 |
Description  |
|
|
BACKGROUND OF
THE INVENTION
The invention relates generally to systems for, and methods of, automatically dispensing medication in a home setting in accordance with a predetermined schedule, and relates specifically to systems which are both easy to use by elderly or
disabled people yet provide protection against underdosage as well as overdosage.
Underdosage protection relates to a device's ability to alert a patient of the proper time to take medication. Overdosage protection relates to the ability of a pill device to prevent a user from taking more than one medication dose in a
relatively short period of time. For example, overdosage could occur if a patient misses taking a medication on time and takes the missed medication immediately prior to the next dosage period. Overdosage would occur if the patient is permitted access
to and takes both the untaken dose as well as the next dose soon thereafter.
Non-compliance with self-administered medication schedules is a costly health care problem. Approximately one third (11 million) of the non-institutionalized elderly experience at least some minor confusion sufficient to interfere with their
normal activities of daily living, such as the taking of medication on a prescribed schedule. As the health care industry changes within the next several years, the importance of avoiding complications by employing preventive procedures such as the use
of intelligent pill dispensers for home use will likely increase. Present pill devices, however are not well suited for such demanding applications.
Present pill providing devices include (1) reference aids for referencing when to take medication, (2) controlled access devices for limiting pill access to predefined periods of time, and (3) controlled medication dispensing devices which eject
medication at predetermined times. Devices of category (1) are passive reference aids which do not prevent access to medication.
Devices of category (2), such as those disclosed in U.S. Pat. Nos. 4,725,997; 4,695,954; 4,572,403; 4,310,103; 4,223,801; 3,762,601; and 3,722,739, generally require that a user reach into the device to retrieve the medication at certain
periods of time. Unfortunately such devices are difficult for individuals having low manual dexterity skills to use due to the requirement that a patient reach into an exposed recess.
Devices of category (3), such as those disclosed in U.S. Pat. Nos. 4,953,745; 4,872,591; 4,763,810; 4,747,514; 4,674,652; and 3,964,638, generally dispense or eject medication automatically on a timed sequence. These devices, however, do not
adequately provide protection against overdosage in the situation when medication is not timely taken. Because such devices eject medication automatically, overdosage may occur.
Additional devices of category (3) include those disclosed in U.S. Pat. Nos. 3,968,900 and 3,368,967. These devices generally dispense or eject medication following a request by a user in cooperation with a timer. Although the dispensing
mechanisms turn off their respective timers such that a predetermined period of time must elapse between dispenses, all of the medication doses for such devices must be the same since it is not known when specific doses will be taken. This may lead to
adverse drug reactions if, for example, certain medication which should not be taken with food is taken at meal time because earlier medications were not taken on time. Also, no record is kept of the scheduling deviations that may occur with such an
altered timing schedule.
Additionally, present devices are not sufficiently flexible in their ability to respond to various conditions involving interruptions in the dispensing schedule. A medication dispenser should be able to respond to interruptions by readjusting
the schedule if necessary, or by preventing certain medication from being made available if requested too late.
Interruptions in a schedule can occur if medication is taken early, taken late, or not taken at all for a certain dosage period. The determination of how to adjust one's medication schedule once an interruption has occurred, is a difficult
decision for many people. Questions whether the schedule should be shifted forward in time, whether the patient should skip the last dose, whether the patient should take both doses, or whether the patient should skip the next dose, are not always
easily answered. Such answers regarding the most appropriate course of action depend upon the medication involved as well as the amount of time of the deviation.
Other shortcomings of present dispensing or access devices include the inability of a patient to take a medication early if he or she will not be able to take the dose at the scheduled time. For example, if medication is to be taken once every 4
hours, and a patient is planning to leave their house fifteen minutes prior to the next dose period, then it may be proper for the patient to take the dose early. In fact, the patient may even wish to take the dose with them. However, it is generally
not possible to do this with present devices while remaining on the appropriate timing schedule.
There is a need therefore, for a medication dispensing device that is easy to use by elderly and disabled individuals, and adequately prevents overdosage. Specifically, there is a need for a device that dispenses medication doses and collects
untaken doses so as to make them unavailable to the patient.
There is a further need for a medication dispensing device which provides ample feedback to a patient's inquiry regarding the status of doses taken or not taken, as well as when the next dose will be made available.
There is also a need for a medication dispensing device which is capable of alerting individuals other than the patient of problems that arise in connection with the administration of medication.
