Microjet wound therapy versus sharp debridement on wound size reduction: a pilot randomised controlled trial

OBJECTIVE

There are several methods of treating hard-to-heal (chronic) wounds, each differing in terms of efficiency, selectivity, speed, cost and pain. The objective is to activate a wound to initiate the healing cascade. For this pilot study we assessed the feasibility of a new microjet wound therapy technology compared to standard sharp debridement in wound outcomes.

METHOD

A randomised, controlled, open-label pilot study was conducted in one outpatient wound clinic in Western Switzerland from March 2022 to May 2023.

RESULTS

A total of 13 consecutive patients were randomly assigned to receive either microjet wound therapy (n=5) or standard mechanical debridement with instruments (n=8). As a feasibility study, there was insufficient power to detect significant differences between the groups. However, in the intervention group, our analysis may indicate a modestly faster reduction in wound area. Microjet wound therapy appears to alleviate patient anxiety and offer cost savings due to the potential for reduced time, as well as the number of required treatments. This meant fewer overall consultations.

CONCLUSION

This study highlights a trend that may indicate that microjet therapy holds value in promoting faster healing of hard-to-heal wounds, and it provides a feasibility basis for a sufficiently powered multicentre trial.

Interdental oral hygiene interventions elicit varying compositional microbiome changes in naturally occurring gingivitis: Secondary data analysis from a clinical trial

AIM

To evaluate the effect of different oral irrigators on the sub-gingival microbiome composition in patients with naturally occurring plaque-induced gingivitis.

MATERIALS AND METHODS

Sub-gingival plaque was collected from adults participating in a clinical trial assessing the efficacy of oral hygiene with two different oral irrigators (Waterpik Water Flosser [Group 1] and Oral-B Water Flosser [Group 2]) versus dental flossing (Group 3) for microbiome analysis. Plaque samples were reflective of naturally occurring plaque-induced gingivitis at baseline and of gingival health at the endpoint (4 weeks). Clinical measures of gingival inflammation were collected, and the sub-gingival microbiome was analysed by 16S rRNA sequencing to identify amplicon sequence variants.

RESULTS

Oral hygiene instruction with self-performed manual toothbrushing and water-jet irrigation led to significant reductions in inflammation for all groups; both oral irrigators outperformed flossing in bleeding-on-probing reduction (p < .001). Microbiome diversity of sub-gingival plaque remained relatively stable over time, but significant changes were noted in certain taxa, consistent with increases in the relative abundance of commensals and reductions in late colonizers and periodontal pathogens in the water-jet groups.

CONCLUSIONS

Reduction in gingival inflammation at 4 weeks within the water-jet groups is accompanied by slight but critical changes in microbiome composition. Although biodiversity does not substantially change within 4 weeks during the resolution of naturally induced gingivitis, significant relative increases in commensal early colonizers such as Streptococcus, Veillonella and Fusobacterium were accompanied by a shift towards a less anaerobic microbiota associated with return to health. These changes were contingent upon the type of interdental hygiene, with Group 1 exhibiting more significant alterations in microbiome composition towards a periodontal-health-compatible community.

Development of a remotely controllable 4 m long aerial-hose-type firefighting robot

In a fire outbreak, firefighters are expected to rapidly extinguish fires to stop the spread of damage and prevent secondary disasters. We proposed the concept of a dragon firefighter (DFF), which is a flying-hose-type firefighting robot. We developed a 3.6 m long DFF equipped with two nozzle units and achieved stable flight. However, the system was not yet completed because the root of the robot, which should have been operated remotely, was operated manually. In addition, the system's reliability was insufficient to successfully repeat the demonstration several times. The development of a robot demonstration system is crucial for the practical application of such a firefighting robot. In this study, we developed a demonstration system for a remotely controllable 4 m flying firehose robot for demonstration at the World Robot Summit 2020 (WRS 2020) opening ceremony in Fukushima as a milestone. This paper focuses on the following issues: 1): installation of the remotely controllable mobile base, 2): redesign of the water channels (the sizes of nozzle outlets) to get enough thrusts to fly with a fire engine, 3): development of nozzle units with a larger movable range (1.5 times larger than the conventional nozzle) in addition to waterproofing technique to improve system reliability, and 4): redesign of a passive damping mechanism to ensure better stability. Thus, a firefighting demonstration was successfully conducted at the opening ceremony of the World Robot Summit 2020 in Fukushima, Japan, and we discuss the lessons learned through the demonstration. We found that the developed DFF system incorporating a mobile base could achieve remote fire extinguishing.

