AU2003248109B2 - Retractable prone supports for proning bed - Google Patents

Description

AUSTRALIA

Patents Act COMPLETE SPECIFICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: Name of Applicant: KCI Licensing, Inc.

Actual Inventor(s): Alan L Bartlett, Stephan A Samuelson, Wladyslaw H Krywiczanin, Chris T Niederkrom Address for Service and Correspondence: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: RETRACTABLE PRONE SUPPORTS FOR PRONING BED Our Ref: 703569 POF Code: 454011/454011 The following statement is a full description of this invention, including the best method of performing it known to applicant(s): -1- 11 2 ThsRetractable Prone notsfrPr~BC Thsapplication is a alvisionainpp i ca iL~o p U eaent 2002250454, 3 the entire disclosure of which i's incorporated herein by refernce.

4 RELATED APPLICATION INFORMATION AND PRIORITY CLAIM: This application claims priority to United States patent application serial 6 number 09/82 1,552 filed March 29, 2001, entitled "PRONE POSITIONING 7 THERAPEUTIC BED," which is incorporated herein by reference, and to 8 09/8 84,749, also entitled "PRONE POSITIONING THERAPEUTIC BED," which 9 is also incorporated herein by reference.

BACKGROUND OF THE INVENTION 1 1 1. Field of the Invention 12 This invention relates generally to therapeutic beds, and more particularly 13 to an improved rotating bed capable of placing a patient in a prone position.

14 2. Long-felt Needs and Description of the Related Art Patient positioning has been used in hospital beds for some time to enhance 16 patient comfort, prevent skin breakdown, improve drainage of bodily fluids, and 17 facilitate breathing. One of the goals of patient positioning has been maximization 18 of ventilation to improve systematic oxygenation. Various studies have 19 demonstrated the beneficial effects of body positioning and mobilization on impaired oxygen transport. The support of patients in a prone position, can be 21 advantageous in enhancing extension and ventilation of the dorsal aspect, of the 22 lungs.

23 Proning has been recognized and studied as a method for treating acute 24 respiratory distress syndrome ("ARDS') for more than twenty -five years. Some studies indicate that approximately three quarters of patients with ARDS will 2 1 respond with improved arterial oxygenation when moved from the supine to the 2 prone position.

3 There are several physiological bases for patient proning. When a person 4 lies flat in the supine position, the heart and sternum lie on top of and compress the lung volume beneath it. Moreover, the abdominal contents push upward against 6 the diaphragm and further compress and increase the pressures on the most dorsal 7 lung units, where perfusion blood flow volume reaching alveolocapillary 8 membranes) is greatest. In an ARDS patient, ventilation in these dorsal regions is 9 inhibited by fluid and cellular debris that settle into the most dependent lung segments. Lung edema may further increase the plural pressures in the most 11 dependent regions. The combination of fluid accumulation with compression by 12 the heart, sternum, and abdominal contents on the dorsal regions of the lung results 13 in a significant ventilation-perfusion mismatch. Expressed more simply, the air 14 entering the patient's lungs is not reaching those parts of the lungs (the dorsal regions where perfusion is greatest) that most need it.

16 Flipping a patient into the prone position improves arterial oxygenation 17 through several mechanisms. First, moving the fluid-filled lungs into a 18 nondependent ventral position facilitates drainage of the fluid and cellular debris 19 that had accumulated in and blocked ventilation to the dorsal regions of the lung.

Second, the weight of the heart is supported by the sternum, rather than the lungs.

21 When a patient is in the supine position, as much as 25-44% of the lung volume 22 may be displaced by the heart, especially if the heart is enlarged due to 23 cardiovascular disease. Rotating the patient into the prone position can reduce that 24 displacement to as little as 1-4% of lung volume. Third, if the patient is supported in the prone position in a manner that allows the abdomen to protrude, then the 1 abdominal contents no longer push upward onto the diaphragm to compress the 2 lungs.

3 Proning minimizes the mechanical forces that pressurize distressed alveolar 4 units into collapse, and can also recruit atelectatic but functional units for gas exchange. Proning also causes changes in pleural pressures, which encourages 6 more uniform distribution of ventilation within the lungs. Proning often reduces 7 the intrapulmonary shunt (defined as the portion of blood that enters the left side of 8 the heart without exchanging gases with alveolar gases) and improves arterial 9 oxygenation. The results of proning can be immediate, resulting in significantly improved oxygenation in as little as one hour.

11 Despite its promises, prone positioning has not been widely practiced on 12 patients because, due to the inadequacies of prior art devices, it is a difficult and 13 labor-intensive process. Logistically, moving a patient to the prone position using 14 prior art technology requires careful planning, coordination, and teamwork to prevent complications such as inadvertent extubation and loss of invasive lines and 16 tubes.

17 "Even when precautions are taken, proning, using prior art technology is 18 fraught with potential complications. For example, it is difficult to provide 19 cardiopulmonary resuscitation to a patient lying in the prone position.

Critical time may have to be spent recruiting a team of personnel to move the 21 patient from the prone to the supine position before performing CPR. Accordingly, 22 there is a need for a motor-operated proning device that will quickly rotate a 23 proned patient from the prone position to the supine position. There is also a need 24 for a system that enables a fast, one-step operation to cause the motor-operated proning device to rotate the patient back to a supine position.

1 A frequently cited complication with prone positioning is the development 2 of pressure, ulcers, especially on the forehead, chin, and upper chest wall.

3 Immobility in the prone position can also result in breast and penile breakdown.

4 Some of the most difficult areas to manage in the prone position are the head, face, eyes, and arms. Increased incidence of eye infection due to drainage, corneal 6 abrasions, and even blindness caused by increased intra-ocular pressure have been 7 reported as a consequence of prone positioning. Also, immobility and pressure on 8 the arms have been reported to result in peripheral nerve injury and contractures.

9 Accordingly, there is a need for a proning device that minimizes the risk of pressure-related complications.

11 Prone positioning using many prior art methods and devices has caused 12 chest tubes, invasive lines, and infusions to become kinked. Worse, the rotation of 13 a patient from the supine to the prone position on some beds has been reported to 14 result in inadvertent extubation and decannulation, which can have catastrophic consequences. Accordingly, there is a need for a proning device with a patient line 16 care management system that will minimize the risk of extubation, decannulation, 17 or kinking of patient care lines.

18 Proning can also increase the risk of aspiration of gastric acid, food, or 19 other foreign material into the lungs. Aspiration of gastric acid can result in severe pneumonia. Another complication, much more frequent than aspiration, is 21 dependent edema. Most critically ill intensive care unit patients develop dependent 22 edema. When moved into the prone position, the face is put into a dependent 23 position, which often results in significant facial edema. Accordingly, there is a 24 need for a proning device that will minimize aspiration and facial edema.

