Abstract:
A system for dynamically adjusting treatment angle under tension to accommodate variations in spinal morphology during spinal decompression therapy is provided. It provides a tensioning device including a patient-positioning means, a tension-producing actuator, a positioning device, a patient interface device, a control system and a display. The control system with feedback on the resultant tension vector applied to patient spine operationally configured to allow for adjustment of either tension producing actuator position, patient position, or both while applying tension to the patient spine during non-therapeutic tension levels. The control system automatically adjusts tension producing actuator work levels such that the resultant tension vector magnitude remains ideally constant during adjustment of resultant tension vector angle, reducing the risk of eliciting paraspinal muscle contraction due to changes in resultant tension vector magnitude.

Description:
PRIORITY CLAIM TO RELATED APPLICATIONS 
     This application is a U.S. National Stage application filed under 35 U.S.C. §371 from International Application Ser. No. PCT/CN2012/086566, which was filed Dec. 13, 2012, and published as WO 2013/087001 on Jun. 20, 2013, and which claims priority to Chinese Application No. 201110415599.1, filed Dec. 13, 2011, which applications and publication are incorporated by reference as if reproduced herein and made a part hereof in their entirety, and the benefit of priority of each of which is claimed herein. 
     RELATED APPLICATIONS 
     The present invention relates to a system that applies tension to a patient&#39;s spine to treat the spine related diseases. More specifically, the present invention relates to a positioning correction system that applies tension to a patient&#39;s spinal lesion area through a range of angles, and that can adjust the angle dynamically under tension without changing the intended tension, for the purpose of fine tuning treatment angle for each patient. 
     BACKGROUND OF THE INVENTION 
     Therapists utilize spinal decompression therapy non-operative in vitro to treat various spinal ailments including herniated discs, degenerative disc disease, sciatica, posterior facet syndrome, and post surgical pain. Decompression therapy is a derivative of traditional traction-based therapy, whereby the spine is pulled by an outside force (such as by a therapist manually or by an automated process). The spine is typically held in a continuous state of tension during traditional traction-based therapy. Decompression therapy differs from traditional traction therapy in that tension is applied to the spine at a specific angle. Also, during decompression therapy, various tensile forces are applied or cycled throughout the treatment period such that paraspinal muscles are relaxed and fatigued, allowing for interdiscal separation. These functions provide for a smooth transition between different levels of tension. In either traditional traction or decompression therapy, spinal tension is typically maintained for periods of 30 minutes or longer. 
     As the spine is placed into a state of tension, the spinal vertebrae will occur morphology change, this requires the control system must have the dynamic positioning correction function. Meanwhile, the dynamic automatic positioning correction processing also allows the lesioned intervertebral disc time to heal in the non-loaded state. Additionally, herniated discs (nucleus pulposa) is produced in back to normal position via negative pressure created by the separation of the vertebrae, realized the intervertebral disc disease to accept reset. Meanwhile, This dynamic positioning correction function can also be aided to implement para-spinal muscles maximum relax according to the patient weight set nonlinear logarithmic minus pressure control system. Since the conscious human (patient) may voluntarily and/or subconsciously flex the spinal muscles in reaction to tensile forces. Either or both patient reactions degrade the effectiveness of spinal traction or spinal decompression therapy. 
     A common spinal decompression therapy utilizes a non-feedback-providing tension producing actuator (any type of electro-mechanical, pneumatic, magnetic, hydraulic, or chemical actuator) connected to a patient via a patient interface device. The patient lay supine upon a treatment bed, head distal to the applied tension source. An upper body patient harness secures the upper patient body to the distal end of the bed (that end of the bed furthest from the source of tensile force generation). A lower body harness secures about the waist, and serves as the point at which the tension strap is connected. Tension-producing actuator output is increased or decreased to produce resultant tension changes at the point where the strap is attached to the patient. A linear actuator (any type of electro-mechanical, pneumatic, magnetic, hydraulic, or chemical actuator) is utilized to pull the patient&#39;s whole spine. And spinal decompression treatment system is based on the weighing data system by weighing the patients, for patients to be automatic setting decompression treatment, through the imaging data combining with a narrative, healthcare provider will complete lesions of the initial position, the positioner raise and lower the point at which the tension strap pulls from (treatment positioner), relative to the place of attachment to the patient, thus adjusting the angle of applied tension. The system also includes a tension measuring device (e.g., a loadcell) that is connected inline with the tension-producing actuator and patient to communicate tension metrics to a tension-producing actuator controlling device (e.g. computer). Thus, the system operates as a controlled-feedback loop whereby a planned tension profile can be applied to the patient and the actual applied forces can be verified by the computer. 
     In the above example, the point at which the tension strap pulls from relative to the place of attachment to the patient is typically fixed during application of tension. As the direction of pull is neither parallel nor perpendicular to the patient&#39;s spine, and as the patient lay supine (in this example) with their head distal to the applied tension source, the applied tension can be modeled as two force vectors, one inline with the patient&#39;s spine and away from the head, and one perpendicular to the patient&#39;s spine. In the event that the patient lay prone, the direction of the horizontal component of the applied tension resultant would remain the same, however the direction of the vertical component of the applied tension resultant would be reversed. 
     One defining characteristic of spinal decompression is that tension is applied at an angle, and that specific angles (which are specific to each device&#39;s design) affect a specific positioning ability to allow healthcare providers to treat location specific injuries, such as herniated spinal discs. In effect, locating the site(s) of spinal elongation maximizes the therapeutic benefit per therapy session. Traction, whereby forces are applied mostly inline with the spine, does not attempt to maximize spinal discs at specific interdiscal locations and spinal elongation position column by the adjustment on the angle of tension in spinal. 
     Devices of the type described above provide general guidelines as to the relative interdiscal space(s) affected by various angles of applied tension. These angles are calculated in many ways; no standards exist for their calculation. Spinal decompression manufacturers calculate which interdiscal space(s) is affected by relating applied tension force vectors (specific to their device) to commonly available radiographical charts. These radiographical charts typically show the ‘average spine’ (based on studies of measurements taken over many patients) or the ‘ideal spine’ (based on best-fit mathematical modeling of the spine). Variations in patient&#39;s spines can mean that a treatment angle designed to align the L4 and L5 vertebra actually is insufficient to align said vertebra or overly much, brining inferior vertebra in-line with unintended superior vertebra. 
     The shape of the human spine varies from human to human. Lordosis, or an inward curve (towards the front of the patient body), and kyphosis, or an outward curve (towards the back of the patient body), exist throughout the spine, and serve to balance the spine and body. Generally, the spine exhibits a lordotic curve between the Thoracic (middle spine) and Lumbar (lower spine) regions, and a kyphotic curve between the Thoracic and Cervical (upper spine or neck) region. The points and degree of inflection and deflection vary across patient populations. 
     At present, Magnetic Resonance Imaging (MRI) is routinely indicated prior to spinal decompression therapy, whereby affected disc levels are identified. Once the MRI-described interdiscal space(s) is established, healthcare providers follow spinal decompression device manufacturer&#39;s recommendations as to appropriate applied tension treatment angles. The healthcare provider is able to judge, by physical examination of the patient, advanced patient imaging (MRI, CT, X-ray, etc.), spinal decompression device manufacturer&#39;s treatment angle design, and experience using spinal decompression devices the ‘most likely’ proper treatment angle for a particular patient. Once the patient is actually on the spinal decompression device, strapped in, the final level of scrutiny by the healthcare provider with regards to treatment angle occurs. The healthcare provider will visually observe the patient&#39;s posture, feel the patient&#39;s spine and or other related bodies, and/or query the patient to make a final determination as to the correct treatment angle for that particular patient. 
