and a single shot precision of 2.33 ps in the Xilinx Kintex-7 FPGA chip. The presented algorithm can be used for any kind of wave union TDCs and is intended for partial hardware implementation.

Hybrid and Double Modular Redundancy (DMR)-Based Fault-Tolerant Carry Look-Ahead Adder Design

The adder is an essential component of data paths, and as a result of the shrinking size of electronic devices, it is becoming more susceptible to manufacturing defects and soft errors. Thus, the design of fault-tolerant adders is crucial to the correct operation of arithmetic circuits. In this paper, we propose different fault-tolerant carry look-ahead adder designs against single-bit soft errors based on double modular redundancy DMR and hybrid fault-tolerant schemes. In DMR-based design, we combine a partial hardware redundancy scheme with a protected C-element to achieve full soft error masking, while in the hybrid design, we employ a partial hardware redundancy combined with a parity prediction scheme to improve fault tolerance capability of the adder while reducing area overhead. We use two different voter circuits for merging the partial hardware redundancy into the carry generation logic and to achieve higher fault masking rate and lower area overhead in comparison with existing approaches. Simulation results show that the proposed design schemes take precedence over other schemes in terms of failure rate, area overhead and delay overhead.

Partial hardware removal in guided growth surgery: A convenient strategy?

BackgroundTension band plates (TPBs) are frequently used in guided growth (CG) surgeries. Recently, the concept of removing the metaphyseal screw only to stop the growth modulating effect rather than completely removing the implant, has gained popularity. Although this strategy would have certain potential advantages, the associated risks are unknown. The aim of this study is to report the experience of three institutions with this strategy. MethodsA database was compiled with the demographic information of patients treated by guided growth using TBPs between January 2014 and January 2019 at three institutions. The cases where only the metaphyseal screw was removed were identified. The records were reviewed to analyze the indications, demographic data, characteristics of the procedure, complications and need for additional procedures. ResultsWe reviewed 28 partial hardware removals, performed in 10 patients (all male). Initial surgery was indicated for angular deformity (N=6), and leg-length discrepancy (N=4). The average age at the time of surgery was 9.5±2.9 years (range 4–13 years). Three procedures were performed on the distal femur, 3 on the proximal tibia, 2 on the distal tibia, and 20 combined. The average follow-up was 23.3±11 months (range 12–52 months). We observed recurrence of deformities in 7 of 28 (22%) limbs that required re-insertion of the metaphyseal screw. Two patients presented complications from the procedure: soft tissue irritation (N=1) and angular deformity (N=1). Both patients required unplanned surgery. DiscussionPartial hardware removal in guided growth surgery could favor the presentation of complications. The benefits of this strategy must be considered against the possible undesired effects generated by its application. Study designTherapeutic study (Level IV).

Retiro parcial del implante en cirugía de crecimiento guiado: ¿Una estrategia conveniente?

BackgroundTension band plates (TPBs) are frequently used in guided growth (CG) surgeries. Recently, the concept of removing the metaphyseal screw only to stop the growth modulating effect rather than completely removing the implant, has gained popularity. Although this strategy would have certain potential advantages, the associated risks are unknown. The aim of this study is to report the experience of three institutions with this strategy. MethodsA database was compiled with the demographic information of patients treated by guided growth using TBPs between January 2014 and January 2019 at three institutions. The cases where only the metaphyseal screw was removed were identified. The records were reviewed to analyze the indications, demographic data, characteristics of the procedure, complications and need for additional procedures. ResultsWe reviewed 28 partial hardware removals, performed in 10 patients (all male). Initial surgery was indicated for angular deformity (N = 6), and leg-length discrepancy (N = 4). The average age at the time of surgery was 9.5 ± 2.9 years (range 4 to 13 years). Three procedures were performed on the distal femur, 3 on the proximal tibia, 2 on the distal tibia, and 20 combined. The average follow-up was 23.3 ± 11 months (range 12 to 52 months). We observed recurrence of deformities in 7 of 28 (22%) limbs that required re-insertion of the metaphyseal screw. Two patients presented complications from the procedure: soft tissue irritation (N = 1) and angular deformity (N = 1). Both patients required unplanned surgery. DiscussionPartial hardware removal in guided growth surgery could favor the presentation of complications. The benefits of this strategy must be considered against the possible undesired effects generated by its application. Study designTherapeutic study (Level IV).