SUMMARY OF THE INVENTION
In a preferred embodiment of the invention, the device prevents prolonged underdosage by monitoring whether medication is both requested by the patient and appropriately dispensed. The device prevents overdosage by storing pills which were not
taken on time so that such medications cannot be taken or otherwise improperly used such as by distribution to others. The device monitors compliance with a dispensing schedule and alerts caregivers when non-compliance has occurred and personal
intervention by a caregiver is advised. The dispenser is easily operated by the visually impaired, the hearing impaired and persons having low manual dexterity abilities, and provides information to the patient regarding medication regimens, such as the
next dosage time, and the previous dosage time. Instructions such as whether to take certain medications with food, or whether replacement or refill cartridges should be ordered are also provided.
In one embodiment of the invention, the pill dispensing device is portable, with all medications which are to be taken at the same time grouped together in a pre-packaged container. An audible signal and visual cue signals the patient when it is
time to take the medication. Under normal conditions the medication is dispensed responsive to a signal from a push button switch. If medications are not dispensed at the proper time then medications which were not timely taken are diverted to a
storage compartment to prevent their improper use by the patient. In addition, the event is recorded and a pharmacist, physician, or other caregiver is notified so that appropriate action may be taken.
The pill dispensing device of the invention is interactive in its ability to respond to a wide variety of situations, and is flexible in its ability to operate in response to the patient's scheduling constraints.
BRIEF DESCRIPTION OF THE
DRAWINGS
The description of the invention may be further understood with reference to the accompanying drawings in which:
FIG. 1 shows an isometric view of a pill device of the invention;
FIG. 2 shows an isometric view of the housing of the device shown in FIG. 1 with the overdosage protection drawer open;
FIG. 3 shows an isometric view of the pill cartridge of the device of FIG. 1;
FIG. 4 shows an exploded view of the pill cartridge shown in FIG. 3;
FIG. 5 shows a rear view of the device shown in FIG. 1;
FIG. 6 shows a sectional view of the device of FIG. 5 taken along line 6--6 from above;
FIG. 7 shows a side view of the interface unit of the device shown in FIG. 1;
FIG. 8 shows a top view of the interface unit of the device shown in FIG. 7;
FIG. 9 shows a bottom view of the interface unit shown in FIG. 7;
FIG. 10 shows a portion of a drive unit of the invention;
FIG. 11 shows a pill device of a non-portable embodiment of the invention;
FIG. 12 shows diagrammatic representation of a control system of the invention;
FIG. 13 shows a flowchart of the set-up procedure for an embodiment of the invention; and
FIGS. 14A-14D show a flowchart of the operational procedure for an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The following description of the illustrated embodiments includes a description of the structure of the illustrated devices, a description of the operation of the embodiments, and concludes with a description of an exemplary program for
implementing the system of the invention.
The illustrated devices:
As shown in FIGS. 1 through 9 an embodiment of a pill dispenser 10 of the invention includes a housing 12, a pill cartridge 14 removably inserted within the housing 12, and a patient interface unit 16 mounted on the top surface 18 of the housing
12. The housing 12 includes an cylindrical wall 20, a top wall 22, a middle wall 24, a bottom wall 26, and first, second and third inner partitions 28,30,32. The housing 12 defines a cartridge receiving area 34, a dispensed pill passage area 36, a
cartridge cover receiving area 38, a power supply area 40, and an expired pill receiving area 42. The housing 12 contains a tapered drive wheel 44, a power supply 46, a motor 48, a radially rotatable overdosage protection drawer 50, an overdosage
protection spring 52, and an overdosage protection solenoid 54 as shown in FIGS. 1, 2 and 6.
The cartridge receiving area 34 is defined by the cylindrical 20, top 22 and middle 24 walls of the housing 12. The dispensed pill passage area 36 is defined by the first partition 28, the drawer 50, the cylindrical wall 20, the middle wall 24,
and an opening 56 in the bottom wall 26 of the housing 12. The cartridge cover receiving area 38 is defined by the first and second partitions 28,30, and the cylindrical 20, bottom 26 and middle 24 walls of the housing 12. The power supply area 40 is
defined by the second and third partitions 30,32, and the cylindrical 20, bottom 26 and middle 24 walls of the housing 12. The expired pill receiving area 42 is defined by the drawer 50, the third partition 32, and the cylindrical 20, bottom 26 and
middle 24 walls of the housing 12.