     At present, The spinal pressure relief devices are employed angle positioning technology, healthcare providers must do one of two things when adjusting treatment angle after initiating treatment. The first option, pausing treatment, adjust treatment angle, and restart treatment, but since the provider can&#39;t dynamic continuous real-time observation of the spine in the minus pressure condition of the patients with feedback in this case, thus even if to adjust, can not ensure the accurate angle, which makes it difficult to realize patients and the provider interactive communication, scanning, and ultimately positioning lesions in the purpose of the position. The second option, in the treatment process and under the action of tension, while the provider observes and adjusts the angle. But this practice, since human operation, will inevitably change dynamic system in the system, which leads to exceed expected tension setting range change. This adjustment, for the present not tension compensation of the closed loop feedback system (with tension compensation feedback closed-loop system can make the expected tension in a time constant), due to the sudden change of angle, will make the expected tension suddenly changes that lead to spinal side muscle strong contraction, thus affecting the treatment effect. 
     The present invention seeks to demonstrate a unique method for fine tuning treatment angle for each patient. The present invention proposes a system designed to allow the healthcare provider to adjust treatment angle without changing intended tension levels. The system proposed would be able to account for mechanical dynamics and mechanical advantages of the system, and be calibrated to anticipate the increases and decreases in resultant tension that would otherwise occur while changing treatment angle under tension. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to a tension producing actuator feedback and correction system. The system is fast enough to allow treatment angle change under tension without changing intended tension, the advantages of this design are numerous. While the patient is under an initial intended tension and treatment angle, the healthcare provider can observe via sight and touch, and additionally querying the patient, the interdiscal sites affected by the initial treatment angle at which the resultant tension is applied to the patient. Keeping the patient at the initial intended tension while changing treatment angle (without changing intended tension level) allows the healthcare provider to observe, via at least the same pathways, the transition in patient posture, without inciting paraspinal muscle contraction due to unintended tension level changes. Dynamically adjusting treatment angle under tension allows the healthcare provider to adjust, up or down, the treatment angle to accommodate increases and decreases in lordosis, as observed under tension. Dynamically adjusting treatment angle under tension also allows the healthcare provider to query the patient for comfort and or increases or decreases in perceived pain, incorporating a measure of biofeedback into the therapy. 
     In general, the patient is positioned supine on the treatment bed, their lower spine over a lordotic support. The lordotic support is used to locate the apex of lordosis, which is utilized as a universal metric for calculating treatment angle across average or ideal patient morphologies. Regardless of the design of treatment angles for a specific spinal decompression or traction device, the device does include treatment angle designations designed to affect specific interdiscal locations. While the inclusion of designer treatment angle designations for a spinal decompression or traction device is not required, it is likely present per the current technology. 
     Average or ideal radiographical spinal models typically include a mean segmental angle and at least the first or second standard deviation measurements. The segmental angle would be an angle of lordosis, in the case of the lumbar spine, between one or more vertebra. The segmental angles utilized would be those between the fifth lumbar vertebra and the first sacral vertebra or L5-S1, the fourth and the fifth lumbar vertebra or L4-L5, the third and the fourth lumbar vertebra or L3-L4, the second and the third lumbar vertebra or L2-L3, and the first and second lumbar vertebra or L1-L2. 
     The design of the spinal decompression device provides treatment angles which would align vertebra (spinal disc) and elongate their intervertebral spaces for an average or ideal spine. As described above, differences in the degree of lordosis between vertebral segments will range slightly above or below the average or ideal models. 
     If the spinal decompression device is designed to allow treatment angle change without changing intended tension, and that treatment angle change is bounded by one standard deviation of measured or calculated (depending on the data used in the design of the device), then the device is capable of accommodating the average or ideal spine and all those patients within one standard deviation of the average or ideal model, formed according to an embodiment of the present invention. The device&#39;s dynamic angle adjustment bounds may be extended to two or even three standard deviations of the average or ideal model, to accommodate even more patients. The device&#39;s dynamic angle adjustment bounds may incorporate the entire angle adjustment range of the device, allowing the healthcare provider to move up and down the entire lower spine. 
     By first utilizing angles described by spinal decompression device manufacturers as treating specific interdiscal locations and by then applying tension at that angle, the healthcare provider is able to initiate therapy in the general location of the interdiscal space(s) to be treated. If the healthcare provider is then capable of further adjusting the angle of applied tension during the application of said tension, and if the tension feedback and correction mechanism of the spinal decompression device is fast and accurate enough such that no noticeable increase or decrease in intended tension is incurred (thus minimizing conscious and subconscious paraspinal muscle contraction), the healthcare provider is then capable of fine tuning the treatment angle. The healthcare provider can observe real-time changes in the patient and the alignment of their spine, under tension. Paraspinal muscles may contract in response to stretching, and definitely will contract in an involuntary guarding response if sudden changes in tension occur. If the spinal decompression device&#39;s tension control feedback and correction loop is fast and accurate enough to allow for angle change and compensate for inevitable changes in mechanical advantage such that the paraspinal muscles are not incited to guard and contract, then the healthcare provider can in effect ‘scan’ the patient&#39;s spine in the vicinity of the interdiscal space(s) of interest. This process may be limited to an initial period of treatment. This process may also be limited to a range of angle adjustment, whereby the healthcare provider selects an initial treatment angle based on diagnostic evidence and device manufacturer design, and then fine tunes only to less than, only to greater than, or above and below the initial treatment angle by a certain amount (e.g., 0.5 degrees). 
     In summary, the present invention describes the device of which as being capable of adjusting the angle of applied tension without changing (significantly) the amount of intended tension, such that the healthcare provider can adjust the angle of tension during the application of tension without inciting conscious or subconscious paraspinal muscle contraction. 
     Additionally, the present invention may be utilized in conjunction with patient feedback to help locate the treatment angle that best addresses the patient&#39;s pain. Just as therapeutic massage addresses muscular tensions, whereupon the recipient of the massage knows instantly when the therapist addresses the correct site or source of pain, so may the patient undergoing spinal decompression therapy recognize when a spinal decompression device addresses the correct interdiscal site or source of pain. If the healthcare provider is then capable of further adjusting the angle of applied tension during the application of said tension, and if the tension feedback and correction mechanism of the spinal decompression device is fast and accurate enough such that no noticeable increase or decrease in intended tension is incurred, the healthcare provider is then capable of querying the patient real-time as to whether increasing or decreasing the angle of applied tension feels more or less appropriate. By scanning the spine and querying the patient as to what feels more appropriate, the healthcare provider has an additional input as to the correct location for spinal decompression to be maximized. 
     According to one respect of the present invention, providing a tensioning device, comprising: a patient-positioning means configured to high precisionly, repeatedly align a target region of a patient spine; a tension-producing actuator configured to place a patient spine in tension; a positioning device operationally configured to position tension producing actuator relative to target region of patient spine; a patient interface device operationally configured to interface tension producing actuator with patient spine; a control system with feedback on resultant tension vector applied to patient spine operationally configured to allow for adjustment of either tension producing actuator position, patient position, or both while applying tension to the patient spine during non-therapeutic tension levels; and a display operationally configured to provide data regarding resultant tension vector to the user or healthcare provider; wherein the control system automatically adjusts tension producing actuator work levels such that resultant tension vector magnitude remains ideally constant during adjustment of resultant tension vector angle, reducing risk of eliciting paraspinal muscle contraction due to changes in resultant tension vector magnitude. 
     The patient positioning means includes a patient bed, wherein a region of the patient bed is identified as the alignment-region over which a target region of the patient spine should be positioned. The patient bed includes physically removable portions of the bed body and a series of physical device related to the treatment attached thereof. 
     The tension producing actuator includes an electro-mechanical device which generates torque through rotation. The tension producing actuator includes a means of increasing or decreasing torque generated. 
     The positioning device includes a removable positioning means by which increases and decreases in the height of the tension producing actuator relative to the target region of the patient spine are accomplished. 
     The patient interface includes a strap connected to a patient harness, one end of the strap includes a connection to the rotation of the tension producing actuator, and a connection to a patient harness at its opposite end, the patient harness cradling a portion of the patient pelvis and the spine. The patient interface is operationally configured to translate the decompression tension generated by the torque generated by the tension producing actuator to the patient spine. 
