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Diagnosis of esophageal disorders is well ahead of available treatment options. With HRM, for example, one can identify numerous conditions and their variants, which may lose meaning if the clinical and therapeutic implications of these subclassifications are limited. We report an exemplary case of a patient with hiatal hernia complaining of reflux, dysphagia, and chest pain refractory to medical treatment. Jackhammer esophagus was diagnosed and a hybrid approach consisting of POEM and concomitant crural repair and Dor fundoplication is proposed.

Introduction and aims: Jackhammer esophagus is a recently identified motility disorder. Experience with the novel pathologic condition has been reported in different studies but there is little information on the subject in Latin America. Our case series conducted in Bogota, Colombia, describes the prevalence of jackhammer esophagus and its demographic, clinical, and manometric characteristics. Materials and methods: A retrospective, observational, cross-sectional study included consecutive patients diagnosed with jackhammer esophagus that were referred for high-resolution esophageal manometry. Their clinical and manometric records were reviewed, and the pertinent information for the present study was collected. Results: Within the study period, 6445 patients were evaluated through esophageal manometry, 27 of whom were diagnosed with jackhammer esophagus (prevalence of 0.42%). The majority of those patients were women (n = 17, 63%) in the sixth decade of life. The most common symptom was regurgitation (n = 17, 63%), followed by dysphagia (n = 15, 56%). The mean distal contractile integral was 9384 (5,095−18,546) mmHg·s·cm. Dysphagia was more common in patients > 60 years of age (79%, p 60 años y regurgitación más frecuente (92%, p

A method is proposed for measuring jackhammer parameters on the SORP test bench. This method may be characterized as correct and metrologically impeccable. In contrast to previous methods, all the parameters are measured in the same rated operating conditions.

The determination of jackhammer parameters in bench tests is considered. Test procedures for determining the energy, vibration, and noise parameters of jackhammers are analyzed. This review provides context for the development of the SORP universal test bench and UIPU measuring system.

Jackhammers are widely used in the construction industry to break up rock, pavement and concrete. They are generally powered by compressed air, electric motors, or hydraulics and can generate a large force for drilling and demolition. However, while they are an efficient tool for this purpose, they also pose a serious danger to the worker, due to the vibrations transmitted. Prolonged exposure to these vibrations can cause ailments such as vibration white finger, Raynaud’s disease and carpal tunnel syndrome (CTS). The objective of this research is to design and fabricate a vibro-isolator attachment to damp and absorb the range of harmful vibrations transmitted to the occupant. The attachment is clamped on top of the jackhammer and makes use of two helical springs in parallel to reduce the higher amplitude vibrations. Handles are provided above the springs for the user to grip the attachment and hence, the jackhammer. The new design, setup feels worker much less hand-arm vibration without reducing the downward drilling force of the jackhammer. Hence, the newly designed vibration isolation, attachment reduces the hand-arm vibration, and the jackhammer can be operated at full power without compromising on the health of the occupants.

BACKGROUND: Hypercontractile or jackhammer esophagus (JE) is a diagnosis made on high-resolution manometry (HRM), defined by the Chicago Classification of esophageal motility disorders (CC v3.0) as ≥20% of swallows achieving a distal contractile integral (DCI, a standardized metric of contraction pressure over time in the distal esophagus) of >8,000 mmHg-s-cm. It is an uncommon finding which can be associated with dysphagia and chest pain. The pathophysiology of JE remains unknown but may be related to medications in certain cases. AIMS: The aim of this study was to determine if theuse of specific classes of medications, based on mechanism of action, are associated with JE, compared to normal controls. We hypothesized a significantly higher use of opioids in our JE group. METHODS: Consecutive HRM studies from November 2013 to September 2018 with a diagnosis of JE were compared to control patients with symptoms who had normal HRM. A complete list of all medications taken at the time of HRM was obtained by the nurse immediately prior to the motility study. Odds ratios for each class of medication comparing JE patients to healthy controls were calculated using Pearson chi-square tests. Multiple linear regression was used to identify medication classes which were predictive of DCI. IRB-approved study. RESULTS: 39 JE and 127 control patients were included. The average age was 57 for JE and 52 for controls (P=0.274). 59% of JE and 68% of controls were female (P=0.060). The JE patients’ primary complaints were dysphagia (51%), chest pain (26%), cough (8%), heartburn (8%), food bolus (3%), wheezing (3%), and regurgitation (3%). The mean DCI was 7,139 mmHg-s-cm in the JE group and 1,285 mmHg-s-cm in the control group (P