A new framework of complex system reliability with imperfect maintenance policy

The interactions and dependencies between software and hardware are often neglected in modeling system reliability in the past few decades due to the mathematical complexity. However, many system failures occurred from the interactions or simultaneous occurrences of software and hardware. This paper first proposes a new diagram of categorizing system-level failures and further incorporates such a diagram into the development of complex system reliability framework. System-level failures result from software subsystem, hardware subsystem, and the interactions of software and hardware subsystems. The focus of this study is on the investigation of the interactions failures generated from the interactions of software and hardware subsystems. In addition to the considerations of total hardware failures, software-induced hardware failures, and hardware-induced software failures introduced by Zhu and Pham (Mathematics 7(11):1049, 2019), we further introduce the partial hardware failures that can be respectively induced by hardware and software to explicitly demonstrate the dependencies and interactions between software and hardware. Hence, a new complex system reliability framework is developed based on such system-level failure categorization with the Markov process. Furthermore, the numerical examples are studied to illustrate the impacts on system reliability with the changes of state transition parameters that modeling the interactions of software and hardware subsystems. Finally, we have studied two maintenance policies of the proposed complex system reliability model.

A Cryptography Core Tolerant to DFA Fault Attacks

This work describes a hardware approach for the concurrent fault detection and error correction in a cryptographic core. It has been shown in the literature that transient faults injected in a cryptographic core can lead to the revelation of the encryption key using quite inexpensive equipments. This kind of attack is a real threat to tamper resistant devices like Smart Cards. To tackle such attacks, the cryptographic core must be immune to transient faults. In this work the DES algorithm is taken as a vulnerable cryptosystem case study.We show how an attack against DES is performed through a fault injection campaign. Then, a countermeasure based on partial hardware replication is proposed and applied to DES. Experimental results show the efficiency of the proposed scheme to protect DES against DFA fault attacks. Furthermore, the proposed solution is independent of implementation, and can be applied to other cryptographic algorithms, such as AES.

Antibiotic Impregnated Catheter Coating Technique for Deep Brain Stimulation Hardware Infection: An Effective Method to Avoid Intracranial Lead Removal.

Few studies have proposed alternative salvage methods of deep brain stimulation (DBS) intracranial lead once the infection has already occurred. To assess the effectiveness of antibiotic impregnated catheter coverage of DBS leads in case of hardware infection. Patients with a hardware infection and consequent partial removal of extension and internal pulse generator (IPG) were reviewed. To diagnose an infection, criteria provided by the Guideline for Prevention of Surgical Site Infection were used. We compared the intracranial lead salvage rate between the group that underwent antibiotic catheter lead protection (group A) and the group that did not (group B). A total of 231 DBS surgeries and 339 IPG replacements were performed from January 2012 to January 2017. Twenty-three hardware-related infections (4%) were identified. Nineteen patients (82.6%) underwent partial hardware removal with an attempt to spare intracranial lead. Of these, 8 patients (42.1%) had antibiotic catheter lead coverage (group A) while 11 patients (57.9%) did not receive any antibiotic protection (group B). At 6-mo follow-up, 6 patients had the extension and IPG successfully re-implanted in group A, whereas only 1 patient was successfully re-implanted in group B (75 vs 9.1%; P<.001). The antibiotic impregnated catheter coating technique seems to be effective in avoiding intracranial lead removal in case of IPG or DBS extension-lead junction infection. This method does not require any surgical learning curve, it is safe and relatively inexpensive. Randomized, prospective, larger studies are needed to validate our results.

Building ATMR circuits using approximate library and heuristic approaches

Approximate Triple Modular Redundancy (ATMR), which is the implementation of TMR with approximate versions of the target circuit, has emerged in recent years as an alternative to partial hardware replication where designers can explore reduced area overhead combined with some compromise on fault masking. This work presents a novel approach for implementing approximate TMR that combines the approximate gate library (ApxLib) technique with heuristics. The algorithm initially defines the gates to be approximated using testability and observability measures and then chooses the gate transformation based on the bits difference. Experimental results showed good trade-off between the ATMR schemes efficiency in terms of area and fault masking and the computational effort needed to generate them.