     The control system allows for user or healthcare provider input and includes a means to set, generate, and keep ideally constant resultant tension vector magnitude during which either resultant tension vector angle or patient spine target region position relative on the device is adjusted by user or healthcare provider. The control system allows for user or healthcare provider to modify resultant tension vector angle while tension is applied to patient spine, the resultant tension vector magnitude kept ideally constant, while patient spine target region position relative to a location on the device is unchanged. 
     The control system allows for user or healthcare provider to modify patient spine target region position relative to a location on the device while tension is applied to patient spine, the resultant tension vector magnitude kept ideally constant, while tension producing actuator position relative to a location on the device is unchanged. 
     The control system allows for user or healthcare provider to set resultant tension vector angle and to modify patient spine target region position relative to a location on the device while tension is applied to patient spine, the resultant tension vector magnitude kept ideally constant, the control system automatically adjusting tension producing actuator position relative to a location on the device to maintain user set resultant tension vector angle. 
     The control system includes a display or means for communicating resultant tension vector angle and magnitude to the user or healthcare provider. 
     The control system allows for a user or healthcare provider to visually assess, physical palpitate, or verbally or otherwise receive feedback from the patient to modify patient position and to achieve concentration of resultant tension vector magnitude near a vertebral area of interest during applied ideally constant resultant tension vector magnitude. 
     The control system indicates the region of the spine where resultant tension is concentrated based on empirical calculation of said location relative to a spinal model and mathematical and medical assumptions. 
     The control system calculates region of the spine where resultant tension is concentrated based on ideal spine models arrived at through clinically cited spinal morphology studies. 
     The user or healthcare provider is able to visually assess, palpitate, and/or query patient to determine optimum pre-treatment treatment angle or resultant tension vector angle while reducing risk associated with eliciting a paraspinal muscle contraction due to changes in resultant tension vector magnitude. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a side view of a spinal therapy system formed according to an embodiment of the present invention. 
         FIG. 2  illustrates the coccyx, sacrum, and lumbar spine, the lumbar spine being modeled about an ellipse, showing angles between adjacent vertebra. 
         FIG. 3  illustrates a side view of a spinal therapy system utilizing a lordotic support, specific patient positioning, and treatment angle structure based on  FIG. 2 , formed according to an embodiment of the present invention. 
         FIGS. 4A and 4B  illustrate two side views of a coccyx, sacrum, and lumbar spine before and after the application of tension at a specific angle designed to align the sacrum and lowest lumbar vertebra (S1 and L5 respectively) and to elongate that interdiscal space (L5-S1), formed according to an embodiment of the present invention. 
         FIGS. 5A and 5B  illustrates two side views of a coccyx, sacrum, and lumbar spine. The upper view illustrates the lower spine after the application of tension at an angle designed to align the sacrum and lowest lumbar vertebra (S1 and L5 respectively) and to elongate that interdiscal space (L5-S1). The lower view illustrates the upper view after the application of tension at an additional specific angle designed to align the lowest lumbar vertebra with the fourth distal lumbar vertebra (L5 and L4 respectively), and to elongate the interdiscal spaces (L5-S1 and L4-L5), formed according to an embodiment of the present invention. 
         FIGS. 6A-6C  illustrates three views of the coccyx, sacrum, and lumbar spine. The upper view represents the lower spine relaxed, before the application of tension at a specific angle. The second (middle) view represents the lower spine after the application of tension at an angle designed(θ T ) (using average or ideal spine radiographical models) to align the first sacral and fifth lumbar vertebra. The second view illustrates the first sacral vertebra rotated overly much upwards beyond alignment with the fifth lumbar vertebra by an angle (θ diff ). The second view shows how the fifth lumbar vertebra L5 is rotating towards an unintended alignment with the fourth lumbar vertebra L4. The third (lowest) view shows the first sacral vertebra rotated downward by a subtractional angle (θ diff ), adjusted during tension by the healthcare provider, sufficient to bring the first sacral vertebra into proper alignment with the fifth lumbar vertebra for that patient segmental angle (θ 1 -θ 0 ), formed according to an embodiment of the present invention. 
         FIGS. 7A-7C  illustrate three views of the coccyx, sacrum, and lumbar spine. The upper view represents the lower spine relaxed, before the application of tension at a specific angle. The second (middle) view represents the lower spine after the application of tension at an angle designed (using average or ideal spine radiographical models) to align the first sacral and fifth lumbar vertebra. The second view illustrates the first sacral vertebra rotated insufficiently upwards towards alignment with the fifth lumbar vertebra by an angle (θ T ) designed to align the vertebra. The third (lowest) view shows the first sacral vertebra rotated upward by an additional angle (θ diff ), adjusted during tension by the healthcare provider, sufficient to bring the first sacral vertebra in proper alignment with the fifth lumbar vertebra, formed according to an embodiment of the present invention. 
         FIG. 8  illustrates a flowchart demonstrating an algorithm for adjusting treatment angle by a predetermined amount while not changing intended tension, formed according to an embodiment of the present invention. 
         FIG. 9  illustrates a spinal decompression treatment graph, showing intended tension, treatment angle, measured tension, and tension correction versus time, formed according to an embodiment of the present invention. 
     
    
    
     The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings, certain embodiments. It should be understood, however, that the present invention is not limited to the arrangements and instrumentalities shown in the attached drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a spinal therapy system  10  used to treat a patient  110  formed according to an embodiment of the present invention. The system  10  includes a microprocessor, control system, or computing device  190  having firmware and/or software that operates to utilize and control an actuator  170 . The computing device  190  is configured to interface with a user, such as by use of a monitor and keyboard setup. By way of example only, the actuator  170  may be electronically, hydraulically, pneumatically, or mechanically operated. The actuator  170  is connected to a patient  110  via a patient interface device  120 . By way of example, the actuator  170  may be operated through a system of gears or pulleys such that the tensile forces applied to the patient  110  by the patient interface device  120  are carefully controlled. This system  10  is used to perform decompression therapy on the patient  110  by applying cycles of tensile forces from the actuator  170  on the spine  108  of the patient  110  through the interface device  120 . Alternatively, the system  10  may be used to perform traction therapy without use of cycles of tensile forces. 
     The patient  110  is positioned supine on a mechanical apparatus  100  that may be a flat surface such as a bed or table. The bed  100  includes a head end  104  where the patient  110  lay his or her head and a base end  106  where the patient  110  lay his or her legs and feet. The bed  100  is positioned such that the patient  110  may be easily placed into alignment for treatment with the system  10 . Additionally, the bed  100  may employ arm supports or rails to position the patient  110 . The patient  110  wears a lower-body harness  118  that is connectable to the patient interface device  120 . This lower-body harness allows for connection to the patient interface device  120  at or near the base of the sacrum, or is designed to locate the origin of the resultant tension vector at or near the base of the sacrum. Alternatively, the patient may wear any other appropriate device that is configured to connect the patient  110  to the interface device  120 , provided the device position the origin or locate the origin of the resultant tension vector at or near the base of the sacrum. The patient  110  wears an upper-body harness  119  that is connectable to the head end  104  of the bed  100 . The upper-body harness  119  secures the upper body of the patient  110  to the bed  100 , and keeps the upper body of the patient  110  from moving towards or away from the tower  130  which houses the actuator  170  and interface positioning device  140 . 
     The healthcare provider positions the patient&#39;s  110  lumbar spine  108  over an adjustable lordotic support  112 . The adjustable lordotic support  112  is pneumatically inflated and deflated to accommodate various degrees of lumbar lordosis between patients  110 . The lordotic support  112  may be adjustable or fixed in shape, and may be adjustable by several methods, including pneumatic, electro-mechanical, hydraulic, chemical, etc. Specifically, the healthcare provider positions the apex of lordosis, the third lumbar vertebra (L3), over the center-top of the lordotic support  112 . Positioning the apex of lordosis over the center-top of the lordotic support  112  and anchoring the patient&#39;s  110  upper body to the head end  104  of the bed  100  forms a reliable and consistent endpoint for the horizontal line (opposite side) of the triangle which is used to calculate treatment angle. 