W.J.T. Mitchell speaks to Tania Bruguera about the relationship between art and activism, play and use, loss and utopia.

A jackhammer pounds away at the concrete outside the front door of the drop-in center as I navigate between the orange construction cones, hopping over wet concrete to unlock the front door. It’s a...

As there are a large number of existing aging bridges in need of maintenance, Ohio Department of Transportation is seeking safer, better, and efficient approaches for patch-repair concrete removal on bridge decks. The current practice to remove concrete is by using pneumatic breakers, which presents a danger to operators and damages to the sound concrete and rebar. Building on an extensive literature review, this study evaluates the current method and alternative methods that can address the limitations of the current method. Based on the findings, the recommendation is to use hydrodemolition robot to remove concrete, as it is time-efficient and does not create potential harm to the bridge deck or operator. In addition, hydrodemolition leaves a coarse finish cut to allow for a more effective and long lasting bond with the repair material, which is important for patch repair. Two potential robots are identified as most suitable for bridge deck concrete removal: Conjet Jetframe 101 Nalta and Conjet Robot 327. While the advantages of Conjet Jetframe 101 Nalta are easy transportability and low capital cost, Conjet Robot 327 has a higher productivity rate and has a built in debris barrier that is safer for the crew and on-going traffic. Lastly, based on the cost analysis, for project size larger than 100 SF, Conjet Robot 327 becomes a better option.

BACKGROUND: Jackhammer esophagus is an hypercontractile esophageal disorder recently brought to light with the advent of high resolution manometry (HRM). As Jackhammer esophagus is purely a manometric diagnosis, little is known about its clinical expression. AIMS: We hypothesized that the extreme esophageal contractions encountered in this disease cause upper digestive symptoms such as dysphagia and chest pain. Thus, the aim of our study was to identify the clinical characteristics associated with this new motility disorder. METHODS: A retrospective observational study was conducted from January 2015 to September 2017 at the CHUM gastro-intestinal motility center. Among all the HRM performed, patients with a diagnosis of jackhammer esophagus were included. This diagnosis is made when at least 20% of the swallows being studied are hypercontractile, with a distal contractile integral (DCI) of >8000 mmHg.s.cm (Chicago classification). Each patient’s chart was reviewed to collect clinical data: age, sex, comorbidities, proton pump inhibitor use, along with manometry, upper digestive endoscopy, biopsies, pH-monitoring and barium swallow results. RESULTS: Among the 1046 HRM done during the study period, 34 patients with jackhammer esophagus were included (mean age 62 ± 13 years, 88% females). Their main symptoms were dysphagia (71%), pyrosis (44%), retrosternal chest pain (38%) and epigastralgia (32%). In half of the patients, at least 50% of swallows were hypercontractile. The mean DCI of the hypercontractile esophageal contractions was 11 600 ± 3600 mmHg.s.cm. Other HRM findings were hypertonia (26%) and/or inadequate relaxation (29%) of the lower esophageal sphincter. Upper digestive endoscopy results were available for 26 patients: 18 normal, 3 hiatal hernias, 2 esophageal dilatations, 2 lower esophageal sphincter hypertonia impressions and one with longitudinal striae. Among the 12 available biopsy results, 2 were abnormal: one lymphocytic exostosis and one esophagitis without eosinophilia. Pathological gastro-esophageal reflux was found in 3 of the 9 patients investigated with pH-monitoring. Among the 8 patients who had a barium swallow, 4 had a normal study, 3 had spastic contractions of the esophagus and one had an incomplete relaxation of the cricopharyngeal muscle. CONCLUSIONS: Jackhammer esophagus was diagnosed in 3% of the patients referred for a HRM to our gastro-intestinal motility center. A strong female predominance is found in this study. In more than two thirds of cases, the clinical presentation of jackhammer esophagus is dysphagia. Malfunctioning of the lower esophageal sphincter can be demonstrated during manometry. Upper digestive endoscopy and biopsies seem unhelpful in suspecting the diagnosis before HRM is performed. FUNDING AGENCIES: None

