Volumetric flow equalizing drive control wheel

• US 6,064,797 A
• Filed: 10/12/1998
• Issued: 05/16/2000
• Est. Priority Date: 10/12/1998
• Status: Expired due to Term

• Current Assignee: B Braun Medical Incorporated (B. Braun Holding GmbH & Co. KG)
• Original Assignee: B Braun Medical Incorporated (B. Braun Holding GmbH & Co. KG)
• Inventors: Crittendon, Joe C., Harrison, David J., Stavely, Roberta, Copp, Harry C.
• Primary Examiner(s): Nappi, Robert E.
• Assistant Examiner(s): Duda, Rina I.
• Application Number:
  US09/169,900
• Time in Patent Office: 582 Days
• Field of Search: 388/800, 388/907, 388/909, 318/767, 318/772, 417/1, 417/7, 417/18, 417/20, 417/22, 417/23, 417/44.1, 417/321, 604/9
• US Class Current: 388/800
• CPC Class Codes: A61M 5/14228 with linear peristaltic action, i.e. comprising at least three pressurising members or a helical member
• CPC Class Codes: F04B 2203/0213 Pulses per unit of time (pulse motor)
• CPC Class Codes: F04B 43/082 the tubular flexible member being pressed against a wall by a number of elements, each having an alternating movement in a direction perpendicular to the axes of the tubular member and each having its own driving mechanism

Abstract

A rotation control for a device to be rotated includes a variable speed DC motor having a constant rotational speed upon receiving a selected fixed voltage electrical input power from an adjustable electrical input power supply connected to the motor for supplying the selected fixed voltage. A switch circuit is connected between the motor and the power supply activatable in response to a first electrical signal to turn the motor "on" and activatable in response to a second electrical signal to turn the motor "off". A selectable frequency, regular interval electrical signal device is connected to the switch circuit to provide electrical signals to activate the switch circuit to turn the motor "on" at regular intervals. An encoder wheel is coupled to the device to be rotated and to the motor for rotation of the timing disk at a speed proportional to the constant rotational speed of the motor. The timing disk has a plurality of openings around the disk with predetermined spacing there between. The spacing corresponds to a desired amount of device rotation. A light sensor is operatively positioned adjacent to the encoder wheel for detecting the spaced openings and connected to the switch circuit to provide the electrical signal to turn the motor off each time a next one of the openings is detected by the sensor thereby allowing the device to traverse the desired amount of device rotation during each regular interval that the motor is turned on.

Claims

1. A rotation control for a device to be rotated comprising:

a. a variable speed DC motor having a constant rotational speed upon receiving a selected fixed voltage electrical input power;

b. an adjustable electrical input power supply connected to said motor for supplying selectably said selected fixed voltage;

c. a switch circuit connected between said motor and said power supply activatable in response to a first electrical signal to turn said motor "on" and activatable in response to a second electrical signal to turn said motor "off";

d. a selectable frequency, regular interval electrical signal device connected to said switch circuit to provide a series of said first electrical signals at regular timed intervals to activate said switch circuit to turn said motor "on";

e. an encoder wheel coupled to said device to be rotated and to said motor for rotation of said encoder wheel at a speed proportional to said constant rotational speed of said motor, said encoder wheel having a plurality of openings around said encoder wheel with predetermined varied spacing there between, said spacing corresponding to a desired amount of device rotation during that part of the rotation of said encoder wheel; and

f. a light sensor operatively positioned adjacent said encoder wheel for detecting said spaced openings and connected to said switch circuit to provide second electrical signals to turn said motor off when a subsequent one of said openings is detected by said sensor thereby allowing said device to traverse said desired amount of device rotation between said spaced-apart opening during said regular timed intervals.

2. A rotation control for a device to be rotated as in claim 1 further comprising:

a) an indexing opening at one position on said encoder wheel;

b) another light sensor operatively positioned adjacent to said encoder wheel for detecting said index opening and to provide a signal to said device for repeatedly synchronizing control of said motor with said encoder wheel.

