New Brunswick Cranberry Industry Update

Abstract: New Brunswick growers produced cranberries on over 900 acres in 2016 and had a record harvest of 13,780 barrels last season. Growers are having difficulty navigating the low price concerns, and have begun to limit expenses and treatments as best they can. They are monitoring for pesticide application more than ever and have moved towards more effective use of irrigation in recent years. Weeds are beginning to be more problematic in fields, but this could also be from a mild winter. Other pest pressures have been low in 2017. One grower had extensive early leaf drop in the spring, but plants have recovered. Under a Growing Forward 2 program, the industry can access financial assistance as an incentive to plant higher yielding or earlier maturing varieties. The program will assist with the purchase of plants and associated movement costs. All other costs are not supported. Approximately 5 acres have been approved for planting. Another program helped support the purchase of the updated “Identification Guide for Weeds in Cranberries”, one for each farm in New Brunswick. Recent herbicide trial results have been inconsistent, mainly due to inadequate weed species and densities in trials from 2013-2016. Crop tolerance has been adequate for most herbicides tested, with improved safety from applications made before bud break

Experimental and numerical investigation of therapeutic ultrasound angioplasty

Therapeutic ultrasound angioplasty is an emerging minimally invasive cardiovascular surgical procedure that involves the delivery of ultrasonic displacements to the distal-tip of small diameter wire waveguides. The ultrasonic distal-tip displacements affect atherosclerotic plaque and thrombus by direct contact ablation, pressure wave components and cavitation, in addition to an acoustic streaming event around the distal-tip. This study uses experimental and numerical methods to investigate ultrasonic displacements in wire waveguides and the effect the distal-tip displacements have on the surrounding fluid. An experimental therapeutic ultrasound wire waveguide apparatus is described that delivers displacements to the distal-tip of 1.0 mm and tapered 0.35 mm diameter nickel-titanium (NiTi) waveguides. The operating frequency of the apparatus has been experimentally determined to be 23.5 kHz and for the power settings tested delivers displacements of up to 85 |im peak-to-peak (p-p) to the distal-tip of 1.0 mm diameter waveguides. The apparatus has been shown to directly ablate calcified materials with a stiffer response when compared with atherosclerotic plaques and to generate cavitation and acoustic streaming. A coupled fluid-structure numerical model of the waveguide and fluid surrounding the distal-tip has been developed that predicts the waveguide displacements and stresses along the entire length of the wire waveguide. The structural results of the model have been validated against experimental measurements of the displacements of the waveguide with the inclusion of a constant damping value of 4.5%. The fluid results of the model predict the pressure amplitudes developed in the surrounding fluid and compare closely with values reported in literature. The model predicts the distal-tip displacements required to cause cavitation, a major disruptive event, and has been compared with experimental observations made with the ultrasonic wire waveguide apparatus. The waveguide numerical model will prove a valuable design tool in the further development and improvement of this emerging cardiovascular technology

Scientific Respiratory Symposium, Paris June 2010

At a 2010 Respiratory Symposium in Paris, chaired by Professors Bousquet and Roche of the University of Paris, recent trends in research, therapy and treatment guidelines for asthma and chronic obstructive pulmonary disease (COPD) were reviewed and discussed by a faculty of expert European and US respiratory physicians. This article reviews five key clinical presentations with particular emphasis given to the importance of small airways in the pathology and treatment of asthma and COPD. Further analysis of the economics of treatment in Europe and the US shows a wide variance in direct and indirect costs

