WO 02/096335
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`(12) INTERNATIONAL APPLICATION PUBLISHED L'NDER THE PATENT COOPERATION TREATY (PCT)
`
`(19) World Intellectual Property Organization
`International Bureau
`
`(43) International Publication Date
`13 July 2006 (13.07.2006)
`
`PCT
`
`(51) International Patent Classification:
`B62M 1/00 (2006.01)
`A61H 3/00 (2006.01)
`
`(21) International Application Number:
`PCT/US2006/000893
`
`(22) International Filing Date: 10 January 2006 (10.01.2006)
`
`(25) Filing Language:
`
`(26) Publication Language:
`
`English
`
`English
`
`(30) Priority Data:
`60/642,836
`
`10 January 2005 (10.01.2005) US
`
`(71) Applicant (for all designated States except US): ATLAS
`SYSTEMS, INC. [US/US]; 2962 Golden Harvest Lane,
`Fort Collins, CO 80528 (US).
`
`(72) Inventors; and
`(75) Inventors/Applicants (for US only): LIVENGOOD,
`Amy. L. [US/US]; 2962 Golden Harvest Lane, Fort
`Collins, CO 80528 (US). LIVENGOOD, Joseph, C.
`[US/US]; 2962 Golden Harvest Lane, Fort Collins,
`(US). PHILLIPS, Barry, T.
`CO 80528
`[US/US];
`
`= (54) Title: MODULAR PATIENT SUPPORT SYSTEM
`
`1111111111111111 IIIIII IIIII lllll 111111111111111111111111111111 IIIII IIIII 111111111111111 IIII IIII
`
`(10) International Publication Number
`WO 2006/074473 A2
`1315 Miramont Drive, Fort Collins, CO 80524 (US).
`ZIEMKOWSKI, Theodore, B. [US/US]; 1041 Sable(cid:173)
`wood Drive, Loveland, CO 80538 (US).
`
`(74) Agents: YASKANIN, Mark, L. et al.; Sheridan Ross P.C.,
`1560 Broadway, Suite 1200, Denver, Colorado 80202-5141
`(US).
`(81) Designated States (unless othervvise indicated, for every
`kind of national protection available): AE, AG, AL, AM,
`AT, AU, AZ, BA, BB, BG, BR, BW, BY, BZ, CA, CH, CN,
`CO, CR, CU, CZ, DE, DK, DM, DZ, EC, EE, EG, ES, Fl,
`GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE,
`KG, KM, KN, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV,
`LY, MA, MD, MG, MK, MN, MW, MX, MZ, NA, NG, NI,
`NO, NZ, OM, PG, PH, PL, PT, RO, RU. SC, SD, SE, SG,
`SK. SL, SM, SY, TJ, TM, TN, TR, TT, TZ, UA, UG, US,
`UZ, VC, VN, YU, ZA, ZM, ZW.
`
`(84) Designated States (unless othervvise indicated, for every
`kind of regional protection available): ARIPO (BW, GH,
`GM, KE, LS, MW, MZ, NA, SD, SL, SZ, TZ, UG, ZM,
`ZW), Eurasian (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM),
`
`{Continued on next page]
`
`(57) Abstract: A patient support platform provides
`a solution for healthcare facilities and nursing
`staff to address patient and staff safety, patient
`mobility, patient comfort, the availability of patient
`information, monitoring drugs and therapy provided,
`and controlling health care expenses. The patient
`support platform preferably includes a transmission
`system that allows the patient and/or medical staff
`member to choose a stop, walk or roll mode. The
`transmission system preferably includes a drag
`wheel for applying a braking force in response to a
`voltage generated by a braking motor. The platform
`supports a plurality of devices that may be attached
`or associated with a patient throughout their stay
`al a healthcare facility. The support platform also
`preferably includes a mechanism for releasably
`attaching the support platform to another structure,
`such as a bed. Embodiments of the present invention
`include multiple non-medical uses of the platform.
