Abstract: A device may include a hollow needle, a dilator mounted coaxially on the needle, and a sheath mounted coaxially on the dilator. The dilator may be slideably displaceable relative to the sheath.

Abstract: A device may include a hollow needle, a dilator mounted coaxially on the needle, and a sheath mounted coaxially on the dilator. The dilator may be slideably displaceable relative to the sheath.

Abstract: A device may include a hollow needle, a dilator mounted coaxially on the needle, and a sheath mounted coaxially on the dilator. The dilator may be slideably displaceable relative to the sheath.

Abstract: A method for producing a low-hysteresis magnetoelastic element comprising applying a magnetoelastic material onto a metal substrate. After the magnetoelastic element is securely bonded to the underlying shaft, a reduction in the outside diameter of the shaft draws the magnetoelastic element radially inward causing it to occupy a smaller volume. This process provides the magnetic anistropy required for the sensor to operate properly, and also results in a densification of the magnetoelastic element making it inherently stable. Several methods of reducing the outside diameter of the shaft to draw the magnetoelastic element radially inward have been devised. Prior to deposition of the magnetoelastic material, the outside diameter of a hollow shaft is elastically expanded by applying force to its inside diameter. This is accomplished by using an expanding insert, by pressurizing the cavity within the shaft, or by inducing a managed thermal expansion of the shaft prior to material deposition.

Abstract: A low-hysteresis torque sensor and method for producing a low-hysteresis magnetoelastic element including thermally spraying a magnetoelastic material onto a metal substrate. During the spraying process, axial compressive pressure is applied to the substrate, and subsequently released after the substrate and magnetoelastic element have substantially cooled. This process has the effect of substantially reducing hysteresis and the axial stress in the magnetoelastic element that would normally occur due to the different coefficients of thermal expansion between the magnetoelastic element and the substrate. In a preferred embodiment, the magnetoelastic element includes nickel and the substrate includes stainless steel. It is further preferred that the substrate include a shaft and the magnetoelastic element comprise a circumferential ring intimately attached thereto.