     The healthcare provider places a knee bolster  117  under the patient&#39;s  110  knees, reducing pressure on the patient&#39;s  110  lower spine  108 . The patient&#39;s  110  position on the bed  100 , supine with a bolster  117  under the knees, forms the basis for selection of radiographical measurements which take into account this position for use in designating treatment angles. 
     The lower-body harness  118  is connected to the actuator  170  by the patient interface device  120 . The harness  118  may be connected to the patient interface device  120  through a clip or buckle that may alternately be secured and removed. The interface device  120  is configured to deliver and align tensile forces generated by the actuator  170  through the harness  118  along the spine  108  of the patient  110 . 
     The interface device  120  may be a strap, belt, or cable that is positioned relative to the patient  110  via a patient interface positioning device  140 . The patient interface positioning device  140  may itself be moved to preferred positions by an vertical actuator  148 , which may be a linear actuator, or any other type of electro-mechanical, pneumatic, hydraulic, or chemical actuator. The vertical actuator  148  may contain a relative or absolute encoder, potentiometer, or optical distance sensor, for use in communicating the position of the patient interface positioning device  140  to an electronic communication hub  155  by way of arrow F. The patient interface device  120 , as it travels up and down via the patient interface positioning device  140  and vertical actuator  148 , may pass thru a slot  145  in the front of the tower  130 , which may utilize some form of flexible material to move with the patient interface device  120  and shield the inside of the tower  130  from outside interference. 
     The head end  104  and base end  106  bed  100  mattresses may be moved together horizontally towards and away from the tower  130  via a horizontal actuator  114  and clevis  116 , which may be a linear actuator or any of electro-mechanical, pneumatic, hydraulic, or chemical type. This would generally be done to accommodate patients  110  of various heights, such that those patient&#39;s  110  feet would not be uncomfortably near to or beyond the base end  106  of the bed  100 . The horizontal actuator  114  may contain a relative or absolute encoder, potentiometer, or optical distance sensor, for use in communicating the position of the lordotic support  112  and head end  104  mattress to either or both the computing device  190  and electronic communication hub  155 . 
     The base end  106  mattress of the bed  100  is designed to be locked into place with and travel horizontally with the head end  104  mattress of the bed  100 . It is also capable of unlocking from the head end  104  mattress of the bed  100 , and traveling a fixed distance away from the head end  104  mattress of the bed  100  along linear guides. This function serves to allow the spine  108  to elongate more easily under tension, as opposed to slipping and sliding down the base end  106  mattress of the bed  100  were it fixed to the head end  104  mattress. The base end  106  mattress and head end  104  mattress were joined entirety, this case would be less favorable for the spine free elongation with the decompression tension. 
     The system  10  further includes a tensile force feedback system  160  which engages the interface device  120  between the actuator  170  and the lower-body harness  118 . The feedback system  160  may include a loadcell or dynamometer  150  that is positioned inline with the actuator  170  and is configured for electronically providing feedback to the electronic communication hub  155  as indicated by arrow E. 
     The electronic communications hub  155  is designed to collect and relay various system  10  metrics to the computing device  190  as indicated by arrow A. This device may synchronize various system  10  measurement device information into a single data stream A designed to be best utilized by the computing device  190 . 
     The actuator  170  electronically communicates with, and is controlled directly by, an actuator controller  192  as shown by arrow B. By way of example only the actuator controller  192  is a servo-amplifier  192 . The actuator  170  may also be attached to, or connected inline with, an encoder  180  that is capable of communicating motor shaft position and other motor metrics with the servo-amplifier  192 . The servo-amplifier  192  may be capable of calculating any number of motor metrics, including work, position, distance, torque, and rate and electronically communicating those metrics to, and receiving them from, the computing device  190  as indicated by arrow C to the computing device  190 . 
     The computing device  190  may be configured to communicate with the servo-amplifier  192 , and the actuator  170 , to monitor and to correct as needed the resultant tensile force and motor metrics applied by the actuator  170  from the servo-amplifier  192 . The computing device  190  may also be configured for use with a user interface system (e.g., keyboard and monitor) which communicates and deciphers the user&#39;s commands to the computer  190 . This interface allows the user to structure treatment parameters. By way of example, all tension-producing and delivery apparatus are contained within a tower  130  located in a position relative to the patient  110 . 
     In operation, spinal treatment begins by positioning the patient  110  correctly onto the bed  100 . The patient&#39;s head is positioned at the head end  104  of the bed  100 , and the patient&#39;s feet are positioned at the base end  106  of the bed  100 . The patient  110  is outfitted with the lower body harness  118  such that the patient  110  is connected to the patient interface device  120 , and the lower body harness  118  is configured to apply tensile forces to the spine  108  of the patient  110 , the origin of the resultant tension vector located at or near the base of the sacrum. The patient is outfitted with an upper body harness  119  which is fixed into position at the head end  104  of the bed  100 . The healthcare provider positions the patient&#39;s  110  apex of lordosis over the center-top of the lordotic support  112 , adjusts the height of the support to match the curvature of the patient&#39;s lordosis there, and adjusts the upper-body harness  119  connection to the head end  104  of the bed  100  to make certain the upper body of the patient  110  is fixed into position on the head end  104  mattress. A bolster  117  is placed under the patient&#39;s  110  knees. 
     The operator of the decompression system  10  may use the patient interface system of the computer  190  to select the proper treatment parameters for the therapy. The operator may then select a tension treatment program for the patient  110  and instruct the computing device  190  to execute the selected treatment profile. The computing device  190  activates the servo-amplifier  192  and/or actuator  170  such that the actuator  170  rotates, for example in the direction of arrow D, to tighten the patient interface device  120  and thus apply tension to the patient&#39;s spine  108  through the lower body harness  118 . The computing device  190  adjusts the tensile output to follow the cycles of tensile forces defined in the treatment program entered by the user. The program may include low and high tension plateaus above, by way of example only, 125 pounds, and may also include any number of decompression therapy variations cyclically applying tension to the patient&#39;s spine  108 . 
       FIG. 2  illustrates the Lumbar Lordosis Elliptical Model 205 formed of radiographic measurements over many patients. Janik et all developed an idealized average subject anthropometric model of the lumbar lordosis from inferior of T12 to superior S1. The elliptical model 205 represents the idealized path of the posterior longitudinal ligament along the posterior aspect of the vertebral bodies 2 . This model 205 represents one method by which spinal decompression device designers may designate treatment angles formed according to an embodiment of the present invention. The ellipse  205  about which the spine  200  is modeled has minor axis B  210  passing through the inferior endplate  212  of T12  275  and a major axis A  215  perpendicular to the minor axis  210  Janik et all found the b/a ratio of 0.32 to be the best fit for the data presented. 
     The lower spine  200  pictured in  FIG. 2  is composed of the first sacral vertebra  230  (S1), the fifth lumbar vertebra  225  (L5), the fourth lumbar vertebra  240  (L4), the third lumbar vertebra  250  (L3), the second lumbar vertebra  260  (L 2 ), the first lumbar vertebra  270  (L1), and the twelfth thoracic vertebra  275  (T12). 
     The tangent lines in  FIG. 2  are drawn according to the Harrison Posterior Tangent (HPT) method. The HPT lines drawn along the posterior bodies of the bony vertebra are shown, the angle between adjacent tangent lines defining the segmental angle between vertebra per the elliptical model 205. 
     The segmental angle between L5  225  and S1  230 , or L5-S1, is determined by the angle between the tangent lines θ 1    235  and θ 0    220 . 
     The segmental angle between L4  240  and L5  225 , or L4-L5, is determined by the angle between the tangent lines θ 2    245  and θ 1    235 . 
     The segmental angle between L3  250  and L4  240 , or L3-L4, is determined by the angle between the tangent lines θ 3    255  and θ 2    245 . 
     The segmental angle between L2  260  and L3  250 , or L2-L3, is determined by the angle between the tangent lines θ 4    265  and θ 3    255 . 
     The segmental angle between L1  270  and L2  260 , or L1-S2, is determined by the angle between the tangent lines θ 5    280  and θ 4    265 . 