`
`108
`
`176
`
`192
`
`148
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`120
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`-
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`152
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`WO 2006/07 44 7 3 A2
`
`1111111111111111 IIIIII IIIII 11111 IIIII IIII I II llllllll lllll 111111111111111111111111111111 IIII IIII
`
`European (AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, For two-letter codes and other abbreviations, refer to the "Guid(cid:173)
`FR, GB, GR, HU, IE, IS, IT, LT, LU, LV, MC, NL, PL, PT,
`ance Notes on Codes and Abbreviations" appearing at the begin(cid:173)
`RO, SE, SI, SK, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA,
`ning of each regular issue of the PCT Gazette.
`GN, GQ, GW, ML, MR, NE, SN, TD, TG).
`Published:
`without international search report and to be republished
`upon receipt of that report
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`PCT /0S2006/000893
`
`MODULAR PATIENT SUPPORT SYSTEM
`
`FIELD OF THE INVENTION
`
`The present invention is directed to an apparatus used in the field of medicine, and
`
`more particularly, to a moveable and modular patient support system with a relatively small
`
`5
`
`form factor.
`
`BACKGROUND OF THE INVENTION
`
`Current practice for patients in a healthcare facility involves having multiple
`
`unrelated treatment, maintenance and/or monitoring devices that are attached to the patient.
`
`These include intravenous fluids and drugs, drainage catheters, suction catheters, leg
`
`10
`
`compression stockings and vital sign monitoring devices. Such devices often create a hazard
`
`for the patient both directly and indirectly. The myriad of devices may become entangled and
`
`inadvertently removed if not adequately accounted for by the patient or caregiver. This may
`
`require an invasive intervention, including surgery, in order to replace the removed device.
`
`The number of devices generally associated with the patient require the patient to
`
`15
`
`have the physical and mental ability to manage organizing or carrying the devices to ambulate
`
`even as far as the bathroom. Since patients are debilitated by the nature of their illness and
`
`medications, two staff persons are frequently required to help the patient move even short
`
`distances. One staff member must assist the patient, providing physical support, while the
`
`other manages the attached devices. The patients thus do not get out of bed and ambulate as
`
`20
`
`often since the staff of the typical health facility is not able to provide this kind of support
`
`readily to all of the patients at all times.
`
`The resulting immobility increases the patient's risk for deep venous thrombosis,
`
`pulmonary embolus and pneumonia. Additionally, mobility improves gut motility and
`
`decreases the time a patient must wait before obtaining enteral nutrition and ultimately
`
`25
`
`discharge from the healthcare facility. Patients that require prolonged hospital stays or
`
`admission to skilled-nursing facilities for non-medical indications related to mobility and
`
`personnel support may be able to be discharged home sooner with a device that provides the
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`same type of care. The cost to the healthcare system may be reduced by decreasing the stays
`
`in expensive healthcare facilities and decreasing complications that are costly both in patient
`
`morbidity and monetary value.
`
`The patient-care staff is also at risk for injury, as they must provide physical supp01t
`
`5
`
`to the debilitated patient. Back injuries are frequent in healthcare staff as a result of the
`
`physical nature of assistance provided. Allowing the patient to rely on an ambulatory assist
`
`device will help the patient-care staff as well by keeping them out of harm's way.
`
`Current poles that provide an intravenous ("IV") fluid and/or liquid medication
`
`delivery source are often times taken with patients when the patient moves around, such as
`
`10
`
`when a patient walks in a hospital hallway. The patient typically places at least one hand on
`
`the IV pole to move the IV pole while walking. However, typical IV poles are approximately
`
`6 to 7 feet tall, and are often unstable for providing weight support to a patient, particularly
`
`when one or more substantially full IV bags are positioned near the top of the pole. As a
`
`result, a patient is at risk of further injury by falling if the IV pole tips and/or falls over. In
`
`15
`
`addition, in order to prevent tipping, conventional IV poles have widely spread wheels, which
`
`require a large amount of floor space. IV poles are completely unable to manage uneven
`
`terrain as is found outside the confines of the patient care facility, and as may be found at
`
`home or in the field for disasters or military operations.