As shown in FIGS. 1, 3 and 4, the cartridge 14 includes several pill containment cavities 58 and a cartridge cover 60 releasably adhered to one side of the cartridge with a releasable adherent 62 (such as a pressure sensitive adhesive), such that
the pill containment cavities 58 are sealed thereby. The cartridge cover 60 is generally circular and includes two end portions 64a, 64b. The first end portion 64a of the cartridge cover 60 is permanently adhered to the cartridge 14 with a permanent
adherent 66 as shown in FIG. 4, and the second end portion 64b includes a securing tab 68 on its leading edge.
The housing 12 also includes a guide key 70 which aids in the insertion of the cartridge 14 by ensuring proper alignment of the cartridge 14 with respect to the housing 12. When the cartridge 14 is inserted into the housing 12, the cartridge
cover 60 is placed in contact with the drive wheel 44, and the securing tab 68 is positioned within the cartridge cover receiving area 38. The cartridge 14 may be made of an ultraviolet light filtering material, and the cover 60 may be made of a thin
metal foil. When adhered to the cartridge 14, the cover 60 seals out dirt, moisture, and other potential contaminants.
The tapered drive wheel 44 is in communication with the cartridge cover 60 such that when the drive wheel 44 rotates in direction A (as depicted in FIGS. 1 and 2), the cartridge cover 60 is drawn toward the drive wheel 44 thus causing the
cartridge 14 to rotate in direction B (as depicted in FIGS. 1 and 3). As the cartridge cover 60 passes over the drive wheel 44, the cover 60 is separated from the cartridge 14 and the cover 60 is directed into the cartridge cover receiving area 38. The
drive wheel 44 is tapered to conform to the circular shape of the cartridge cover 60, and is driven by the motor 48 under the direction of the controller 72 as discussed below. The motor 48 and the controller 72 are powered by the power supply 46. The
wheel 44 may include frictional material to facilitate engagement with the cover 60. Alternatively, the cover 60 may include frictional adhesive strips on the surface of the cover for facilitating engagement with the drive wheel 44. The housing 12 may
also include an opening 74 in its cylindrical wall 20 for assisting the user in inserting and removing the pill cartridge 14.
In certain embodiments, when insertion is complete the partition closes to engage the cover's leading edge between the drive wheel 44 and the surface of the partition top 15b, forming a nip as shown in FIG. 11. The coefficient of friction
between the cover 60 and the drive wheel 44 is greater than the coefficient of friction between the cover 60 and the surface of the partition 15b. As the drive wheel 44 turns, the cover 60 is pulled through the nip. As the cover 60 is pulled through
the nip, the cartridge 14 is rotated.
When the cartridge 14 rotates, an uncovered pill cavity 58 of the cartridge 14 is positioned above the dispensed pill passage area 36, and pills contained within the cavity 58 are then free to fall through the dispensed pill passage area 36,
through the bottom wall 26 of the housing 12, and into a cup or hand placed beneath the housing 12. The permanent adhesive 66 is located at the trailing edge of the last containment cavity 58 to be rotated over the pill passage area 36.
Also contained within the housing 12 is an overdosage protection unit which includes the radially rotatable drawer 50, the spring 52 and the solenoid 54. When the solenoid 54 is energized the drawer 50 is rotated in direction C, as shown in
FIGS. 1, 2 and 6, pills falling from the cartridge 14 are directed onto the sloped surface 76 of the drawer 50 and into the expired pill containment area 42 within the housing 12. When the solenoid 54 in de-energized, the spring 52 returns the drawer 50
to its non-rotated position. The drawer 50 is shown in FIGS. 1 and 6 in its non-rotated position, and shown in FIG. 2 in its rotated position. The solenoid 54 is energized by the power supply 46 under the direction of the controller 72 as discussed
below. Optionally, the overdosage protection unit may include a position sensor, such an LED and receiver pair to indicate the relative position of the overdosage protection drawer, thus determining whether or not the drawer is open, i.e., whether the
drawer is directly below the pill passage area.
As shown in FIGS. 5 and 6, the cylindrical wall 20 of the housing 12 further includes a power supply access door 78 and an expired pill receiving area access door 80. Each of these doors may include locks 82, 84 as shown in FIG. 5. The expired
pill access door 80 permits removal of untaken pills which are contained within the expired pill receiving area 42. In alternative embodiments, the access door 80 may be positioned in either of middle wall 24 or bottom wall 26. The power supply access
door 78 permits access to a battery 86 which may be periodically replaced or recharged.
