A portable device for finger tendon rehabilitation that provides an isotonic training force and records exercise behaviour after finger tendon surgery.

For most hand surgeons, flexor tendon repairs in zone 2 of the hand still present a clinical problem. The surgeon is placed in a dilemma: on the one hand, if repair is achieved and the finger is kept immobile during the healing phase, dense adhesions may bind the tendons within the sheath and limit motion. On the other hand, uncontrolled early flexion may disrupt the tendon repair. Early 'controlled motion' increases tensile strength, reduces the formation of adhesions and improves clinical results. To investigate the relationship between the patient's compliance concerning the post-operative motion regimen and the final range of motion, a device has been developed which records when and how often the patient exercises. The device is attached to a modified Kleinert splint. This configuration enables comparison of the outcome of the rehabilitation of patients who exercise according to the rehabilitation programme with patients who exercise less often. The device measures for up to one week. It is possible to download the available measurement samples (exercise count per quarter of an hour) for inspecting the training course or for further analysis/statistics.

In vitro evaluation of a novel bioreactor based on an integral oxygenator and a spirally wound nonwoven polyester matrix for hepatocyte culture as small aggregates.

BACKGROUND/AIMS: The development of custom-made bioreactors for use as a bioartificial liver (BAL) is considered to be one of the last challenges on the road to successful temporary extracorporeal liver support therapy. We devised a novel bioreactor (patent pending) which allows individual perfusion of high density cultured hepatocytes with low diffusional gradients, thereby more closely resembling the conditions in the intact liver lobuli. METHODS: The bioreactor consists of a spirally wound nonwoven polyester matrix, i.e. a sheet-shaped, three-dimensional framework for hepatocyte immobilization and aggregation, and of integrated hydrophobic hollow-fiber membranes for decentralized oxygen supply and CO2 removal. Medium (plasma in vivo) was perfused through the extrafiber space and therefore in direct hepatocyte contact. Various parameters were assessed over a period of 4 days including galactose elimination, urea synthesis, lidocaine elimination, lactate/pyruvate ratios, amino acid metabolism, pH, the last day being reserved exclusively for determination of protein secretion. RESULTS: Microscopic examination of the hepatocytes revealed cytoarchitectural characteristics as found in vivo. The biochemical performance of the bioreactor remained stable over the investigated period. The urea synthesizing capacity of hepatocytes in the bioreactor was twice that of hepatocytes in monolayer cultures. Flow sensitive magnetic resonance imaging (MRI) revealed that the bioreactor construction ensured medium flow through all parts of the device irrespective of its size. CONCLUSIONS: The novel bioreactor showed encouraging efficiency. The device is easy to manufacture with scale-up to the liver mass required for possible short-term support of patients in hepatic failure.