Technology and Health Care - Volume 28, issue 4

Authors: Murata, Jun | Murata, Shin | Yamagata, Shigeki | Ohyama, Michie | Kogo, Haruki | Umeki, Naho

Article Type: Short Communication

Abstract: BACKGROUND: Prolonged wheelchair sitting is known to lead to venous stasis and results in leg edema. OBJECTIVE: To clarify how a dynamic cushion affects leg edema in people with spinal cord injuries (SCI) evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with a dynamic air cushion or a static cushion. METHODS: Seven wheelchair users with SCI participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed 10 cm proximally from the medial malleolus). Following a period of …rest, the subjects sat on a reclining wheelchair containing a dynamic cushion for 15 min. Then, the protocol was repeated with a static cushion. The above two procedures were performed in a random order. These data were statistically compared between the two procedures. RESULTS: The change in leg volume observed during sitting on the dynamic cushion (- 0.02 ± 0.21 ml/100 ml) was smaller than that observed during sitting on the static cushion (0.18 ± 0.28 ml/100 ml) (P < 0.05). CONCLUSIONS: These results suggested that the dynamic air cushion relieved leg edema induced by wheelchair sitting in individuals with SCI. Show more

Keywords: Wheelchair cushion, leg volume, spinal cord injury, plethysmography

DOI: 10.3233/THC-192045

Citation: Technology and Health Care, vol. 28, no. 4, pp. 447-452, 2020

Authors: Wang, Heng Li

Article Type: Short Communication

Abstract: BACKGROUND: The use of transcutaneous electrical stimulation for neuromodulation is an important treatment strategy for functional nerve diseases. It can not only reduce patient pain and prevent the development of drug-resistant disease, but is also more effective than alternative treatment methods. OBJECTIVE: Ag/AgCl electrodes are commonly used for transcutaneous stimulation. However, the silver ions can dissolve in tissue during electrical stimulation, which can lead to heavy metal poisoning and other issues. This study analyzed the amount of residual silver ions found in tissue after electrical stimulation. METHODS: Saline solution and animal skin were …chosen as experimental analogs for human tissue and the amount of residual silver ions were analyzed via ultraviolet spectrophotometer. RESULTS: After a volume-to-quantity conversion, we found that after using a pair of electrodes for three hours, the concentrations of silver ions dissolved in the saline solution and the skin were less than 0.1 ppb and 0.5 ppb, respectively, due to its low solubility. CONCLUSIONS: By analyzing the ion dissolution concentration, we found that the residual silver ion concentration in vivo was less than 0.1 ppb, which is within the safe range for humans. Therefore, we believe it is safe to use Ag/AgCl electrodes for transcutaneous electrical stimulation. Show more

Keywords: Transcutaneous electrical stimulation, neuromodulation, saline experiment, pigskin experiment, Ag ion dissolution concentration

DOI: 10.3233/THC-202192

Citation: Technology and Health Care, vol. 28, no. 4, pp. 453-459, 2020