Jackhammer esophagus (JE) is a hypercontractile disorder, the pathogenesis of which is incompletely understood. Multiple rapid swallows (MRS) and rapid drink challenge (RDC) are complementary tests used during high-resolution manometry (HRM) that evaluate inhibitory and excitatory neuromuscular function and latent obstruction, respectively. Our aim was to evaluate esophageal pathophysiology using MRS and RDC in 83 JE patients (28 men; median age: 63 yr; IQR: 54–70 yr). Twenty-one healthy subjects (11 men; median age: 28 yr; range: 26–30 yr) were used as a control group. All patients underwent solid-state HRM with ten 5-ml single swallows (SS) and one to three 10-ml MRS; 34 patients also underwent RDC. Data are shown as median (interquartile range). Abnormal motor inhibition was noted during at least one MRS test in 48% of JE patients compared with 29% of controls ( P = 0.29). Mean distal contractile integral (DCI) after MRS was significantly lower than after SS [6,028 (3,678–9,267) mmHg·cm·s vs. 7,514 (6,238–9,197) mmHg·cm·s, P = 0.02], as was highest DCI ( P < 0.0001). Consequently, 66% of JE patients had no contraction reserve. At least one variable of obstruction during RDC (performed in 34 patients) was outside the normal range in 25 (74%) of JE patients. Both highest DCI after SS and pressure gradient across the esophagogastric junction (EGJ) during RDC were higher in patients with dysphagia versus those without ( P = 0.04 and 0.01, respectively). Our data suggest altered neural control in JE patients with heterogeneity in inhibitory function. Furthermore, some patients had latent EGJ obstruction during RDC, which correlated with the presence of dysphagia. NEW & NOTEWORTHY Presence of abnormal inhibition was observed during multiple rapid swallows (MRS) in some but not all patients with jackhammer esophagus (JE). Unlike healthy subjects, JE patients were more strongly stimulated after single swallows than after MRS. An obstructive pattern was frequently observed during rapid drink challenge (RDC) and was related to presence of dysphagia. MRS and RDC during high-resolution manometry are useful to show individual pathophysiological patterns in JE and may guide optimal therapeutic strategies.

The jackhammer esophagus is a rare hypercontractile disorder and diagnosis is based on high-resolution manometry. Peroral endoscopic myotomy (POEM) of the spastic esophagus segments has been described. We report a pediatric patient with jackhammer esophagus that was treated endoscopically.

Initial esophagogastroduodenoscopy (EGD) shows segmental contractions right above the gastro‐esophageal junction, which may be related to the symptoms. A clip was applied during a previously performed manometry. There was no evidence of stricture. High‐resolution manometry before peroral endoscopic myotomy shows a hypercontractile esophagus expressed as distal contractile integral > 8000 mmHg cm s two times out of 10.

