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We present clinical investigation results of a novel, wearable, orientation and mobility assistive device that uses radar technology. The radar device sends radio signals, detects objects in the environment, and conveys this information to the users by way of sound or vibration feedback. The aim of this investigation is to assess the effectiveness of the device for the visually impaired. During a two-week period of the investigation, 25 visually impaired participants used the device in their everyday activities and kept a diary of their experiences. The investigation included a training session as well as opening and closing interviews, including a standard QUEST 2.0 form to evaluate user satisfaction with assistive technology devices. 92 percent of the participants observed that the device improved their ability to perceive their environment, and 80 percent observed that it increased their confidence in independent mobility.

The crystal polymorphism of ibopamin has been investigated and the measurements suggest that ibopamin exists in two polymorphic forms I and II. The polymorphic monotropic transformation has been verified using differential thermal analysis (DTA) connected with thermomicroscopy (HSM), differential scanning calorimetry (DSC), thermogravimetric analysis (TG) and X-ray powder diffractometry (XRD) equipped with a self-constructed heating device. True densities and specific surface areas of the polymorphs have also been determined. The melting points of forms I and II are (134.8 ± 0.4)°C and (130.2 ± 0.5)°C, respectively.

The effects of moisture on the structure of two commercial (batch A and batch B) and one pure grade (batch C) of magnesium stearate have been examined by using differential scanning calorimetry (DSC), thermogravimetry (TG), X-ray powder diffractometry (XRD) and thermomicroscopy (HSM). The results suggest that the role of water is different in both of the commercial batches. Powder A showed a two-stage mass loss at temperatures between 25°C and 100°C indicating that the water present was tightly bound. The scans from batch B exhibited a continual mass decrease indicating that the moisture present was more loosely bound. With high purity magnesium stearate (batch C) water was bound in the ratio of two molecules to every one of the fatty acid salt. During storage to hydrate at 76% RH and 93% RH, powder A became more crystalline while powder B remained amorphous. Magnesium stearate dihydrate exhibited no tendency to form a trihydrate or higher hydrated forms. A short review of previous studies on magnesium stearate is given in the Introduction.

The effect of humidity on the crystal structure of a new drug substance, dexmedetomidine hydrochloride (DMH), a novel selective α2-adrenoceptor agonist, has been studied using X-ray powder diffractometry (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and the gravimetric method for hygroscopicity determinations. The measurements suggest that dexmedetomidine hydrochloride appears in two different structural forms representing the anhydrous and the hydrous form. Although the ambient relative humidity affects the hydration process, the hygroscopic property of this material is significant only at high relative humidities. Also, true density and specific optical rotation of DMH have been figured out.

The effect of four physical forms on the rate and extent of bioavailability of erythromycin has been studied in healthy volunteers. The different forms — amorphous form, anhydrate, dihydrate, and commercially available “base” — are characterized by X-ray, TG, and DSC measurements. Erythromycin anhydrate and dihydrate are obviously faster and more completely absorbed than the amorphous form or commercially available “base”.