Effectiveness of Waterpik® for oral hygiene maintenance in orthodontic fixed appliance patients: A randomised controlled trial

OBJECTIVE

To establish whether the use of a WaterPik® alongside a manual toothbrush (WaterPik® + MTB) is more effective for maintaining oral hygiene compared to the use of a manual toothbrush alone (MTB) in patients wearing fixed orthodontic appliances.

DESIGN

A single-centre, two-arm, parallel-group, single-blind, randomised controlled clinical trial with a 1:1 allocation ratio.

SETTING

Orthodontic department at York Hospital, York Teaching Hospitals NHS Foundation Trust, UK.

PARTICIPANTS

A total of 40 fit and well participants, aged 10-20 years, being treated with upper and lower fixed orthodontic appliances.

METHODS

Participants were randomly allocated, using stratified block randomisation, to the control group (MTB) or intervention group '(Waterpik® + MTB)'. Plaque, gingival and interdental bleeding indices were recorded at baseline, 8 weeks, 32 weeks and 56 weeks. A generalised linear mixed model was used to assess differences between groups.

RESULTS

An interim analysis of results was performed with 40 patients recruited and 85% of data collected. The overall mean differences between the groups were as follows: plaque index = 0.199 (P = 0.88, 95% confidence interval [CI] -0.24 to 0.27); gingival index = -0.008 (P = 0.94, 95% CI -0.22 to 0.20); and interdental bleeding index = 5.60 (P = 0.563, 95% CI -13.22 to 24.42). No statistical difference between the two groups was found for any variable. The trial was stopped at this point.

CONCLUSIONS

In terms of oral hygiene, our study did not find evidence to support the claim of benefit of using a Waterpik® in addition to a manual toothbrush for patients wearing fixed orthodontic appliances.

Analysis of the Erosivity of High-Pressure Pulsating Water Jets Produced in the Self-Excited Drill Head

The dynamic impact of a water jet with a periodically changing structure can be used in various industries. The paper presents a design solution for a self-excited pulse head. This head can be used in mining for drilling holes and breaking rocks. The design of the head was developed based on computer simulations, which made it possible to learn the mechanism of impulse shaping inside the head. Tests of the water jet produced in the self-excited pulsation head showed the occurrence of periodic changes in its internal structure and pulsation frequency. A significant increase in the dynamic stream pressures was demonstrated for the head working in the water environment compared to the head working in the air environment For example, for nominal medium and highest pressures, this increase is up to 82%, while for the lowest pressures (10 MPa), the pressure force values increase by 46%. It was found that an increase in the nominal water pressure causes a decrease in the frequency of hydrodynamic pulses in the head operating in both the water and air environment.

Experimental Study on the Coating Removing Characteristics of High-Pressure Water Jet by Micro Jet Flow

In this paper, coating removal characteristics of water jet by micro jet flow affected by cleaning parameters is analyzed. Numerical simulation of fluid field calculates the velocity and pressure distribution of a water jet impinging on a rigid wall, which is used for design experiments of coating removal affected by jet pressure, traversal speed, and repeated impacting times. The removal width is used as a measure of water jet coating removal capability. Experiment results show that the coating removal width is constant, independent with traversal speed or repeated times when total exposure time of waterjet impingement is fixed. According to results of coating removal by a linear moving water jet, this study also analyzes characteristics of coating removal by rotating jet disc, especially residual coating affected by rotational and moving speed of the cleaning disc. The research is helpful to improve the coating removal efficiency of cleaning disc devices.