     The segmental angles discussed above are utilized according to an embodiment of the present invention to determine angles specific to the device of  FIG. 1  for treating various portions of the lumbar spine  200 . Different radiographical methods and data may be more or less appropriate for a specific spinal decompression device design. It is important to choose measurement data that befits the patient&#39;s  110  position on the device, in the system of  10  that being supine and with a bolster under the knees. 
       FIG. 3  illustrates a side view of the system  10  formed by an embodiment of the present invention, detailing the designation of treatment angles. The patient  110  is positioned supine on the bed  100 , head on the head end  104  of the bed. The patient&#39;s  110  spine  108  is shown over the lordotic support  112 , the apex of lordosis L3  250  over the center-top of the lordotic support  112 . Although not shown, the lower body harness  118  is present, as indicated by the vertical and horizontal components  304  and  306 , ‘x’ and ‘y’ respectively, of the resultant tension vector with origin  302  at the base of the sacrum  230 . Also not shown, the upper body harness  119  is affixed to the head end  104  of the bed  100 . The bolster  117  is not shown; however the patient&#39;s  110  legs are angled as if over the bolster  117 . 
     As the patient interface device  120  is retracted by the actuator  170 , S1  230 , by way of the lower body harness  118 , is rotated upward. The apex of lordosis, L3  250  acts as the fulcrum  310  for this rotation, as S1  230 , L5  225 , and L4  240  all reside below L3  250 . L3  250  acts to oppose the movement of S1  230  in the vertical direction ‘y’  304  as L3  250  upon the lordotic support  112 . This opposition continues until the treatment angle is sufficient to act upon the L3  250  vertebral body. As L3  250  is acted upon and lifted, so the fulcrum  310  shifts superior to L2  260 . As L2  260  is acted upon by a sufficient treatment angle, so the fulcrum  310  shifts superior once again to L1 270. In all cases the fulcrum  310  is formed by the opposition to an increase in treatment angle and more specifically to the vertical component of the resultant tension ‘y’  304  against the lordotic support  112 . 
     The hypotenuse  328  is formed of the patient interface device  120  at the point where it exits the tower  130  through slot  145  and the point  310 . The treatment angle  338  is equivalent to the angle formed by the HPT lines  235  and  220  formed of the posterior sides of S1  230  and L5  225 , (θ 1 -θ 0 )  338  or L5-S1 
     The hypotenuse  326  is formed of the patient interface device  120  at the point where it exits the tower  130  through slot  145  and the point  310 . The treatment angle  336  is equivalent to the angle formed by the HPT lines  245  and  235  formed of the posterior sides of L5  225  and L4  240 , (θ 2 -θ 1 )  336  or L4-L5. The entire treatment angle however would consist of (θ 2 -θ 1 )  336 +(θ 1 -θ 0 )  338 . 
     The hypotenuse  324  is formed of the patient interface device  120  at the point where it exits the tower  130  through slot  145  and the point  310 . The treatment angle  334  is equivalent to the angle formed by the HPT lines  255  and  245  formed of the posterior sides of L4  240  and L3  250 , (θ 3 -θ 2 )  334  or L3-L4. The entire treatment angle however would consist of (θ 3 -θ 2 )  334 +(θ 2 -θ 1 )  336 +(θ 1 -θ 0 )  338 . 
     The hypotenuse  322  is formed of the patient interface device  120  at the point where it exits the tower  130  through slot  145  and the point  310 . The treatment angle  332  is equivalent to the angle formed by the HPT lines  265  and  255  formed of the posterior sides of L3  250  and L2  260 , (θ 4 -θ 3 )  332  or L2-L3. The entire treatment angle however would consist of (θ 4 -θ 3 )  332 +(θ 3 -θ 2 )  334 +(θ 2 -θ 1 )  336 +(θ 1 -θ 0 )  338 . 
     The hypotenuse  320  is formed of the patient interface device  120  at the point where it exits the tower  130  through slot  145  and the point  310 . The treatment angle  330  is equivalent to the angle formed by the HPT lines  280  and  265  formed of the posterior sides of L2  260  and L1  270 , (θ 5 -θ 4 )  330  or L1-L2. The entire treatment angle however would consist of (θ 5 -θ 4 )  330 +(θ 4 -θ 3 )  332 +(θ 3 -θ 2 )  334 +(θ 2 -θ 1 )  336 +(θ 1 -θ 0 )  338 . 
     The patient interface device  120  and interface positioning device  140  is raised and lowered by the vertical actuator  148  to accommodate the various designated treatment angles  320 .  322 ,  324 ,  326 , and  328 . The system  10  utilizes passive or absolute encoder, potentiometer, optical distance sensor, or other distance metering feedback to determine vertical position of the patient interface device  120 . The bed  100 , composed of the base end  106  mattress and head end  104  mattress, is moved together horizontally towards and away from the tower  130  via the horizontal actuator  114 . The position of the horizontal actuator  114  is known to the system  10  via passive or absolute encoder, potentiometer, optical distance sensor or other distance metering feedback. Together, the vertical position of the patient interface device  120  at the interface positioning device and the horizontal position of the center-top  310  of the lordotic support  112  via the horizontal actuator  114  are known to the system and are used to calculate treatment angle. 
       FIGS. 4A and 4B  contain two views of the lower spine,  400  and  401 . The upper view of  FIG. 4A, 400 , illustrates the spine before the additional application of resultant tension vector F  402  at treatment angle  490 . The lower view of  FIG. 4B, 401 , illustrates the spine after application of said resultant F  402 . 
     The HPT tangent lines  420 ,  430 ,  440 ,  450 ,  460 , and  470  are drawn posterior to the vertebral bodies S1  410 , L5  411 , L4  412 , L3  413 , L2  414 , and L1  415 . 
     The resultant F  402  is applied to the patient  110  via the patient interface device  120  via the lower body harness  118 . The lower patient harness  118  is designed to originate the resultant tension vector F  402  at the base of the sacrum  410 , underneath the supine patient  110  in this embodiment of the present invention. The resultant F  402 , when broken down into a vertical Fy and horizontal Fx component  404  and  403 , acts in two ways on the lower spine  400 / 401 . First, the vertical component Fy  404  can be thought of as lifting, from the sacrum  410 , countered by the third vertebra L3  413 , the apex of lordosis, upon the center-top  310  of the lordotic support  112 . The horizontal component Fx  403  can be thought of as pulling through the aligned spinal segments to elongate the spine. 
     In  400 , none of the spinal segments  410 ,  411 ,  412 ,  413 ,  414 ,  415 , and  416  have a segmental angle of zero (aligned) as there are no external forces acting on the spine and it is assumed some amount of lordosis is naturally present in between all segments of the lower spine in the patient. Were there no natural lordosis whatsoever in the lower spine  400 , and simultaneously no natural kyphosis, then there would be no need to utilize any treatment angle other than zero degrees. 
     The lower spine in  401  is acted upon by the resultant  402 . The vertebral segment S1  410  is acted upon via the resultant  402  via the lower body harness  118  via the patient interface device  120 . The magnitude of the resultant tension  402  is set as a general guideline to ½ patient body weight as is customary in the art; however the healthcare provider is responsible for tuning this magnitude sufficient to lift the lower and rotate the lower patient body, sacrum/pelvis/hips, into position. The vertebral segment S1  410  is caused to lift and rotate relative to the inferior endplate of L5  411  per the vertical component Fy  404  of resultant tension  402 . The angle of application  490  of resultant tension  402  is θ 1 -θ 0 ,  430 - 420 , which is sufficient to bring the posterior sides of the vertebral bodies S1  410  and L5  411  parallel to each other, and so into ‘alignment’. Once the vertebral bodies S1  410  and L5  411  are aligned, the intervertebral discs are decompressed uniformly  480 , anterior and posterior. Through the cycling of resultant tension  402 , between maximal and minimal levels, the vertebral bodies S1  410  and L5  411  are brought into and out of alignment. 