`
`In addition to being relatively unstable, current IV poles do not provide for the
`
`20
`
`additional needs of a patient that is moving about. For example, IV poles do not include an
`
`oxygen source for assisting the patient with breathing. Current IV poles also do not include
`
`various pumps or suction devices that may be necessary for continuous operation to provide
`
`proper medical treatment to the patient. In addition, vitals monitoring equipment and
`
`connnunication devices are typically not present on a standard IV pole. Furthermore, even if
`
`25
`
`an IV pole is adapted to include a monitoring device or pump, the IV pole tends to become
`
`even more unstable because the resulting added weight of the device typically is positioned
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`relatively high along the pole.
`
`In connection with patients that require assistance walking, various "walker" devices
`
`are available. A typical walker includes handrails interconnected to a stable base. However,
`
`because use of a walker usually requires both hands of the patient, a patient is typically unable
`
`5
`
`to take an IV pole with them when using a walker.
`
`A further difficulty exists when a patient needs to be moved from one room to
`
`another while in their bed. If the patient requires oxygen, an oxygen bottle must be provided,
`
`and is typically placed on the bed while moving the bed. This can create difficulties
`
`depending upon the size of the bed and the patient. Additionally, portable suction and vitals
`
`IO monitoring are not readily available for every patient. Accordingly, it would be advantageous
`
`to provide an apparatus that includes oxygen and other physiological support adjacent to the
`
`bed, wherein the apparatus can be attached to the bed while moving the bed. Such an
`
`apparatus would therefore also be advantageous to overcome the difficulty of maintaining
`
`monitoring equipment and/or IV fluids adjacent to the patient while moving the patient's bed.
`
`15
`
`The efficiency of the staff will benefit since only a single staff member will be required to
`
`move a patient since a second staff member is not required to push the IV pole and
`
`attachments. This also prevents the need for the staff member to move the patient to a
`
`wheelchair for transfer as is currently often done in order for a single staff member to manage
`
`the transfer. Eliminating this move prevents an opportunity for a patient fall resulting in
`
`20
`
`injury with only a single staff member assisting.
`
`Patient care devices and services such as suction and oxygen are not built in to the
`
`facilities of several countries and regions. This is also true in field situations of military
`
`conflict or civilian disaster. Patients may be far from a medical facility or in the hallway of a
`
`medical facility not equipped with patient support equipment/services.
`
`25
`
`Yet a further difficulty exists in maintaining electrical power to electronic devices
`
`such as monitoring equipment, suction pumps and/or injection pumps while the patient is
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`walking with an IV pole or walker, or while the patient is being moved in their bed or while
`
`the patient is not located next to an electrical outlet. This may occur in: 1) the operating
`
`room while needing to adjust the bed height or keep the pumps charged during a long
`
`procedure, 2) during a disaster when patients may be stationed in hallways or temporary
`
`5
`
`areas, 3) during military conflict or civilian situations that require creation of field hospitals
`
`with limited generator availability, and 4) in countries or regions that do not have consistent
`
`access to power. Accordingly, an apparatus that maintains electrical power to these devices
`
`would be advantageous, as would an apparatus that provides power in case of an electrical
`
`outage or blackout.
`
`10
`
`SUMMARY OF THE INVENTION
`
`The present invention solves the above-mentioned deficiencies by providing a mobile
`
`cart or platform that is structurally stable, and can thereby provide weight-bearing assistance
`
`to a patient without being predisposed to tipping over. In addition, the platform preferably
`
`15
`
`includes one or more additional features, such as an oxygen source, power supply, injection
`
`pump, suction pump, body fluid collection devices, vital monitoring equipment, integrated IV
`
`pole and communication equipment.
