Evaluation of transdermal drug delivery using terahertz pulsed imaging

Transdermal drug delivery (TDD) is widely used for painless dosing due to its minimally invasive nature compared to hypodermic needle injection and its avoidance of the gastrointestinal tract. However, the stratum corneum obstructs the permeation of drugs into skin. Microneedle and nanoneedle patches are ways to enhance this permeation. In this work, terahertz (THz) imaging is utilized to compare the efficacy of different TDD methods including topical application and via a needle patch. Our work shows the feasibility and potential of using THz imaging to quantify and evaluate different transdermal application methods

Outcomes of therapy and ulnar nerve transposition for elbow stiffness after pediatric medial epicondyle fractures

PURPOSE: Following medial epicondyle fractures, a subset of pediatric patients has persistent limitations in elbow motion. This study soughted to understand the patient characteristics of this group and to assess the effectiveness of intensive therapy and ulnar nerve transposition in improving elbow range of motion and patient-reported outcomes. METHODS: A cohort of 31 pediatric patients with stiffness after elbow trauma was narrowed to 8 pediatric patients (7 female) ranging in age from 9 to 14 years, who were diagnosed with medial epicondyle fractures and underwent intensive therapy and ulnar nerve transposition with or without elbow joint release. We collected demographic and objective data as well as subjective data including Patient-Reported Outcome Measurement Information System (PROMIS) scores before and after ulnar nerve transposition. RESULTS: Following initial intensive therapy, elbow range of motion improved by an average of 56°, and 7 of the 8 patients reached a functional motion arc of 100°. Subsequently, following ulnar nerve surgery with or without elbow release, motion improved by an average of 22°, and 5 of the 8 patients demonstrated improvement from this intervention. Surgery led to improvements in subjective outcomes with an improvement in PROMIS mobility scores by an average of 9 points, pain interference by 6 points, and upper extremity scores by 3 points. Based on a previously determined minimally important difference of three points, these indicate significant clinical improvements. CONCLUSIONS: A subset of pediatric patients with persistent stiffness following medial epicondyle fractures may benefit from additional interventions, including intensive therapy, transposition of the ulnar nerve, and open capsular release. However, not all patients were improved after ulnar nerve surgery, and the identification and treatment of ulnar nerve irritability may not fully resolve preoperative symptoms in all patients. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV

A robust protocol for in vivo THz skin measurements

This work presents an experimental setup to control the way in which pressure interferes with the repeatability of in vivo THz skin measurements. By integrating a pressure sensor circuit into our THz system, it is possible to identify which measurements were taken within a previously specified pressure range. The live response of the pressure sensor helps to acquire data within the desired pressure leading to greater consistency of data between measurements. Additionally, a protocol is proposed to help achieve repeatable results and to remove the effects of the natural variation of the skin through the course of the day. This technique has been shown to be able to quantify the changes induced in the skin following the application of a moisturising skin product and shows the measured result to be significantly different from natural skin variation. This research therefore prepares the way for further studies on the effectiveness of different skin products using in vivo THz measurements

THz sensing of human skin : a review of skin modeling approaches

The non-ionizing and non-invasive nature of THz radiation, combined with its high sensitivity to water, has made THz imaging and spectroscopy highly attractive for in vivo biomedical applications for many years. Among them, the skin is primarily investigated due to the short penetration depth of THz waves caused by the high attenuation by water in biological samples. However, a complete model of skin describing the THz–skin interaction is still needed. This is also fundamental to reveal the optical properties of the skin from the measured THz spectrum. It is crucial that the correct model is used, not just to ensure compatibility between different works, but more importantly to ensure the reliability of the data and conclusions. Therefore, in this review, we summarize the models applied to skin used in the THz regime, and we compare their adaptability, accuracy, and limitations. We show that most of the models attempt to extract the hydration profile inside the skin while there is also the anisotropic model that displays skin structural changes in the stratum corneum

