Hand-held analytical devices and methods of use thereof
View Patent ↗Hand-held analytical devices are provided for blood sugar tests. The devices can incorporate a replaceable test tape cassette having a test tape with a plurality of analytical aids and have a tape drive having a DC motor and gearing that can be coupled to the test tape cassette for successive provision of the analytical aids. The devices also include a control device for rotational speed control of the DC motor. Methods also are provided for operating such hand-held analytical devices.
1. A hand-held analytical device comprising:
a replaceable test tape cassette comprising a test tape with a plurality of consecutive analytical aids; and
a tape drive comprising:
a DC motor and gearing that can be coupled to the test tape cassette for successively providing the analytical aids, and
a control device for controlling rotational speed of the DC motor, wherein the control device comprises a rotary pickup arranged on the DC motor to record actual rotational speed of a motor drive shaft, and wherein the rotary pickup comprises an interrupter seated in a rotationally fixed manner on the motor drive shaft and a light barrier fixed to the device and interacting with the interrupter.
2. The hand-held device of claim 1 , wherein the rotary pickup comprises an optoelectronic encoder for optically sampling rotation of the motor drive shaft while generating a rate of electrical pulses proportional to rotational speed as an output signal.
3. The hand-held device of claim 1 , wherein the interrupter is a vaned wheel or a perforated disk and the light barrier is a fork light barrier.
4. The hand-held device of claim 1 further comprising a clock generator for generating time clock pulses and a counter for counting time clock pulses between two signal edges of an output signal of the rotary pickup.
5. The hand-held device of claim 1 , wherein the control device further comprises a comparator for forming a control difference between the actual rotational speed and a setpoint rotational speed specified as a control variable.
6. The hand-held device of claim 1 , wherein the control device further comprises a control processor to which a control difference can be applied on an input side for adjusting a setpoint rotational speed in a closed control loop.
7. The hand-held device of claim 6 , wherein the control processor comprises at least one proportional control element and at least one integral control element formed by a software routine.
8. The hand-held device of claim 1 , wherein the control device further comprises a pulse-width modulator as an actuating element for driving the DC motor with a pulse-width modulated DC voltage.
9. The hand-held device of claim 1 , wherein the control device achieves a tape speed of the test tape of about 15±2 mm/s with an adjustment time in a range from about 0.1 s to about 0.25 s.
10. The hand-held device of claim 1 , wherein the control device further comprises a setpoint value generator for establishing a setpoint rotational speed in accordance with a constant provision time for provision of the analytical aids.
11. The hand-held device of claim 10 , wherein the control device further comprises a setpoint value memory for storing a setpoint value table, in which a value of the setpoint rotational speed of the DC motor is respectively assigned to a test number of the consecutive analytical aids.
12. The hand-held device of claim 11 , wherein the test tape cassette further comprises a storage means for usage-dependent storage of a test number of the consecutive analytical aid currently provided.
13. The hand-held device of claim 12 , wherein the storage means is a RFID chip.
14. The hand-held device of claim 1 , wherein the consecutive analytical aids can be drawn by tape transport from a stock spool shielded from the surroundings and can be provided at an application site.
15. A method for operating a hand-held analytical device in which a test tape provided with a plurality of analytical aids is used in the form of a replaceable test tape cassette in the hand-held device, the method comprising the steps of:
providing the plurality of analytical aids successively by a tape drive;
recording actual rotational speed of a motor drive shaft by a rotary pickup of a control device, wherein the rotary pickup is arranged on the DC motor; and
controlling rotational speed of the DC motor with the control device by forming a control difference between the actual rotational speed and a setpoint rotational speed specified as a control variable, wherein the rotary pickup comprises an interrupter seated in a rotationally fixed manner on the motor drive shaft and a light barrier fixed to the device and interacting with the interrupter.
16. The method of claim 15 , wherein the rotary pickup further comprises an optoelectronic encoder that optically samples rotation of the motor drive shaft while generating a rate of electrical pulses proportional to the actual rotational speed.
17. The method of claim 15 , wherein the control device achieves a tape speed of the test tape of about 15±2 mm/s with an adjustment time in a range from about 0.1 s to about 0.25 s.
18. The method of claim 15 , wherein an angular frequency of the DC motor in a range of about 600 rad/s to about 1000 rad/s.
19. The method of claim 15 , wherein a comparator forms the control difference between the actual rotational speed and the setpoint rotational speed.
20. A hand-held analytical device comprising:
a replaceable test tape cassette comprising a test tape with a plurality of consecutive analytical aids; and
a tape drive comprising:
a DC motor and gearing that can be coupled to the test tape cassette for successively providing the analytical aids, and
a control device for controlling rotational speed of the DC motor, wherein the control device comprises a rotary pickup arranged on the DC motor to record actual rotational speed of a motor drive shaft, and wherein the control device further comprises a pulse-width modulator as an actuating element for driving the DC motor with a pulse-width modulated DC voltage.
21. A hand-held analytical device comprising:
a replaceable test tape cassette comprising a test tape with a plurality of consecutive analytical aids; and
a tape drive comprising:
a DC motor and gearing that can be coupled to the test tape cassette for successively providing the analytical aids, and
a control device for controlling rotational speed of the DC motor, wherein the control device comprises a rotary pickup arranged on the DC motor to record actual rotational speed of a motor drive shaft, wherein the control device further comprises a setpoint value generator for establishing a setpoint rotational speed in accordance with a constant provision time for provision of the analytical aids, and wherein the control device further comprises a setpoint value memory for storing a setpoint value table, in which a value of the setpoint rotational speed of the DC motor is respectively assigned to a test number of the consecutive analytical aids.