There are many prior art devices used to facilitate patient proning. One 26 example is the Vollman Prone Device

T

made by the Hill-Rom Co., Inc.®. The 1 Vollman.Prone Device comprises a set of foam pads to support the patient's head, 2 chest, and pelvis and which are secured to a.patient with straps, belts, and buckles 3 while the patient in the supine position. After the foam pads are secured, the 4 patient is manually rotated into the prone position on a regular hospital mattress.

Of course, no special device is needed to place a patient in the prone position.

6 Towels, blankets, egg crate mattresses, and foam positioning pads can be used to 7 help maintain proper alignment in the prone position.

8 One difficulty with devices such as the Vollman Prone Device is that 9 several personnel are still required to turn the patient over. Moreover, medical personnel must revisit the patient frequently to turn the patient toward different 11 positions to prevent pressure sores and other complications from developing.

12 To make it easier to turn a patient into the prone position, other prior art 13 devices have been provided comprising a rotatable frame to rotate a patient into the 14 prone position. The Stryker Wedge@ Turning Frame, for example, comprises a rotatable frame having a supine support surface and a prone support surface in 16 between which a patient is wedged. The frame is manually rotated into the desired 17 position. But the frame still suffers several shortcomings. One of its 18 shortcomings, as with other manually-operated prior art proning devices, is 19 inadequate compliance by medical personnel. Because it is difficult and labor intensive to manually operate a proning bed, many doctors do not begin proning 21 ARDS patients until late in the course of the patient's disease process, after other 22 recruitment measures have failed. However, there is a general consensus that if 23 prone positioning is provided earlier, in the more exudative stages of ARDS, a 24 patient will be more likely to respond positively. Accordingly, there is a need for a therapeutic bed that makes it simpler and less labor-intensive for medical personnel 26 to prone a patient.

1 Another problem with manually-operated prior art beds such as the Stryker 2 Wedge Frame is that unless manually rocked back and forth, patients will be left 3 immobile, in a fixed position, for extended periods of time. Immobility leads to 4 many of the complications discussed above that hinder the widespread adoption of prone positioning as a therapy for ARDS patients. Accordingly, there is a need for 6 a therapeutic bed that provides not only prone positioning but also automated 7 alternating side-to-side rotational therapy to intermittently relieve pressure from the 8 dependent surfaces of the body.

9 Other beds made by Kinetic Concepts, Inc.®, such as the TriaDyne® .II, also facilitate prone positioning. Specially designed proning cushions have been 11 provided to accommodate moving a patient to the prone position and maintaining 12 the patient there. The TriaDyne's low air loss pressure relief surface reduces the 13 risk of certain complications like skin breakdown. While the TriaDyne has many 14 benefits, its protocol calls for a team of about 5 to 8 people to move a patient from the supine to the prone position. One person should be assigned at the head of the 16 bed to secure and manage the airway during the maneuver. The procedure also 17 calls for the team to disconnect as many of the invasive lines as possible to simply 18 the procedure, and then reconnect them when the patient has been placed in the 19 prone position. Caution must be exercised with head positioning to prevent applying pressure directly to the eyes, ears, or endotracheal tube.

21 While it is possible to program the TriaDyne to perform continuous lateral 22 rotation therapy while the patient is in the prone position, the TriaDyne is incapable 23 of automatically rotating the patient from the supine to the prone position, and 24 from there applying kinetic therapy. Moreover, the arc of rotation in the prone position is limited because of the absence of restraints to keep the patient centered 26 on the bed while turning to a significant angle from the prone position. In practice, 1 the range of motion in the TriaDyne is generally limited to no more than 30 degrees .2 to the.left and right of.prone. The Centers for Disease Control defines 3 kinetic therapy as lateral rotation of greater than 40 degrees to the horizontal left 4 and right, or an are of at least 80 degrees.

Moreover, the TriaDyne and many other beds are not capable of rotation 6 beyond 62 degrees from even the supine position, much less so from the prone 7 position, because the beds lack restraints to hold the patient on the bed. It is the 8 belief of the inventors that further therapeutic benefits could be obtained by 9 rotating patients to angle limits beyond 62 degrees in either direction, to, for example, 90 degrees or more in either direction, in order to recruit further areas of 11 a collapsed lung to participate in gas exchange, and also to further reduce pressure 12 on the dorsal regions of the patient's body. Accordingly, there is a need for a 13 therapeutic bed that can automatically rotate a patient from the supine to the prone 14 position and back, and that is capable of providing kinetic therapy with an arc of at least 80 degrees) while still securing the patient to the center of the bed.

16 Another type of prone positioning bed comprises a base frame, a patient 17 support platform rotatably mounted on the base frame for rotational movement 18 about a longitudinal rotational axis of the patient support platform, and a drive 19 system for rotating the patient support platform on the base frame. Such therapeutic beds are described in international patent applications having 21 publication numbers WO 97/22323 and WO 99/62454. This type of bed is 22 particularly advantageous for the treatment of patients with severe respiratory 23 problems. Preferably, as described in publication number WO 99/62454, each end 24 of the bed has a central opening at or near the longitudinal rotational axis of the patient support platform for efficiently managing the numerous patient care lines 26 that are generally necessary for treating a patient on the patient support platform.

S

8 IIn the therapeutic bed of WO 99/62454, the central opening for receiving patient care lines at the head of the bed is provided by a continuous upright end ring, which also serves as a means for rotatably mounting the patient support platform on rollers. One drawback of such an arrangement is that the continuous end ring obstructs access to the head of the patient. Additionally, the initial placement of a patient on the bed requires disconnection of all patient care lines, and to remove a patient care line from the end ring requires that one end of the patient care line be unplugged from either the patient or the piece of 00 equipment to which the line is attached, which can be very inconvenient and may jeopardize the patient, depending on the particular condition of the patient.

(To retain a patient on the patient support platform in the prone position, the bed of WO 99/62454 has a pair of side rails fixedly mounted to the patient support platform in an upright position using stanchions and complementary sockets. A plurality of patient support packs are pivotally mounted on the side rails, and associated straps are buckled over the patient to hold the patient in place. Although the patient support packs may be flipped to the outside of the bed to uncover the patient in the supine position, the side rails remain upright and thus obstruct access to the patient in the supine position. To improve access to the patient in the supine position, it would be desirable to be able to move the side rails completely out of the way without removing them from the bed. Also, it would be advantageous to have a reliable way to ascertain whether the straps that buckle over the patient are property tensioned to support the patient prior to moving the patient to the prone position.