BACKGROUND: Dysphagia and non-cardiac chest pain are common referrals for esophageal motility testing. Hypertensive esophageal peristalsis, previously classified as “nutcracker esophagus,” has been re-labelled as “jackhammer esophagus” by the Chicago Classification of esophageal motility disorders (CC v3.0). Although the pathophysiology of jackhammer esophagus (JE) has yet to be elucidated, gastroesophageal acid reflux (GERD) has been implicated as a possible causative factor, based on the higher than expected incidence of GERD on patients with JE that has been seen in previous studies (43 - 47%). AIMS: The aim of this present study is to determine if GERD is associated with JE when compared to symptomatic controls with normal HRM. METHODS: Consecutive symptomatic patients who were referred for esophageal high-resolution manometry (HRM) studies in Calgary, AB from Nov 2013 to Sept 2018 were retrospectively analyzed. Patients with a manometric diagnosis of Jackhammer esophagus by CC v3.0 (≥ 2 hypercontractile swallows with distal contractile integral [DCI] > 8000 mmHg-s-cm) who also underwent ambulatory pH studies were compared to patients with normal HRM (controls). Groups were compared with Pearson’s chi-square testing and ANOVA as appropriate. This study was IRB approved. RESULTS: 20 JE patients and 82 controls who underwent both HRM and ambulatory pH testing were identified. Age and gender breakdown were similar between both groups (see Table 1). The most common presenting complaint in the JE group was dysphagia (35.0%) and in controls was heartburn (26.8%). Similar numbers of both groups were on PPI (50.0% JE, 51.2% controls). 3 (25.0%) JE patients and 14 (17.1%) controls had evidence of abnormal acid exposure on 24h ambulatory pH study (defined as DeMeester score > 14.7); this difference was not significant (p = 0.56). When abnormal acid exposure was defined as acid exposure time (AET) > 4.2%, there was no significant difference seen between both groups (p = 0.50). There were no significant differences seen between other parameters of the DeMeester score (see Table 1). CONCLUSIONS: Abnormal acid exposure on ambulatory pH study does not appear to be associated with JE, when compared to patients with normal HRM. This finding suggests that abnormal esophageal acid exposure is unlikely to be a causative factor for the peristaltic abnormalities seen in Jackhammer esophagus. FUNDING AGENCIES: None

Background: Hypercontractile esophagus (HE) is a primary hypercontractile disorder of the esophageal musculature not frequently seen in the general population. It is characterized by the presence of at least one contraction with a very high amplitude and duration (DCI > 8,000 mmHg/s/cm) in patients with esophageal symptoms. The aim of our study was to assess the clinical context and manometric characteristics in patients with HE using high-resolution manometry (HRM). Methods: We thoroughly reviewed the clinical features and manometric findings of a total of 720 patients with esophageal symptoms that were attended in the Department of Gastroenterology of our hospital between June 2011 and June 2013. Results: We found seven patients that met criteria for HE according to the Chicago Classification (2012). All of the patients were women (100%). Mean age was 64 years old. Most frequent symptoms were: Chest pain, dysphagia and heartburn. In one patient (14%) the HE was related to a gastroesophageal reflux disease (GERD) and gastroesophageal junction (GEJ) outflow obstruction. Three patients (43%) had more than one hypercontractile contraction in the study. Four patient (57%) hade multipeaked pattern (Jackhammer esophagus) and y two of them were synchronized with respiration. Two patients (29%) were diagnosed with hiatus hernias. Integrated relaxation pressure (IRP) was not higher in hypercontractile contractions than in normal contractions. Only one patient presented a slight alteration of the relaxation (IRP-4s = 15 mmHg) with normal peristalsis, GEJ outflow obstruction and not multipeakeded pattern. One patient presented pathological acid exposure (PAE) in 24-hours pH-metry. Conclusions: HE is a rare disorder and HRM is essential for its correct diagnosis and characterization. The treatment of HE should achieve the disappearance or at least improvement of the patient's symptoms and avoid unnecessary diagnostic testing.

