Abstract: An atherectomy system includes a handle and a drive motor that is adapted to rotate a drive cable extending through the handle and operably coupled to an atherectomy burr. A control system is adapted to regulate operation of the drive motor, including providing the drive motor with a high frequency pulse width modulation (PWM) drive signal in order to operate the drive motor. The control system monitors a motor performance parameter such as motor speed or motor torque, and when the motor performance parameter approaches a limit of a performance range, the control system adds a low frequency PWM signal to the high frequency PWM drive signal, thereby causing the drive motor to produce a tactile signal that signals to the user that the motor performance parameter is approaching the limit of the performance range.

Abstract: A matched glass-to-metal connecting device for use in a vacuum tube collector for a solar energy collecting apparatus is made of a glass envelope and a metal sleeve directly bonded to the glass envelope. The glass envelope is made of a glass having a composition, in percent by weight on the basis of oxide content, consisting essentially of B2O3, 19; Al2O3, 8; Na2O, 2; K2O2, 3; BaO, 3; LiF, 1; and balance of SiO2 and the metal sleeve consists of metal material number 1.3981 of DIN 17745. The glass envelope has a thermal expansion coefficient that deviates from the metal part's thermal expansion coefficient by no more than 4% in the temperature range from 25° C. to 350° C.

Abstract: A method and system is provided for reducing chatter in multi-capacity compressors having disengageable eccentric structures. The multi-capacity fluid compressor includes a compression chamber having a discharge end and an inner surface. The compressor also includes a compression member having a disengageable eccentric structure allowing the compressor to provide discrete compression capacities. A valve portion is disposed adjacent to the discharge end of the compression chamber and is arranged and disposed to discharge a compressed fluid when the compression member has completed. A discharge arrangement is arranged and disposed to discharge at least a portion of fluid remaining in the compression chamber at the completion of the compression cycle. The discharge of at least a portion of the fluid remaining in the compression chamber reduces or eliminates forces on the disengageable eccentric structure to limit rotational acceleration of the disengageable eccentric structure.

Abstract: A method and system is provided for reducing chatter in multi-capacity compressors having disengageable eccentric structures. The multi-capacity fluid compressor includes a compression chamber having a discharge end and an inner surface. The compressor also includes a compression member having a disengageable eccentric structure allowing the compressor to provide discrete compression capacities. A valve portion is disposed adjacent to the discharge end of the compression chamber and is arranged and disposed to discharge a compressed fluid when the compression member has completed. A discharge arrangement is arranged and disposed to discharge at least a portion of fluid remaining in the compression chamber at the completion of the compression cycle. The discharge of at least a portion of the fluid remaining in the compression chamber reduces or eliminates forces on the disengageable eccentric structure to limit rotational acceleration of the disengageable eccentric structure.