Bilateral Assessment of Functional Tasks for Robot-assisted Therapy Applications

This article presents a novel evaluation system along with methods to evaluate bilateral coordination of arm function on activities of daily living tasks before and after robot-assisted therapy. An affordable bilateral assessment system (BiAS) consisting of two mini-passive measuring units modeled as three degree of freedom robots is described. The process for evaluating functional tasks using the BiAS is presented and we demonstrate its ability to measure wrist kinematic trajectories. Three metrics, phase difference, movement overlap, and task completion time, are used to evaluate the BiAS system on a bilateral symmetric (bi-drink) and a bilateral asymmetric (bi-pour) functional task. Wrist position and velocity trajectories are evaluated using these metrics to provide insight into temporal and spatial bilateral deficits after stroke. The BiAS system quantified movements of the wrists during functional tasks and detected differences in impaired and unimpaired arm movements. Case studies showed that stroke patients compared to healthy subjects move slower and are less likely to use their arm simultaneously even when the functional task requires simultaneous movement. After robot-assisted therapy, interlimb coordination spatial deficits moved toward normal coordination on functional tasks

Deferoxamine-fibrin accelerates angiogenesis in a rabbit model of peripheral ischemia

The intramuscular (i.m.) injection of a modified fibrin meshwork plus deferoxamine was tested in a rabbit model of acute hind-limb ischemia. After excision of the left external iliac and femoral arteries, 12 rabbits at the Milwaukee Heart Institute were divided into two groups: control and fibrin meshwork plus deferoxamine (FDEF) i.m. The rabbits underwent angiography before surgery, immediately after, and 1 month postoperatively. These data were compiled through counting by means of a grid overlay. Another 12 rabbits at the Vakhidov Center of Surgery, which did not undergo angiography, underwent lower limb-calf blood pressure (L-CBP) measurements made immediately after surgery and at postoperative days 10, 20 and 30. Biopsies from thigh skeletal muscles of rabbits that had L-CBP measurements underwent alkaline phosphatase staining on day 30 to determine the percentage of biopsied area that was occupied by capillaries. The number of arteries and arterioles crossing 71 grid intersections immediately post-surgery decreased from 30.2 +/- 2.3 to 18.0 +/- 2.0 (p \u3c 0.05). One month postsurgery this number increased to 29.2 +/- 2.4 in controls (p \u3c 0.05 vs immediately post-surgery) and to 59.6 +/- 3.2 in the FDEF group (p \u3c 0.001 vs immediately post-surgery). By day 30 the L-CBP ratio improved in the FDEF group (0.8 +/- 0.02) vs controls (0.3 +/- 0.04). By day 30 the capillary density increased from that of normal muscle tissue (198.6 +/- 12.9/mm2) to 292 +/- 12.4/mm2 in the FDEF group (p \u3c 0.05), but decreased in the control group to 98.7 +/- 7.7/mm2. I.m. injection of FDEF considerably accelerated angiogenesis in severely ischemic hind-limb tissue in this model, making it a viable treatment method for clinical use in patients who have critical limb ischemia

Effect of electrical stimulation on arteriogenesis and angiogenesis after bilateral femoral artery excision in the rabbit hind-limb ischemia model

The effects of electrical stimulation (ES) on arteriogenesis (the opening of preexisting collaterals) and angiogenesis (formation of new capillaries) were studied after acute bilateral hind limb ischemia was induced via bilateral femoral artery excision in a rabbit model. The study evaluated the rabbit hind limbs\u27 normal response to acute ischemia and to application of ES by calculating changes in arterial and capillary densities. Comparisons were made with our prior study, in which the femoral artery was unilaterally excised, as we attempted to expand on the topics of arteriogenesis and angiogenesis. Twelve adult New Zealand white rabbits were randomly assigned to 1 of 2 series. In Series 1, the control group, both femoral arteries were excised and no ES was applied. In Series 2, both femoral arteries were excised and ES was applied to the left limb. One lead was implanted into the left adductor muscle near the site of the excised left femoral artery (Series 2), and a stimulator (Thera, Medtronic, Inc, Minneapolis, MN) was implanted in a separate pocket. ES was applied at a rate of 3 V, 30 contractions per minute, beginning immediately after surgery and continuously for 1 month. Angiography was performed in all 12 rabbits 1 month after surgery to establish the anatomy of the collateral vessels and to demonstrate that the femoral artery stump continued to be an end artery. Contrast-opacified arteries (COAs) that crossed the grid\u27s midline, and the total number of grid lines intersected by COAs, were tallied according to an established method. Capillary density was calculated as the number of capillaries per square millimeter of muscle. In Series 1, after 1 month, the number of COAs crossing the grid\u27s midline was 4.5 +/-1.5 on the left and 4.8 +/-1.2 on the right side. In Series 2, the number of COAs crossing the grid\u27s midline was 7.9 +/-1.8 on the left side (