Background: Jackhammers are commonly used on construction sites, and their general use comes with several injury risks, especially focused on lifting the jackhammer. A Lift-assist (LA) device is available that is aimed at eliminating the risk to the user from lifting. However, to date no scientific study has been conducted to determine if the LA provides any benefits to the user. The goal of this study was to make quantitative comparisons and qualitative assessments of operating a jackhammer with and without a LA. Methods and findings: Eight experienced jackhammer operators broke a 0.9 × 0.9 m section of concrete with two different weights of jackhammers with and without a lift-assist. Muscle activity of the upper body was reduced (approx. 40%) during the lifting portion of the task when using the LA. The reduction of the muscle activity required to lift the jackhammer also enabled the subjects to retain a better posture throughout the lift. Additionally, grip pressure was reduced in the lifting portion of the task. While the LA reduced the time required to lift the jackhammer, no change in overall task completion time was observed due to large variations in the time effect of the lift-assist among subjects and the relatively minor contribution of lifting time to the total task time. A longer study that allowed subjects to better adapt to the LA might be required to assess potential effects on task efficiency. Overall the subjects perceived the LA to provide a benefit to the user during the jackhammer task, and reduced the physiological stress experienced by the operator during the lifting portion of the task. Conclusions: These results indicate that use of the LA can potentially translate to a reduction in lifting related injury risks to the operator.

There are currently relatively few interventions designed to decrease the risk of injury while operating a jackhammer. One intervention that is aimed at reducing the risks of overexertion and repetitive lifting injury is the lift assist attachment. However, research on the effectiveness of this device is non-existent. This study investigated the effectiveness of the lift assist device through the muscle activity and grip pressure variations while using a light weight jackhammer. The lift assist reduced grip pressure by 31%, along with the left and right Bicep Brachii muscle activity by 49% and 45% respectively. These results show that the effort required to lift the jackhammer is being reduced through the use of the lift assist. With less effort required by the operator, the risk of an overexertion or repetitive lifting injury is decreased.

Drilling is an important operation of mining. Without drilling hardly any mine may be developed and worked. Drilling is such an operation which involved in creating pollution and health hazard. While dry drilling the cuttings of the stone along with fine dust is thrown out of the hole with air pressure and the driller remains directly close in touch and inhale this thrown out dust specially while drilling with jackhammer. Dry Jackhammer drilling also pollute the atmosphere with the evolution of dust in the air, containing silica particles and other crucial hard mineral particles which are dangerous for living existence. As such wet drilling can overcome the dust evolution and will suppress the dust and keep healthy inhalable atmospheric conditions. Keyboard: - Jackhammer wet-drilling, protective nut, adaptor, nozzle etc. I. INTRODUCTION Most of mines producing building stone such as sandstone, Kota stone, marble, granite, silica-sand, asbestos, manganese, feldspar and quartz or any other hard minerals require constant jackhammer drillings. These stone mines are based on the silica contents of rocks. Therefore during dry drilling, the drillers are inhaling thrown out dust containing silica and also this dust pollutes the atmospheric air. The operators may suffer with Silicosis which is a chronic lung disease caused by inhaling silica dust. As such wet drilling can overcome the dust evolution and will suppress the dust and keep healthy inhalable atmospheric conditions. II. DRILLING SUGGESTED MODIFICATION Authors are proposing to develop a simple modified method of wet drilling with jackhammer. This method involves no expenditure and not much extra labor except only an understanding to keep an eco-friendly atmosphere at drilling operations. Authors propose simple modifications in the ordinary jackhammer as detailed below: 1. The top head protective nut and adapter has to be drilled hole of 1.5 mm through the top head. 2. The protective nut hole should be joined with 2 mm nozzle with gas welding as shown in fig. no. 1 3. In the adapter hole, pass a 1.5 mm steel hollow tube of 20 cm. length and get it gas welded at the top around the side of the tube keeping the hole clear for passing water through it as shown in the fig no. 1

We wish to report a case of Jackhammer esophagus in a patient with laparoscopic gastric band, with confirmed resolution of hypertensive peristalsis on deflation of the band. This finding adds to the growing body of evidence that outlet obstruction plays an important role in the pathophysiology of Jackhammer esophagus, which remains incompletely defined.