Respiratory muscle specific warm-up and elite swimming performance

Background: Inspiratory muscle training has been shown to improve performance in elite swimmers, when used as part of routine training, but its use as a respiratory warm-up has yet to be investigated. Aim: To determine the influence of inspiratory muscle exercise (IME) as a respiratory muscle warm-up in a randomised controlled cross-over trial. Methods: A total of 15 elite swimmers were assigned to four different warm-up protocols and the effects of IME on 100 m freestyle swimming times were assessed.Each swimmer completed four different IME warm-up protocols across four separate study visits: swimming-only warm-up; swimming warm-up plus IME warm-up (2 sets of 30 breaths with a 40% maximum inspiratory mouth pressure load using the Powerbreathe inspiratory muscle trainer); swimming warm-up plus sham IME warm-up (2 sets of 30 breaths with a 15% maximum inspiratory mouth pressure load using the Powerbreathe inspiratory muscle trainer); and IME-only warm-up. Swimmers performed a series of physiological tests and scales of perception (rate of perceived exertion and dyspnoea) at three time points (pre warm-up, post warm-up and post time trial). Results: The combined standard swimming warm-up and IME warm-up were the fastest of the four protocols with a 100 m time of 57.05 s. This was significantly faster than the IME-only warm-up (mean difference=1.18 s, 95% CI 0.44 to 1.92, p<0.01) and the swim-only warm-up (mean difference=0.62 s, 95% CI 0.001 to 1.23, p=0.05). Conclusions: Using IME combined with a standard swimming warm-up significantly improves 100 m freestyle swimming performance in elite swimmers

Acupuncture and reflexology for patients undergoing chemotherapy : a cohort study

Purpose: Around three quarters of individuals undergoing chemotherapy self-report multiple symptoms. There is clinical trial evidence of effectiveness for acupuncture for commonly experienced symptoms, and emerging evidence for reflexology, but little is known about the effects of these therapies on multiple symptoms when implemented in a real world setting during active chemotherapy treatment. Methods: This was a cohort study of participants receiving reflexology and/or acupuncture while attending chemotherapy. Participants received a 20 minute reflexology treatment or a 20 minute acupuncture treatment or a combination of both. Patient reported outcome measures were administered before and after the treatment using the Edmonton Symptom Assessment Scale (ESAS). Results: During the study period, 330 unique patients received a total of 809 acupuncture and/or reflexology treatments. Participants had, on average, 5.3 symptoms each which they reported as moderate to severe (≥4/10) using the ESAS at baseline. Following treatment, participants reported 3.2 symptoms as moderate to severe. The symptom change for all participant encounters receiving any therapy was statistically significant for all symptoms, and clinically significant (a reduction of more than 1) for all symptoms except financial distress, appetite, and memory. Clinically significant levels of global distress (<3) were reduced in 72% of all participants receiving either therapy. No adverse events were recorded. Conclusions: The results indicate that acupuncture and reflexology administered alongside chemotherapy may reduce patient reported symptom burden and patient global symptom related distress. Future research would include an active control group, and consider confounding factors such as chemotherapy stage and medication

Evaluation of in vivo THz sensing for assessing human skin hydration

Terahertz (THz) in vivo reflection imaging can be used to assess the water content of the surface of the skin. This study presents the results of treating 20 subjects with aqueous, anhydrous and water-oil emulsion samples and observing the changes induced in the skin using THz imaging. These regions were also measured with a corneometer, the present gold standard for skin hydration assessment within the cosmetics industry. We find that THz imaging is effective at observing the presence of oil and water on the surface of the skin, these results can be verified with the measurements of capacitance taken by the corneometer. The THz measurements reveal a distinction between the responses of subjects with initially dry or well hydrated skin, this observation is particularly noticeable with the oil-based samples. Additionally, moderate correlation was found between the THz reflected amplitude and capacitance of untreated skin with a correlation coefficient of r = -0.66, suggesting THz imaging has promising potential for assessing skin hydration

Real time THz imaging - opportunities and challenges for skin cancer detection

It was first suggested that terahertz imaging has the potential to detect skin cancer twenty years ago. Since then, THz instrumentation has improved significantly: real time broadband THz imaging is now possible and robust protocols for measuring living subjects have been developed. Here, we discuss the progress that has been made as well as highlight the remaining challenges for applying THz imaging to skin cancer detection