A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that that document or matter was, in Australia, known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

SUMMARY OF THE INVENTION The present invention provides a therapeutic bed including: a base frame; a patient support platform having a longitudinal rotational axis, the patient support platform being rotationally mounted on the base frame such that the patient support platform is capable of rotation about the longitudinal rotational axis between a supine patient position and an inverted prone patient position; W:\sha onlDanieANS1eciDKMC 2003 248100 sDecd 24aug06 doc at least one prone support extension mounted on the patient support platform; and one or more prone support cushions pivotally mounted on the at least F. one prone support extension, the prone support cushions being operable to support a patient on the patient support platform when the patient support platform is in the prone patient position; wherein the at least one prone support extension is movable from an extended position with the prone support cushions extending above the patient 00 support platform to a retracted position with the prone support cushions stored beneath the patient support platform.

(Preferably, the therapeutic bed may include a base frame, a patient support platform rotatably mounted on the base frame for rotational movement about a WAh-DanctSe"fMC 2003 248109 spedl 2420808000 1 longitudinal rotational axis of the patient support platform, and a drive system for 2 rotating the patient support platform on the base frame. An upright end ring at the 3 head end of the bed is split into an upper section and a lower section. The upper 4 section is removable from the lower section to allow improved access to the head of the patient and to allow placement or removal of the patient from the bed by 6 removal of patient care lines from the end ring without removing the patient care 7 lines from the patient or the equipment to which the lines are attached.

8 Additionally, the bed is provided with pivotally mounted side rails that may 9 be folded neatly out of the way underneath the patient support platform for improved access to the patient in the supine position. Straps are provided to secure 11 the opposing side rails over the patient before rotation into the prone position.

12 Preferably, a pressure-sensitive tape switch is mounted on the patient support 13 platform adjacent each side rail. When the side rail straps are properly tensioned, 14 the side rails engage the tape switches, which allows the patient support platform to be rotated into the prone position. Alternatively, the straps that secure the 16 opposing side rails over the patient may be connected to the patient support 17 platform with tension-sensitive strap connectors that provide an indication of 18 whether. the straps are sufficiently tensioned before the patient is rotated into the 19 prone position. The tension-sensitive strap connectors -provide both a visual indication and an electrical signal that may be used by a controller to control the 21 rotation of the patient support platform.

22 BRIEF DESCRIPTION OF THE DRAWINGS 23 Fig. 1 is a perspective view of a therapeutic bed in accordance with the 24 present invention.

Fig. 2 is a perspective view of the head portion of the therapeutic bed of 26 Fig. I looking toward the foot of the bed.

1 Fig. 2A is a perspective view of an alternative head restraint for the 2 therapeutic bed of Fig. 1..

3 Fig. 3 is a perspective view of the head portion of the therapeutic bed of 4 Fig. 1 looking toward the head of the bed.

Fig. 3A is an exploded perspective view of the clamping mechanism for the 6 head restraints of the therapeutic bed of Fig. 1.

7 Fig. 4 is a perspective view of a side rail of the therapeutic bed of Fig. 1.

8 Fig. 4A is a perspective view of the detent for the side rail of Fig. 4.

9 Fig. 5 is a side elevational view of a strap connector for the side rail of Fig. 4.

11 Fig. 6 is a rear elevational view of the strap connector of Fig. 12 Fig. 7 is a perspective view of the therapeutic bed of Fig. 1 showing 13 symmetric lateral support pads and leg abductors.

14 Fig. 8 is a perspective view of the foot portion of the therapeutic bed of Fig. 1 looking toward the foot of the bed.

16 Fig. 9 is a front elevational view of a portion of Fig. 8.

17 Fig. 10 is a front elevational view of the rotation limiter of the therapeutic 18 bed of Fig. 1 shown in a position of maximum negative rotation.

19 Fig. 11 is a front elevational view of the rotation limiter of the therapeutic bed of Fig. 1 shown in a position of maximum positive rotation.

21 Fig. 12 is a perspective view of the foot portion of the therapeutic bed of 22 Fig. 1 looking toward the head of the bed.' 23 Fig. 13 is a rear elevational view of the therapeutic bed of Fig. 1.

24 Fig. 14 is a perspective view of the quick release mechanism for the drive system of the therapeutic bed of Fig. 1.

1 Fig. 15 is a perspective view looking up at a side rail folded under the 2 patient support platform of the therapeutic bed of Fig. 1.

3 Fig. 16 is a side elevational view of a side rail and cooperating tape switch 4 on a therapeutic bed in accordance with the present invention.

Fig. 17 is a cross-sectional view of the tape switch of Fig. 16.

6 Fig. 18 is a rear elevational view of a flexible PCB disposed within an 7 annular channel of a therapeutic bed in accordance with the present invention.

8 Fig. 19 is a cross-sectional view of the flexible PCB and annular channel of 9 Fig. 18.

Fig. 20 is an enlarged cross-sectional view of the flexible PCB of Fig. 18.

11 Fig. 21 is a top view of a lock pin assembly for a therapeutic bed in 12 accordance with the present invention.

13 DETAILED DESCRIPTION 14 Referring to Figs. 1 and 2, a therapeutic bed 10 in accordance with the present invention preferably comprises a ground engaging chassis 12 mounted on 16 wheels 14. A base frame 16 is mounted on chassis 12 with pivot linkages 18.

17 Rams 15, 17 housed within base frame 16 cooperate with pivot linkages 18 to form 18 a lift system to raise and lower base frame 16 on chassis 12. A patient support 19 platform 20 having upright end rings 22, 24 is rotatably mounted on base frame 16 with rollers 26 such that patient support platform 20 may rotate about a 21 longitudinal axis between a supine position and a prone position. Mattress or foam 22 padding (not shown for clarity), such as the type described in co-pending and 23 commonly assigned application for letters patent serial number 0-9/588513 filed 24 June 6, 2000, entitled "MATTRESS WITH SEMI-INDEPENDENT PRESSURE RELIEVING PILLARS INCLUDING TOP AND BOTTOM PILLARS," overlays 26 patient support platform 1 Side support bars 28, 30 extend between end rings 22, 24. At the head of 2 bed 10, a guide body 32 haying a plurality of slots 34 for routing patient care lines 3 (not shown) is slidably mounted on rails 36 with support rod 31. Similarly, at the 4 foot of bed 10, a central opening 118 is provided for receiving a removable patient care line holder (not shown) having a plurality of circumferential slots for routing 6 patient care lines.

7 Central opening 118 is preferably of sufficient size to allow passing of 8 patient connected devices, such as foley bags (not shown), through the central 9 opening 118 without disconnecting such devices from the patient. For stich purposes, central opening 118 is preferably as large as possible, provided that 11 strength and configuration requirements of the bed are maintained. More 12 particularly, the inner diameter of central opening 118 is preferably at least eight 13 inches, more preferably, at least about 12 inches, in diameter. The foregoing basic 14 structure and function of bed 10 is disclosed in greater detail in international application number PCT/IE99/00049 filed June 3, 1999.