`
`In accordance with embodiments of the present invention, a modular patient support
`
`system is provided, wherein the support system typically resembles a platform, and includes a
`
`20
`
`handrail interconnected to a base having three or more wheels. The support system or
`
`platform additionally may include a battery or uninterruptible power supply for serving as an
`
`emergency power supply, and/or for powering associated equipment, including the bed, while
`
`the patient is walking or being moved in a bed with the support system positioned adjacent
`
`the bed. The support platform also may include modular receptacles for receiving a variety of
`
`25
`
`devices, including suction pumps, injection pumps, collection devices, monitoring equipment,
`
`and communication devices. An electrical wiring network may be provided such that the
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`modular devices interconnected to the support platform receive electrical power directly at the
`
`modular receptacles, thereby minimizing the presence of numerous power cords. Such
`
`additional equipment is powered by the uninterruptible power supply when the support
`
`platform is disengaged from a stationary power supply, such as an electrical wall outlet.
`
`5
`
`In accordance with other embodiments of the present invention, the support platform
`
`may include an on-board communication system to send monitoring information or other data
`
`to a nurses' PDA, central station or alarm system. The communication system may include
`
`wireless communication to transmit a patient's vitals, equipment status, fluid volumes,
`
`therapy status and location for providing information while a patient is using the support
`
`10
`
`platform as a walking aid. An interface may be provided for the healthcare providers to be
`
`able to access and interact with the facility's electronic medical record system.
`
`In accordance with other embodiments of the present invention, the support platform
`
`may include a checkpoint validation system to ensure the correct therapy is administered to
`
`the correct patient. This may involve identification of the patient, platform and therapy (such
`
`15
`
`as intravenous fluids, medications or equipment) with devices such as barcodes,
`
`radiofrequency identifiers or other similar technology to match and track all therapy provided.
`
`In accordance with other embodiments of the present invention, the support system
`
`also may also include an on-board oxygen supply and associated tubing. Additionally, the
`
`support platform may include an IV fluids/medication support assembly, such as an IV pole
`
`20 with an attachment hook.
`
`The support platform may be configured in a variety of ways, to include a cabinet or
`
`other enclosure for holding items such as a urine collection bag, body fluid collection bag and
`
`suction canister. The configuration of the support platform also may include specially sized
`
`compartments for bottles or cups, and may include other built-in features such as a tray, radio,
`
`25
`
`television, phone, computer or other communication device, wherein some of these devices
`
`may also be interconnected to the support platform's power supply.
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`In a separate aspect of the invention, an attachment device is provided for detachably
`
`attaching the support platform to another structure, such as the patient's bed. The attachment
`
`device may include an attachment adapter capable of being interconnected to a variety of bed
`
`frame structures, regardless of whether the framing includes square or round rails or posts.
`
`5
`
`The attachment device not only secures the support platform to the bed so that it is not moved
`
`when accidentally bumped, but it also enables the support platform to be moved with the bed
`
`without the need for a separate attendant to move the support platform. In at least one
`
`embodiment, a plurality of bed hooks are used to enable the platform to grasp another object,
`
`such as a bed, when the bed is raised to impinge upon the underside of the bed hooks.
`
`10
`
`In a separate aspect of the invention, the support platform includes an umbilical cord
`
`having a common plug for interconnecting a plurality of systems to a single outlet, such as a
`
`wall outlet. The umbilical cord may support a variety of systems, including electrical power,
`
`oxygen, suction, and/or a communication connection.
`
`In accordance with embodiments of the present invention, a locking brake may
`
`15
`
`optionally be provided to limit movement of the platform if the brake is engaged. The brake
`
`may have mechanisms that engage it actively and/or passively. This may include a 'kill(cid:173)
`
`switch' device that detects separation of the patient from the platform in situations that may
`
`result in patient injury if such event occurs.