     The bringing of into and out of alignment of the vertebral bodies S1  410  and L5  411  results in a confusion and relaxation of paraspinal muscles, especially when resultant tension  402  is cycled smoothly. Additionally, the bringing of into and out of alignment of the vertebral bodies S1  410  and L5  411  results in increased imbibition by the intervertebral discs at the end plates of the vertebral bodies, as the process by which imbibition occurs is a mechanical movement of vertebral bodies relative to each other, as described by the bringing into and out of alignment of said bodies. Further, the elongation  480  of aligned vertebral bodies S1  410  and L5  411  results in a drop in interdiscal pressure at the location of elongation, which acts to move nucleosus pulposus through the spine. 
       FIGS. 5A and 5B  contain two views of the lower spine,  500  and  501 . The upper view of  FIG. 5A, 500 , illustrates the spine before the additional application of resultant tension vector F  502  at treatment angle  591 . The upper view of  500  is analogous to the lower view  401  of  FIG. 4B , rotated by  490  and elongated  480 . The lower view of  FIG. 5B, 501 , illustrates the spine after application of said resultant F  502 . 
     The HPT tangent lines  530 ,  540 ,  550 ,  560 , and  570  are drawn posterior to the vertebral bodies L5  511 , L4  512 , L3  513 , L2  514 , and L1  515 . 
     The resultant F  502  is applied to the patient  110  via the patient interface device  120  via the lower body harness  118 . The lower patient harness  118  is designed to originate the resultant tension vector F  502  at the base of the sacrum  510 , underneath the supine patient  110  in this embodiment of the present invention. The resultant F  502 , when broken down into a vertical Fy and horizontal Fx component  504  and  503 , acts in two ways on the lower spine  500 / 501 . First, the vertical component Fy  504  can be thought of as lifting, from the sacrum  510 , countered by the third vertebra L3  513 , the apex of lordosis, upon the center-top  310  of the lordotic support  112 . The horizontal component Fx  503  can be thought of as pulling through the aligned spinal segments to elongate the spine. 
     In  500 , only S1  510  and L5  511  are aligned, as described in  401  of  FIG. 4B . None of the other spinal segments  511 ,  512 ,  513 ,  514 ,  515 , and  516  have a segmental angle of zero (aligned) as the resultant  402  acting on the spine is at a treatment angle sufficient only to align  510  and  511 . Additionally, it is assumed some amount of lordosis is naturally present in between all segments of the lower spine in the patient  110 . Were there no natural lordosis whatsoever in the lower spine  500 , and simultaneously no natural kyphosis, then there would be no need to utilize any treatment angle other than zero degrees. 
     The lower spine in  501  is acted upon by the resultant  502 . The vertebral segments L5  511 , and by way of the initial resultant  402  S1  510 , are acted upon via the resultant  502  via the lower body harness  118  via the patient interface device  120 . 
     The magnitude of the resultant tension  502  is set as a general guideline to ½ patient body weight as is customary in the art; however the healthcare provider is responsible for tuning this magnitude sufficient to lift the lower and rotate the lower patient body, sacrum/pelvis/hips, into position. The vertebral segments L5  511 , and by way of  402  S1  510 , are caused to lift and rotate relative to the inferior endplate of L4  512  per the vertical component Fy  504  of resultant tension  502 . The angle of application  591  of resultant tension  502  is θ 2 -θ 1 ,  540 - 530 , plus that of  590 , is sufficient to bring the posterior sides of the vertebral bodies L5  511  and L4  512  parallel to each other, and so into ‘alignment’. Once the vertebral bodies L5  511  and L4  512 , and by way of  402  S1  510  and L5  511 , are aligned, the intervertebral discs are decompressed uniformly  581  and  580 , anterior and posterior. Through the cycling of resultant tension  502 , between maximal and minimal levels, the vertebral bodies L5  511  and L4  512 , and S1  510  and L5  511 , are brought into and out of alignment. 
     The benefits of decompressing,  580  and  581 , and bringing into and out of alignment the vertebral bodies have been described in  FIGS. 4A and 4B . It should be noted that according to this embodiment formed of the present invention, to align two vertebral bodies for the purpose of decompressing, increasing imbibition, and creating an interdiscal local nucleous pulposus pressure drop, it is required to first bring into alignment all distal vertebral segments, starting with S1  510  and L5  511 . 
       FIGS. 6A-6C  illustrates three views of the coccyx ( 600 ,  695 ,  696 ). The upper view  600  represents the lower spine relaxed, before the application of resultant tension vector  602  at treatment angle (θT)  608 . The second (middle) view  695  represents the lower spine after the application of resultant tension vector  602  at treatment angle (θT)  608  designed (using average or ideal spine radiographical models) to align the first sacral vertebra S 1   610  and fifth lumbar vertebra L5  611 . The third (lower) view  696  represents the lower spine after the application of resultant tension vector  607  at the treatment angle dynamically adjusted during tension to a reduced (θT)  608  −(θdiff)  609 . 
     The HPT tangent lines  620 ,  630 ,  640 ,  650 ,  660 , and  670  are drawn posterior to the vertebral bodies S1  610 , L5  611 , L4  612 , L3  613 , L2  614 , and L1  615 . 
     The resultant F  602  is applied to the patient  110  via the patient interface device  120  via the lower body harness  118  in the second view  695 . The lower patient harness  118  is designed to originate the resultant tension vector F  602  at the base of the sacrum  610 , underneath the supine patient  110  in this embodiment of the present invention. The resultant F  602 , when broken down into a vertical Fy and horizontal Fx component  604  and  603 , acts in two ways on the lower spine  600 / 695 / 696 . First, the vertical component Fy  604  can be thought of as lifting, from the sacrum  610 , countered by the third vertebra L3  613 , the apex of lordosis, upon the center-top  310  of the lordotic support  112 . The horizontal component Fx  603  can be thought of as pulling through the aligned spinal segments to elongate the spine. 
     In  600 , none of the spinal segments  610 ,  611 ,  612 ,  613 ,  614 ,  615 , and  616  have a segmental angle of zero (aligned) as there are no external forces acting on the spine and it is assumed some amount of lordosis is naturally present in between all segments of the lower spine in the patient. Were there no natural lordosis whatsoever in the lower spine  600 , and simultaneously no natural kyphosis, then there would be no need to utilize any treatment angle other than zero degrees. 
     The lower spine in  695  is acted upon by the resultant  602 . The vertebral segment S1  610  is acted upon via the resultant  602  via the lower body harness  118  via the patient interface device  120 . The magnitude of the resultant tension  602  is set as a general guideline to ½ patient body weight as is customary in the art; however the healthcare provider is responsible for tuning this magnitude sufficient to lift the lower and rotate the lower patient body, sacrum/pelvis/hips, into position. The vertebral segment S1  610  is caused to lift and rotate relative to the inferior endplate of L5  611  per the vertical component Fy  604  of resultant tension  602 . 
     The second view  695  illustrates the first sacral vertebra S1  610  rotated overly much upwards beyond alignment with the fifth lumbar vertebra L5  611  by treatment angle (θ T )  608 . While treatment angle (θ T )  608  was designed for system  10  to bring only the first sacral vertebra S1  610  into alignment with the fifth lumbar vertebra L5  611 , in this particular patient the treatment angle (θ T )  608  exceeds the patient&#39;s natural segmental angle L5-S1, (θ 1 -θ 0 )  338 , by a difference of angle (θ diff )  609 . The second view  695  shows how the fifth lumbar vertebra L5  611  is rotating towards an unintended alignment with the fourth lumbar vertebra L4  612 . At the treatment angle (θ T )  608 , resultant tension vector  602  is causing intentionally the first sacral vertebra S1  610  and the fifth lumbar vertebra L5  611  to align and elongate  618 , and unintentionally the fifth lumbar vertebra L5  611  and fourth lumbar vertebra L4  612  to align and elongate  619 . 