16 Still referring to Fig. 1, bed 10 preferably comprises one or more folding 17 side rails 62 pivotally mounted to patient support platform 20 to assist in securing a 18 patient to support platform 20 before rotation into the prone position. As further 19 described below in connection with Fig. 15, side rails 62 fold underneath platform 20 for easy access to a patient lying atop cushions 21a, 21b, 21c in the 21 supine position. Bed 10 also preferably has a head rest 50 and a pair of head 22 restraints 48, which are described in more detail below in connection with Fig. 3.

23 Although not shown for the sake of clarity, a fan may be mounted on the patient 24 support platform 20 near the end ring 24 at the foot of bed 10 to ventilate a patient's legs.

1 As shown in Fig. 2, end ring 22 at the head of bed 10 is split into two 2 sections for improved access to a patient lying on bed 10. Upper section 22a is 3 removable from lower section 22b. Upper section 22a has a pair of shafts 40 that 4 are inserted into vertical stabilizer tubes 38 in the closed position. Likewise, tabs 46 on upper section 22a mate with tubular openings on lower section 22b.

6 Latches 44 secure upper section 22a to lower section 22b in the closed position.

7 When latches 44 are unlatched, upper section 22a may be raised, pivoted about the 8 vertical axis of one of the shafts 40, and left in an open position supported by one 9 of the shafts 40 in corresponding stabilizer tube 38. Alternatively, upper section 22a may be removed entirely. In either case, upper section 22a may be 11 moved out of the way for unobstructed access to the patient and manipulation of 12 patient care lines.

13 One of the key challenges in patient proning is adequately supporting the 14 head in a manner that facilitates proper alignment of the patient's vertebrae in both the prone and supine positions, as well as at all angular positions of rotation.

16 Other challenges include minimizing the risk of skin, face, and ear abrasions and 17 avoiding entanglement or kinking of patient care lines to the patient's head, throat, 18 or face.

19 Referring now to Figs. 3 and 3A, head restraints 48 are slidably mounted to transverse support rails 58, 60 on guides 54 with mounting arms 52. For the sake 21 of clarity, only one head restraint 48 is shown in Figs. 2 and 3. Each guide 54 has a 22 clamp 56 that is manually operable by a handle 56a and serves to secure each 23 guide 54 in a desired lateral position as further described below. Mounting 24 arms 52 are slidably mounted in holes 56h of bosses 56b to provide vertical positioning of head restraints 48. Handle 56a is attached to a drum 56f that is 26 rotationally mounted to flanges 54a of guide 54 by shaft 56g which is disposed 1 within hole 56d of drum 56f. Drum 56f has a ramp 56c for engaging one of the 2 flanges 54a, and hole 56d is offset from the central axis of drum 56f to form a 3 cam 56e. Movement of handle 56a in the appropriate direction causes ramp 56c to 4 engage one of the flanges 54a and thereby spread flanges 54a apart slightly, which causes one of the flanges 54a to frictionally engage mounting arm 52 and thereby 6 fix the vertical position of head restraint 48. Simultaneously, such rotation of 7 handle 56a causes cam 56e to frictionally engage one of the transverse support 8 rails 58, 60 and thereby fix the lateral position of head restraint 48. Thus, 9 clamps 56 simultaneously provide both lateral and vertical positioning of head restraints 48, which have pads 48a for comfortably engaging the front and sides of 11 the head of a patient whose head is resting on head rest 50. Head rest 50 may be 12 mounted to transverse support rails 58, 60 or to pad 21a. Head restraints 48 13 thereby provide increased stability and comfort for a patient when bed 10 is rotated 14 to the prone position.

Although not shown for the sake of clarity, a camera for taking images of a 16 patient's face may optionally be mounted over or proximate to the head restraints 17 48 using another guide and mounting arm slidably mounted on transverse support 18 rails 58, 60. Providing a camera would help medical personnel monitor the effect 19 of kinetic therapy on a patient from a remote location.

If a particular patient requires only partial rotation for therapy such that 21 patient support platform 20 need not be rotated beyond about, for example, 22 degrees in either direction, alternative head restraints 248 as shown in Fig. 2A may 23 be mounted in clamps 56 using mounting arms 252 in like manner as head 24 restraints 48. Alternative head restraint 248 is designed to provide lateral support for the patient's head in instances when the patient will not be rotated into the 26 prone position such that vertical restraint of the head is not required.

1 Figures 4 and 15 illustrate a preferred structure and operation of folding 2 side rails 62,. Preferably, four. independently operable side rails 62 are pivotally 3 mounted on each side of bed 10. For each side rail 62, main rail 66 is slidably 4 mounted on shaft 80 with mounting cylinders 82. Shaft 80 has a slot 80a for receiving guides such as set screws 83 installed in holes 82a of mounting 6 cylinders 82. Preferably, set screws 83 are not tightened against slot 80a but 7 simply protrude into slot 80a to prevent side rail 62 from rotating with respect to 8 shaft 80. In that regard, set screws 83 could be replaced with unthreaded pins.

9 When set screws 83 are loosened, side rail 62 is free to slide longitudinally along shaft 80 for proper positioning with respect to the patient. When set screws 83 are 11 tightened, side rail 62 is fixed with respect to shaft 80. Shaft 80 is rotatably 12 mounted to side support bar 28, 30 with rail mounts 78. Pivot link 68 is hinged to 13 main rail 66 with hinge 72, and cushion 64 is hinged to pivot link 68 with hinge 14 which has a hinge plate 70a for attaching cushion 64. Side rails 62 are thus capable of folding under patient support platform 20 as shown in Fig. 15, which is a view 16 looking up from beneath patient support platform 20. A strap 174 with one end 17 secured around shaft 80 may be provided to retain cushion 64 in the folded under 18 position with mating portions of a snap respectively provided on cushion 64 and 19 strap 174. A pair of straps 74 and an adjustable buckle 76 are provided to fasten each opposing pair of side rails 62 securely over the patient. One end of strap 74 is 21 secured to side support bar 28 with.a strap connector 88, which is slidably. mounted 22 in slot 28a of side support bar 28. When strap 74 is properly secured with the 23 appropriate tension using buckle 76, tabs 160 on strap connector 88 are sandwiched 24 between main rail 66 and side support bar 28, which further helps to prevent longitudinal movement of side rail 62. Side rails 62 thus serve to hold the patient 1 securely in place as bed 10 is rotated into the prone position, and side rails 62 fold 2 neatly out of the way for easy access to the patient in the supine position.