Evaluation of Factors Affecting Local Failure of Radiation for Long Bone Metastasis Following Orthopedic Stabilization

For patients with long-bone metastases who undergo orthopedic stabilization followed by radiotherapy (RT), it is unclear what extent of hardware coverage by the radiation field is needed for optimal tumor control. We investigated factors that contribute to tumor recurrence in a long bone after orthopedic stabilization and RT. One hundred one patients with 107 long-bone metastases managed with orthopedic stabilization followed by RT at our institution from 8/2011 to 3/2017 were included. Patients who did not receive RT within 4 months following orthopedic stabilization and those who did not have follow up imaging at least 3 months following completion of RT were excluded. Local failure (LF) was defined as any in-bone recurrence, whether in-field or out-of-field from radiation. Univariate analysis (UVA) assessing relation of various factors to LF was performed for age, time from surgery to RT, tumor histology, biologically effective dose using an alpha/beta of 10 (BED10; < vs ≥ 39Gy), extent of orthopedic hardware included in RT field (whole vs partial), and which bone contained metastasis. LF among patients with whole versus partial hardware coverage by RT was estimated with the Kaplan-Meier (KM) method and compared using the log-rank test. Median follow-up was 12.3 months (range 2.8 - 47.5). Median time to RT was 1.4 months (range 0.2 – 3.9) and median BED10 was 39 (range 14.4 – 59.5). There were 53 bones (49.5%) that received RT to whole hardware, while 54 (50.5%) received partial hardware RT. Long-bone metastases were located in femur (69%), humerus (21%), tibia (8%), radius (1%), and ulna (1%); 56% were right-sided and 44% left-sided. There were 23 local failures (21.5%) with median time to failure 9.6 months (range 2.8 – 27.2). In bones treated to whole hardware there were 9 local failures (17.0%), while there were 14 local failures (25.9%) in bones treated to partial hardware. Among the 14 local failures in partial hardware treatment, 5 failures were out-of-field or marginal (9.3%). On UVA, LF was not associated with age, time from surgery to RT, tumor histology, BED10, extent of orthopedic hardware coverage, or which bone contained metastasis. KM analysis and log-rank testing showed no statistically significant difference (p=0.30) in freedom from local failure for patients with whole versus partial hardware coverage. This analysis did not find a significant association between extent of hardware coverage and LF, indicating that whole hardware coverage may not be required for treatment of bone metastasis following surgical stabilization. Further study is needed to evaluate what factors may play a role in LF among patients receiving radiation for long bone metastasis following orthopedic stabilization.

Design of approximate-TMR using approximate library and heuristic approaches

Approximate Triple Modular Redundancy (ATMR), which is the implementation of TMR with approximate versions of the target circuit, has emerged in recent years as an alternative to partial hardware replication where designers can explore reduced area overhead combined with some compromise on fault masking. This work presents a novel approach for implementing approximate TMR that combines the approximate gate library (ApxLib) technique with heuristics. The algorithm initially defines the gates to be approximated using testability and observability measures and then choose the gate transformation based on the bits difference. Experimental results compare the proposed new approach with another state of the art technique that uses approximate gate libraries with genetic algorithm showing a good trade-off between the ATMR schemes efficiency in terms of area and fault masking and the computational effort needed to generate them.

Dynamic partial reconfigurable hardware architecture for principal component analysis on mobile and embedded devices

With the advancement of mobile and embedded devices, many applications such as data mining have found their way into these devices. These devices consist of various design constraints including stringent area and power limitations, high speed-performance, reduced cost, and time-to-market requirements. Also, applications running on mobile devices are becoming more complex requiring significant processing power. Our previous analysis illustrated that FPGA-based dynamic reconfigurable systems are currently the best avenue to overcome these challenges. In this research work, we introduce efficient reconfigurable hardware architecture for principal component analysis (PCA), a widely used dimensionality reduction technique in data mining. For mobile applications such as signature verification and handwritten analysis, PCA is applied initially to reduce the dimensionality of the data, followed by similarity measure. Experiments are performed, using a handwritten analysis application together with a benchmark dataset, to evaluate and illustrate the feasibility, efficiency, and flexibility of reconfigurable hardware for data mining applications. Our hardware designs are generic, parameterized, and scalable. Furthermore, our partial and dynamic reconfigurable hardware design achieved 79 times speedup compared to its software counterpart, and 71% space saving compared to its static reconfigurable hardware design.

Ultrasound gel minimizes third body debris with partial hardware removal in joint arthroplasty.