     The initial treatment angle (θ T )  608  of the resultant tension vector  602  produces the changes described above, at which point the healthcare provider may observe visually and by touch, and additionally by diagnostic equipment and/or patient feedback that L5  611  and L4  612  are unintentionally partially or wholly aligned and elongated  619 . The healthcare provider may decide to dynamically adjust treatment angle (θ T )  608  under tension. As the treatment angle is adjusted dynamically, the healthcare provider can more accurately judge the proper segmental angle L5-S1, (θ 1 -θ 0 )  338 , for that patient. 
     The third (lowest) view  696  shows the first sacral vertebra S1  610  rotated downward by angle (θ diff )  609 , adjusted dynamically during tension by the healthcare provider, sufficient to bring the first sacral vertebra S1  610  into proper alignment with the fifth lumbar vertebra L5  611  for that patient&#39;s segmental angle (θ 1 -θ 0 )  338 , formed according to an embodiment of the present invention. The new resultant tension vector  607  has the same magnitude as the initial resultant tension vector  602 , but is applied to the patient  110  at a new treatment angle (θ T )  608  minus (θ diff )  609 , equivalent to (θ 1 -θ 0 )  338 . 
     By reducing the treatment angle (θ T )  608  by (θ diff )  609 , the fifth lumbar vertebra L5  611  is no longer in alignment with the fourth lumbar vertebra L4  612 . As L5  611  and L4  612  are not aligned, elongation  619  between L5  611  and L4  612  is minimized. The new treatment angle (θ T )  608  minus (θ diff )  609  maximizes elongation only at L5-S1,  618 . 
       FIGS. 7A-7C  illustrates three views of the coccyx( 600 ,  695 ,  696 ). The upper view  700  represents the lower spine relaxed, before the application of resultant tension vector  702  at treatment angle (θT)  708 . The second (middle) view  795  represents the lower spine after the application of resultant tension vector  702  at treatment angle (θT)  708  designed (using average or ideal spine radiographical models) to align the first sacral vertebra S1  710  and fifth lumbar vertebra L5  711 . The third (lower) view  796  represents the lower spine after the application of resultant tension vector  707  at the treatment angle dynamically adjusted during tension to an increased (θT)  708 +(θdiff)  709 . 
     The HPT tangent lines  720 ,  730 ,  740 ,  750 ,  760 , and  770  are drawn posterior to the vertebral bodies S1  710 , L5  711 , L4  712 , L3  713 , L2  714 , and L1  715 . 
     The resultant F  702  is applied to the patient  110  via the patient interface device  120  via the lower body harness  118  in the second view  795 . The lower patient harness  118  is designed to originate the resultant tension vector F  702  at the base of the sacrum  710 , underneath the supine patient  110  in this embodiment of the present invention. The resultant F  702 , when broken down into a vertical Fy and horizontal Fx component  704  and  703 , acts in two ways on the lower spine  700 / 795 / 796 . First, the vertical component Fy  704  can be thought of as lifting, from the sacrum  710 , countered by the third vertebra L3  713 , the apex of lordosis, upon the center-top  310  of the lordotic support  112 . The horizontal component Fx  703  can be thought of as pulling through the aligned spinal segments to elongate the spine. 
     In  700 , none of the spinal segments  710 ,  711 ,  712 ,  713 ,  714 ,  715 , and  716  have a segmental angle of zero (aligned) as there are no external forces acting on the spine and it is assumed some amount of lordosis is naturally present in between all segments of the lower spine in the patient. Were there no natural lordosis whatsoever in the lower spine  700 , and simultaneously no natural kyphosis, then there would be no need to utilize any treatment angle other than zero degrees. 
     The lower spine in  795  is acted upon by the resultant  702 . The vertebral segment S1  710  is acted upon via the resultant  702  via the lower body harness  118  via the patient interface device  120 . The magnitude of the resultant tension  702  is set as a general guideline to ½ patient body weight as is customary in the art, however the healthcare provider is responsible for tuning this magnitude sufficient to lift the lower and rotate the lower patient body, sacrum/pelvis/hips, into position. The vertebral segment S1  710  is caused to lift and rotate relative to the inferior endplate of L5  711  per the vertical component Fy  704  of resultant tension  702 . 
     The second view  795  illustrates the first sacral vertebra S1  710  rotated insufficiently upwards toward alignment with the fifth lumbar vertebra L5  711  by treatment angle (θ T )  708 . While treatment angle (θ T )  708  was designed for system  10  to bring the first sacral vertebra S1  710  into alignment with the fifth lumbar vertebra L5  711 , in this particular patient the treatment angle (θ T )  708  is less than the patient&#39;s natural segmental angle L5-S1, (θ 1 -θ 0 )  338 , by a difference of angle (θ diff )  709 . At the treatment angle (θ T )  708 , resultant tension vector  702  is insufficient to cause the first sacral vertebra S1  710  and the fifth lumbar vertebra L5  711  to align and elongate. 
     The initial treatment angle (θ T )  708  of the resultant tension vector  702  produces the changes described above, at which point the healthcare provider may observe visually and by touch, and additionally by diagnostic equipment and/or patient feedback that S1  710  and L5  711  are not fully aligned and elongated. The healthcare provider may decide to dynamically adjust treatment angle (θ T )  708  under tension. As the treatment angle is adjusted dynamically, the healthcare provider can more accurately judge the proper segmental angle L5-S1, (θ 1 -θ 0 )  338 , for that patient. 
     The third (lowest) view  796  shows the first sacral vertebra S1  710  rotated upward by angle (θ diff )  709 , adjusted dynamically during tension by the healthcare provider, sufficient to bring the first sacral vertebra S1  710  into proper alignment with the fifth lumbar vertebra L5  711  for that patient&#39;s segmental angle (θ 1 -θ 0 )  338 , formed according to an embodiment of the present invention. The new resultant tension vector  707  has the same magnitude as the initial resultant tension vector  702 , but is applied to the patient  110  at a new treatment angle (θ T )  708  plus (θ diff )  709 , equivalent to (θ 1 -θ 0 )  338 . 
     By increasing the treatment angle (θ T )  708  by (θ diff )  709 , the first sacral vertebra S1  710  and the fifth lumbar vertebra L5  711  are brought into alignment, maximizing elongation  719  between at L5-S1,  718 . 
       FIG. 8  illustrates a flowchart demonstrating an algorithm for adjusting treatment angle by a predetermined amount while not changing intended tension, formed according to an embodiment of the present invention. 
     The algorithm proceeds from initial powering-on of the spinal decompression device  800 . As part of the system  10  initialization routine  802 , the vertical linear actuator  148  is reset to the lowest position. Any passive or active encoder data, or potentiometer data, relayed by an internally or externally mounted distance metering device relative to vertical linear actuator  148 , will be measured against this initial zero point. Also as part of the system  10  initialization routine, the horizontal actuator  114  is reset to the position nearest the tension producing actuator  170 . Any passive or active encoder data, or potentiometer data, relayed by an internally or externally mounted distance metering device relative to horizontal linear actuator  114 , will be measured against this initial zero point  802 . At this point the device calculates the initial treatment angle  804 . Optionally, the device may employ absolute distance metering devices, which do not require the device to initialize vertical and horizontal actuators as in  802 . Optionally, the device may commit to non-volatile memory the last known location of the vertical and horizontal linear actuators, and so not require initialization  802 . The system of  10  then displays the treatment angle  806 . 
     The healthcare provider may enter  808  into the treatment computer  190  the intended maximum and minimum tension for spinal decompression therapy. They may also enter the initial treatment angle and treatment time, among other parameters. This may be done before physical patient setup  810  as shown, or afterwards. 
     The healthcare provider then physically configures  810  the patient  110  upon the bed  100 . The upper body harness  119  is secured to the head end of the bed  104 . A knee bolster  117  is placed under the patient&#39;s knees. The bed  100  is adjusted horizontally and/or the patient  110  is adjusted on the bed  100  to locate the apex of lordosis, L3  250 , over the center-top  310  of the lordotic support  112 . The lower body harness  118  is connected to the patient interface device  120 . The healthcare provider may then initiate treatment  812 . 