BACKGROUND Jackhammer Esophagus is defined as intact esophageal peristaltic contractions with extremely elevated amplitudes. We conducted a retrospective study to identify the frequency of esophageal hypercontractility and the clinical characteristics of Jackhammer Esophagus. METHODS Charts for the patients referred for manometric study at a tertiary-care motility center were reviewed. Data were collected utilizing the new Chicago classification criteria for Jackhammer Esophagus. Concomitant clinical variables were also explored. RESULTS Eight patients were identified with Jackhammer Esophagus from a total of 205 (127 female/77 male) patients referred for high-resolution esophageal manometry. Jackhammer patients had an average distal contractile integral (DCI) of 9061 mmHg/ sec/ cm and median maximal DCI of 16,433 mmHg/ sec/ cm. The greatest DCI from 15 swallows was 28,875 mmHg/ sec/ cm. Hypercontractility was associated with multipeaked contractions in every Jackhammer patient. The mean lower esophageal sphincter (LES) pressure was 41 mm Hg with 4 patients having a hypertensive pressure of >40 mm Hg. Three of the 8 (37.5%) Jackhammer group had incomplete LES relaxation by integrated relaxation pressure criteria (>15 mm Hg residual pressure). Dysphagia (8/8) was the dominant indication for the manometric study, whereas the clinical background setting was gastroesophageal reflux disease (4/8) and hiatal hernia (1/8). Treatments included smooth muscle relaxation, antireflux regimens, and pneumatic dilation of the LES. CONCLUSIONS Jackhammer Esophagus, an extreme manometric phenotype, was identified in 4.0% of patients referred to a University Motility Center. The patients with these esophageal hypercontractility states present mainly with dysphagia. A subgroup of Jackhammer did have accompanying incomplete LES relaxation and responded to targeted therapy with pneumatic dilatation.

Jackhammer manufacturers have recently developed lightweight (45-60 lbs) jackhammers intended to reduce the required lifting and pushing forces during operation. However, the vibration characteristics of the lightweight jackhammers and their effect on muscle activity are currently unknown. The objective of this study was to compare the measured vibration and muscle activity between: (i) conventional (90 lb) and light weight (60 lb) jackhammers, (ii) different pavement type/thickness combinations, and (iii) pneumatic and hydraulic jackhammers. Five jackhammers were tested on 4 and 6 inch thick asphalt and concrete pavements by four experienced operators. Analysis of the results revealed that both weight classes averaged 9.7 m/s(2) at the 20 Hz weighted 1/3 octave band frequency, and the TLV of daily exposure for either weight class of jackhammer was less than 1.5 hours/per day. There was an approximately 33% difference in vibration measured on the hand of the operators due to pavement thickness, 30% due pavement type, and no difference due to power source. Conventional jackhammers overall produced higher muscle activity than lightweight jackhammers. Although selection of the correct jackhammer for the job involves many factors including pavement type and thickness, the results of this research can be used to assist in selecting the appropriate jackhammer.

A new celebrity with a lusciously curved body is turning heads on France's Cote d'Azur. No, not that kind of body. This one belongs to the AirPod, a 220-kilogram car with a sculpted composite shell and a back-to-the-future energy supply: 80 kg of air compressed to 350 times sea-level atmospheric pressure, roughly 350 bars. The engine of this tiny three-seater converts that air into mechanical energy, just as a pneumatic jackhammer does to blast apart concrete. The AirPod won't exactly tear up the road, though: The current version tops out at 45 kilometers per hour (28 miles per hour). And yet there's definitely something addictive in its joystick steering and featherlike suspension. With expanding air pumping its pistons, the exhaust is literally a superchilled breeze. Grab the stick, step on the accelerator, and any guilt you may be harboring from driving an ordinary smog-producing carbon spewer falls away. Wouldn't life be great if everybody got around town in these clean little machines?

