Infiltration of medications during infusion therapy results in complications ranging from erythema and pain to tissue necrosis requiring amputation. Infiltration occurs from improper insertion of the cannula, separation of the cannula from the vein, penetration of the vein by the cannula during movement, and response of the vein to the medication. At present, visual inspection by the clinical staff is the primary means for detecting intravenous (IV) infiltration. An optical sensor was developed to monitor the needle insertion site for signs of IV infiltration. Initial studies on simulated and induced infiltrations on a swine model validated the feasibility of the methodology. The presence of IV infiltration was confirmed by visual inspection of the infusion site and/or absence of blood return in the IV line. Potential sources of error due to illumination changes, motion artifacts, and edema were also investigated. A comparison of the performance of the optical device and blinded expert observers showed that the optical sensor has higher sensitivity and specificity, and shorter detection time than the expert observers. An improved model of the infiltration monitoring device was developed and evaluated in a clinical study on induced infiltrations of healthy adult volunteers. The performance of the device was compared with the observation of a blinded expert observer. The results show that the rates of detection of infiltrations are 98% and 82% for the optical sensor and the observer, respectively. The sensitivity and specificity of the optical sensor are 0.97 and 0.98, respectively.

More marginal results and complications occur as a result of knee ligament surgery than of other common surgical procedure. Long-term success rates of anterior cruciate ligament reconstruction range between 75 and 90%. The goal of knee surgery is to restore the normal kinematics of the knee. If the tension is too high, the range of motion of the joint is restricted, resulting in abnormal stresses on the articular cartilage and the meniscuses, and interfering with the revascularization of the graft. The use of Raman spectroscopy for the measurement of tension in ligaments and tendons is described. Measurements of the Raman spectrum demonstrate that the Raman frequencies shift with applied tension.

We have measured the Raman spectrum of NaCN in the two orthorhombic low temperature phases under hydrostatic pressure up to 6 kbar. At the order–disorder phase transition from the disordered phase D252h to the ordered phase D132h the unit cell doubles and new phonon bands fold from the zone boundary to the center and appear in the Raman spectrum. We analyze the transition group theoretically and assign the different phonon bands in the Raman spectrum. The pressure shift of the CN− librational mode is larger than the shift of the lattice modes, which supports our band assignment. We estimate the mode Grüneisen parameters using an approximated value for the bulk modulus of NaCN and compare the results with the averaged Grüneisen parameter of NaCl.

Blood velocity measurements in the skin of pigs are reported. Measurements were obtained using laser speckle contrast analysis with a multiple scattering correction. Laser speckle contrast analysis is a rapid technique for obtaining a velocity mapping of perfused tissue. Measurements of blood velocity in pig skin were obtained using a laser and a monochrome digital camera. Blood velocities were measured in tissue prior to and after elevation of flaps. The effect of Iloprost and nitroglycerine on local blood velocity was also examined in nonexcised tissue.

The IrDA wireless protocol has been applied to a fiber optics based point-of-care system for the detection of intravenous infiltration. The system is used for monitoring patients under infusion therapy. It is optimized for portability by incorporating a battery source and wireless communication.The IrDA protocol provides secure data communication between the electronic module of the system and the PDAs carried by the nurses. The PDA is used for initiating the actions of the electronic module and for data transfer. Security is provided by specially designed software and hardware.