As shown in FIGS. 1, and 8, the patient interface unit 16 includes three push switches 88, 90, 92, a speaker 94, a two row liquid crystal display (LCD) unit 96, a port 98 for connecting the interface unit 16 to a programming device and a phone
line port 100 for connection to a standard telephone unit connector plug. As shown in FIGS. 5, 7 and 9 the patient interface unit 16 also includes a microprocessor 102 and three light emitting diode (LED) and receiver pairs 104, 106, 108. The first
pair 104 detects whether the cartridge 14 is fully inserted within the housing 12. Upon removal of the cartridge 14 from the housing 12, the second pair 106 detects whether the cartridge 14 has been fully removed from the housing 12. The LED of the
second pair 106 is mounted on the insertion guide key 70 which is formed as part of the housing 12.
The third pair 108 detects whether a cavity 58 is positioned between the LED and the receiver. The information from the third pair 108 is used to index the rotation of the cartridge 14 such that one cavity is positioned above the passage 36 each
time the cartridge 14 is rotated. The receiver, or photoeye, of the third pair 108 detects the trailing edge of the pill cavities 58 as they rotate between the LED and the receiver.
The three push switches 88, 90, 92, the LCD display 96, and the speaker 94 are mounted on one side 110 of a printed circuit board 112 as shown in FIG. 8. One or more of the push switches may be illuminated. The microprocessor 102, the
LED/receiver pairs 104, 106, 108, and the ports 98, 100 are mounted on the opposite side 114 of the printed circuit board 112 as shown in FIG. 9. The serial port 98 may be a female nine pin "D type" serial port connector or a 5 pin in-line connector,
and the phone line port 100 is a standard telephone modem port. All switch inputs are debounced in accordance with the art.
FIG. 10 shows an embodiment of a drive unit of the invention 150. Specifically, the first partition 152 is subdivided into two hinged portions 154a, 154b, the upper one of which 154a includes an angled top 156. The first partition 152 also
includes a biasing spring 158 which urges the angled top 156 of the upper hinged portion 154a against the drive wheel 160. This enhances the cartridge cover drive capabilities of the drive unit. Alternatively the upper hinged portion 154a could be
selectively urged against the drive wheel 160 using, for example, a solenoid.
To accomplish the drive capabilities of the drive unit, the cover must be held against the wheel with sufficient force to prevent relative motion (e.g., slipping) between the wheel and the cover. The wheel may include a frictional coating or
covering to prevent slipping, or alternatively, frictional strips may be disposed on the cover side that is facing the wheel to prevent slipping.
FIG. 11 shows a non-portable embodiment of the invention 174 including a housing 178, a pill cartridge strip 180 having a number of pill containment cavities 182, and a patient interface unit 184. The housing 178 generally defines a pill
cartridge strip cover receiving area 186, a dispensed pill passage area 188, and an expired pill receiving area 190. The housing 178 further includes a drive wheel 192, an overdosage protection ramp 194, and an expired pill access door 196. In
alternative embodiments, the drive wheel 192 may cooperate with a second wheel to pinch the strip 180 therebetween.
As the drive wheel 192 is rotated in the direction depicted by "D" in FIG. 11, the pill cartridge strip 180 moves in the directions depicted by "E". Alternatively, the take-up reel 200 itself may be powered as well. In either case, as the
cartridge strip 180 moves away from the wheel 192, medications from the uncovered pill containment cavities 182 fall through the dispensed pill passage area 188 and the pill cartridge strip cover 202 is directed toward the cartridge cover receiving area
186.
Power is provided either by use of a battery as discussed above in connection with the embodiment shown in FIGS. 1 through 10, or a voltage regulator and an AC power cord may be included such that the cord can be connected to a standard 120 volt
AC outlet to supply power to the unit. The patient interface unit 184 operates as discussed below with reference to FIGS. 12-14.
Operation:
The controller 204 includes a microprocessor and, as shown in FIG. 12, receives input signals from the three pushbutton switches 206, 208, 210, the three LED/receiver pairs 212, 214, 216, and any of a number of external programming devices such
as a computer 218, an external keyboard 220 or a card reader 222. The controller 204 sends output signals to the display 224, the illuminated pushbuttons 206, 208, 210, the speaker 226, the motor 228, the overdosage protection solenoid 230, and the
phone line port 232 for connection to a telephone line 233. The controller 204, as well as the motor 228, solenoid 230, display 224 and speaker 226, are all powered by the power supply 234. As shown in FIG. 12 a speech synthesizer 236 may be used in
connection with the speaker 226 to further enhance its audio signaling capabilities. Reports and other messages may be sent via the phone line port 232 through telephone lines to a receiving unit (at, for example, a doctor's office or a relative's home)
which monitors the repo | | |