3 As best illustrated in Fig. 4A, an indexed disc 86 is preferably provided on 4 one end of shaft 80 for cooperation with a pull knob 84 to form a detent that holds side rail 62 in one or more predetermined rotational positions. To that.end, disc 86 6 preferably has one or more recesses 228 for receiving a pin 84a which is manually 7 operated by pull knob 84. Pull knob 84 is fixedly mounted to rail mount 78 with 8 boss 230. Preferably, pin 84a is biased into engagement with disc 86. By engaging 9 one of the recesses 228, pin 84a prevents rotation of shaft 80 and thereby functions as a detent to hold side rail 62 in a predetermined rotational position. Side rail 62 1 1 may be moved to a different predetermined rotational position by pulling knob 84 12 sufficiently to disengage pin 84a from the given recess 228 so that shaft 80 is free 13 to rotate. Preferably, one of the predetermined rotational positions of side rail 62 14 corresponds to the folded under position.

Referring now to Figs. 5 and 6, each strap connector 88 comprises a 16 tension-sensitive mechanism that provides both visual and electrical indications of 17 whether strap 74 is properly secured over the patient. The following description 18 describes the attachment of a strap connector 88 to side support bar 28. It will be 19 understood that strap connectors 88 may be similarly attached to side support bar 30. Each strap connector 88 comprises a tension plate 90 that partially resides 21 within a housing 96. A cover plate 176 is attached to housing 96 by fasteners 182 22 inserted into holes 96a. Tabs 160 extend from housing 96, and studs 178 protrude 23 from tabs 160 as shown. Discs 180 are mounted to studs 178 with screws 183.

24 Slots 28b on the inner side of support bar 28 provide access for installation of screws 183. Studs 178 are adapted to slide in slots 28a of side support bar 28, and 26 discs 180 serve to retain strap connector 88 on side support bar 28. Tension 1 plate 90 has a slot 92 to which strap 74 is attached and a central cut-out 93 that 2 forms a land 100. Inverted U-shaped channels 102 protrude from the back of 3 housing 96 into central cut-out 93 of tension plate 90. Land 100 of tension plate 4 cooperates with channels 102 of housing 96 to capture springs 98 which tend to force tension plate 90 downward toward lower edge 95 of housing 96 such that 6 switch 104 is disengaged when strap 74 is slack. Switch 104 is connected to an 7 electrical monitoring and control system (not shown) in a customary manner.

8 When strap 74 is buckled and tightened sufficiently, the tension in strap 74 9 overcomes the biasing force of springs 98, and tension plate 90 moves upward to engage switch 104, which sends a signal to the electrical monitoring and control 11 system indicating that strap 74 is properly tensioned. Preferably, the electrical 12 monitoring and control system is programmed such that bed 10 cannot rotate until 13 each strap 74 is properly tensioned to ensure that the patient will be safely secured 14 in bed 10 as it rotates to the prone position. Additionally, tension plate preferably has a tension indicator line 94 that becomes visible outside housing 96 16 when strap 74 is properly tensioned.

17 More preferably, as illustrated in Fig. 16, instead of utilizing tension- 18 sensitive strap connectors 88, a pressure-sensitive tape switch 234 may be installed 19 to side support bars 28, 30 adjacent each side rail 62. Tape switch 234 is preferably of the type commonly available from the Tape Switch company.

21 Strap 74 is attached to a crossbar 240 that spans main rails 66. When strap. 74 is 22 properly tensioned, main rails 66 depress tape switch 234, which sends a signal 23 through electrical leads 238 to the monitoring and control system indicating that 24 side rail 62 is properly secured over the patient. Preferably, the monitoring and control system is programmed such that the patient support platform 20 is not 26 allowed to rotate into the prone position unless all side rails 62 have been properly 1 secured as indicated by tape switches 234. To help calibrate each tape switch 234, .2 a pad 236 may be attached to side support bars 28, 30 below the tape switch 234 3 adjacent each side rail 62. Pads 236 are made of a compressible material, such as 4 rubber, having a suitable hardness and thickness so that, as strap 74 is buckled, main rails 66 will first compress pads 236 and then depress tape switch 234 when 6 strap 74 is buckled to the appropriate tension.

7 Fig. 17 illustrates a preferred embodiment of tape switch 234. A mounting.

8 bracket 242, which is preferably made of extruded aluminum, houses two 9 conductive strips 250 and 246 that are separated at their upper and lower edges by insulator strips 248. Conductive strip 250 is a planar conductor oriented in a 11 vertical plane as shown. Conductive strip 246 is installed under a preload such that 12 it is bowed away from conductive strip 250 in its undisturbed position. Conductive 13 strips 250, 246 and insulator strips 248 are enclosed within a plastic shroud 244.

14 When main rails 66 engage tape switch 234 with sufficient pressure, conductive strip 246 is displaced to the position shown at 246a, which completes the circuit 16 with conductive strip 250 and sends a signal through leads 238 indicating that the 17 strap 74 is properly secured.

18 As shown in Fig. 7, bed 10 preferably comprises a pair of lateral support 19 pads 116 for holding a patient in place laterally. Lateral support pads 116 are connected to mounts 108, which are slidably mounted on transverse support 21 rails 106 that span the gap between side support bars 28, 30. Mounts 108 are also 22 threadably engaged with a threaded rod 112, the ends of which are mounted in side 23 support bars 28, 30 with bearings 110. Mounts 108 are symmetrically spaced from 24 the longitudinal centerline of bed 10. Preferably, another bearing 111 supports the middle portion of rod 112, and a manually operable handle 114 is provided on at 26 least one end of rod 112. With respect to element 114, the term "handle" as used 1 herein is intended to mean any manually graspable item that may be used to impart 2 rotation to rod 112. Alternatively, rod 112 may be motor driven. One side. 112a of 3 rod 112 has right-hand threads, and the other side 1 12b has left-hand threads. By 4 rotating handle 114 in the appropriate direction, lateral support pads 116 are symmetrically moved toward or away from the patient, as desired. Due to the 6 symmetrical spacing of mounts 108 and the mirror image threading 112a, 112b of 7 rod 112, lateral support.pads 116 provide for automatic centering of the patient on 8 bed 10, which enhances rotational stability. Similarly, leg abductors 184 having 9 straps 186 for securing a patient's legs may be mounted to mounts 108 in like manner as lateral support pads 116. The term "patient support accessory" is used 11 herein to mean any such auxiliary equipment, including but not limited to lateral 12 support pads and leg abductors, that is attachable to mounts 108 for the purpose of 13 providing symmetric lateral support to a patient on bed 14 Figures 8 through 13 illustrate an apparatus at the foot of bed 10 for supplying a direct electrical connection between non-rotating base frame 16 and 16 rotating patient support platform 20. As best shown in Figs. 8 and 13, end ring 24, 17 which is fastened to rotating patient support platform 20, is also connected to an 18 annular channel 126 that serves as a housing for a cable carrier 148. Cable 19 carrier 148 carries an electrical cable (not shown) comprising power, ground, and signal wires as is customary in the art. Channel 126, which preferably has a C- 21 shaped cross-section, may be attached to end ring 24 by way of support bars 192.