Ultrasonic Angioplasty: Assessing the Risk of Arterial Perforation

Atherosclerosis is a cardiovascular disease that effects large and medium muscular arteries (such as coronary and iliac) and also large elastic arteries (such as aorta) [1]. It causes thickening of the arterial wall and over time can result in a completely blocked artery or chronic total occlusion (CTO). While the majority of atherosclerotic lesions can be attempted by typical Percutaneous Transluminal Coronary Angioplasty (PTCA) such as balloon and stent implantation, calcified CTOs are often problematic as they do not lend themselves to be accessed by the guidewire which is required to implant the balloon and stent. Excessive guidewire pushing force may result in arterial perforation with CTOs often requiring invasive by-pass surgery. An alternative method proposes the use of low frequency high power ultrasound transmitted through wire waveguides for the removal of the calcified material from advanced atherosclerotic lesions. This type of energy manifests itself as a mechanical vibration at the distal tip of the wave guide with amplitudes of up to 100 microns and frequencies ranging between 20-45 kHz commonly reported. The ultrasound acts to disrupt calcified diseased tissue by means of direct contact ablation, cavitation, acoustic steaming and other pressure wave components while the elastic tissue remains largely unaffected [2]. In this study the effects of this form of ultrasound on healthy arterial tissue (porcine aorta) is examined. Experiments were carried out to determine the force required to perforate healthy porcine arterial tissue both with and without ultrasound at various distal tip displacements

Ablation of Chronic Total Occlusions Using Kilohertz-Frequency Mechanical Vibrations in Minimally Invasive Angioplasty Procedures.

Certain minimally invasive cardiology procedures, such as balloon angioplasty and stent implantation, critically require that the site of an arterial blockage be crossed by an intraluminal guidewire. Plaques resulting in near or totally occluded arteries are known as chronic total occlusions (CTOs), and crossing them with conventional guidewires is a significant challenge. Among the most promising proposed solutions is the delivery of high power, low frequency ultrasonic vibrations to the occlusion site via an intraluminal wire waveguide. The vibrating distal-tip of the ultrasound wire waveguide is used to transmit energy to the surrounding plaques, tissues and fluids in order to ablate or weaken atherosclerotic plaque. Potential mechanisms of interaction with the plaque and adjacent fluids identified in the literature include; (i) direct contact with the waveguide distal tip, (ii) subcavitational acoustic fluid pressure fluctuations, (iii) cavitation, and (iv) acoustic streaming. This article will summarize developments in this area over more than two decades, describing experimental methods for device performance characterization, preclinical tests, early clinical investigations and, later, full clinical trials. The article will also review theoretical foundations, and numerical models suitable for device design and analysis. Finally, important issues for future research and for the development of this technology will be considered

Perforation of Arterial Tissue Using Kilohertz Frequency Ultrasound Delivered via Wire Waveguides

An emerging technology proposes the use of low frequency-high power ultrasound transmitted via wire waveguides for the disruption and ablation of atherosclerotic lesions, more specifically advanced fibrous or calcified plaques such as chronic total occlusions (CTO). This energy delivery selectively ablates rigid diseased tissue by means of direct mechanical contact, cavitation and other forces generated by the intense dynamic pressure fields generated. The first clinical device using this energy delivery was granted FDA approval in 2007 [1] for the ablation of CTOs and most research to date has focused on ablation and disruption of hard, fibrous or calcified tissues [2]. This work, however, investigates the affects this energy delivery has on the perforation of soft healthy tissue (porcine aorta). Materials and methods An ultrasonic apparatus has been developed with operational characteristics similar to clinical devices reported in the literature i.e. frequency of operation (22.5kHz) and distal-tip ultrasonic amplitudes of vibration (~15-50μm). This apparatus delivers ultrasound via 1mm nitinol wire waveguides (132mm in length) with flat distal tips. An experimental test rig was developed to perform controlled tests (ultrasonic power delivery and feedrates) on tissue samples in a thermostatic tank (37oC). Perforation force measurement was achieved by means of a strain gauge arrangement on a cantilever tissue holder. A miniature hydrophone was also incorporated for the detection of cavitation by analysing the acoustic spectrum while the device was activated. Sub, super and ultra harmonics of the fundamental are all considered indicative of stable cavitation, whereas an increase in the broadband noise, in regions absent of significant harmonics, are indicative of inertial cavitation [3]. Porcine aorta was exhumed, stored in saline and tested less then 24 hours after death. Connective tissue was removed and samples (10x20mm) were cut from the descending aorta. Wires were advanced towards the tissue at a constant feedrate of 38 mm/min until perforation. Results As shown in Figure 1, an increase in distal tip amplitudes of vibration reduced the perforation force. It was found that stable cavitation occurred at all power settings (\u3e 15μm). At the high power displacement amplitude setting of 34.3μm the perforation force was 1.2N when compared with 5.5N with no ultrasonic activation. The inertial cavitation threshold was crossed at distal-tip amplitudes of vibration greater than 30μm. However, no significant decrease in perforation force was evident in the inertial cavitation region. At the macro level, the tissue appears to fail in a similar manner for all distal-tip amplitudes of vibration. Discussion Perforation force of soft arterial tissue does not appear to be significantly effected by the onset of inertial cavitation. Further histological examination may be required to determine residual tissue damage from cavitation. Additional studies are needed to determine to what extent tissue is ablated, cut or removed at various power levels. It is suggested, however, that tissue removal using this energy on soft tissue is minimal when compared to that of hard brittle tissue ablation