`
`In accordance with embodiments of the present invention, a transmission system may
`
`20
`
`be provided to allow a user or other person to place the platform in one of a plurality of
`
`possible translation modes. In at least one embodiment, the transmission system includes
`
`stop, walk and roll modes. The stop mode engages a brake to contact the underlying surface,
`
`thereby substantially preventing the platform from rolling. In addition, in at least one
`
`embodiment, both a drag wheel and a brake are in contact with the floor when the platform is
`
`25
`
`set in the stop mode. The walk mode includes raising the brake, if present, and engaging a
`
`drag wheel to contact the floor. Although not prevented from moving, the walk mode helps
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`prevent undesirable fast movement of the platform. fu one embodiment, the drag wheel may
`
`comprise a wheel that is preset to turn at a very slow rate. Alternatively, in at least one
`
`embodiment the drag wheel may be interconnected to a braking motor, operated as a
`
`generator powered by the drag wheel, that applies a resistive force or an increased resistive
`
`5
`
`force to the drag wheel when velocities increase above an undesirable level. For example, if a
`
`patient is standing adjacent the support platform and starts to slip while holding the handle of
`
`the platform, the braking motor will apply a resistive force to the drag wheel, thereby
`
`preventing the support platform from moving away from the patient and/or moving away
`
`from the patient at a high rate of speed. A variety of motor braking circuit configurations and
`
`10
`
`braking functions are available for controlling the resistive force applied to the drag wheel
`
`using the braking motor. For example, a motor braking circuit may provide different resistive
`
`loads to the braking motor based on the velocity of the braking motor. fu addition, the motor
`
`braking circuit does not require any source of power other than the power generated as a
`
`result of the rotation of the braking motor by the drag wheel. fu the roll mode the
`
`15
`
`transmission disengages both the brake and the drag wheel, such that the platform may be
`
`easily rolled. This setting is anticipated for use, for example, when an attendant is moving the
`
`platform.
`
`Thus, in accordance with at least one embodiment of the present invention, a personal
`
`support platform for traversing an underlying surface is provided, the platform comprising a
`
`20
`
`frame and a plurality of wheels interconnected to the frame. fu addition, the platform
`
`comprises a transmission system interconnected to the frame, the transmission system
`
`providing a number of user selectable modes, the user selectable modes comprising at least a
`
`stop mode, a walk mode and a roll mode. Finally, in at least one embodiment, the platform
`
`further comprises a means for selectively choosing one of the stop, walk and roll modes by a
`
`25
`
`user from a standing position adjacent the frame.
`
`fu a separate aspect of the invention, a transmission system of the platform comprises
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`a drag wheel that is selectively moveable from a first raised position in the roll mode to a
`
`second lowered position in the walk mode, and wherein the drag wheel is for contacting the
`
`underlying surface when in the second lowered position. In addition, in accordance with at
`
`least one embodiment, the transmission system comprises a cam interconnected to the frame
`
`5
`
`and the drag wheel, wherein the cam is rotatably movable to raise and lower the drag wheel
`
`from the first raised position in the roll mode to the second lowered position in the walk
`
`mode. The transmission system may also further comprise an automatic brake interconnected
`
`to the drag wheel, wherein the automatic brake comprises a braking motor driven by the drag
`
`wheel and circuitry, wherein the circuitry provides a resistive load to the braking motor to
`
`10
`
`apply a braking force on the drag wheel. In addition, in at least one embodiment, the resistive
`
`load comprises a number of load ranges, wherein a first load range provides a first resistive
`
`load within a first velocity range for the braking motor, and wherein a second load range
`
`provides a second resistive load within a second velocity range for the braking motor. Also,
`
`the second velocity range may be automatically selected once a threshold velocity of the
`
`15
`
`braking motor is reached.