Hundreds of thousands of revision surgeries for hip, knee, and shoulder joint arthroplasties are now performed worldwide annually. Partial removal of hardware during some types of revision surgeries may create significant amounts of third body metal, polymer, or bone cement debris. Retained debris may lead to a variety of negative health effects including damage to the joint replacement. We describe a novel technique for the better containment and easier removal of third body debris during partial hardware removal. We demonstrate hardware removal on a hip joint model in the presence and absence of water-soluble gel to depict the reduction in metal debris volume and area of spread.

Volar Marginal Rim Fracture Fixation With Volar Fragment-Specific Hook Plate Fixation

To review the outcomes of patients treated with a volar hook plate specifically designed to capture volar marginal rim fractures. A retrospective study was performed over 18 months of patients treated with a volar hook plate in the management of AO type B or C distal radius fractures with a volar marginal rim fragment. Clinical and radiographic outcomes were evaluated. The series included 26 wrists in 25 patients, average age 55 years. Average follow-up was 9 months (range, 3-30 mo). Twenty patients had AO type C fractures and 6 had AO type B fractures. All 6 AO type B were B3 fractures. Of the AO type C, 1 had C1, 7 had C2, and 12 had C3. No patients had loss of fixation of the critical volar ulnar corner and there was no evidence of carpal subluxation. Five patients required hardware removal. Four patients experienced hardware irritation requiring removal of all hardware including the volar hook plate. One patient required partial hardware removal that did not include the volar hook plate. All patients with volar hardware irritation had hook plates that were of second-generation design that had a prominent bend, which has since been modified. There were no cases of tendon rupture. Volar marginal rim fragments of intra-articular distal radius fractures are not amenable to standard volar plate fixation. Fragment-specific fixation using a volar hook plate designed specifically for these fragments allowed for stable fixation when combined with other fragment-specific fixation techniques. There was no loss of fixation of the critical corner in this series. Although hardware irritation can occur, fully seated hooks and subsequent modification of the design of the hook bend has diminished this complication. Therapeutic IV.

Design of Embedded Smart Home System Based on Internet of Things

This paper presents an Embedded Smart Home system solution using the Internet of things. The Smart Home system can be sectioned into four parts: wireless sensor network, embedded smart gateway, Server and Client. The major technical of the wireless sensor network is ZigBee. The wireless sensor network is developed based on the Z-Stack protocol stack and the wireless chip CC2530. Its main work is to sensor the environmental parameter of the house and the automation control of the electrical equipment in the house. It can also support the RFID access control and camera monitor. ARM microprocessor is the core of the Embedded Smart Home control system. It adopts the embedded Linux technology, the development platform is Qt. The gateway communicates with the wireless sensor network by the serial port. It communicates with Server by the TCP socket and transmits to each client, or communicates with the client by using the wireless communication module directly. It also provides the user interface for sensor data check and real time control equipment. The server plays a role of bridge. It is mainly responsible for the communication and big data processing between the client and the control center. Partial hardware electric diagram and software flowchart were provided. Field using indicates that this system is economical and flexible.

Application of Wireless Sensor Network in Embedded Smart Home System

This paper presents an Embedded Smart Home system solution using wireless sensor network (WSN). The Smart Home system can be sectioned into four parts: wireless sensor network, embedded smart control centre, Server and Client. The major technical of the wireless sensor network is ZigBee. The wireless sensor network includes coordinator node and Sensor node. It is developed based on the Z-Stack protocol stack and the wireless chip CC2530. It is mainly responsible for collecting the environmental parameter of the house and controlling the electrical equipment in the house. It can also support the RFID access control and camera monitor. The control centre communicates with the wireless sensor network by the serial port. It communicates with Server by the TCP socket and transmits data to each client, or communicates with the client by using the wireless communication module directly. Partial hardware electric diagram and software flowchart were provided. Field using indicates that this system is economical and flexible.

Performance Analysis of VBLAST Based MIMO OFDM System in Vehicular Channel

Vehicular communication is emerging as an important ingredient for successful implement of Intelligent Transportation Systems(ITS). But the development of suitable communications systems plays an important role in mobility condition. The desired system should support dynamic wireless exchange of data between nearby vehicles or road side infrastructure. In this regards multiple input and multiple output (MIMO) orthogonal frequency domain multiplexing (OFDM) system is possibly the best solution. This paper deals with the performance analysis of the MIMO OFDM system in Nakagami-m channel with Doppler shift and also partial hardware implementation of baseband signal processing.