     As treatment is initiated  812 , the treatment computer  190  relays C treatment profile data, tension profile, to the servo-amplifier  192 , which in-turn communicates B with the servo-motor  170 , in this embodiment of the present invention. The tension producing actuator  170  rotates D, increasing tension on the patient interface device  120 . The loadcell  150  registers tension, and relays E that metric to electronics  155 . The electronics  155  relay A that information to the treatment computer  190 . The treatment computer  190  sends updated tension profile information C to the servo-amplifier  192 , completing a closed-loop feedback profile  814 . 
     The healthcare provider may decide they want to increase or decrease treatment angle dynamically, under tension, after initiation of treatment  812 . The healthcare provider would either want to increase treatment angle by pressing a button corresponding to vertical linear actuator  148  movement upwards  816 , or want to decrease treatment angle by pressing a button corresponding to vertical linear actuator  148  movement downwards  832 . 
     In the case of  816 , treatment angle increase is indicated, and the treatment computer  190  decides if, based on software presets, dynamic angle adjustment is allowed  818 . If dynamic angle adjustment is allowed  818 , then the treatment computer  190  communicates A with electronics  155  to very slowly start and very slowly maintain vertical linear actuator  148  movement while the upwards-indicating vertical linear actuator button is pressed  820 . In this embodiment of the present invention, no immediate or step transition in vertical linear actuator  148  movement is allowed. Once the upwards-indicating button is pressed  816 , and for as long as it is pressed  826 , the vertical linear actuator will continue to move slowly upwards  820 . If the upwards-indicating button is no longer pressed, then the treatment computer  190  and electronics  155  will initiate a very slow stop of vertical linear actuator  148  movement  828 . During that time  828 , both the upward or downward indicating vertical linear actuator buttons are disabled  828 . Once the vertical linear actuator  148  movement is stopped, as verified by distance metering devices, both the upward and downward indicating vertical linear actuator buttons are enabled  830 . 
     While vertical linear actuator  148  movement is increasing treatment angle  820 , the treatment computer  190  and electronics  155  continuously monitor the loadcell  155  information, and any other system  10  metrics, such that the magnitude of the resultant tension vector applied to the patient remains on its intended tension profile, while treatment angle is adjusted  822 . As treatment angle is adjusted  820 , the treatment computer  190  and electronics  155  monitor distance metering devices relative to the vertical linear actuator  148  and recalculate and display treatment angle  824 . 
     It should be noted that treatment angle may be allowed to increase or decrease only by a small amount, based on perhaps one or more standard deviations away from average or ideal segmental angles for a particular treatment angle. Regardless of the bounds of dynamic angle adjustment amongst the full range of vertical linear actuator movement, as the vertical linear actuator approaches these bounds, it automatically slow-stops to avoid immediate change in treatment angle. 
     Once the actions  818 ,  820 ,  822 ,  824 ,  826 ,  828 , and  830 , as initiated by the healthcare provider  816 , are completed, the device returns to monitoring the tension profile under assumed static vertical linear actuator  148  position  814 . 
     In the case of  832 , treatment angle decrease is indicated, and the treatment computer  190  decides if, based on software presets, dynamic angle adjustment is allowed  834 . If dynamic angle adjustment is allowed  834 , then the treatment computer  190  communicates A with electronics  155  to very slowly start and very slowly maintain vertical linear actuator  148  movement while the downwards-indicating vertical linear actuator button is pressed  836 . In this embodiment of the present invention, no immediate or step transition in vertical linear actuator  148  movement is allowed. Once the downwards-indicating button is pressed  832 , and for as long as it is pressed  842 , the vertical linear actuator will continue to move slowly downwards  836 . If the downwards-indicating button is no longer pressed, then the treatment computer  190  and electronics  155  will initiate a very slow stop of vertical linear actuator  148  movement  844 . During that time  844 , both the upward or downward indicating vertical linear actuator buttons are disabled  844 . Once the vertical linear actuator  148  movement is stopped, as verified by distance metering devices, both the upward and downward indicating vertical linear actuator buttons are enabled  846 . 
     While vertical linear actuator  148  movement is decreasing treatment angle  836 , the treatment computer  190  and electronics  155  continuously monitor the loadcell  155  information, and any other system  10  metrics, such that the magnitude of the resultant tension vector applied to the patient remains on its intended tension profile, while treatment angle is adjusted  838 . As treatment angle is adjusted  836 , the treatment computer  190  and electronics  155  monitor distance metering devices relative to the vertical linear actuator  148  and recalculate and display treatment angle  840 . 
     Once the actions  834 ,  836 ,  838 ,  840 ,  842 ,  842 ,  846 , and  830 , as initiated by the healthcare provider  832 , are completed, the device returns to monitoring the tension profile under assumed static vertical linear actuator  148  position  814 . 
       FIG. 9  represents a treatment screen  900  as may be displayed on the spinal decompression device of system  10  and/or printed. In  900 , four graphs  901 ,  902 ,  903 , and  904  are shown, vertically aligned, all plotted against the same horizontal scale (time). 
     In  901 , the intended tension profile is shown. In this embodiment of the present invention, the intended tension profile is a series of maximum and minimum tension level plateaus, connected by logarithmic increases and decreases in tension  911 . The y-axis  910  for  901  is tension, plotted in pounds, shown from zero to 160 lbs. From the plot  901 , the maximum tension plateaus are 140 lbs., and the minimum tension plateaus are 30 lbs. 
     In  902 , the treatment angle is plotted versus time. The y-axis  920  is treatment angle, plotted in degrees. The y-axis  920  is centered about the initial treatment angle  923 , 12°, which is shown enlarged and bounded for clarity. In this embodiment of the present invention, 12° is the setting for the L5-S1 intervertebral space, and the first standard deviation of segmental angles for L5-S1 are plus and minus 1.5°. In this embodiment of the present invention, the bounds for dynamic angle adjustment are one standard deviation away from the spinal decompression device&#39;s designed treatment angles. 
     In  902 , as treatment is initiated, the healthcare provider is able to dynamically adjust tension for a period including up to the end of the first maximum tension plateau  921 . Beyond  921 , the ability to dynamically adjust treatment angle is disabled  922 , as set in software, in this embodiment of the present invention. As treatment is initiated, the healthcare provider dynamically adjust treatment angle downward 0.5°  924 . The healthcare provider then adjusts treatment angle 2° upwards to 13.0°  925 . The healthcare provider then adjusts treatment angle downwards to 12.5°  926 , where it is maintained for the rest of the treatment. 
     The current treatment angle  927  is displayed in a box to the right of  902 . This display  927  changes and is updated as treatment angle is changed. 
     In  903 , the measured tension  931  is displayed, as relayed by the loadcell  155  in this embodiment of the present invention but that may be relayed by any load or torque sensing device. The measured tension  931  is plotted against y-axis  930  in lbs. which is the same as scale  910 . It should be noted that, according to this embodiment of the present invention, measured tension  931  is the same as intended tension profile  911 , even during dynamic angle adjustment period  921 . 
     In  904 , tension correction  944  is displayed. Tension correction  944  is plotted against y-axis  940  in lbs. In the system  10  formed of one embodiment of the present invention, as treatment angle is adjusted downwards  924 , tension must be increased momentarily  941  to counteract changes in system dynamics and system mechanical advantages, keeping measured tension  931  the same as intended tension  911 . In the system  10  formed of one embodiment of the present invention, as treatment angle is adjusted upwards  925 , tension must be decreased momentarily  942  to counteract changes in system dynamics and system mechanical advantages, keeping measured tension  931  the same as intended tension  911 . In the system  10  formed of one embodiment of the present invention, as treatment angle is adjusted downwards  926 , tension must be increased momentarily  943  to counteract changes in system dynamics and system mechanical advantages, keeping measured tension  931  the same as intended tension  911 . Variations in the design of spinal decompression devices may change the way the system&#39;s  10  tension producing actuator  170  reacts to changes in treatment angle, as reflected in that particular system&#39;s  10  tension correction profile for a treatment period  904 . 
     The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.