`
`In a separate aspect of the invention, a transmission system of the platform may
`
`comprise a brake interconnected to the frame, wherein the brake is selectively moveable from
`
`a first raised position in the walk and roll modes to a second lowered position in the stop
`
`mode, and wherein the brake is for contacting the underlying surface when in the second
`
`20
`
`position. In at least one embodiment, the brake comprises a stopper frictionally engaging the
`
`underlying surface. In yet a separate aspect of the invention, the platform may comprise a
`
`cam having a first channel interconnected to the brake. In at least one embodiment of the
`
`invention, the cam comprises a second channel interconnected to a drag wheel. In accordance
`
`with at least one embodiment of the invention, the first channel comprises a first ramp for
`
`25
`
`raising and lowering a first post interconnecting the drag wheel to the cam, and wherein the
`
`second channel comprises a second ramp for raising and lowering a second post
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`interconnecting the stopper to the cam.
`
`In a separate aspect of the invention, a means for selectively choosing the mode of the
`
`transmission system comprises a first handle at a rear portion of the frame, wherein the handle
`
`is selectively adjusting a setting of the transmission system. In at least one embodiment, the
`
`5
`
`transmission system may further comprise a second handle at a front portion of the frame,
`
`wherein the second handle can also be used for selectively adjusting a setting of the
`
`transmission system.
`
`In a separate aspect of the invention, the platform comprises at least one grasping
`
`mechanism for interconnecting the frame to another structure. In at least one embodiment of
`
`IO
`
`the invention, the grasping mechanism comprises a rotatable gripper arm that engages the
`
`other structure. In addition, in at least one embodiment, the rotatable gripper arm rotates
`
`about a first axis in a direction away from the frame, and rotates about a second axis to grasp
`
`the other structure, wherein the second axis is transverse to the first axis.
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`It is a further aspect of the present invention to utilize a variety of devices to provide
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`functionality to a personal support platform. Accordingly, in at least one embodiment of the
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`present invention, a personal support platform for traversing an underlying surface is
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`provided, comprising a frame and means for rotating interconnected to said frame and
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`contacting the underlying surface. The platform further comprises means for frictionally
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`engaging the underlying surface and interconnected to said frame; and means for variably
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`controlling a resistance provided by said means for frictionally engaging. In at least one
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`embodiment of the invention, the means for rotating comprises a plurality of wheels. In
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`addition, it in at least one embodiment of the invention the means for frictionally engaging
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`comprises a drag wheel. In accordance with at least one embodiment of the invention, the
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`means for frictionally engaging is interconnected to a means for adjusting a position of said
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`25 means for frictionally engaging, wherein said means for adjusting may alter a position of said
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`means for frictionally engaging from a first position in contact with the underlying surface to
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`second position wherein said means for frictionally engaging does not contact the underlying
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`surface. In at least one embodiment of the invention, the means for adjusting comprises a
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`selectably positionable cam for raising and lowering said means for frictionally engaging. In
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`addition, in at least one embodiment of the invention the means for variably controlling a
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`resistance comprises a passive braking motor. In a separate aspect of the invention, the
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`passive braking motor comprises a motor braking circuit interconnected to the passive braking
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`motor. In at least one embodiment, the braking circuit includes a first circuit stage, including
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`a switching mechanism, wherein an activation voltage for the first circuit stage is defined.
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`The circuit also includes, a load resistor, wherein when the passive braking motor produces an
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`IO
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`amount of power sufficient to produce a voltage at the switching mechanism that is equal to
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`or greater than the activation voltage and above a current is allowed to pass through the load
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`resistor.
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`As noted above, embodiments of the present invention may comprise a braking
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`system. Thus, in accordance with at least one embodiment of the invention, a passive variable
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`braking system is provided, comprising:
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`a motor;
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`a motor braking circuit interconnected to the motor, including:
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`a first circuit stage, including:
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`a switching mechanism, wherein an activation voltage for the first
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`circuit stage is defined; and
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`a load resistor, wherein when the motor produces an amount of
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`power sufficient to produce a voltage at the switching mechanism that is equal to or
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`greater than the activation voltage and above a current is allowed to pass through the load
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`resistor.