22 Because channel 126 is attached to end ring 24, channel 126 rotates with patient 23 support platform 20. As shown in Figs. 12 and 13, an annular cover 198 is 24 connected to upright foot frame 144, which extends upward from base frame 16.

Cover 198 is. preferably mounted on a ring 196 with fasteners 200, and ring 196 is 26 preferably mounted to support bars 194 that extend from stiffeners 144a of foot 1 frame 144. Cover 198, which is preferably made of metal to shield cable .2 carrier 148 from. radio. frequency signals .external of bed, 10,. is positioned 3 longitudinally adjacent channel 126 to retain cable carrier 148 within channel 126, 4 but cover 198 is not connected to channel 126. Thus, channel 126 is free to rotate with end ring 24, but cover 198 is stationary. One end 150 of cable carrier .148 is 6 attached to channel 126, and the other end 152 of cable carrier 148 is attached to 7 cover 198. The length of cable carrier 148 is preferably sufficient to allow patient 8 support platform 20 to rotate a little more than 360 degrees in either direction.

9 This arrangement provides a-direct, wire-based electrical connection to the rotating part of bed 10 while still allowing a complete rotation of patient support 11 platform 20 in either direction.

12 More preferably, as shown in Fig. 18, instead of cable carrier 148, a flexible 13 PCB 252 may be used to supply a direct electrical connection between non-rotating 14 base frame 16 and rotating patient support platform 20. Fig. 18 is a view of a preferred embodiment in the same direction as Fig. 13, but Fig. 18 shows only 16 flexible PCB 252 and its channel 260 and cover 264 for the sake of clarity. Like 17 channel 126 described above, channel 260 is basically C-shaped in cross-section as 18 shown in Fig. 19. However, channel 260 has an inner flange 258 to which 19 cover 264 is attached, preferably with fasteners 262. Flexible PCB 252 resides generally within channel 260. A gap 266 exists between channel 260 and 21 cover 264 through which one end of flexible PCB 252 may pass for attachment to 22 non-rotating base frame 16 (not shown) at connection 256. The other end 254 of 23 flexible PCB 252 is attached to channel 260, which is attached to rotating patient 24 support platform 20. Like cover 198, above, cover 264 is preferably made of metal to shield flexible PCB 252 from radio frequency signals external of bed 10. As 26 shown in Fig. 20, flexible PCB 252 comprises a plurality of flexible conductive 1 strips 268 surrounded by a flexible insulator 270. Conductive strips 268 carry 2 signals or ground connections, as desired, and multiple flexible PCB's 252 may be 3 used if necessary, depending on the number of signals required. Like cable 4 carrier 148 above, flexible PCB 252 is preferably long enough to allow patient support platform 20 to rotate a little more than 360 degrees in either direction.

6 To. prevent excessive rotation of patient support platform 20 and the 7 attendant damage that excessive rotation would cause to cable carrier 148 or 8 flexible PCB 252 and its enclosed electrical wires, a rotation limiter 128 is 9 provided on the inner surface of upright foot frame 144 as shown in Figs. 8, and 11. Rotation limiter 128 is pivotally mounted on frame 144 at point 162 and 11 comprises contact nubs 128a and 128b for engaging a boss 134 that protrudes from 12 frame 144. Thus, rotation limiter 128 may pivot about point 162 between the two 13 extreme positions illustrated in Figs. 10 and 11. Rotation limiter 128 preferably 14 has a pair of tabs 130, 132 that cooperate with sensors 140 and 142, respectively, which are mounted in frame 144. Sensors 140, 142 are preferably micro switches 16 but may be any type of sensor that is suitable for detecting the presence of tabs 130, 17 132. By respectively detecting the presence of tabs 130 and 132, sensors 140 and 18 142 provide an indication of the direction in which patient support platform 20 has 19 been rotated. A spring 136 is attached to rotation limiter 128 at over-center point 164 and to boss 134 at point 166. Spring 136 keeps rotation limiter 128 in 21 either of the two extreme positions until rotation limiter 128 is forced in the 22 opposite direction by a stop pin 146, as discussed below.

23 Still referring to Figs. 8, 10, and 11, rotation limiter 128 has fillets 128c, 24 128d and flats 128e, 128f for engaging stop pin 146, which is rigidly attached to crossbar 168. When patient support platform 20 is in its initial supine position 26 the position corresponding to zero degrees of rotation and referred to herein as 1 the "neutral supine position"), stop pin 146 is located at the top of its circuit 2 between flats 128e and 128f. As used herein to describe the rotation of end ring 24 3 and, necessarily, patient support platform 20, "positive" rotation means rotation in 4 the direction of arrow 170 as shown in Fig. 8, and "negative" rotation means rotation in the direction of arrow 172. As end ring 24 is rotated in the positive 6 direction, stop pin 146 engages flat 128f and forces rotation limiter 128 into the 7 extreme position shown in Fig. 11 under the action of spring 136. End ring 24 may 8 be rotated slightly more than 360 degrees in- the positive direction until stop 9 pin 146 engages fillet 128c, at which point rotation limiter 128 prevents further positive rotation. End ring 24 may then be rotated in the negative direction to 11 return to the neutral supine position. As end ring 24 approaches the neutral supine 12 position, stop pin 146 will engage flat 128e. Further rotation in the negative 13 direction beyond the neutral supine position will force rotation limiter 128 into the 14 extreme position shown in Fig. 10 under the action of spring 136. End ring 24 may be rotated slightly more than 360 degrees in the negative direction until stop 16 pin 146 engages fillet 128d, at which point rotation limiter 128 prevents further 17 negative rotation. In this manner, stop pin 146 and rotation limiter 128 cooperate 18 to limit the rotation of platform 20 so that the electrical wires in cable carrier 148 19 will not be ripped out of their mountings and the direct electrical connection will be preserved. Limiting- rotation also serves to prevent tangling or extubation of 21 patient care lines.

22 Referring to Figs. 8, 9, 12, and 13, the foot of bed 10 preferably has a 23 positioning ring 122 with a central opening 118 through which patient care lines 24 may pass as discussed above. Positioning ring 122, which is preferably fastened to support bars 192, has one or more circumferential holes 124 for cooperation with 26 one or more longitudinal lock pins 120 to lock patient support platform 20 into one 1 or more predetermined rotational positions. Preferably, the one or more lock pins 2 120 can only lock..the patient support platform 20 into the zero degree supine 3 position, so that the step of removing the lock pin will not impede quick rotation of 4 the patient support platform 20 to the zero degrees supine position in the event that emergency care, such as cardiopulmonary resuscitation, is needed by the patient.