Increased Susceptibility of Arterial Tissue to Wire Perforation with the Application of High Frequency Mechanical Vibrations

High frequency mechanical vibrations (20–50 kHz), delivered via small diameter flexible wire waveguides represent a minimally invasive technology for the treatment of chronic total occlusions (CTOs) and in other tissue ablation applications. Tissue disruption is reported to be caused by repetitive mechanical contact and cavitation. This work focuses on the effects of vibrating wire waveguides in contact with arterial tissue. An apparatus with clinically relevant parameters was used, characterized as operating at 22.5 kHz and delivering amplitudes of vibration of 17.8 - 34.3 µm (acoustic intensity, ISATA: 1.03 - 3.83 W/cm2) via 1.0 mm diameter waveguides. Inertial cavitation (in water at 370C) was determined to occur above amplitudes of vibration greater than 31.4 µm (ISATA = 3.21 W/cm2). The energized waveguides were advanced through tissue samples (porcine aorta) and the force profiles were measured for a range of acoustic intensities. The results show that the tissue perforation initiation force, perforation initiation energy and total energy required to perforate the tissue reduces with increasing acoustic intensity. No significant reduction in perforation force or energy was observed in the inertial cavitation region. Multistage perforation was evident through the force profile and histological examination of the tissue samples post wire waveguide perforation

Soft Tissue Cutting with Ultrasonic Mechanical Waveguides

The use of ultrasonic vibrations transmitted via small diameter wire waveguides represents a technology that has potential for minimally invasive procedures in surgery. This form of energy delivery results in distal tip mechanical vibrations with amplitudes of vibration of up to 50 μm and at frequencies between 20-50 kHz commonly reported. This energy can then be used by micro-cutting surgical tools and end effectors for a range of applications such as bone cutting, cement removal in joint revision surgery and soft tissue cutting. One particular application which has gained regulatory approval in recent years is in the area of cardiovascular surgery in the removal of calcified atherosclerotic plaques and chronic total occlusions. This paper builds on previous work that was focused on the ultrasonic perforation of soft vascular tissue using ultrasonically activated mechanical waveguides and the applied force required to initiate failure in soft tissue when compared with non-ultrasonic waveguides. An ultrasonic device and experimental rig was developed that can deliver ultrasonic vibrations to the distal tip of 1.0 mm diameter nickel-titanium waveguides. The operation of the ultrasonic device has been characterized at 22.5 kHz with achievable amplitudes of vibration in the range of 16 – 40μm. The experimental rig allows the ultrasonically activated waveguide to be advanced through a tissue sample over a range of feedrates and the waveguide-tissue interaction force can be measured during perforation into the tissue. Preliminary studies into the effects of feedrate on porcine aortic arterial tissue perforation forces are presented as part of this work. A range of amplitudes of vibration at the wire waveguide distal tip were examined. The resulting temperature increase when perforating artery wall when using the energized wire waveguides is also examined. Results show a clear multistage failure of the tissue. The first stage involves a rise in force up to some critical force and tissue displacement whereby the cut is initiated. The results show that with increasing ultrasonic amplitude of vibration the perforation force decreases considerably. The current results show that for the range of feedrates investigated 19-95 mm/min at an amplitude of vibration of 34.3 μm there was no significant effect on the perforation initiation force. The ΔT in the tissue 3.0 mm from the point of entry is also presented for a range of amplitudes of vibration