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`In a separate aspect of the invention, the motor braking circuit of the passive variable
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`braking system further comprises:
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`a second circuit stage in parallel with the first circuit stage, the second circuit
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`stage including:
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`a switching mechanism, wherein an activation voltage for the second stage
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`is defined;
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`5
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`a load resistor, wherein when the motor produces an amount of power
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`sufficient to produce a voltage at the switching mechanism that is equal to or greater
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`than the activation voltage and above a current is allowed to pass through the load
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`resistor, wherein the activation voltage for the second stage is greater than the
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`activation voltage for the first stage, and wherein when the activation voltage for the
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`second stage is met or exceeded a current continues to be allowed to pass through the
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`load resistor of the first circuit stage.
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`In yet a separate aspect of the invention, the passive variable braking system further
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`comprises:
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`a switch, wherein the first and second circuit stages comprise a number of load
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`resistors, wherein the switch is operable to select one of each of the load resistors included in
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`the rrrst and second circuit stages to provide a selected resistance at the motor.
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`In a separate aspect of the invention, the motor braking circuit of the passive variable
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`braking system further comprises:
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`a second circuit stage in parallel with the first circuit stage, the second circuit stage,
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`20
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`including:
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`a switching mechanism, wherein an activation voltage for the second stage
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`is defined; and
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`a load resistor, wherein when the motor produces an amount of power
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`sufficient to produce a voltage at the switching mechanism that is equal to or greater
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`than the activation voltage and above a current is allowed to pass through the load
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`resistor, and wherein the activation voltage for the second stage has a polarity that is
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`opposite the activation voltage for the first stage.
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`In a separate aspect of the invention, the switching mechanism of the passive variable
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`braking system comprises a zener diode.
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`5
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`In a separate aspect of the invention, the switching mechanism of the passive variable
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`braking system comprises a pair of voltage dividing resistors and a transistor, wherein a
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`voltage divided by the pair ofresistors is provided to a gate of the transistor.
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`In yet a separate aspect of the invention, the switching mechanism of the passive
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`variable braking system comprises a resistor interconnected to a Silicon Controlled Rectifier.
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`In yet a separate aspect of the invention, the passive variable braking system further
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`comprises a drag wheel interconnected to the motor, wherein the motor is driven by the drive
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`wheel. In yet a separate aspect of the invention, the drive wheel is interconnected to the
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`motor by a gearbox.
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`In still yet a separate aspect of the invention, the switching mechanisms of the passive
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`15
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`variable braking system of the first and second circuit stages each comprise a zener diode, and
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`wherein the first and second stages each additionally include a blocking diode.
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`It is a separate aspect of the present invention to provide a method of using a support
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`platform that comprises one or more features of the device described herein. Accordingly, a
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`method of using a personal support platform is provided, the method comprising selecting a
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`transmission mode for a transmission system operably associated with the personal support
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`platform, wherein the transmission system provides a number of user selectable transmission
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`modes, and wherein the user selectable transmission modes comprise at least a stop mode, a
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`walk mode and a roll mode. In accordance with at least one embodiment of the present
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`invention, the personal support platform for use includes a frame, a plurality of wheels
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`interconnected to the frame, and a transmission control device operably interconnected to the
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`transmission system, the transmission control device adapted for allowing a user to selectively
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`choose one of the stop, walk and roll modes. In the method of use, the selecting step
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`comprises manipulating the transmission control device to one of the stop, walk and roll
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`modes. In addition, in at least one embodiment, the manipulating step comprises moving a
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`control bar operably interconnected to the frame and a cam, wherein the control bar controls
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`5
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`positions of a drag wheel and a brake that are operably interconnected with the cam. In a
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`separate aspect of the invention, in at least one embodim