An overview of thermal necrosis: present and future

Introduction: Many orthopaedic procedures require drilling of bone, especially fracture repair cases. Bone drilling results in heat generation due to the friction between the bone and the drill bit. A high-level of heat generation kills bone cells. Bone cell death results in resorption of bone around bone screws.Methods: We searched in the literature for data on parameters that influence drilling bone and could lead to thermal necrosis. The points of view of many orthopaedists and neurosurgeons based upon on previous practices and clinical experience are presented.Results: Several potential complications that lead to thermal necrosis are discussed and highlighted.Discussion: Even in the face of growing evidence as to the negative effects of heat induction during drilling, simple and effective methods for monitoring and cooling in real-time are not in widespread usage today. For that purpose, we propose some suggestions for the future of bone drilling, taking note of recent advances in autonomous robotics, intelligent systems and computer simulation techniques.Conclusions: These advances in prevention of thermal necrosis during bone drilling surgery are expected to reduce the risk of patient injury and costs for the health service.

Toroidal plasmoid generation via extreme hydrodynamic shear

Saint Elmo's fire and lightning are two known forms of naturally occurring atmospheric pressure plasmas. As a technology, nonthermal plasmas are induced from artificially created electromagnetic or electrostatic fields. Here we report the observation of arguably a unique case of a naturally formed such plasma, created in air at room temperature without external electromagnetic action, by impinging a high-speed microjet of deionized water on a dielectric solid surface. We demonstrate that tribo-electrification from extreme and focused hydrodynamic shear is the driving mechanism for the generation of energetic free electrons. Air ionization results in a plasma that, unlike the general family, is topologically well defined in the form of a coherent toroidal structure. Possibly confined through its self-induced electromagnetic field, this plasmoid is shown to emit strong luminescence and discrete-frequency radio waves. Our experimental study suggests the discovery of a unique platform to support experimentation in low-temperature plasma science.

Optimisation of water-cannon cleaning for deposit removal on water walls inside waste incinerators

Deposits in municipal waste incinerators are very inhomogeneous in structure and constitution. They cause corrosion and reduce the efficiency, so they need to be removed frequently. Among other systems, operators use water cannons for the deposit removal. Two different removal mechanisms of water-cannon cleaning are suggested: A direct shattering of the deposit by the impact of the water jet, as well as the cracking caused by thermal stresses where droplets cool the deposits. As the contribution of each of the aforementioned mechanisms to the overall cleaning efficiency is unknown, we performed empirical investigations to determine the dominating effect. In a first experimental setup focusing on thermal stress, cold droplets were applied onto hot deposits taken from a waste incinerator. Results showed that the cleaning effect strongly depends on the deposit thickness and structure, so that the deposits could be categorised in three different groups. A second measurement campaign focused on the influence of deposit material, deposit temperature and water jet momentum. It could be shown that both deposit material and temperature have a significant effect on the cleaning efficiency, whereas an increase in water jet momentum only led to modest improvements. The combination of these two parameter studies implies that the influence of the thermal stress outweighs that of the momentum. This knowledge is applicable to the cleaning setup by increasing the temperature gradient.

Fatal Penetrating Injuries Sustained by High-pressure Water Jet Unit

The high-pressure water jet unit is a generator of frequent burst of water jets. The water jet reaches very high speeds and is able to cause wounds similar to those of high-velocity projectiles. In the presented case, unusual fatal injuries sustained by water jet are presented. Operating with the unit, an untrained worker accidentally activated a high-pressure water jet unit, and the extremely high pressure of water liberated the jet unit from his hand and whirled it around him. A jet stream of water ran across his body and caused fatal penetrating injuries in the femoral region. The edges of the wound were mainly sharp with contusion rings on the skin beyond the edges. Exploring the inside of the canals during the autopsy, the left femoral artery and vein were found to be completely transected. The resemblance to a firearm entry wound and the severity of the internal injury make it a noteworthy entity.