6 Lock pin 120, Which is mounted in upright frame 144, is capable of limited 7 longitudinal movement along its central axis to engage or disengage a hole 124 of 8 positioning ring 122, as desired. Preferably, lock pin 120 and positioning ring 122 9 include a twistable locking mechanism for preventing accidental disengagement of lock pin 120 from positioning ring 122. For example, lock pin 120 may be 11 provided with a protrusion such as nub 120a that fits through slot 124a of hole 124.

12 After pin 120 is pushed through hole 124 sufficiently for nub 120a to clear 13 positioning ring 122, handle 120b may be used to twist lock pin 120 such that 14 nub 120a prevents retraction of pin 120. Alternatively, lock pin 120 and positioning ring 122 may be respectively provided with cooperating parts of a 16 conventional quarter-turn fastener or the like. Any such suitable device for 17 preventing disengagement of lock pin 120 from positioning ring 122 by twisting 18 lock pin 120 about its central axis is referred to herein as a twist lock.

19 Fig. 21 illustrates a lock pin 274 with a spring-loaded detent 278 and proximity switches 288, 290 may be mounted to frame 144 with a bracket 272.

21 Lock pin 274 has a central boss 292 with a peripheral groove 280 for cooperation 22 with ball 282 of detent 278 in the neutral position shown in Fig. 21. In the neutral 23 position, pin 274 is disengaged from hole 124 of locking ring 122, and proximity 24 switches 288, 290 preferably send "neutral" signals to the control system to electrically prevent rotation of patient support platform 20. If handle 276 is used to 26 push pin 274 into engagement with a hole 124 of locking ring 122, ball 282 of 1 detent 278 engages edge 284 of boss 292, and proximity switch 288 senses 2 edge 286 of boss 292 and sends a "locked" signal to the control system to 3 electrically prevent rotation of patient support platform 20 in addition to the 4 mechanical locking of pin 274 in locking ring 122. If motor-operated rotation of patient support platform 20 is desired, handle 276 may be used to pull pin 274 to 6 its fully retracted position in which ball 282 of detent 278 engages edge 286 of 7 boss 292, and proximity switch 290 senses edge 284 of boss 292 and sends an 8 "unlocked" signal to the control system to allow automated rotation of patient 9 support platform As discussed in international application number PCT/IE99/00049, bed 11 preferably has a drive system essentially comprising a belt drive between patient 12 support platform 20 and an associated electric motor 152 at the foot end of base 13 frame 16. The drive system may be of the type described in Patent Specification 14 No. W097/22323. As illustrated in Fig. 14, bed 10 preferably includes a quick release mechanism 156 installed on foot frame 144 to provide a means to quickly 16 disengage patient support platform 20 from the belt drive system. Quick 17 release 156 may be conveniently made from a tool and jig lever available from 18 WDS Standard Parts, Richardshaw Road, Grangefield Industry Estate, Pudsey, 19 Leeds, England LS286LE. Quick release 156 comprises a mounting tube 210 secured to foot frame 144. A lever 222 is pinned to tube 210 at point 220. A 21 tab 218 extends from lever 222, and a linkage 214- is pinned to tab 218 at 22 point 216. Linkage 214 is also pinned at point 212 to a shaft 208 that is slidably 23 disposed within tube 210. Shaft 208 extends through foot frame 144 toward 24 belt 204 which is engaged with pulley 202 of the drive system. A roller 206 is attached to shaft 208 for engaging belt 204. By rotating lever 222 in the direction 26 of arrow 224, roller 206 is forced into engagement with belt 204, which provides 1 sufficient tension in belt 204 to engage patient support platform 20 with the drive 2 system. By rotating. lever 222 in the direction of arrow 226, roller 206 is retracted 3 from belt 204, which disengages patient support platform 20 from the drive system 4 thereby allowing manual rotation of patient support platform 20. This capability of quick disengagement of the drive system to allow manual rotation of patient 6 support platform 20 is very useful in emergency situations, such as when a patient 7 occupying bed 10 suddenly needs CPR. In such a circumstance, if patient support 8 platform 20 is not in a supine position, a caregiver may quickly and easily 9 disengage the drive system using quick release 156, manually rotate patient support platform 20 to a supine position, lock the support platform 20 in place, and begin 11 administering CPR or other emergency medical care.

12 As disclosed in international application number PCT/IE99/00049, the 13 rotational position of patient support platform 20, which is governed by motor 152 14 of the aforementioned drive system, may be controlled through the use of a rotary opto encoder. Alternatively, the rotational position of patient support platform 16 may be controlled through the use of an angle sensor 232 (shown schematically in 17 Fig. 13) of the type disclosed in U.S. Pat. No. 5,611,096. As disclosed in the '096 18 patent, angle sensor 232 comprises a first inclinometer (not shown) that is sensitive 19 to its position with respect to the direction of gravity. By mounting angle sensor 232 to patient support platform 20 in the proper orientation, the output 21 signal from angle sensor 232 may be calibrated to control the rotational position of 22 patient support platform 20 in cooperation with motor 152. Likewise, angle 23 sensor 232 may include another properly oriented inclinometer (not shown) that 24 may be used in association with rams 15 and 17 (see Fig. 1) to control the Tretidelenburg position of patient support platform 26 1 Although the foregoing specific' details describe a preferred embodiment of 2 this invention, persons reasonably skilled in the art will recognize that various 3 changes may be made in the details of the method and apparatus of this invention 4 without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, it should be understood that this invention is not to be 6 limited to the specific details shown and described herein.

7

Claims (21)