3. A rotation control for a device to be rotated as in claim 1 wherein said switch circuit comprises a gate array coupled between said electrical signals to turn said motor on and off and a microprocessor.

4. A rotation control for a device to be rotated as in claim 3 wherein said gate array is responsive to a command signal from said microprocessor to interrupt said motor control only after skipping a predetermined number of sensory signals from said detection of said openings around said encoder wheel.

5. A rotation control for a device to be rotated as in claim 1 further comprising

a) a control panel by which an operator can input a desired volumetric flow rate;

and

b) a microprocessor responsive to said signals from said regular intervals, to said signals from said light sensor and to said input desired volumetric flow rate from a control panel to operate said device to be rotated according to said encoder wheel electrical signals below a predetermined desired input flow rate and for controlling said motor speed with a continuous voltage power above said predetermined desired input flow rate.

6. A rotation control for a device to be rotated as in claim 5 wherein said predetermined desired input flow rate is in the range of about 80 ml./hour to about 160 ml./hour.

11. A rotation control for a linear peristaltic pump as in claim 1 further comprising

a) a control panel by which an operator can input a desired volumetric flow rate;

and

b) a microprocessor responsive to said first electrical signals from said regular intervals, to said second electrical signals from said light sensor and to said input desired volumetric flow rate from said control panel to operate said device to be rotated according to said first and second electrical signals below a predetermined desired input flow rate and for controlling the speed of said variable speed DC motor with a continuous voltage power above said predetermined desired input flow rate.

12. A rotation control for a linear peristaltic pump as in claim 11 wherein said predetermined desired input flow rate is in the range of about 80 ml./hour to about 160 ml./hour.

7. A linear peristaltic pump having rotation control comprising;

a) a rotary cam mechanism operably connected to pumping fingers for successfully acting against a flexible tubing to pump fluid therethrough;

b) a variable speed DC motor connected for rotating said rotary cam mechanism, said DC motor having a constant rotational speed upon receiving a selected fixed voltage electrical input power;

c) an adjustable voltage electrical input power supply for adjustably supplying a fixed voltage connected to said variable speed DC motor for supplying selectably said selected fixed voltage to said variable speed DC motor;

d) a switch circuit connected between said variable speed DC motor and said power supply activatable in response to a first electrical signal to turn said variable speed DC motor "on" and activatable in response to a second electrical signal to turn said variable speed DC motor "off";

e) a selectable frequency, regular interval electrical signal device connected to said switch circuit to provide a series of said first electrical signals at regular timed intervals to activate said switch circuit to turn said variable speed DC motor "on";

f) encoded wheel coupled to said linear peristaltic pump and to said variable speed DC motor for rotation of said encoder wheel at a speed proportional to said constant rotational speed of said variable speed DC motor, said encoder wheel having a plurality of openings around said encoder wheel with predetermined, differing spacing there between, said spacing corresponding to a desired amount of device rotation, wherein said predetermined differing spacing provides approximately equal delivery volume increments of fluid pumped through said flexible tubing; and

g) a light sensor operatively positioned adjacent said timing wheel for detecting said spaced openings and connected to said switch circuit to provide a second electrical signal to turn said variable speed DC motor off when a subsequent one of said openings is detected by said sensor thereby allowing said pump to traverse said desired amount of rotation of said pumping cam to provide said approximately equal delivery volume increments of pumped fluid during said regular timed intervals.

8. A linear peristaltic pump as in claim 7 further comprising:

a) an indexing opening at one position on said encoder wheel;

b) another light sensor operatively positioned adjacent to said encoder wheel for detecting said index opening and to provide a signal to said pump for repeatedly synchronizing control of said motor with said encoder wheel.

9. A a linear peristaltic pump as in claim 7 wherein said switch circuit comprises a gate array coupled between said electrical signals to turn said motor on and off and a microprocessor.

10. A linear peristaltic pump as in claim 9 wherein said gate array is responsive to a command signal from said microprocessor to interrupt said motor control only after skipping a predetermined number of sensory signals from said detection of said openings around said encoder wheel.