The aim of our study was to characterize jackhammer esophagus symptoms and their relationship with the distal contractile integral (DCI) and bolus transit.Jackhammer esophagus is defined by the Chicago Classification version 3.0. This diagnosis is relatively new, with the most current definition being established in 2014. The forerunners of this diagnosis, nutcracker (or hypercontractile) esophagus, have been associated with noncardiac chest pain (NCCP).A retrospective chart review was performed of motility studies from 2011 to 2016. Studies with a diagnosis of jackhammer esophagus, hypercontractile esophagus, nutcracker, esophagogastric junction outflow obstruction, or hypertensive lower esophageal sphincter were reread using Chicago Classification version 3.0, and were included if they met criteria for jackhammer esophagus. Unpaired t-tests were used for analysis (P≤0.05).In total, 142 studies were identified with the above diagnoses. After excluding 84 studies, 58 remained for analysis and 17 were found to have jackhammer esophagus (29%). The mean age was 54 (28 to 75), 5 (29%) were males and 12 (71%) were females. The primary indications were NCCP (5), dysphagia (8), and other causes (4) (cough, heartburn, or regurgitation). The mean DCIs were 17,245 mm Hg×s×cm (NCCP), 14,669 mm Hg×s×cm (dysphagia), and 11,264 mm Hg×s×cm (other causes). The mean DCIs were compared: NCCP versus dysphagia (P=0.41), and NCCP versus other causes (P=0.05). Fifteen (88%) had normal bolus transit for both liquid and viscous swallows.In our small sample size, dysphagia was frequently the presenting symptom followed by NCCP. Those with NCCP have a trend toward a higher DCI. Bolus transit appeared to be normal in this patient population. More data are needed to further elucidate the genesis of symptoms and how they relate to the degree of contractility.

Hypercontractile esophagus (nicknamed jackhammer esophagus) is a recently defined disease within the esophageal motility disorders classification. Responses to treatments for jackhammer esophagus have been inconsistent in previous trials, possibly due to its heterogeneous manifestation. Thus, we reviewed 10 patients diagnosed with jackhammer esophagus and compared their clinical and manometric features at baseline. Additionally, manometric and symptomatic responses after treatment with known smooth muscle relaxants, including anticholinergic drugs (cimetropium bromide and scopolamine butylbromide) and a phosphodiesterase-5 inhibitor (sildenafil) were compared. We observed two distinct subgroups in the findings: one with hypercontractility and normal distal latencies (“classic jackhammer esophagus,” n=7) and the other with hypercontractility and short distal latencies (“spastic jackhammer esophagus,” n=3). The two types also differed in their responses to medications in that symptoms improved upon treatment with an anticholinergic agent in classic jackhammer esophagus patients, while spastic jackhammer esophagus was unresponsive to both the anticholinergic drugs and the phosphodiesterase-5 inhibitor. In conclusion, hypercontractile esophagus may be a heterogeneous disease with different underlying pathophysiologies. We introduced two novel terms, “classic jackhammer esophagus” and “spastic jackhammer esophagus,” to distinguish the two types. (Gut Liver 2016;10:859-863)

A robust chisel damper for quieting a jackhammer is presented. The noise produced from a jackhammer chisel is dominated by the ringing of the chisel moil resulting from impacts of the internal hammer against the end of the chisel producing airborne radiation of the transverse bending and longitudinal modes. A model steel chisel moil point was constructed with geometric properties similar to a jackhammer chisel and designed so as to not fail during severe acceleration impacts from the reciprocating hammer. Anechoic tests of the maximum overall unweighted sound pressure level for the undamped chisel due to a longitudinal impact was 86.8 dB linear (re. to 20 μ Pa) at 1 meter with the strongest ring tone at 1.37 kHz and harmonics; the overall sound pressure level for the damped chisel with identical axial impacts was reduced by 16.5 dB to 70.3 dB with severe reduction of 40 dB of the dominant chisel ring tone, and the harmonics.Copyright © 2015 by ASME