1. 2. The therapeutic bend of claim 1, wherein the at least one prone support extension includes a first section pivotally attached to a side of the patient support platform, wherein the first section extends upward from and substantially perpendicular to the patient support platform when the prone support extension is in the extended position, and underneath and substantially parallel to the patient support platform when the prone support extension is in the retracted position.
2. 3. The therapeutic bed of claim 2, wherein the first section of the prone support extension includes at least two rails.
3. 4. The therapeutic bed of either claim 2 or claim 3, wherein the prone support extension further includes a second section connected to the first section, the second section extending substantially perpendicularly from the first Wsmn~aefSpeoADMC 2003 248109 speds 24a0006 doc section and substantially parallel to the patient support platform when the prone support extension is in the extended position.
4. 5. The therapeutic bed of claim 4, wherein the second section of the prone support extension is pivotally connected to the first section.
5. 6. The therapeutic bed of either claim 4 or claim 5, wherein the prone support extension further includes a third section connected to the second section, wherein one or more of the prone support cushions are mounted on the third section.
6. 7. The therapeutic bed of claim 6, wherein the third section of the prone support extension includes a hinge plate.
7. 8. The therapeutic bed of either claim 6 or claim 7, wherein the third section of the prone support extension is pivotally connected to the second section, so that the one or more prone support cushions mounted on the third section are operable to be folded inwardly toward the first section when the prone support extension is in the retracted position.
8. 9. The therapeutic bed of claim 8, wherein the prone support extension further includes a strap operable to retain the one or more prone support cushions mounted on the third section in the inwardly folded position.
9. 10. The therapeutic bed of any one of the preceding claims, further including a detent mounted to the patient support platform that is operable to hold the at least one prone support extension in the extended position.
10. 11. The therapeutic bed of claim 10, wherein the detent is also operable to hold the at least one prone support extension in the retracted position.
11. 12. The therapeutic bed of any one of the preceding claims, wherein the prone support extension is slidably mounted on a shaft adjacent a side of the patient support platform. W sharonOanietSpeciNDMC 2003 248109 spec~ 24aug06 Odoc 4 29 O
12. 13. The therapeutic bed of claim 12, further including means for preventing the prone support extension from rotating with respect to the shaft.
13. 14. The therapeutic bed of claim 12, further including: an indexed disc on an end of the shaft; and a pull knob mounted on the patient support platform and adjacent the indexed disc; 00 wherein the pull knob cooperates with the indexed disc to hold the prone support extension in one or more predetermined rotational positions. The therapeutic bed of any one of the preceding claims, further including a plurality of spaced-apart complementary pairs of prone support extensions pivotally mounted on opposite sides of the patient support platform, each pair of prone support extensions having an associated locking strap to releasably lock the prone support extensions together in the extended position.
14. 16. A prone-positioning bed including: a base frame; a patient support platform having a longitudinal rotational axis, the patient support platform being rotationally mounted on the base frame such that the patient support platform is capable of rotation about the longitudinal rotational axis between a supine patient position and an inverted prone patient position; at least one prone support extension mounted on the patient support platform; one or more prone support cushions mounted on the at least one prone support extension, the prone support cushions being operable to support a patient on the patient support platform when the patient support platform is in the prone patient position; a strap operable to secure the one or more prone support cushions in a position adjacent a patient lying on said patient support platform; and a strap connector connected to the strap, the strap connector having an indicator that indicates whether the strap is sufficiently tensioned. WNsharonDanierSpedUDMC 2003 248109 speci 24aug06 doc 4 t S17. The prone-positioning bed of claim 16, wherein the strap connector is O slidably mounted on said patient support platform.
15. 18. The prone-positioning bed of either claim 16 or 17, wherein the indicator provides a visible indication of whether the strap is sufficiently tensioned.
16. 19. The prone-positioning bed of any one of claims 16 to 18, wherein the indicator provides an electrical signal representative of whether the strap is 0O sufficiently tensioned. The prone positioning bed of claim 19, further including: a motor to rotate the patient support platform; and a control system to operate the motor; wherein the control system is operatively connected with the indicator to prevent rotation of the patient support platform into the prone patient position unless the indicator's electrical signal indicates that the strap is sufficiently tensioned.
17. 21. A prone-positioning bed including: a base frame; a patient support platform having a longitudinal rotational axis, the patient support platform being rotationally mounted on the base frame such that the patient support platform is capable of rotation about the longitudinal rotational axis between a supine patient position and an inverted prone patient position; at least one prone support extension mounted on the patient support platform; one or more prone support cushions mounted on the at least one prone support extension, the prone support cushions being operable to support a patient on the patient support platform when the patient support platform is in the prone patient position; a strap operable to secure the one or more prone support cushions in a position adjacent a patient lying on said patient support platform; and a tape switch connected to said patient support platform; W.Wshronl:anieASpeo\DMC 2003 248109 spec 24aug06 doc 31 IND wherein the at least one prone support extension is engageable with the O Otape switch to provide an electrical signal representative of whether the strap is sufficiently tensioned.
18. 22. The prone-positioning bed of claim 21, further including a compressible pad for engagement with the at least one prone support extension to control 1 activation of the tape switch. 00
19. 23. The prone positioning bed of either claim 21 or 22, further including: a motor to rotate the patient support platform; and a control system to operate the motor; wherein the control system is operatively connected with the tape switch to prevent rotation of the patient support platform into the prone patient position unless the tap switch's electrical signal indicates that the strap is sufficiently tensioned.
20. 24. A therapeutic bed including: a base frame; a patient support platform having a longitudinal rotational axis, the patient support platform being rotationally mounted on the base frame such that the patient support platform is capable of rotation about the longitudinal rotation axis between a supine patient position and an inverted prone patient position; a motor operationally engaged with operable to provide controlled alternating rotational movement to the patient support platform about an arc of rotation; at least one prone support extension mounted on the patient support platform; and one or more prone support cushions mounted on the at least one prone support extension, the prone support cushions being operable to support a patient on the patient support platform when the patient support platform is in the prone patient position; wherein the at least one prone support extension is movable from an extended position with the prone support cushions extending above the patient WWrnOaieftSpePD~fMC 2003 248100 sped 248,.g06.doc 4 32 Ssupport platform to a retracted position with the prone support cushions stored beneath the patient support platform.
21. 25. A therapeutic bed, substantially as herein described with reference to any one of the accompanying drawings of embodiments of the invention. 00 ^-i Wsmn ie iSpeoDMC 2003 248109 Speo 24a3,g08dOC 1 2 23. The prone positioning bed of claim 21, further comprising: 3 a motor to rotatethe patient support platform; and 4 a control system to operate the motor; wherein the control system is operatively connected with the tape switch to 6 prevent rotation of the patient support platform into the prone patient position 7 unless the tape switch's electrical signal indicates that the strap is sufficiently 8 tensioned. 9 24. A therapeutic bed comprising: 11 a base frame; 12 a patient support platform having a longitudinal rotational axis, the patient 13 support platform being rotationally mounted on the base frame such that the patient 14 support platform is capable of rotation about the longitudinal rotational axis between a supine patient position and an inverted prone patient position; 16 a motor operationally engaged with and operable to provide controlled 17 alternating rotational movement to the patient support platform about an arc of 18 rotation; 19 at least one prone support extension mounted on the patient support platform; and 21 one or more prone support cushions mounted on the at least one prone 22 support extension, the prone support cushions being operable to support a patient 1 on the patient support platform when the patient support platform is in the prone 2 patient position; 3 wherein the at least one prone support extension is movable from an 4 extended position with the prone support cushions extending above the patient support platform to a retracted position with the prone support cushions stored 6 beneath the patient support platform. 7 DATED: 17 September,..2003 PHILLIPS ORMONDE FITZPATRICK Attorneys for: KCI LICENSING, INC