WO1997010023B1 - Equipment for transporting chemical and biological agents through tissue - Google Patents

Abstract

A pump system for the delivery of liquid chemical and biological agents by diffusion from a prepackaged replaceable container into tissue by means of a combination of pressure waves including a base pressure. The pump system comprising a pump having a plurality of pistons driven by actuators, controlled by an electronic controller, at a certain repetition frequency and certain waveforms (up-ramp, peak and downramp) in combination with other signals of acoustic (sonic or ultrasonic) frequencies. The pump system also comprising a cap, in fluid communication with the pump via tubing and pressed against the tissue. The container being placed between the tissue and a membrane within the cap which transmits the pressure waveforms and acts as a piston pushing the agent out of the container and into the tissue. The cap also being capable of transmitting laser pulses to generate heat shock waves in the tissue aiding in the diffusion process in combination with the pressure variations.

Claims

AMENDED CLAIMS

[received by the International Bureau on 18 June 1997 ( 18 06 97), original claims 8 and 9 amended, remaining claims unchanged (2 pages)]

The cap (120) is formed out of material transparent for radiation in

the visible and infrared range with provisions for coupling to an optical

fiber for the transmission of laser pulses from a laser via the annular

cross-section of the cap to the tissue for generating pressure waves within

the tissue.

7. The pump system (10) of claim 1, wherein

the cap (120) is formed out of material transparent for radiation in the

visible and infrared range with a small-diameter coaxial cylinder in its

cavity, said cylinder having means, like a specifically placed mirror, for coupling laser pulses via an optical fiber via a cross-section of said

cylinder to the tissue for generating pressure waves within the tissue.

8. The pump system (10) of claim 1, wherein

the controller (210) comprises control circuitry including frequency

generators (220, 230 and 240) and controlled counters (260, 270) feeding into a digital-to-analog converter (280) for generating piecewise linear

waveforms, like upramp, peak, downramp and pause, at a certain

repetition frequency, said digital-to-analog converter (280) feeding into

the summing input of an operational amplifier (290), in conjunction with an acoustic frequency waveform from another oscillator (285), to generate

a resulting waveform for operating electromechanical actuators (50, 80)

driving pistons (40, 70) in the pump (20) for generating pressure wave¬

forms, including a base pressure with a minimum of zero, to be communi- cated via tubing (110) to the cap (120) and via the membrane (126) to the

agent to be transported into the tissue (125), said pressure waveforms

being adaptable to specific kinds of tissue.

9. The pump system (10) of claim 8, wherein

the controller comprises circuitry controlling via a plurality of actuators

(50, 80) a plurality of pistons (40, 70) allowing one piston (30) to generate pressure waves of one acoustic frequency and another piston (80) to

generate pressure waves of another acoustic frequency and to maintain a

constant base pressure in the cap compensating for volume of agent

diffused into the tissue (125).

10. The pump system (10) of claim 8, wherein

the controller (210) and said plurality of pistons (40, 70) allow for a

suckback of said fluid medium via a valve (90) into said reservoir (100)

allowing the insertion of another container (130) and the start of another

pump process.